Diet as a factor in length of life and in structure and composition of tissues of the rat with aging

Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

Diet as a Factor in Length of Life
and in Structure and Composition of Tissues
of the Rat with Aging —

Home Economics Research Report No. 24
ae Agricultural Research Service .

UNITED STATES DEPARTMENT OF AGRICULTURE —

Diet as a Factor in Length of Life
and in Structure and Composition of Tissues
of the Rat with Aging

by >
Mildred Adams |

Human Nutrition Research Division
Agricultural Research Service

UNITED STATES DEPARTMENT OF AGRICULTURE

Home Economics Research Report No. 24

Washington, D.C. Issued October 1964

For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C. 20402 © Price 70 cents

Preface

This research was done as part of a project
supported by an allotment made by the Secretary
of Agriculture from Special Research Funds (Bank-
head-Jones Act of June 29, 1935).

Staff members in the Human Nutrition Re-
search Division responsible for the results reported
in this publication were as follows:

Mildred Adams, Research Chemist. Organi-
zation and evaluation of data; preparation of
report.

Elizabeth C. Hartman,! Nutrition Physiologist.
Initiation of this investigation ; general supervision
for the longevity studies.

Anna M. Allen Durand, Medical Officer (His-
tology). Evaluation of histological findings in
the tissues.

Murray Fisher, Biologist. General supervision
of experimental animals; collection of data on
organ weights; evaluation of gross findings at
necropsy; preparation of tissues for histological
examination.

Doris D. Taylor, Nutrition Specialist, and
Emily 8S. Conway, Biological Aid (Gen.). Chemi-
cal analysis of diets, livers, kidneys, and serum
cholesterol. Mrs. Conway also assisted in com-
piling and tabulating the data.

Hazel E. Hildebrand, Nutrition Specialist.
Calorie determinations.

Florence L. Lakshmanan,
Donald Higginbotham,’
phoretic analysis of serum.

Mention of specific products throughout this
publication does not imply recommendation by
the U.S. Department of Agriculture over other
products of a similar nature not mentioned.

Biochemist, and
Biochemist. Electro-

1 Present address: Chief, Training Grants and Awards
Branch, Extramural Programs, National Institute of
Neurological Diseases and Blindness, National Institutes
of Health, Bethesda, Md.

2 Present address: E. I. duPont deNemours & Co.,
as Fibers Department, Dacron Division, Kinston,
N.C.

ENxpenlment al Maes) s eee eae See a ee ae

Description and management of animals_-_-_---
DiCtS me ea eee eee ee ee eee
Criteria for evaluating response to diet__-_----

Results and discussion_______________----------

IO oa fF w

Composition of experimental diets_____-_----
Proteins aan eee oe ee eee ae eee

Gi (aes See eae ee ee ee eS
Body weight, intake, and age (stock, SP
8 HVO, and SPE diets) __________-_--_-
Growth and food intake of young rats (all
Gilets) eee Ake ote Woes hoo Sed
Body weight in relation to age and diet in
adulijratsse" 28e eos See! 22 oo eee
Calories for maintenance of body weight _-
Maximum body weight and diet________-

Experimental Diets

. Diet codes and description of experimental

CLIC ES eae atts Cee Maal Siok, coer S es Be ay

. Protein and amino acid content per 100 grams

of diet, and suggested requirements for the
DE sng ee Lg a

. Fatty acid content per 100 grams of diet and

iodine value of dietary fat______-----------

. Fat, fatty acid, and cholesterol content per 100

PTAMSHOMGiCtH ee es oe ea eee
Vitamin content of diets, and suggested require-
mentsiorthe:rats £2 7 #42222 25-2 e

. Ash and mineral content per 100 grams of diet,

and suggested requirements for the rat__-__-

. Calorie values per 100 grams of diet, and per-

centage of calories as carbohydrate, fat, and
T OVOR HEY BO pee ee pg

Body Weight

. Growth, food intake, and calories per gram of

gain in young rats fed various diets__--_---

. Body weight of rats at different ages fed various

CIS ES mate ae Same we Ue Pea Le ee =

. Calories per gram of body weight per week for

maintenance of adult rats fed various diets_-

. Maximum weight of rats fed various diets, sac-

rificed before or after 500 days of age__---_--

. Age at death and mortality rate of rats fed

VATLOUS GICtS a een ee eee eee ee eS

Contents

a)
©
og
o

OOO OOo > NR

ar —~ = an
co — lo —

wee)
oo

Results and discussion—Continued

Body weight and longevity as influenced by
diet— Continued

Histology of liver__.__..__._.._....._____-
Kidney and liver weight________________
Adrenal weight_______________________-
Thyroid weights: = 2 3-2 ee
Thymus weight
Chemical investigations____________________
IG eh iYehi eee en een

Serum protein components_____________-

General summary and implications for future re-

SCAT Chase ome Sate ee oe ea ae a ed ns he eR ee

HN 0) {SOG Bb Cee ke a Se eg is a ee ate

Tables

Page

13.

14.

15.

16.

Body Weight—Continued

Maximum age of rats before weight loss in
relation to caloric intake during the first
300 days on SP 8 HVO and SPE diets______

Histology

Kidney damage determined microscopically
for rats maintaining weight at different ages
on stock, SP 8 HVO, and SPE diets________

Kidney damage determined microscopically
for rats losing weight at different ages on
stock, SP 8 HVO, and SPE diets__--__-_---

Calcium determined microscopically in kidneys
of fasted and nonfasted rats losing weight
at different ages on SPE diet____-_-_------

. Kidney damage determined microscopically for

rats maintaining or losing weight at different
ages on SPM, SPB, and SPPB diets______--

. Kidney damage determined microscopically for

rats fed all other diets__.________--____-_---

. Liver fat determined microscopically for fasted

and nonfasted rats maintaining or losing
weight at different ages on SPE diet___-__--

. Liver fat determined microscopically for rats

fed SPM, SPB, and SPPB diets___---------

. Liver fat determined microscopically for rats

fed other experimental diets__-_-----------

Page

Page

30

44,

45.

Kidney and Liver Weight

. Kidney weights in fasted and nonfasted rats

maintaining weight at different ages on stock,
SP 8 HVO, and SPE diets_____...__.-__--

. Liver weights in fasted and nonfasted rats main-

taining weight at different ages on stock, SP
8 HVO, and SPE diets____..__-__________

. Correlation of liver, kidney, and body weights

in fasted and nonfasted rats fed stock and
SPS HVO dietss cc. 26 ee

. Kidney weights in fasted and nonfasted rats

losing weight at different ages on stock, SP 8
HYVO, and SPE diets...-.-2.-.<22shs52.38.-

. Liver weights in fasted and nonfasted rats losing

weight at different ages on stock, SP 8 HVO,
SandsbP Hi diets.. ios Joke

. Kidney weight as related to kind and extent of

damage in fasted and nonfasted rats fed
stock, SP 8 HVO, and SPE diets__________

. Liver weight as related to kind and extent of

kidney damage in nonfasted rats maintaining
weirht onistock diceti2- 2. 25o.c2 4 252222

. Kidney and liver weights of fasted and non-

fasted rats maintaining weight at different
ages on diets with protein-fat-containing
1TOO0S nes. SoS a Se ee

. Kidney and liver weights of fasted and non-

fasted rats losing weight at different ages on
SPM, SPB, and SPPB diets... 02-22.2.-.-

. Kidney and liver weights of rats losing weight

on SPE diet containing added purified nu-
(PlentSe se Se See ae eee ee

. Kidney and liver weights of fasted and non-

fasted rats maintaining or losing weight on
diets containing different kinds and levels of

on SP 8 HVO diet modified to contain the
protein and fat level of SPE diet__-__-_-__-

. Kidney and liver weights of rats fed various

diets containing egg, egg yolk, or egg white__

. Kidney and liver weights of rats fed stock or

SPE diets reversed at 250 days__________--

. Kidney and liver weights in two strains of rats

at terminal age from parents fed two stock
diets, with young fed SP 8 HVO and SPE
lets sec bowed se a ee oe Seo

Adrenal Weight

. Adrenal weights of rats maintaining weight at

different ages on stock, SP 8 HVO, and SPE
CN GUS ea coe ee So ae ene a i lene

. Adrenal weight in relation to body weight of

rats fed stock, SP 8 HVO, and SPE diets__

. Adrenal weights of rats losing weight at different

ages on stock, SP 8 HVO, and SPE diets____

. Adrenal weight in relation to extent and kind of

kidney damage in rats maintaining or losing
weight on stock, SP 8 HVO, or SPE diets. __

. Adrenal weights of rats maintaining weight at

different ages on SPM, SPB, and SPPB diets_

. Adrenal weights of rats losing weight in two age

eroups fed SPM, SPB, and SPPB diets___-_-_

. Adrenal weights of rats fed other experimental

ANGUS hts i Roe tee ERA Le nee eS

Thyroid Weignt

Thyroid weights of rats maintaining weight at
different ages on stock, SP 8 HVO, and SPE
@lets..2% 22. 8 Nene Sn en Ron - dees Bae ee

Thyroid weight in relation to body weight of
rats maintaining weight on stock, SP 8 HVO,
and SEH dlets 222242222 eee ee ee

Page

44

45

46

47

48

49
49
49

50

57

58

46.

47.

48.

49.

50.

55.

63.

64.

65.

Thyroid Weight—Continued,

, and SPE

of kidney damage for rats maintaining or
oe weight on stock, SP 8 HVO, and SPE
iets

Ds a a a

Thymus

Thymus weights of rats at different ages on
stock, SP 8 HVO, SPE, SPM, SPB, and
SPPB diets

Kidney Chemistry

. Protein, fat, and ash in kidneys from rats main-

taining or losing weight at different ages on
stock, SP 8 HVO, and SPE diets

. Protein, fat, and ash in kidneys of different

weights from rats fed stock, SP 8 HVO,
ang OS PE diets’: = 22 .etee see oe ee

. Protein, fat, and ash in kidneys from rats

maintaining or losing weight on SPM, SPB,
and SPPB diets

. Protein, fat, and ash in kidneys from rats

fed other experimental diets

Urinary Protein

Urinary protein of fasted and nonfasted rats
at different ages on various diets__.________

Liver Chemistry

. Protein, fat, and ash in livers from rats main-

taining weight at different ages on stock,
SP 8 HVO, and SPE diets_.__.....______-

. Protein, fat, and ash in livers of different

weights from fasted and nonfasted rats fed
stock, SP 8 HVO, and SPE diets___________

. Liver fat and body weight of fasted rats main-

taining weight on SP 8 HVO diet__________

. Protein, fat, and ash in livers from fasted and

nonfasted rats losing weight on stock, SP 8
EV ©) and S:Pidietss. 200 2ee- = eee

. Kidney damage and liver fat in nonfasted rats

losing weight on SP 8 HVO diet___________

. Protein, fat, and ash in livers from fasted rats

maintaining weight on SPM, SPB, and
SPPB diets). 22. emes-4sutunoce steers

. Liver fat in rats of different body weight

maintaining weight on SPM, SPB, and
SPPB diets 2. 222 5. oe ae ee ee ee
Protein, fat, and ash in livers from fasted and
nonfasted rats losing weight on SPM, SPB,
and S PPB idiets22:52 252 ee eee
Protein, fat, and ash in livers from rats fed
other experimental diets___--._.-----------

Serum Cholesterol

Influence of diet and age on serum cholesterol

Page

58

59

60
61

63

64

65
66

67

78

66.

67.

68.
69.
70.

71.

72,

73.

PF WwW WN

Serum Cholesterol—Continued

Influence of diet and age on serum cholesterol
levels, in rats losing weight on stock, SP 8
HVO, SPE, SPM, SPB, and SPPB diets___-

Serum cholesterol levels of rats with kidneys of
different weights on stock, SP 8 HVO, SPH,
SPM, SPB, and SPPB diets______________-

Serum cholesterol levels of rats with normal kid-
neys at different ages on SP 8 HVO diet____

Serum cholesterol levels and organ weights for
rat littermates fed SPE diet______________-_

Serum cholesterol levels in rats fed other experi-
mental diets: 2. 34 sthee2 oat eo. eet ee

Serum Protein

Protein components of sera from rats maintain-
ing weight at different ages on stock, SP 8
EVO-andiSPH diets: 222225202. 55-22=. =.

Protein components of sera from rats losing
weight at different ages on stock, SP 8 HVO,
and: SP Eidietss=) 22. =2-- Lo 2fh22 b22e25 5 =

PA, serum cholesterol, kidney weight, and kind
and extent of kidney damage in rats fed SP 8
HVO and SPE diets_......_...__.__.__.--.._-

. Average weight gain and food intake of rats fed

SP 8 HVO and SPH diets_________________-_

. Weight in relation to age of selected individual

rats fed SP 8 HVO and SPE diets__________

. Average weight in relation to age of rats fed

stock, SP 8 HVO, and SPE diets__--________

. Percentage of total number of rats dying within

different age intervals on SP 8 HVO and SPE
GILG GS ta reyatat ee ites al eieens Ty eo tet ok

. Percentage of total number of rats dying within

Page

79

80
80
81
81

87

88

89

Serum Protein—Continued

74. Protein components of sera from rats at differ-
ent ages on SPM, SPB, and SPPB diets___-

Appendix Tables

75. Protein and amino acid composition per 100
grams of ingredients in experimental diets__
76. Lipid composition per 100 grams of crude fat
and of ingredients in experimental diets_-_-__-
77. Vitamin composition per 100 grams of ingre-
dients in experimental diets_____________-_-
78. Ash and mineral composition per 100 grams of
ingredients in experimental diets___________
79. Weekly weight gain and food intake of rats fed
SP 8 HVO, SPE, SPM, SPB, and SPPB diets
for first Ziweeksaeeees a2 8-2-2 ees
80. Weight, weight gain, and food intake of rats for
100-day intervals on SP 8 HVO, SPE, SPM,
SPB and SPPB diets: 2-22-22 22222 22222
81. Body weight, food intake, survival, and organ
weights of individual BHE nonfasted rats
fed stock and SPE diets throughout life or
reversed at 250 days____-_---__----------

Figures

Page
12
13
13

24

different age intervals on SPM, SPB, and
SRP Bidictse" sesso eae eee ea ee
6. Comparison of growth curves of obese rats fed SP
8 HVO and SPE diets with those of long-lived
rats fed the same diets____.-_-------------
7. Comparison of growth curves of obese rats fed
SPM, SPB, and SPPB diets with those of long-
lived rats fed the same diets_-_-_-----------
8. Liver weight in relation to kidney weight in
fasted and nonfasted rats fed stock diet_____-_

Page

90

102
103
104
105

106

107

108

Page

Diet as a Factor in Length of Life and in
Structure and Composition of Tissues
of the Rat with Aging

By Mitprep ApAms

Human Nutrition Research Division, Agricultural Research Service

Early investigations with the laboratory rat as
experimental animal have dealt with nutritional
factors important for normal growth and develop-
ment of the young animal, and have provided
much information of basic importance to human
nutrition. In recent years, increasing emphasis
has been placed on the need for information con-
cerning the requirements of adult animals at
various stages of their lifespan.

In this laboratory, investigations have been
underway for several years to determine the
influence of various dietary combinations on the
length of life and on the appearance of changes in
the structure and composition of tissues of the
rat. <A preliminary report (39) ? from this labora-
tory has indicated that the substitution of cooked
dried egg for 25 percent of a nutritionally adequate
basal diet accelerated development of degenera-
tive changes in tissues of the adult rat. When
the diet consisted of 100 percent whole egg, the
tissue changes observed were less severe and
occurred later in life, suggesting that an imbalance
of nutrients rather than egg itself may have been
responsible for the adverse results with the diet
containing 25 percent egg.

In this publication are reported results of ex-
tensive investigations using the rat as the experi-

mental animal and dealing with the influence of
diet on survival and some of the factors, including
diet, that may affect the presence or absence of
pathological lesions and the size and proximate
composition of selected organs. Included also are
results showing the influence of age and diet on
cholesterol and on various protein fractions in the
blood serum.

The majority of the experimental diets were
modifications of a relatively simple diet composed
chiefly of semipurified components. In one group
of diets, protein and fat were varied by replacing
20 to 25 percent of the semipurified diet with egg,
milk, beef, or peanut butter. In a second group
of diets, the source and level of protein remained
constant but the kind and level of fat varied.
The fats were hydrogenated vegetable oil (HVO),
lard, and butter; the levels were 8 and 16 percent.
In addition, limited data are reported on the effect
of supplementing the diet containing 25 percent
ege with various B vitamins alone or in combina-
tion. The results of feeding diets containing rela-
tively high levels of egg yolk or ege white or
consisting solely of whole egg or egg yolk are also
included.

3 Italic numbers in parentheses refer to Literature Cited,
p. 93

Experimental

Description and Management of Animals

A strain of rats (BHE) developed in this labora-
tory by crossing Albino (Yale strain obtained from
Columbia University) and black and white hooded
rats (Pennsylvania State College) served as the
chief source of the experimental animals. The

litters included white, black, or black and white
rats. The parent stock animals were raised on a
standard pelleted ration* that is employed in our
breeding laboratories and has been found to be
efficient for growth, reproduction, and lactation.

4 Animal Foundation Laboratory Diet, Standard Brands,
Inc., N.Y.

1

A small group of young from a colony of Wistar
animals ® raised on a different stock ration ® was
also investigated to determine if the dietary
response would differ with another strain of rat.
To obtain information on the possible carryover
effect of the diet of the parents, a few BHE rats
were raised on the stock diet on which the parents
of the Wistar rats had been maintained and the
response of their young to diet was determined.
Male rats were used throughout these investiga-
tions because preliminary studies had indicated
that males were more susceptible than females to
certain dietary regimens that caused early death
and accelerated degenerative changes in the
tissues.

Rats were placed on the experimental diets at
weaning, when they were between 21 and 24 days
of age. The majority of weanling rats weighed
between 40 and 50 grams. Except for one series,
the animals were maintained on a constant diet
throughout life. To determine whether the re-
sponse to diet could be influenced by the age at
which consumption of the diet was begun, the
influence of changing the dietary regimen at 250
days of age was investigated. For each series,
only those litters were used that contained enough
males to permit placing one littermate on each
experimental diet in the series. The average
initial weights of the animals fed each diet were
kept as nearly uniform as possible.

All animals were kept in an air-conditioned
laboratory maintained at a temperature of 78°-
82° F. and at a relative humidity which averaged
37 percent, although not rigorously controlled.
The animals were fed ad libitum and had access to
water at all times. The animals fed the pelleted
stock ration were taken directly from the stock
colony. They were housed five to six to a cage,
and no data were obtained on their food intake.
Rats fed the experimental diets were housed in
individual metal cages with raised screen floors.
When urine collections were made, the animals
were transferred to wire metabolism cages with
half-inch mesh bottoms supported above glass
funnels 9 inches in diameter.

The rats fed experimental diets were weighed
daily for the first 2 to 3 weeks and weekly there-
after. For many of the series, food intake
records were maintained. Food intake was
recorded daily during the first 2 to 38 weeks
and twice weekly throughout the remainder of
their life. Scattered food was collected and
weighed at the time of recording food intake.
Observations were made regularly of the general
physical condition of the animals.

5 Kindly supplied to us by Arthur M. Hartman, Animal
Husbandry Research Division, Agricultural Research
Service, Beltsville, Md.

6 Stock colony ration consisted of: yellow cornmeal,
68.5 percent; linseed oil meal, 14.0 percent; meat scrap,
9.0 percent; commercial casein, 4.0 percent; alfalfa meal,
2.0 percent; bone meal, 2.0 percent; and sodium chloride,
0.5 percent. Supplements of lettuce and carrots were fed
once a week.

2

For some experiments, urine was collected over
a 7-hour period, during which time the animals
had access to water but not to food; for others,
urine was collected over a 16- to 17-hour period,
with the rats having access to both food and water.
To collect the urine samples, 50-ml. glass centrifuge
tubes containing toluene were placed under glass
funnels. Plugs of extremely fine wire mesh were
placed in the neck of each funnel to screen out
feces, feed, and hair.

To determine the changes that occur with
aging, some animals were sacrificed at scheduled
ages while they were maintaining or gaining
weight and were showing no obvious signs of
illness. Other animals designated for survival
studies were continued on the experimental diets
until they became obviously ill. These rats
reduced their food intake or stopped eating
entirely, they became listless, and their coats
became rough. These animals consistently lost
weight and occasionally suffered from obvious
respiratory disturbances.

It was not possible, without 24-hour vigilance,
to keep animals until they died naturally and
still obtain tissues suitable for microscopic exami-
nation. Thus the results of the longevity studies
were dependent upon arbitrary decisions as to
when the rats were approaching death. At first,
animals were allowed to continue until extremely
ill, with weight losses often equal to as much as
one-third of their maximum body weight. Un-
expected deaths resulted in failure to obtain
tissues that were suitable for histologic or chemical
analysis because of post-mortem changes. Later,
to avoid loss of suitable tissues, rats for longevity
studies were sacrificed as soon as there was con-
sistent weight loss for at least 3 weeks and/or
when weight loss exceeded 50 grams.

During the early investigations, rats were sacri-
ficed by injecting 0.5 ml. of 2 percent solution of
sodium amytal per 100 grams body weight without
a preliminary fasting period. When the criteria
under investigation were extended to include
measurements of various serum protein fractions,
it became necessary to sacrifice the animals after
a 17-hour fast and to obtain blood samples by
cardiac puncture.

Diets

The semipurified diet, which served as a basis
for most of the experimental diets, consisted of:

Inaredient Percent
Oasein 1. 22 a a eee 16
Tactalbumin' 2. 4-2 2-432 oe = eee ee 8
A= tj re oe eS yk MM re se Ea BR 10
Saltwmixture 4? 22 = eee eae 4
Hydrogenated vegetable oil (HVO) °_------------ 8
Sucrose <6) eg ee ee 52
Celluflours. 2... 24 ee eee 2

1 High-nitrogen, acid-washed, edible product, from Sheffield Farms Co.
2 Labeo Lactalbumin containing some lactose, from Borden Co.

3 Dried brewer’s yeast, type 200B, from Standard Brands, Inc.

4 Source: Osborne and Mendel (149). : ;

5 Crisco, from Procter & Gamble Co., Cincinnati, Ohio.

The following supplements per animal were fed
with all diets: Percomorph oil, 2 drops weekly,
supplying 395 I.U. of vitamin A and 56 I.U. of
vitamin D daily; d/-alpha-tocopherol acetate, 36
mg. in 0.01 ml. of cottonseed oil weekly, or 5.1
mg. daily; fresh kale, 10 grams twice weekly.

In table 1 are summarized the modifications of
this diet and the codes used in the text. Egg,
milk, beef, or peanut butter were substituted for
part of the semipurified diet in such a way that
all of these diets contained approximately the
same amount of protein and of fat. The fat con-
tent of these diets was approximately twice that
present in the semipurified diet. The foods
themselves provided the extra fat in SPE or
SPPB diets. Extra fat beyond that in the food
to be studied was provided by butterfat in the
SPM diet and by suet in the SPB diet. The
diets containing 8 and 16 percent HVO, lard, or
butter were all identical except for the kind and
level of fat and the reduced level of sucrose when
16 percent fat was used. Other modifications of
the SP 8 HVO diet and the diets consisting of 100
percent whole egg, 100 percent egg yolk, or 97
percent egg yolk with added salt mixture (3 per-
cent) were included in an attempt to elucidate the
possible role of egg fat or protein, or both in the
response of rats to the SPE diet. In addition,
the effect of adding certain supplements (selected
vitamins and cholesterol) to the SPE diet was
investigated to obtain some information on the
possibility that an imbalance of nutrients was a
factor in the response of rats to this diet.

To each 100 grams of SPE diet the following
supplements were added:

Choline, 0.5 gram

Vitamin By», 0.01 mg.

Choline, 0.5 gram-+ vitamin B,»2, 0.01 mg.

Vitamin B,, 0.5 mg.

Choline, 0.5 gram-+-vitamin Bez, 0.5 mg.

Choline, 0.5 gram-+vitamin Be, 0.56 mg.+
vitamin By, 0.01 mg.

Cholesterol, 0.46 gram

Cholesterol, 1.38 grams

Ascorbic acid, 0.2 gram

Cholesterol, 0.46 gram-ascorbic acid, 0.2
eram.

The dry ingredients for the experimental diets
were weighed in the proportions already described
and placed in a Hobart mixer, with the sucrose
added last. The melted fat was poured onto the
sucrose, and the diet was prepared by blending
in the mixer. This procedure resulted in a more
uniform product than that obtained when the fat
was added to the mixed dry ingredients.

Dried whole egg, before being added to the SPE
diet, was blended with water, then cooked in a
double boiler and stirred constantly until the egg
was firm and dry in appearance; the lumps were
broken in a Foley mill, dried at 150° F. with forced
draught, and ground.

For the SPB diet, the beef was cut in 4-inch
cubes and cooked in water, in a large steam-

TaBLE 1.—Dvet codes and description

of experimental diets

Code Description

SP Si HViOl. 22. Semipurified.

hoyle) ahaa ee Aes SP 8 HVO, 75 percent + whole egg,
commercially dried,! 25 percent.

SBI eee SP 8 HVO, 75 percent + skim milk,?
15 percent + butterfat,? 10 percent.

SP Betas sje 722 SP 8 HVO, 75 percent + beef,! 15 per-

cent + beef suet,> 10 percent.

SPBBa22 222424 SP 8 HVO, 80 percent + peanut but-
ter,® 20 percent._

SP 16 HVO____| SP 8 HVO with HVO level increased to
16 percent and sucrose decreased to
44 percent.

SP’ 8 lards—.— 2 SP 8 HVO with lard? replacing HVO.

SP 16 lard_____ SP 16 HVO with lard replacing HVO.

SP 8 butter___-_
SP 16 butter___
SPa 16 HVO__-

SPb 8 HVO_-_--

Y97-+salt
mixture______

SP 8 HVO with butter * replacing HVO.

SP 16 HVO with butter replacing HVO.

SP 16 HVO with casein increased to 20
percent, lactalbumin increased to 10
percent, and sucrose decreased to 38
percent.

SP 8 HVO with casein increased to 20
percent, lactalbumin increased to 10
percent, and sucrose decreased to 46
percent.

SP 8 HVO, 86 percent, except HVO, 15
percent; sucrose, 41 percent; and egg
white,’ 10 percent.

SP 8 HVO, 66 percent, except no HVO;
sucrose, 43 percent; and egg yolk,$
30 percent.

SP 8 HVO with egg white, 24 percent,
replacing casein and lactalbumin.

Whole commercially dried egg, 100
percent.

Fresh egg yolk, cooked and dried, 100
percent.

Y100, 97 percent, + salt mixture, 3
percent.

1 Whole egg, spray dried, from Henningsen Bros., Inc.
2 Starlac, from Borden Co.

3 Butter washed free of protein and _ salt.
Husbandry Research

Animal

Division, Agricultural Research

Service, Beltsville, Md.
4 Beef rounds from dual-purpose cattle with all visible

fat removed.

Meat Quality Laboratory, Animal Hus-

bandry Research Division, Agricultural Research Service,

Beltsville, Md.

5 Beef suet from kidney area. Meat Quality Laboratory,

Animal

Husbandry Research Division,

Agricultural

Research Service, Beltsville, Md.
6 Peanut butter from two sources: (1) Prepared from

roasted white Spanish peanuts by Southern Utilization
Research Laboratory in accordance with directions
published by the Laboratory (18). The peanut butter
contained 1.2 to 1.3 percent commercial hydrogenated
peanut oil (Onesta Hardener, Procter and Gamble Co.).
(2) Peter Pan Peanut Butter containing salt was used for
most of the investigations.

7 Lard. Animal Husbandry Research Division, Agri-
cultural Research Service, Beltsville, Md.

8 Prepared in the laboratory from hard-boiled eggs.

jacketed kettle, for 30 minutes. The beef was
then ground, dried, and reground to produce a fine
powder for blending with other ingredients of the
diet. The beef suet was rendered and refrigerated
until used.

For diets containing egg yolks or whites, hard-
boiled eggs were used. Yolks and whites were
separated, ground, and dried at 150° F. The
whites were reground after drying. The diet
containing a high level of egg yolk was reground
after mixing.

Cholesterol or vitamin supplements, except for
choline, were added dry and mixed with the SPE
diet by blending in the Hobart mixer. Choline
was dissolved in water first and then added to the
dry ingredients before final blending.

The diets were prepared fresh at least every 2
weeks and were kept refrigerated until used. All
of the fats and the ingredients containing fat
were kept under refrigeration. Aliquots of the
dietary ingredients and of the experimental diets
were kept for chemical analysis.

The dietary ingredients and the experimental
diets were analyzed for moisture, nitrogen, fat,
and ash. Moisture was determined by drying
in a vacuum oven at 70° C. Ash values were
obtained by incineration in a muffle furnace at
575° CC. Nitrogen was determined by the
Kjeldahl-Wilfarth-Gunning method using mercury
as a catalyst (12) and distilling into boric acid
(175). Protein values were obtained by applying
to the nitrogen values the factors indicated.
Fat was determined by a modification’ of the
AOAC acid hydrolysis procedure (13). Carbo-
hydrate values were calculated by subtracting
the weight of fat, protein, and ash from the total
dry weight. Mineral components were deter-
mined by spectrochemical analysis for the various
dietary ingredients and for most of the diets.
Those diets not actually analyzed were calculated
from the values for the dietary ingredients.
Gross calorie values were obtained for some of
the diets by use of the Parr Bomb Adiabatic
Calorimeter; others were calculated by application
of appropriate gross calorie values for the proteins,
fats, and carbohydrates which they contained.
The values for thiamine, riboflavin, niacin, pyri-
doxine, folic acid, pantothenic acid, vitamin By,
choline, essential and nonessential amino acids,
fatty acids, and cholesterol were all calculated.

Criteria for Evaluating Response to Diet

Physical measurements, histological examina-
tion of the tissues, and limited chemical analyses
of liver, kidney, blood serum, and urine provided
the criteria used for evaluating the changes
occurring in the rat with age and/or with diet.
Measurements obtained on BHE rats fed the
stock diet provided information on the charac-

7 Unpublished.

teristics of the rats that served as a source of
the experimental animals. A group of rats fed
SP 8 HVO diet was included for comparative
purposes in each of the experimental series alinged
chiefly with modifications of this diet. Rats fed
SPE diet served as a basis of comparison for the
series of rats fed SPE diets containing various
supplements and for those fed high levels of egg
or egg fractions.

Weight and intake data provided the informa-
tion needed to compare the rate of growth,
maximum weight attained, and efficiency of food
utilization. The influence of age and/or diet on
the size of the organs was determined by weighing
immediately, at the time of sacrifice, the liver,
right kidney, right adrenal, and right lobe of
the thyroid.

Also, at the time of sacrifice, any gross abnor-
malities in the animals were noted. The left
kidney and adrenal, the left lobe of the thyroid,
and part of the median lobe of the liver (approxi-
mately 20 percent by weight of the total liver)
were fixed in 10 percent formalin to preserve these
tissues for histological examination. Other tissues
prepared routinely for histological examination
included the heart, lungs, aorta, salivary glands,
spleen, pancreas, and testes. These tissues were
embedded in paraffin, sectioned, and stained with
hematoxylin and eosin.

The methods used for rating the microscopic
findings and the results of gross and microscopic
examination of the tissues are being reported in
detail elsewhere (54). This report includes only
those phases of the histological findings that are
related to the chemical investigations reported,
and deals chiefly with the kidney and _ liver.
Damage to the liver and kidney was rated arbi-
trarily 1 to 4, with 4 the most extensive damage.

Chemical analyses included determinations of
moisture, fat, protein, and ash in livers and kid-
neys, cholesterol and protein fractions in blood
serum, and coagulable protein in urine. Most of
the chemical analyses were obtained for rats that
were fasted before sacrifice. Immediately after
removal of the section of liver retained for histo-
logical examination, the weight of the remaining
portion was recorded and both the liver and kid-
ney were stored frozen, for chemical analysis.
Homogenates of these organs were prepared by
use of a Virtis homogenizer, and the various
analyses were carried out on weighed aliquots of
these homogenates. The values reported for the
liver content are for the whole liver, based on the
assumption that the composition of the sections
analyzed was similar to that of sections removed
for histological examination.

During the early series, small kidneys were
pooled in order to obtain sufficient material for

duplicate analysis. Once the conditions had been
established for producing a uniform homogenate
from the kidney, the results from chemical analyses
showed excellent reproducibility. It then seemed
preferable to analyze individual kidneys to permit
a direct comparison of the results with the other
measurements under consideration and to avoid
masking differences that may result from average
values. Only one analytical value could be
obtained for kidneys weighing 2 grams or less.
Duplicate values were obtained when sufficient
material was available.

The methods for analysis of tissues were the
same as those used for the food samples, except
that fat determinations were done by the AOAC
acid hydrolysis method (13). The coagulable

protein in the freshly collected urine samples was
determined by precipitating with 5 percent acetic
acid (63) and weighing the washed, dried precipi-
tate. Blood serum samples collected at the time
of sacrifice were stored, refrigerated, at 4° C. until
analyzed for cholesterol and for the various protein
components. Serum cholesterol was determined
by the direct method of Zlatkis, Zak, and Boyle
(192). It has been established (108) that the
values obtained by the use of the direct method
are high, but further investigations in this labora-
tory have indicated that the relationships reported
here are substantially correct. Serum protein
components were determined by electrophoretic
analysis, using the method of Tiselius (183) as
modified by Longsworth and Jacobsen (118).

Results and Discussion

Composition of Experimental Diets

On the basis of current information, the majority
of the diets investigated provided adequate
amounts of the nutrients essential for the growing
rat and amounts generally considered adequate or
more than adequate for maintenance of the adult
animal. Admittedly, our knowledge of the re-
quirements of the rat at various stages of life is
far from complete.

The analyzed or calculated values for the
nutrient content of the diets are summarized in
tables 2 through 7. Corresponding information
for the ingredients used in preparing these diets
is summarized in tables 75 through 78 of the
appendix. To facilitate evaluation of the
adequacy of the experimental diets under con-
sideration, the amounts of nutrients suggested
as requirements for the growing rat and for the
adult rat have been included when such informa-
tion was available. Many factors may influence the
requirement for a specific nutrient such as the
heredity of rats under investigation and the pro-
portion of other dietary components. Most of
the values for nutrient requirement that are re-
corded represent the average of results obtained
by several investigators, and have been limited to
requirements of rats fed relatively simple diets
similar to the semipurified diet used in the in-
vestigations reported in this bulletin.

Protein

The protein content (table 2) of all but three of
the experimental diets was within the range of 25
to 30 percent of the diet—an amount suggested
for optimum growth of the rat. Two diets, SPM
with 23.8 percent protein and SPW with 24.6
percent protein, were only slightly below the 25-
percent level; the third diet, consisting of 100
percent whole egg, provided a considerable excess.
The stock diet contained most of the essential
amino acids in relatively small amounts when
compared with the other diets under investigation
but still provided sufficient amounts to meet

requirements. The diet consisting of 100 percent
ege with its high protein content supplied the
essential amino acids in amounts considerably in
excess of requirements. The other diets provided
from two to four times the amount of the essential
amino acids required for the growing rat, and still
greater excesses for the adult animal. Considering
tryptophan as the base line, no marked differences
in the amino acid patterns of these diets were
observed except for stock and SPW diets. The
stock diet contained relatively small amounts of
tryptophan when compared with the other amino
acids. Methionine and cystine were high in
SPW diet in relation to its tryptophan content.

Fat

Data for the fatty acid composition of the diets
are presented in table 3 as a percentage of the
dietary fat and in table 4 as a percentage of the
diet. No data were available for the fatty acid
composition of yeast fat, and the results recorded
are exclusive of the fat from this source. The
small amount of fat in the yeast (0.5 percent or
less of the diet) would not be sufficient to change
materially the major characteristics of the dietary
fat. Table 3 also includes the iodine values for
the dietary fats, and table 4 includes the choles-
terol content of the diets.

The iodine values of the food fats (table 3)
ranged from 33.4 for SP 8 butter or SP 16 butter
to 87.8 for SPPB diet, reflecting the relatively
high linoleic acid content of peanut butter. Of
the fat in SP 8 HVO, SP 16 HVO, SPa 16 HVO,
SPb 8 HVO, SPEW, and SPW diets, more than
60 percent was oleic acid. Saturated fatty acids
of chain length 16 or less accounted for more
than 40 percent of the fat in the diets containing
8 and 16 percent butter.

The concentration of fat in these diets (table 4)
differed widely, with the smallest amount 6.3
percent in the stock diet and the largest amount
58 percent in the diet consisting of 100 percent
egg yolk. Although the daily intake of the
latter diet was less, fat consumption was higher
on this diet than on any of the other experimental

3

“poqiodoi BVP ON 9
‘lomnqovynuevur Aq pofddns son[va yotp YooIS = ("gL o[ vy x~puodde oag)

‘son[@aA pozA[Cuy 5

“(L9T-98T ‘dd ‘9) “stnburpy :001n0g ¢

(861) LOQOW ‘90.1n0g ¢

“SpOOJ [VNPLATIPUL ULOIJ PoPL[NO[VI SoON]VA “JoIp 3904S OJ ydoox gy 1

0 LG ise es CGM.» ee nea 08° 02° 83° $9" 83" ee | ates = |e? in ance noes nas |e nue oan ~“Wnpy
L° are or Samer aa ey ia OT 8° ¢° g° z OG=OG a ae duno xX
1S] U0UL
-dUINDOI POYVUALSHL
OL'T 96° Go" bre €9'T OF" 86° 0€ 'T T OL'T oe 62° 80°T 9 'T T9'T £6" ca" SSG, eee a Gh Gee lero oP wr aes MOT
£68 09% 99 °T 109 82 °8 CLT 20°€ 8P'E z OLS 60°T OL'T 00°E GL ¥ TE'é £8 °% LL* 8 OF ~~ ysl
:S}OIP AOJ os UvYT
29% 4 ral b0'T $9 '¢ €9'T 29° G0°% £073 if 08 'T og * 9L° 96'T 6h % 18 'T 09 'T er" 9°66 =| 93'9 «| SLR PT ~~" 00TA
£6 86'T 99°T 62 °9 82'S alt L0°€ 8h'E G OLS 60°T Lb'T 00°€ ama, IL'€ £83 LL” 8°OF | S6°O | GFL PO ~~" 00TH
68 'T 96° 00°T brs IL'Z 99° 68 'T 68 'T T QP 'T eo° OL'T £91 L0°% oo alt RE° 9 °bG “OAH 8 MdS
8L°T 181 89° GE 'b 66°T 99° Té'T PLT T GT 18" 19° 96 °T PFS 6¢ T $21 OF" 8°96 | 089 | GOR PTT ~""AAdS
16° CLS LL’ LE°9 99% 92° LE'T 80°% I 8o'T 8F° 88° St 68% L8°T 88 'T LY* Tos | 189 | 82° J "MAS
8L'T 09°% 29° 109 L9°% 68" ¥e'T G0'% I 09 'T OF" 18° 6h S OL's 16°1 eP'T OF" 9°66 | 889 | 89% J “OAH 8 4d8
8L'°T 09% 29" 109 29° a8" ¥e'T 60% I 09 'T OF" 18° 6h '% OLE 16'T eT OF’ 9°62 | 89 | 89°F | “OAH 91 ®d8
6P'T GL SG gg" o6 0 % 89° F0'T OL‘T T ¥e'T ee" 19° L0°% go % 8o'T 02 'T IF" $9 «=| 889 | 668 [OO ~~ dyn 9T dS
6h 'T GL % 99° G6'P G 89° POT OL'T I ¥e'T ee" 49° L0% Go'% 89'T 00 'T ia €9e «86| €8°9 «| 66° ~doyNG 8 ds
6F'T SL's gg 96°F % 89° b0'T OL'T I FT ee" 19° LOS Go '% 89 'T 02 'T ia be GRA ESA i Je PAB OL ds
6P'T SL % gg: 96°F % 89° b0'T OL'T T ¥G'T £e° 19° L0°% go'% 8o'T 02 °T Ir’ 9G =| 889 | 668 PU Pll 8 ds
6P'T CLG gg" 969 4 89° $0'T OL'T T aa | ee" 19° 10°% 99% 891 02 °T iz €9G | 889 | 668 fe “““OAHL 9T dS
69 'T 10% 82° eleg G 69° 8F'T 99 'T I 08 T 98° 69° 18° iad T9'T aa | 6S: 6°96 «6©| 819) | SLR OT a add 8
09°T 9L'% CLT brS 7% 16° Co 'T 16 'T T OFT a 8L° ca'% 98% 8L°T OFT th O°0g =| 089 | OLR [OT ~~ a dS
ert 81% og" 96°F % 99° 86° 49 'T I 6I'T 08° £9° 96 °T bb G co 'T PLT 88° BES. VEO! GGA Go WW d8
OL'T 60°% £8" 91 '¢ % 62° go'T FG a! 19 'T Zo ° 18° 08% $6% 96°T 8h 09° 8°08 | 089 | eB pO Hd 8
6F'T a ard go°0 96h % 89° 60'T OL ‘T 161 bo'T ee" 19° L0°% co'% 8¢o'T 02 'T I 6°99 | 889 | 66° | “OATL 8 dS
(9) (9) (9) (9) (9) OF 0 eh 08 'T (9) OL'T £10 620 80°T $91 99 'T £6°0 a) aL CN (SAR a © A i i a 90S
SULDIP) | SULDIF) | SULDAZ) | SULDIY | SDL | SULDI | SULDID | SULDIY | SDI | SULDLID | SULDID | SDL | SULDLD | SULDLH | SULDLDH | SUDI | SDI | WL | SULDLYD SULDLE
prow
oULIOg jouTporg jouATH] ole, | prlovoy jouruvtpy} outp Oulu | OUNVA | oUIS | oUTURTeloUTJsAO]} oUTUO | OUISATT joUTONOT| OUTDO our | ueyd jutojorg |; aojory | , uod 4oldL
ApH | -aedsy “suey | -18.0y -O1AK, |-[Auoy “TOTAL -N9OST | -Oo1qyL, |-OVdAAT, ULoJO1 | -O.UYIN

wu ayy Lof ., spuamaunbas pasabins pup Yap fo swoub oop vad JUazywod , pap OULD PUD UWII}I0NJ—"Z LIAN J,

“uIBIS GO’ UY} SsoT z
“qBy ysvod JO DAISNIOXO o1B SONTeA

DUTIPOT puB sploe 447R] {ysvod IOJ o[qRTIVAR BIVP ON (‘92 21G¥} xIPUOdde 99g) ‘SpOO} [VNPIAIPUL UI 4BJ JO WOTJISOduIOD UIOIJ PoPB[NI[VO SPOIp IOJ SONTBA _

sist ood

xi
COMMr~OKOARDH WoO

HOWMAHHHROHOOO oO
Pe Rarkarhenkond ys A>]

+]
wR

8°28

ony[Ba
aurTpoy

(z) ea Gee |r Se T° F 6g | oo 6 S| 6220s T° (z) (2) Ree Ie SECC i eee aaa MOT

$3 FT ¢ to | y'S9 | GG O82 | LOS LPL | Sl0S) 1 62% 9°E Sia: 8° La 0'€ (Ohl (T = Ue ae ESOS Ys
:SJOIp JOJ osuey

G3 ian 8'2 Slr | ¢°¢ Lee Oae a es 6S He ize lege lee co oP © walle oe al wee NUS eee btn” “““O00TA
G3 VT 82 8 27> SS ae |e 6 a 6°S atte ae Wie aiec ss aller. ei = eae eg OHS Gane eo ioe OOTH
SKS Se (és Gad ¥99 | €° OSzZ, (9-8 €°9 OTE 9 Se Soen lpr le ces |ss = eae) IOEGG penises OAH Sods
TG FT Leek e-lp | pS CaO | aes T 9 G VS | 9 ii (z) (2) lie {hy hoes are aor eet es ae AUdS
ile Go QRZ 6°€9 | Fv’ 912) 9 T 9°9 9 FI | 6 (a i (z) T° | GAUGE | eae ae MudS

(<) tia ve9) 9'19 | G° 0°69 | FT OL CGT) || tGeat T° oe la (Oe Ve OSOGa i tie week OAH 8 4d8

(z) G 69 PCO] F- 602 | ST 49 8F7L | OT Oh eae (z) les (a AVG |e nana a OAH 9T ®d8
Sp 8° 6G PSE | 0G TAGST |e oe oe 0 ‘ZGI | 8°S% | 6°L 9°E tae 8° ZI: ORS GOS | sae ae eas 1094nq 9T dS
ca 8° 6G FSS. (3006 V i6€- io 2 eae 0O'CI | 8°92 | 672 9°E ET Sai Ley 0'¢ CrOGs |e 2 eae = 133404 8 d§
a 9 TOL | o°Sh | T° i aS ae pt We ¢ ‘0s | v° Gc" TE? () 1 Gc" GG Sale ae nes pre, 91 dS
a 9° 8 6 9h | 3° 9 GG J 6°L €°0€ | 8 ian lee le (an ca ONOF) |Get i teens Soe PIeT 8 dS

(z) (a 0°2 2°€9 |v €'1L | ST 9°9 Levit OT GS" ey (2) | Bae G- CAG: sa lee OAH 9T dS
Tis Ee G ‘3S | OLY | 6° 8 69 | To 69 Oh Gl er Gaall G | te (z) T° i SNS Gate tee ogee addd$8

(z) ls Le | $09 4.o° bre | ¢° 2PM SSG aes Ti (2) () | T° [be GuGSr an ab Le adds
(a 9° v PT 8 FF | PT y1¢ | 9° 0OOr | 2°1¢ | €°S € 7S 6° ¢° LT 0G GColValepe eae WdS
GT OT VL €°Eo |) 9S 8 ‘99 | 9° €°9 £.'O6- |Z." IE (z) (z) T° ibe 8 Gu eos canes eee adds

(2) oO 8°9 & 769 | § 0 2°69 | ST 69 G GE. | 26-0 FO T 0 TO (am) SO GES Gish cerns nna OAH 8 d$
SUDAE) SUD 14) UD LE) SUD LE) SUDLY) SUDLY SUDIYH SU DL) SUD LE) SUD LE) SUDLE) SUD LE) SWDLE) SUD ALE) SULD LE) SUDLE)
er) 08) Id Le) 8Iry 1 @ ear®)

ow 1#30.L Or) bl) re) se) ate) 1) 8 ie) 78) 1820,
ITV UL -Id -ouoy, pd
spioe £448} poyeinyesuy, sploe A448} poyeinyeg

yof hapjarp fo anjoa aurpor pup , yarp fo suns QQ] 4ad yuajuoa prov hyyoy—'§ ATAV I,

“WMBIS [Q'Q UB SSOT ,
(92 9148} xIpuodds 90g) ‘syusTpolSul ULOIJ PoJB[NITVD ¢
C92 9148} xtpuodde 00g) ‘syuoIpoisul AIvJoIP WO] POYE[No[BO SontBA—ysRoA WUOIJ SPIOw A44BJ JO QAISNTOXAT z

“qey ysvod Sulpnyout ‘sonpea pozATeuy

0 () |20° |9Z° {26° |Z0° o¢’s (60° |o¢° |er‘t |So° |Z0° (s) () |30° (20° |I8‘T |e@°9 [U7TTTTTT MOT
082‘ (SPT 18° |@S°h I02°246 |61°€ |92°48 |88° irs [PO FT [GST |T9° |eo° WT’ (66° |eS° l69'ZT [OSS |777 77777 Ysiy
‘SZOIP IOJ oSUBY

082‘% ISh'T 18° |S °F |O@L°20 1618 = =J9L LE [7777 Gracin HORI ICG ee Lee alee lease Slee el ce 69: -21..|0 S89! (2-355 ee OOTA
O88 ‘T 40'T |0o9° |€8'°S Th ‘Os’ |e‘ l08‘4e |--77 77 Glace CS Ole le S| eee | eles epee, irate GOLGI: eG ram |e enenen a teed ae OOTH
Om lec ZO° {8g° |€z°¢ |Z0° wSeS: LIST, AOS: CmelGiely OGOhe Wiha plese, Fae een gee 1S) 21.9 Se Pie eazes OAH 8 Md§g
18 er’ GZ°|88T «(joe's 26° PSRs eee OLE |Ser It’ 120: () GSO ZO = VEO Gi pte eer sr ANds
6 ra €0° |OT ‘LE |90 OT 90° 8S ‘Il 83° POT joe's iT" |so° Zo" GP 1Z0rn “NCOs “WSs WGCOT. leap ee MWdS
€1 (5) |€0 19° |o9’¢ {60 126°9 |Sl° 9° IPT |FT° [0° |Z0° () (20° |PO GPG FG OT OAH 8 4d$
SI () |€0° |ST'L |P8 ‘OT 120° GIGI |9S° = IPT TT «OSS @ JLT SCO 20° () |Z0° |€0 Coy |LLE | OAH 9F ®d8
8F GO° 4 en (6) A a a ggg) oT €0'% |98% [SET |T9° |eo° IHL’ (63° [2S° \6r'6 |T‘zL [77777 10nd OT dg
6% £0" 10 93° |26'6 0%" Oss [Po 20'T |66°% |OL° [aE ZT° {20° |ST 10° «|66'b | 6 [TTT royynq 8 dg
6% 10° Ol’ OL T I$9°2 [20° CSG) hecns, Of T [Sts {20 €0° |20° (G) |20° {0 699 ILA. ro Pll OT dg
02 FO" go" 6{248° 96S «/Z0* VS.Ves | es OL° (69°% |20° |FO° (y) )" 120i" 01S 9G 83 poG Sale =e PLBL 8 dg
Or (5) {80° |ST‘T [SZ ‘OL |20° PO GT \SS° LTT ‘IT s«8h'@ IAT" O80 *a0° G) (20° [80° OL‘ JL 2ZE yo 77 OAH 91 d9
8 ZO * ZO" 3=6j98'€ 120°8 [0° 86 TT |88° |90'T ]1Z'%3 |1%° |go° |Z0° (He IO ICO \SRae “\Ge20, Vesa Sse ddds
GP () |20° OL’ |ee'6 {0° 12°01 60° |SL°% |PR P [60° [20° () G) 120° (20° |9F°2 I@°6E [TTT TTT ads
9g €0° Ol’ |tl° |SS°L |ro- 99 ‘8 |OT 89'T |F9'€ [68° |6e° [St'O |s0'0 IST rE CVoL clo Ll i\petats 5: wo Wds
Lb 920 = {LT 82 TL |Fo 6 109° 8¢ ‘TL |Or 60'T [6S °E ler Z0 ° () G) (20° (20° |86‘R fRoZt Jo tttttTtT Wds
OL () |20°0 j09 0 |2¢°S |F0°0 |6t9 {et 0 {190 |SE't |2t-o io 0 (+) G) |20°0 |s0'0 joe's | 6 TTT OAHS8 d§8
tema ima Waa aie Sigg | nee nro (tee ae if weg | ee pale ge eee ad leer peg ae acell ere tee [ieee oe |r ee gee egg eer eg e'9 Toner ==" 904

“BIN SUDLE) | UDLE) | SWDL) | SUWDAD) | SUDAE) |SUDID) | WDIE) |SWDLY| SUDLY |SWDLD | WDA | UDI | WDA | UDI | Wd |supsy | sUDLyH ee

8Iry alr) 8Ir4y 0 a ®)
e)—08)
ww i ih. WV = 4 - | [Rqo7,.)) 2% Bry are) re) cate) fe) 8 9%) ve) [BIOL

¢ [O10 “UL -Iq -OuOJy 1 3BJ VIC

-sojoug, TROL
z Splow A44RBj poyeunyesuy z Sploe A44BJ poywainyeg

jaup fo supib QO] sad yuazwod pouaysajoya pun ‘prop fiqof Qo g—p WAV J,

diets. The total fat content of the diet was, of
course, a determining factor in the total content
of the individual fatty acids and was responsible
for the large amounts of oleic and linoleic acid
in the diets composed entirely of whole egg or egg
yolk. Although the linoleic acid content of the
egg-yolk diet was higher than that of the SPPB
diet, the total consumption of this fatty acid
when egg yolk was fed was about 60 percent of
the consumption for SPPB diet. The latter diet
supplied about eight times as much linoleic acid
as did the diet containing a comparable level of
fat, chiefly as butter fat. Linoleic acid, the only
fatty acid so far shown to be essential for the rat,
was present in all of the diets in amounts sufficient
to supply the 25 mg. per day reported (122)
necessary to prevent the development of skin
lesions in the young rat and to permit growth to
proceed at a normal rate. Linoleic acid as well
as other fatty acids may play a role in other
phases of lipid metabolism, but the importance
of specific fatty acid patterns in the nutrition of
the rat has not yet been established.

The cholesterol content of the diets was rela-
tively low, amounting to less than 50 mg. per 100
grams of diet except for those diets containing egg.
The concentration of cholesterol was 478 mg. per
100 grams of SPE diet and was exceedingly high—
2,780 mg. per 100 grams—in the diet consisting of
100 percent egg yolk.

Vitamins

The data in table 5 summarizing the vitamin
content of the diets and the requirements for the
growing rat indicate that all of the vitamins
known to be required by the rat were supplied
in ample amounts. The high level of some of the
B vitamins in the semipurified diet and its modi-
fications was provided by the brewer’s yeast,
which was present in all of these diets. Although
the thiamine content of the stock diet and of the
100 percent whole-egg or egg-yolk diet was low in
comparison with the other diets, it was sufficient
to supply the amount of this vitamin considered
essential.

Choline requirements depend on many factors
(85) such as sex, strain, age, and dietary methi-
onine, cystine, betaine, or cholesterol. Although
10 to 20 mg. daily have been fed by many investi-
gators to supply the needs of the actively growing
rat, this amount is considerably more than is
necessary under some circumstances. In diets
containing from 24 to 30 percent casein, chloine
requirements are small (0 to 6 mg. daily). The
requirement of the rat over 30 days of age is also
small. According to Slanetz (173) only from 1
to 3 mg. daily are required by older rats. Although
the level of choline was low in most of the experi-
mental diets reported in this publication, the
amount supplied should be adequate for the adult
rat and even for the growing rat in view of the
methionine content of these diets. Levels con-
siderably in excess of requirements were provided

by the diets containing egg or egg yolk unless the
high cholesterol content of these diets increased
the need for choline.

Vitamins A, D, and E were not incorporated
into the diets, and the values recorded for these
vitamins are in terms of daily intake. The chief
source of vitamins A and D for all except rats fed
the stock diet was the supplement of percomorph
oil. Carotene from the kale supplement also con-
tributed to the vitamin A potency of the diets.
Egg and egg yolk were the only other foods to
provide significant amounts of this vitamin. The
supplement of dl-alpha-tocopherol acetate supplied
generous amounts of vitamin E compared to
reported requirements.

Nerurkar and Sahasrabudhe (137) reported that
pure vitamin A is toxic to young male rats when
given orally at a dose of 40,000 I.U. daily. When
feeding was continued for 10 days, there was a
gradual decrease in the percentage retention of
calcium, phosphorus, and nitrogen. The toxic
dose of vitamin D is generally high, but no exact
data can be given. In man and dogs (161, p. 430),
20,000 I.U. daily may produce toxic symptoms.
The amounts of vitamins A and D in the experi-
mental diets under consideration in this publication
were in excess of requirements, but they were
considerably below the amounts that have been
reported to be toxic for relatively short-term
studies.

Minerals

The salt mixture used for preparing the semi-
purified diet was the chief source of minerals and,
as seen in table 6, relatively small differences were
observed in the ash content of these diets. The
stock diet contained from two and a half to three
times the ash content of the experimental diets,
and large amounts of calcium and phosphorus in
satisfactory proportions. Diets consisting of 100
percent egg or egg yolk were low in calcium, with
a ratio of calcium to phosphorus below the
desirable range. Potassium intakes were consider-
ably in excess of requirements. Manganese
tended to be low. Aluminum values have not
been included. The were high and variable be-
cause of comtamination with aluminum from the
erinders used in preparing these diets.

Calories

The data for the calorie values of the experi-
mental diets are summarized in table 7. In the
majority of the diets, sucrose was the chief carbo-
hydrate. The cereal starches supplied most of
the carbohydrate in the stock diet. Fat supplied
less than 20 percent of the gross calories from the
stock diet and from the various modifications of
the semipurified diet containing approximately 9
percent of fat. The remaining diets, except for
E100 and Y100, supplied 30 to 35 percent of the
calories as fat. The calories from fat in diet
Y100 were 74 percent of the total gross calories
from this diet.

(66 “4 “@e7) AOD :oo1n0g = *oywyUT UIvAS-QT JO SISUq UO “YT OF 10 ‘pooj Jo Wes aod ‘AI € JO UOTyIppe Aq poaoad
“WI ST qolp ‘osuvd sty opisyng “yuosoad st snaoydsoyd quooaod ¢'Q puv ‘fz puv [:] UdoMyod SI yoIp oYyy UL OTyUA snaoydsoyd-wntoywo jl paatnbod YON}
“(8LP “d ‘797) Sanquosoyy :o01M0g g
"p 9JOUYOO} OVG = “Yolp OY} UT ST UTosvo UOYA [eIyUOSSe JON ,
‘p 9JOUYOO} OSTV
90g ‘ose pu “UIRAYS ‘xos SuIpNpoul ‘s1ojovy AULA UO YUopUDdop syuoWoIMboy °z OYOUYJOOJ DOG ‘SAOATT AYJVJ PUG SUOISOT [VUOI JUDADIG 04 JUDLOTYNE 4
‘syed poyo[dop-ey ULHULYTA JO 0FRA YIMOIS YOoM-F UO posuq JoIp JO SURAT YO] 10d “Sr T YIM wUNWIXeUL 04 OSOPD YYMOIS Sulyworputr
wyep Wor “pL “OASIog ‘OolAdog youvosoy [eang[Nosy ‘UOISTAIGE Youvosoy AIpueqsnyy PeuUTUy ‘UvlaqQIv YT “JY INYAy YM VOTYworuNWIWOD [CUOSIOG ¢
“(¢E) JUBADJINGG puv UMOIG :od1IN0g “A[Iep swILAS QT JO UOTYduINSUOD UO poseg ,
“(@B1) AODOVJT 2091N0g ¢
069 Osud ‘TF o[qey Ul VYEp WOAT poyL[NoTvo “(Sf) Toned, :00an0g
“Avp dod ‘sur | Apoywwurxoidde poynqiayuoo 4044nq ynuvod Sururezuoo sylqE *yuoor0d QT
SUM [OAR] UOYM “HUT gE IO “RJ SIYY JO yuooIOd g SUTUILIUOD SJoIp UL OAH Aq poynqiayuoo Avp aod “Sur g*y AToywurrxoadde ‘uory[ppt uy “quouroyddns sv pogp ;
‘lounjovjnuvw Aq pol[ddns yolp yoo4s toy vyeqE “22, o[qv4 xIpuoddy oog —“syuotpoasul woay poyepnopeo o1aM SonTeA “JoIp YOo4s oJ ydooxny y

OTe O€-OT 8 OF ‘¢ GST +
(ear O€ 6 Vy O. O€-02 9 OTe O'Ts OOT re Joo 0+ “GZ s OOM ¢. |p otn esse 2 tae pel SUNOX

‘SPU WIN DIL poyeulysny
Tg COR 006 F'8 GG G8 LL° io) a 10° Or - 99 ° SG” OP een MOTT
T'¢ 9¢ 090 ‘T 0 “St OFL ‘ZS LT 66 °L ST T TS ° 96 °L 61 T EOD Ee UST]

‘SPOIP LOF OSUBYT
1g 9g 0f0‘T | 0 FF OL ‘SZ Ll | 26°. Sit 60° OL’ 99° ST et eee ne oe oes OOTA
Tg 9S OS6 0 SP P98 ‘T 0 OL PEL PG ° TO" 0Z ° 90 'T VG ele ee a ea ees OOTEL
Lg 9G O19 8 ‘61 OG) ia ee GST GG * TS ° LI ¢ 6T T O0K98 Tae oe OAH 8 Md§
T‘¢ 9g O18 6 ‘8ST 6E8 IT ¢ 13 '€ OS * T° LEE ay ia Vila: D lncaw. hs Ss oo AUds
Leg 9¢ O19 GGL GG 06° 61 T 6L° ST° 96 'T 6° TASS "eae a ee ea se MiUdS
T'S 9¢ O19 4°8 9G GE UT ee T GG 13° ZO “G 68° LOO ie eel bee oe mraae OAH 8 dd8
T'S 9¢ O19 1°83 9G GET Se ‘1 GG 13° ZO “G 68° OOD” | PS Bes Ses rs OAH 9T ®dS
Eg 9¢ 069 9°8 9G 90 'T oe T GG 13° OG Gg ° TOMO”, il ie aime cea eee 10990q OT dS
jie 9S 0S9 9°8 9% 90 'T Ge OT GS 13° 60 °G G8 ° LOEOe eS Sage ines ee 199ING § dS
Ls 9G O19 9°8 9% 90 ‘T Goa GG” 13° 20'S G3° ROMO ree ne ae ee Plvy OT dg
T'¢ 9S O19 9°8 9% 90 T Gs UT (a 13° ZO “G G8 ° TOg0) Biles? he sac ~ ag oo ares PBT 8 dS
fea: 9G O19 9°8 9G 90 'T GET GG 1G ° GO 'G Gg TOO UN Ho ge oa OAH 91 dS
T¢ 9¢ O19 6 PI OP G8 6F T GS * roe 96 “2 hee Voie Wer oo gg ee ee dddS
tg 9¢ O19 v8 (Ay) 06° GST 6E ° 9T° 09 °¢ a Wao Glee oces 30 a ee adds
T'¢ 9G 099 LTT OF 9¢ ‘T 6F 'T GG 9T° G6 E 6 Oa, wives. we ge, ee ee INdS
T'S 9¢ OSL LOR OSPF O€ € GS GS O€ OT ° G8 ES 06 OORT ei ee a ere tldS
Tg 9¢ O19 9°8 9% 90 'T GE CT GG 1G O'S G8 Os Vi ee wie a OAH 8 d§8
aa we Cex 006 0 ‘ST Tél Gh ZG Le0 83 ‘0 LO 96 °E 90 ‘T ad: ec ape ign @ ae ge IOS
OW eae | at “bn ‘OW ‘bn OW 5 OW “OW OW “ON
plow
2 OL ral Vv ulyorg | ourpoyp ley oruoyy oUuIxXOp poe UlDBIN, UAB]. OUTWIT,
UlUUBITA | ULUUBITA | UTIL A UIWIBITA | -OJUBT Whig DIJO, -Oqnyy
PIC
ayByul ATIVE Jolp JO SUIBIS YOT Jod yuoquog

JDL OY} LOf syuamawnbas paysabins pun ,‘syap fo yuayuoa UUDLA—'G ATAV

Ada

10

TABLE 6.—Ash and mineral content per 100 grams of diet, and suggested requirements for the rat

Ratio—
Diet Ash! }Caleium| Phos- | Iron | Copper | Sodium | Potas- Mag- Man- |Boron|Calcium:
phorus sium nesium | ganese hos-
phorus
Grams| Grams | Grams | Mg. Mg. Grams | Grams q. q. Mg.
Stockiweesn see 2s 0. 0 2.17 1, 22 | 17 0. 7 0. 64 0. 59 290 3.20 eels 1.8
SPs) H VO 82.2 eS 3. 6 . 56 . 52 | 14 5 . 16 . 78 83 . 66 0. 14 ial
Fel Go) the eee ie ans 3.1 . 41 .o1 | 14 .9 . 22 . 68 72 solo. 13 .8
SIR Nisa tee Pi 3.9 . 58 .42 | 12 .8 Ss . 81 57 .46 | .12 1.4
SR Bsteet nese ole 3. 1 . 36 .45 | 12 1.1 13 aie 67 .45 | .17 .8
SREB ems st ake 3.1 . 46 .48 | 14 1.0 15 . 95 110 1.50 | . 32 10
SP 16 HVO 4_______ 3. 6 . 56 .52 | 14 1.5 16 . 78 83 . 66 | . 14 1.1
SiRSilardst2 2-3-2. 22 = 3. 6 . 56 . 52 | 14 1.5 16 . 78 83 . 66 | . 14 1. i
SP 16 lard 4_________ 3. 6 . 56 .52 | 14. 1.5 . 16 . 78 83 66 | . 14 ieee
SP 8 butter 4________ 3. 6 . 56 .52 | 14 1.5 . 16 . 78 83 66 | .14 eet
SP 16 butter 4_______ 3. 6 . 56 .52 | 14 1.5 . 16 . 78 83 66 | . 14 ial
SPa 16 HVO 4______- 4.1 . 54 .51 | 13 .9 . 16 . 98 85 . 46 | . 06 ial
SPb 8 HVOt_______- 4.1 . 54 . 51 | 13 9 . 16 . 98 85 . 46 | . 06 11
IPE Wie tees re ae 3. 3 47 .43 | 11 a7, . 22 “93 82 . 40 | . 06 11
SBHYatee se See eS 3. 3 . 43 .54 | 11 .6 14 . 69 61 . 34 | . 06 .8
SPW 8 HVOt________ 4,4 . O4 .44 | 12 nat 35 1.18 104 45 03 1,2
LOO 3 eo ee 3.5 .21 . 62 8 .4 . 40 50 42 .18 aL 7¢ .3
WT OO Goce Biri eb et 2 3. 2 . 24 . 72 8 2 11 13 16 13 10 an)
Range for diets:
Migherss. =) 2! 10.0 2.17 2A ay, 1.5 . 64 1.18 290 3.20 | . 32 1.8
Wows eee 3.1 .21 . 42 8 .2 ail 13 16 Beales | Pes} a3
Estimated require-
ments:°
Young ratevso |b 2 . 50-. 60 |. 45-. 55 2.5] .5-1.0 . 07 ~ 15 Dili ero . 008 | 1:1-2:1

1 Analyzed values.

2 Except for ash values, data supplied by manufacturer.

3 Analyzed spectrochemically by A. W. Specht and J. W.
Resnicky, Soil and Water Conservation Research Division,
Agricultural Research Service, Beltsville, Md.

TasLE 7.—Calorie values per 100 grams of diet,
and percentage of calories as carbohydrate, fat,
and protein

Percentage of gross
Heat of calories as—
Diet com-
bustion
Carbo- | Fat | Protein
hydrates
Calories
SHO 6) feats ay St aa 1399 AT 14 39
SIRES EIA, © ew ie eet 1470 50 19 31
ft Bl ab sceet etl Rig tn sc 1520 35 32 33
RO PANY Legieteee ok aS. ee ee 1493 41 32 27
SIRI ee pa eee at 1520 33 35 32
SIP IRIB Bese pr cere yn (2 1498 39 33 28
SP 16 HVO2 220222. 1504 40 32 28
SP 8 lard_____ sue AR al 1470 50 19 31
SP ligulardias 2s 1503 40 32 28
SP Sbuttersea 22 470 50 19 31
SP 16 butter_______- 503 40 32 28
SPa 16 sHVOe 222-2 506 35 31 33
SPb CO VOn. ee 468 44 19 36
SIR Wise aa cane 2 511 37 30 33
SIRs Pg 523 38 33 29
SPW 8 HVO_______- 460 52 18 30
OOS Seas ae 684 2 59 39
Ys TO Ochs et ca 739 3 74 23
Range for diets:
Wen spl oe ae re 739 52 74 39
E70 i ee ay re 399 2 14 23

1 Analyzed values; all other values were calculated by
using 5.65 Calories per gram for protein, 4.00 Calories per
gram for carbohydrates (chiefly sucrose), and 9.3 Calories
per gram for fat.

4 Calculated from ingredients. See appendix table 78.

5 Source: McCoy (122).
6 Minimal requirements for reproduction.

Body Weight and Longevity as Influenced
by Diet

Body weight, intake, and age (stock, SP 8 HVO, and
SPE diets)

WEIGHT GAIN IN RELATION TO FOOD INTAKE
(SP 8 HVO anv SPE prers).—Records of food
intake and weight throughout life were maintained
for 44 rats fed SP 8 HVO diet and for 38 rats fed
SPE diet, and included 4 separate experimental
groups of animals allocated for longevity studies
on each of these diets. Data for individual groups
as well as average values for all animals are sum-
marized in appendix tables 79 and 80. Figure 1
represents graphically the average food intake and
gain in weight of these rats from weaning until 300
days of age, a period relatively uncomplicated by
the occurrence of excessive weight loss or death.
The general pattern of food intake and weight
gain was similar for both diets, although young
rats fed SP 8 HVO diet tended to gain more slowly
than did those fed SPE diet. From the second
to the sixth week on the experimental diets, the
animals progressively increased their food intake
and maintained a relatively constant average rate
of gain of approximately 40 grams weekly on SP 8
HVO diet and of 45 grams on SPE diet. The rats
were still continuing to gain weight at 300 days
of age, although their intake was relatively
constant after the sixth week.

i1

WEIGHT GAIN
(Grams per week)

SP 8 HVO

0 40 80 120

DIET

FOOD INTAKE
(Grams per week)
120
FOOD WEIGHT 80
INTAKE GAIN
oA s—A
SPE o--0
40
0

160 200

DAYS ON DIET

Figure 1. Average weight gain and food intake of rats fed SP 8 HVO and SPE diets.

Bopy WEIGHT AND AGE—INDIVIDUAL RATS FED
SP 8 HVO anv SPE prsets.—Many of the rats
continued to gain as long as they appeared to
remain healthy, increasing their food intake when-
ever there was a tendency for their body weight
to remain constant. This response is best illus-
trated in figure 2, which shows the change of
weight with age of three individual animals.
Curve | represents data for a rat that was fed SPE
diet and died before he reached 400 days of age.
This animal gained rapidly for 350 days, at which
time a precipitous weight loss occurred in spite of
a food intake averaging 17 grams per day. Curve 2
shows the continued gain for 550 days of a rat
fed SPE diet and the rapid loss in weight that
occurred during the 25 days before death. This
animal had decreased his food intake slightly from
14 to 12 grams daily. Curve 3 represents the
body weight of a rat that was fed SP 8 HVO diet
and was still gaining when 800 days old. A
marked decrease in food intake from 19 to 9 grams
daily paralleled the decrease in body weight ob-
served between 800 and 900 days of age, at which
time the animal was obviously moribund.

AVERAGE BODY WEIGHT AND AGE (sTocK, SP 8
HVO, anv SPE piers).—Data for weight changes
throughout life were obtained for 53 rats fed SP 8
HVO diet and for 74 fed SPE diet. The tendency
for continuing increase in weight with age noted
for individual rats (fig. 2) was not apparent in the
average weight curves of rats fed these two diets
(fig. 3). The third curve in figure 3 represents
cross-sectional data available for a large group of
rats from the stock colony that were sacrificed at
different age intervals. Animals fed the stock

12

diet tended to be smaller than those fed SP 8 HVO
or SPE diets and showed little change in average
weight after 250 days. Of these animals 52 per-
cent weighed between 450 and 500 grams; 2 per-
cent exceeded 600 grams. In contrast, 59 percent
of the rats fed SP 8 HVO diet and 61 percent of the
SPE-fed rats weighed 600 grams or more, and 21
and 18 percent, respectively, exceeded 700 grams in
weight. Rats fed SPE diet appeared to have
reached their maximum weight by 350 days,
whereas those fed SP 8 HVO diet attained a
comparable average weight between 500 and 600
days of age. The lower average weights observed
for the older surviving rats fed SP 8 HVO and
SPE diets seem to be due to the early death of
many of the heavy rats, and will be discussed
further in relation to the longevity data.
Discussrion.—Reports in the literature on
weight changes in the rat throughout life have been
chiefly for diets of natural foods suitable for raising
stock animals. Changes made in the diets of
stock animals based on increasing knowledge of
their nutritional requirements have resulted in an
appreciable increase in their size. Mendel and
Hubbell (128) have reported a gradual increase in
rate of growth of their stock (‘“‘Yale”’ strain) rats
over a period of 25 years, with the most marked
change occurring when the diet of Anderson and
Smith (9) was introduced. This diet produced
adult animals weighing about twice as much as
rats on the earlier stock diets. This change was
attributed to diet rather than to selective breeding,
and the improved growth rate was accompanied
by superior reproductive performance. Mayer
(127), also using the ‘‘Yale” strain of rats, reported

GRAMS

600

200 400

#]. a----o SPE
#2. a---a SPE
#3. o——o SP 8 HVO

600
DAYS

800 1,000

Figure 2.—Weight in relation to age of selected individual rats fed SP 8 HVO and SPE diets.

still more rapid weight gains for animals fed a
synthetic diet.

Inherent differences in the growth potential of
different strains of rats complicate comparison of
the size of animals from different laboratories.
Mature animals from the stock colony maintained
in this laboratory appear to weigh as much as or
more than most stock rats of comparable age from
other laboratories. Their average maximum
weight was slightly less than the 522 grams re-
ported for the rapid-growth-producing diet of
Anderson and Smith (9). Rats fed the semipuri-
fied diet reached weights comparable to those
observed by Mayer (127) using a synthetic diet.

Numerous equations have been suggested to
represent changes of weight with age, and several

investigators (44, 53, 78) provided evidence for
the usefulness of the equation proposed by Zucker,
Hall, Young, and Zucker (/94) for evaluating rat
growth and relative efficiency of various experi-
mental diets. These authors proposed an empiri-
cal formula for expressing growth which defines K,
a growth intensity factor, and A, an inherent size
factor. When the formula was applied to data
from their laboratories as well as to data from
other laboratories, these authors report that a
straight line was generally observed and_ that
neither size nor growth rate appeared to affect
the growth property measured by K, the slope of
the line, as long as the diets were free from growth-
inhibiting factors. Dunn, Murphy, and Rock-
land (53), however, observed a change in the

GRAMS

600

400

CROSS-SECTIONAL DATA**

LONGITUDINAL DATA *

a—a~ SP 8 HVO
o----0 SPE

o—ao Stock

400
DAYS

% NUMBER OF RATS SURVIVING; ANIMALS INCLUDED AS LONG AS HEALTHY.

REACH POINT REPRESENTS DATA

FOR AT LEAST 35 ANIMALS,

Ficure 3.—Average weight in relation to age of rats fed stock, SP 8 HVO, and SPE diets.

13

slope of the line at about 14 weeks of age for rats
fed the rapid-growth-producing Anderson-Smith
diet, and suggested that this deflection may be
related to the beginning of a normal adult period.
Copping, Crowe, and Pond (44) observed a deflec-
tion at 11 weeks on two of the eight diets that
they investigated, and suggested that this deflec-
tion may be due to the rapid early growth of rats
on these two diets that contained more than ade-
quate amounts of protein.

When Zucker’s formula was applied to the
data here reported for rats on SP 8 HVO and SPE
diets, a straight-line relationship was found to
hold reasonably well until the rats reached 15
weeks of age. During this period no deflection
was apparent that would indicate any nutritional
deficiencies. The K values of 3.8 for SP 8 HVO
and of 4.0 for SPE diet were similar to the 3.8
value reported by Zucker for male rats. The
change in the slope of the line after 15 weeks
provided further evidence that the age range over
which this formula applies may be limited when
very rapid growth occurs in the young rat.

Everitt (58) and Berg and Harmison (20),
reporting data relating body weight to age
throughout life, observed a rapid period of growth
followed by a plateau similar to the results re-
ported here (fig. 3) for rats fed SP 8 HVO and
SPE diets. The subsequent decline in body
weight which these authors observed was also
noted for the majority of rats fed SP 8 HVO and
SPE diets, as seen in figure 2 in the examples for
individual rats. Although there is general agree-
ment that such weight loss frequently occurs
before death, there still seems to be some question
as to whether or not weight loss is a necessary
accompaniment of the aging processes. Everitt
(58) reported an average decrease in weight from
381 to 249 grams during the last 200 days of life
of 68 male rats. Eighty percent of the animals
had lung abscesses, but their loss in weight was
similar to that in a comparable number of rats
with healthy lungs. No data were reported on
the incidence of other lesions except for three
tumors. According to Everitt and Webb (59),
this weight loss may be due to disease or to
senescence.

Results obtained with BHE rats in this labora-
tory, however, as well as those reported by Berg
and Harmison (20), indicate that weight loss in
older animals generally reflects some pathological
condition. These authors separated the results
for rats with no lesions from those with lesions.
The average age of the group without lesions was
681 days. The body weight of these rats increased
with age up to 522 days, with no marked difference
thereafter. A progressive decrease in weight with
age was observed in the older rats with lesions.

Growth and food intake of young rats (all diets)

A pattern of weekly weight gain and food intake
similar to that discussed for rats fed SP 8 HVO
and SPE diets was observed for rats on the other

14

dietary regimens under investigation. Data for a
minimum of 10 rats were generally obtained with
each of the experimental diets. Although there
was considerable variation in the response of
individual rats to any one diet, the data reported
for SP 8 HVO and SPE diets summarized in
appendix tables 79 and 80 indicate that average
values for groups of approximately 10 rats
generally agree well with those obtained for the
larger number of animals.

In table 8 are summarized data on the weight
gains during the first 12 weeks on each of the
experimental diets, and except where indicated,
the data reported have been confined to groups of
littermates. Included also are data obtained on
food intake in grams and in calories and on the
efficiency with which these diets were used as
measured by the calories-per-gram gain. Calories
are reported as gross calories throughout this
publication. To determine available calories from
these diets, data are needed on the digestibility
by the rat of the various diets under investigation,
on the energy from protein that is stored in the
body of the growing animal, and on the loss of
energy in the urine either as protein or as incom-
pletely oxidized products from protein. The
factors 4, 9, 4, frequently used for calculating
available energy from dietary protein, fat, and
carbohydrate, were developed for use with man
from the extensive investigations of Atwater and
Bryant (14). Metta and Mitchell (131) showed
that these factors are not applicable to the rat.

MopIFICATIONS OF SEMIPURIFIED DIET—WITH
SELECTED FooDS.—Young rats grew well on all
of the experimental diets. The most rapid growth
was observed with animals fed the diets in which
ego, milk, beef, or peanut butter replaced 20 to
25 percent of the semipurified diet. Weight gains
were similar for all of the diets containing these
foods and were consistently greater than were
those observed on the semipurified diet. The
difference between 16.8 Calories-per-gram gain on
SP 8 HVO diet and 15.3 on SPE diet was highly
significant (P <0.01). Differences in digestibility
of these two diets do not explain the differences
observed in food utilization. Marshall and Hilde-
brand (/25) recently reported that BHE rats
were able to digest SP 8 HVO and SPE diets
equally well. No significant differences were
noted in the utilization of the diets containing
ego, milk, beef, or peanut butter.

SPE DIET WITH PURIFIED NUTRIENTS.—No
change in rate of growth or in calories-per-gram
gain was observed as the result of adding the
various nutrient supplements to SPE diet.

KIND AND LEVEL OF FAT.—Data for the group of
diets containing different kinds and levels of fat
were limited, and the calorie values of the diets
were less accurately established than those for
the semipurified diet or for the SP diets containing
egg, milk, beef, or peanut butter. There was a
consistent trend for rats fed diets containing 8
percent fat to grow more slowly than those fed the

diets containing the same fat at the 16-percent
level. Rats fed the diet containing butter tended
to be smaller than those fed comparable levels
of HVO or lard. The diet containing 16 percent
lard was the only one used with an efficiency
comparable to that seen for the diets containing
ego, milk, beef, or peanut butter. The range
of values observed was wide, and more data on
this group of diets are needed to establish the
significance of these trends.

LEVEL OF PROTEIN AND FaAtT.—When diets
contained 30 percent protein as casein and
lactalbumin (SPb 8 HVO and SPa 16 HVO),
erowth rate and calorie-per-gram gain were similar
to the results obtained for comparable levels of
fat when the diet contained 25 percent protein
(SP 8 HVO and SP 16 HVO).

EGG AND EGG COMPONENTS.—Rats fed a diet
(SPEW) in which egg white replaced 30 percent of
the protein in SPa 16 HVO diet tended to be
smaller. Growth response and utilization of diets
in which egg yolk replaced approximately 50 per-
cent of the protein and approximately 80 percent
of the fat in SP 16 HVO were similar to the results
for rats on SPE diet. Rats fed a diet (SPW) in
which egg white replaced all of the casein and
lactalbumin in the semipurified diet were small.
No data were obtained on the calories-per-gram
gain for this diet. Evaluation of growth on and
utilization of diets of 100 percent whole egg or
egg yolk was complicated by the tendency to
frequent diarrhea in the rats fed these diets.
Food consumption and caloric intake of these two
high-fat diets were low, and rate of growth was
correspondingly reduced.

WISTAR RATS FED SP 8 HVO anv SPE piEets.—
Wistar rats fed SP 8 HVO and SPE diets ate less
and grew at a slower rate than did BHE rats fed
comparable diets. Wistar rats seemed to use
both diets more efficiently for growth than did
comparable BHE rats, but the differences ob-
served may be due in whole or in part to the
smaller weight that was being maintained by the
Wistar rats during this period of rapid growth.
However, both Wistar and BHE rats tended to
grow more rapidly and to use their food more
efficiently when fed SPE diet than when fed SP
8 HVO diet.

Discusston.—Although the levels of fat in the
diets investigated were not considered excessive,
there appeared to be a consistent trend for rats to
become larger at an earlier age when the fat level
was 17 to 19 percent than when it was 9 percent
or less. In some instances, the increased growth
rate appeared to be explained by differences in
intake alone; in others, a decrease in calories-per-
gram gain—that is, more efficient utilization of
the diet—accompanied the increased growth rate
observed.

Deuel (48) in reviewing the subject of dietary
fat and growth, concluded that the preponderance
of evidence favors the hypothesis that in the rat
greater increases in weight and improved effi-

ciencies of the diet are associated with increased
consumption of fat. In studying the associative
dynamic effects of protein, carbohydrate, and fat,
Forbes and Swift (64) showed that fat is particu-
larly effective in reducing the specific dynamic
effects of diets.

Reports in the literature on the response of the
rat to fat have dealt chiefly with the influence of
different kinds and levels of fat rather than with
fat-containing foods such as egg, milk, beef, or
peanut butter. Lard has been most frequently
used in investigations dealing with the response to
dietary fat. In weanling rats fed for a period of
from 8 to 10 weeks, there has been a tendency for
weight gain to correlate with the level of this fat.
The differences reported have usually been small
and in some investigations have not proved
statistically significant.

Hoagland and Snider (93) found weight gains
per 100 Calories to be approximately the same for
diets containing 15, 30, or 54 percent lard, but at
these levels the gains were significantly greater
than those observed with 5 percent of this fat.
Hoagland, Snider, and Swift (94) found that the
differences were not significant when isocaloric
amounts of diets containing 5, 10.98, or 18.27 per-
cent lard were fed. Forbes, Swift, Elhot, and
James (65) reported weight gains to correlate with
level of fat when rats were fed isocaloric quantities
of diets containing 2, 5, 10, or 30 percent fat.
Two percent corn oil was present in all of the
diets, and the additional fat was lard. The
largest difference observed was that between the
diets containing 2 percent fat and those containing
5 percent fat. Forbes, Swift, James, and others
(67) reported a similar experiment using large
increases in the intake of 10 of the vitamins, and
again demonstrated that fat confers efficiency of
utilization of food energy for the growing albino
rat; however, the small increments in weight gain
observed as the level of fat increased from 2 to
30 percent were not statistically significant.

Hoagland and Snider (93) compared the relative
efficiency of lard and hydrogenated cottonseed oil
as dietary fats. At all except the lowest level
tested (5 percent), lard proved significantly more
efficient in promoting growth than did hydroge-
nated cottonseed oil. The diet containing 15 per-
cent hydrogenated cottonseed oil appeared some-
what more efficient than the diet containing 5 per-
cent of this fat; at still higher levels the response
was similar to that observed with diets containing
15 percent fat. Marshall, Hildebrand, Dupont,
and Womack (126) fed ad libitum diets containing
15 percent hydrogenated vegetable oil or lard.
Weight gain per 100 Calories during the period of
rapid growth was slightly more on the diet con-
taining lard, but the differences were small and
not statistically significant.

According to Barki, Collins, Elvehjem, and Hart
(17), conclusions with regard to the growth-pro-
moting properties of fats may be misleading if
comparisons are confined to one level of fat. These

15

j

Or~ndao Oe

roid © mereid xs

NO hwOMO10 80

‘61-0 ‘ST | 2°91 OzE ‘2-O9T ‘¢ | 026 ‘SG | 099 ‘T-OOT ‘T | G2z‘T | Sgh—-G6z | 8gE 09-68 | LF Ole + ipa Ne gaaes caer OAH 8 4d8
4I-Z] ‘ST | 6 ST OLE ‘2-082 ‘S | OFT ‘9 | OFF ‘T-OGO‘T | OTZ‘T | GLP-FZE | S8E 9G-IPF | 9F OR J Secsore 2 eee OAH 91I %d8
‘61-24 ‘ST | 6 ‘OT 0&2 ‘9-020 “F | 0&8 ‘G O€F ‘I-080‘T | OFZ ‘T 96E-E0E | SFE 09-68 OF Ol vs 92") =o rene OAH 8 dS
—poj So} euLIoyyvyT
‘81-0 ‘91 | O'LT Og ‘2-000 ‘S | 080 ‘9 | OSF ‘T-000 ‘T | 00Z‘T | L2h-G8z% | FSE IG-88 | 2P (One se bee eee zoynq 9T dS
Sl=G Ol wea OLO ‘2-082 ‘G | O88 ‘G O6F ‘I-OTT ‘T | 0&2 ‘T P6E-68S | LEE CS-8E PP OL at eo era 1099NG § dS
OTe Si Oe ST 000 ‘2-001 ‘¢ | 068 ‘G 068 ‘IT-O10 ‘T | o21 ‘T LGV-8EE | LLE PS-6E $V (1 Ss gee ll Sie nen cml piv] 9T dS
‘8T-9 “GIT | 9 OT 092 ‘L-0F6 ‘F | 086 ‘G OFS ‘T-OG0 ‘T | 092 ‘T 61P-90E | OSE 8P-8E cP Oly . it ae ee ane ee ee ple, § dS
il—-OmG ia seob 029 ‘9-0&T ‘G | O10 ‘9 OTS ‘T-0z0 ‘T | S61 ‘I TZP-GOE | OLE OS-8$ PV Ollie el 1k iene rane OAH 91 dS
‘21-0 91 | 2 9T O€¢ ‘9-028 ‘F | OT8 ‘G 068 ‘I-OFO ‘T | OFZ ‘I LOP-ELS’ | OGE OS-8E PP Ci Sith sees ce ee OAH 8 dS
—povj $0} BULI04 VT
aaa — = a —= — SSP-IPE | OOF Gcg-LEé LV ()) Ot eee | aE tee Ne ag % OF) ‘[O10}4
-sopoyo + %Z'0 ‘plow’ oIqIoosy
— == = aa a aan OLP-¥CE | LOD Co-SE LY OR! ‘ales se ee: %S'O ‘plows o1q1oosy
= =— a aa == = GhP-OTE | TOP PS-LE LP OW, J Res Sen) WET “Jor19ysopoy
— = = = — _ 61G-16z | SOF 09-28 | SP OL —' |e er. %OP'O ‘o19ysoToyD,
= —e = a = ce OSP-IEE | S6E 9S-6E LP Oi i/o era ae ae i Se ouoN
—yYIM pejusuelddns qqs
—po9j soyvur4e} qr]
‘OT=G FL | SST 098 ‘9-014 ‘G | 092 ‘9 0ZE ‘T-020 ‘T | 002 ‘T O9P-TEE | SOF I9-8€ SP Ole. ult ire re SS sees See ws
OOT/ sur 100 “E+ "us OOT
/su gO “Ga+%G'o ‘ourfoypD
‘OI-G ‘FI | € ST 002 ‘2-OT2 ‘E | OZT ‘9 OSs ‘T-OOT ‘T | OST ‘T L6b-SGE | 66E 69-LE SP OV, | et oe ws OOT
fs oo “gq+%s'o ‘oulfoyg
‘QI-G ‘GI | 3ST 000 ‘2-0FZ ‘¢ | OLT ‘9 ocs ‘T-O10 ‘T | O6T ‘T TCF-G9OE | SOF T9-8€ OF Ol "Weaver es ws QOT/ su GO “_
Gi=p SL, (| 1 Sia OSF ‘9-OTG ‘¢ | OST ‘9 OFZ ‘T-090 ‘T | OST ‘T EFP-F9E | SOF G9-GP 6P Ole Vike sote oS ae MEO ‘ourpoyg
‘OI-G ‘FI | $ ‘ST OZT ‘2-002 ‘G | O86 ‘E OL€ ‘I-000 ‘T | OST ‘T FSP-8SE | OSE I9-LE SP Ole i ae oe ae ae 9u0 NT
—Y IM poyusweddns WdS
—pery $O}PBULIO} IVT
‘OI-G ‘PI | 2°ST 089 ‘2-069 ‘G | OG ‘9 | OSPF ‘T-OOT ‘T | 092 ‘T €IG-19E | 6ZPF Lo-GE | SP Ollie 0 |) 22 ete ne ws OOT
jsut 100 “gq +% "0 ‘ourjoypD
O-8 "St | bk St Oss ‘2-086 ‘S | OOF ‘9 OTF ‘I-OFT ‘T | OFZ ‘T P8P-68E | 8ZP 09-OP cP ORD Ales 2 ws QOT/sut TOO “ef
‘GI-9 ‘SI | 6 FT 089 ‘8-029 ‘G | 009 ‘9 O6F ‘IT-060 ‘T | 022 ‘T CSG-L8E | SPP 8S-€€ OF Oli WP yea er a %GO ‘ourpoyg
‘ST-¥ ‘SI | 6 FT OT8 ‘9-029 ‘G | 092 ‘9 OTS ‘T-060 ‘T | 002 ‘T LSP-Z9E | OCP Z9-OF cy Oi ee ei caeee ne ae ouoN
—yUM pojyuswmoetddns Wqs
—podj soyvuliozqyy
‘OI-I ‘FI | 6 FI 020 ‘2-022 ‘S | O21 ‘9 | OZF ‘T-OGO ‘T | O&Z‘T | SLZP-OTE | ZIP 09-68 | LP oak, Vinee xanga a > ne oe addds
‘OT-O FI | VST OFS ‘L-08Z ‘G | OFT ‘9 06 ‘T-000 ‘T | OST ‘TL €9F-LVE | OOF 9¢-6E LY UGA eli. eee ee We Ce Pe dds
‘LI-* FI | SST OOF ‘2-089 ‘G | 06Z‘9 | OOG ‘T-OFT ‘T | 082 ‘T GOS-TEs | SOP 6S-LE | LP Pam Ae ee ee i Wds
‘OI-9 FI | € ST O6T ‘2-020 “G | 002 ‘9 OSS ‘T-096 O61 ‘T IL¥-OLE | FOF LS-6€ Lv ate i|iaeaiebs Sea Re et HdS8
‘SI-6 FI | O'LT OFg ‘2-002 ‘S | OEE ‘9 009 ‘T-OLT ‘T | 0¢¢ ‘T 90S-T0€ | €L4& f9-8E LY Tome hile = oO ee OAH 8 dS
—prj $0} BULI09 VT
‘OIF ‘ET | € ST O6T ‘2-020 ‘¢ | OFT ‘9 OSE ‘T-096 OST ‘T TL¥-OLE | OOF 69-6E OF Sie a ile « © ree ee ye ent Ads
‘61-6 FT | 8 9T OFS ‘2-028 ‘F | 0G0 ‘9 009 ‘I-OF0 ‘T | 062 ‘T 90S-EL¢6 | O9E o9-8E SP PG ae. |i; es ape eee en ay OAH 8 dS
$91.0]D/) S$91L0]D) SULDLE) SULDLY) SULDLE) SULDLE) SUDLE) SUDLY) aque NAT —pvj IV
syetl WHA
asUeyy ISBINOAY ddUBYIT OSBIDAY aSUBY aseIoAy | osuny |oseioay | osuvy | odeIoAy
Szyey JoIp pues UIBIYS
ules wield SyooM Z[—-oyeyUI SYOOM ZT YSIy SyooM ZT Say QYySIOM
-lod-salloyeEg DILOTBI SSOINH dYVIUL POO UIVS JUSIOM SUIUBI AA

spp snoiupa paf syou Bunoli ur urob fo wosb sad sarsojpo pup ‘aypjur poof ‘Yjnogg—S ATAY J,

16

g
6

NoRTa}

TS Taeci:
‘OI-4 FI

‘LT-0 ST
‘02-G “ST

SS ISSSST
‘02-Z@ “ST
‘SI-I “ST

‘6I-L OT
iOTSS 71
‘ST-I “ST
‘SI-G FI

LO
K
o

092 ‘S-082 ‘F
0&2 ‘9-OLT ‘F

OOF ‘S-060 ‘F
06 ‘S-082 ‘F

OSF ‘S-019 ‘F
OF8 ‘F-008 ‘€
09% ‘9-022 “¢

029 ‘9-092 ‘F
096 ‘9-09T ‘¢
029 ‘9-026 ‘F
046 ‘9-O&T ‘¢

00 ‘¢
OLT ‘¢

OIL 'F
00¢ ‘¢

OOT ‘¢
OOF ‘F
028 ‘¢

008 ‘¢
O12 ‘9
098 ‘¢
00 9

OOT ‘T-026
0ZE ‘T-068

0&L
OL8

092
099

002 ‘T-O10 ‘T

0OL6

—0S¢

—002

—0¢9
—OT¢

—00L

OLE ‘1-066
062 ‘I-026
OVE ‘T-066

6ZP—-9CE
O8E—-99G

IVE-LES
GGE-ELS
PSE-ZIS

PEE—GIST
90E-S8T
SOF—-608

ESE-EVS
PLVVEE
80P-E8G
69P-FIE

POE
VEE

666
STE
082

£0
8hS
EGE

962
OOF
CGE
LLE

€G-LE
Go-6E

9S-8E
6P-68
TL-SP

€9-6&
89-68
6S-IP

€S-6E
TS-8€
1G-68
6S-6&

SP
SP

OT
Or

ST
Or

—poy soyeur9} yy]

$y@d Jest

—pay $o}vurs19}}1] JON
yea Wore ‘ornyxtur y[es+ 16H

eS Fa es te napa ere eT MddS
SS tO Ce ae (330 Yselj) Ads
—pe2j Soyeuse} qT

17

investigators reported that early growth of young
pair-fed rats was consistently less when the diet
contained 10 or 28 percent butterfat than when
it contained a comparable level of corn oil. When
the level of butterfat was increased to 35 percent,
rats were as large as or larger than those on diets
containing 10, 28, or 35 percent corn, soybean, or
coconut oll. More efficient utilization of the diets
was observed as the level of butter was increased;
no such relation was noted for corn oil. Pair
feeding and ad libitum feeding gave similar results.

Hoagland and Snider (92) observed a growth-
promoting value of peanut oil (gain per 100
Calories) similar to that obtained with lard or
hydrogenated cottonseed oul when the level of fat
was 5 percent. At 30-percent levels, diets con-
taining lard were used more efficiently than either
hydrogenated cottonseed oil or peanut oil. Aaes-
Jorgensen and Dam (1, 2) included peanut oil in
many of their investigations, and in general found
similar growth-promoting qualities for lard and for
peanut oil. The increase in growth rate that
resulted when the fat level was increased from 7
to 28 percent was not due to increased caloric
intake.

Body weight in relation to age and diet in adult rats

SP 8 HVO, SPE, SPM, SPB, anp SPPB
piets.—Differences were observed in the rate at
which adult rats gained weight and in the maxi-
mum weight eventually attained, even when diets
produced a similar growth response in young
animals. In table 9 are summarized data showing
the influence of diet on body weight at different
ages. Included also for ready reference are the
more extensive data already considered for SP 8
HVO and SPE diets. Adult rats fed the diets
containing milk, beef, or peanut butter continued
to gain throughout their healthy lifespan and were
consistently heavier than rats of similar age fed
the semipurified diet. They also tended to become
heavier than rats fed the SPE diet. The older
surviving rats fed SPM or SPPB diet tended to
be larger than those of comparable age fed SPB
diet. Differences in caloric intake did not account
for some of the weight differences observed. For
example, between 500 and 600 days of age the rats
fed SPM diet gained, on the average, 70 grams,
whereas those fed SPB diet gained 22 grams.
The intakes for rats fed these two diets were
simil: and 9,340 Calories respectively.
Additional data on the caloric intakes of these
rats at different ages are included in appendix
table 80.

KIND AND LEVEL oF FAT.—Differences in the
weights of rats fed diets containing HVO, lard,
or butter seemed to be attributable chiefly to
differences in caloric intake except for rats fed 16
percent lard. At 300 days of age on a similar
caloric intake, the average weight of rats fed
semipurified diet was 60 grams less than that for
the corresponding littermates fed SP 16 lard.

18

LEVEL OF PROTEIN AND FAT.—The caloric con-
sumption of rats fed SPa 16 HVO and SPb 8 HVO
Was approximately 5 percent more than that of
rats fed the semipurified diet, and accounted for
the tendency to larger animals on these two diets.

Eee AND EGG COMPONENTS.—No appreciable
change in the weight curve of adult rats resulted
from replacing 30 percent of the protein of SPa 16
HVO diet with egg white (SPEW). When egg
yolk supplied all of the fat in the diet (SPEY),
weight changes for the adult, like those for the
young rat, resembled those observed with SPE
diet. Rats fed 100 percent egg (E100) remained
relatively small but did eventually reach weights
similar to those of stock rats. On SPW diet, ‘Tats
tended to be small throughout life although the
weight of the older rats was Ss somewhat oreater than
that of the rats fed E100 diet. On 100 percent
egg yolk, food consumption increased with age,
so that weights of rats surviving 400 days were
comparable to those of SP 8 HVO rats.

WISTAR RATS FED SP 8 HVO anv SPE piets.—
Wistar rats fed SP 8 HVO and SPE diets showed
a somewhat different age-weight relationship than
did BHE rats. On the semipurified diet, Wistar
rats were consistently smaller than BHE rats of
comparable age; on SPE diet, Wistar rats even-
tually became much heavier.

Discusston.—Reports in the literature on diet
in relation to weight throughout the life of the
adult rat are limited and, as with the growing rat,
deal chiefly with the level or kind of dietary fat.
No reports have been located dealing with protein-
fat-containing foods such as have been included in
this publication. In general, the results obtained
in this laboratory and elsewhere provide consider-
able evidence that differences in weight gain are
not necessarily associated with differences in
caloric intake.

With mature rats 205 to 212 days old, Forbes,
Swift, Elliott, and James (66) and Forbes, Swift,
Thacker, and others (68) observed that the energy
expense of utilization of isocaloric diets decreased
as the level of dietary fat (chiefly lard) increased
from 2 to 30 percent. A reduction in heat from
the catabolism of carbohydrates and from fat
synthesis was responsible for the resulting economy
of utilization of food energy as the level of fat
increased. French, Ingram, Uram, and others
(69) reported that by the time rats were 28 weeks
old on a diet in which 20 percent of the stock diet
was replaced with corn oil, their weight exceeded
significantly that of animals fed a diet in which
20 percent of the stock diet was replaced with
sucrose. Lundback and Stevenson (1/9) obtained
a gain of 0.6 gram per day for adult rats fed a
diet containing 60 percent fat chiefly as lard, in
contrast to no weight gain for rats on a comparable
caloric intake of a diet containing 71 percent
sucrose.

*peqyVoIpUl Sosv ayy

JB JYUSIOM SUIUTRIUTVUT [YS S]VI JO JeqUINU dy} OJBOIpPUL SesoyjuoIed UI SIOqUINN ‘OfI]T INOYSNOAYY PoYwoIpuUl SJoIp oY} UO POUTVJUIVUL S}VI OJ 1B BIVG |

|

(€) TLL 902 (9) 889 c99 | (4) 289 | (8) Ogg
(Z) 669 |(¢) F9g (2) Sho | (8) STS £6F oLP
ee (1) 109 | (#) Sse | (2) OTS
e32--5-2--|---+--5+--|------2--- (9) gg¢ GPS ets
Sees. See (2 0G ™ Ose Lit |..C8) CLF v6P
Bee ees Se eae Sea (e)e7eo sO) 629 969
car wes (Z) 829 (F) 209 | (4) 199 | (8) @T19 66
eeeasoesks Se ale == el be 980) WCE). 99 419
= Saar a (¢) £69 (¢) #89 | (4) 829 | (6) 29 92S
a oa (1) 182 (Z) 999 | (€) 889 | (8) zE9 909
Sir aaa (1) 209 (F) Z9L | (24) 029 409 eg¢
ere s2=-"==-==|\(e)<7ee> |e) Yeo | (9). O6¢ $68
eis ee (1) T¢¢ (G) 629 | (2) $09 | (8) 209 | (6) 86g
Saga (1) OS (Z) 699 | (¢) 689 | (2) OT9 OF9
Pie Ee ChE PT (F) 799 | (F) Ze9 | (9) 66g +09
ery (@) $02 (¢) g¢9 | (2) Ze9 | (6) 929 L19
Saar (@) 88¢ (F) 22g | (9) 89¢ | (6) 69¢ 18g
oe (z) OT8 (G) 832 | (9) 799 | (6) $¢9 |(ZT) 8T9
Spree (S) 934 (F) 299 | (¢) e99 |(OT) Ze9 609
ee ici ee (9) GLL (9) z€2 | (2) 689 |(TI) 299 9
~---------/S25-205_.- (1) OSS | (Z) SIS | (F) PLE 868
(1) e6¢ |(z) F2¢g (€) ZS | (2) 999 (OL) F8E |(eT) Tg¢
Soo a Soe (€) G6¢ |(€T) €09 |(¥E) FZ9 |(69) LES
(€) 819 |(2) 109 |(1%) 6z9 |(Se) G09 |(Zh) Sse |(ZG) TEE

SUDL) SUWDLY) SUDLY) SWDLO SUWDLE) SULDLD)
sdep 008 | Shep 004 | Shep 009 | skep 00g | SAep OOF | Sep 008

—1 38 FYSTIOM

Cie | 86g e1Z SF OW | Rieibe Genacire wets Ads

ccp | 9g e61 SF OULD Sek eee rae OAH 8 dS
—pyj $0} BUI} 4VT

SJV1 IVISIA

(6) 69% | eTE LEI GP (ens | asi a ia OOTA

6cr | LIE 061 6S i naa eae nae a MdS
— po] 8e7yVULI9}4}1] JON

err | zee OST CF Ohl en ak Sta die eee OOTa

$8S | P&P 91Z CF (Oe Riera ol ae eee Adds

Ife | 8ge $02 FF (0) | Galen pa es MUdds

og | SIF C1Z GF O12 = Ne Saas Se (389 Yselj) Hds
—peoj SO}VULIO} YT

L0G | 688 902 LP (Senge cme Sea gene OAH 8 4d8

(6) 89 | LIP 102 OF (0) eee cag 2 ee ae OAH 91 ®d8

L8¢ | SLE 10Z OF (0) oa | aes OAH 8 dS
—p2} SOYBVULIOP IVT

61g | 78e Z61 Gr Oe” se ees ~1099nq 9T dg

FOE =| 89 68I +P Olney So cas ee as Joyyng 8 dg

gg | SOF $02 +P (Nin (teehee se ear pie] 91 dS

91g | ese 102 GF (i SS Se eS are PleT 8 dg

Ges | 00F C0Z +P Oat |e ends OAH 91 dS

IZ | O88 161 +P OR Blirie se oa OAH 8 dS
—p9j soyvurI044yWT

(81) 899 | ZtF 02% OF A neice Pegioeereece, S Mineo Neca ge dddg

sec | O&F SIZ oF Pile seas Eo Ge Eat eee oe eee ads

(81) 99¢ | 6aF 602 OF Filho Mase Dias Pee CS a ea a Wds

LES | S&F 12% 9F Pe a Gar ae ice Se ace eae Ads

F6r | 668 602 9F Pilg arg aoe ae kaos SS ee oy OAH 8 dS
—podj soyeul194TT

(€2) Ze | OF TOG OF 2 Raed tee em cic ears tarts a Ads

96F | F8E 002 oF CG Ne See Fane) nay OAH 8 dS
SUWD.L) SULDLY) SULDLE) SUD) | LaQUNNT —p2J IIV

sel THE
skep 00Z |sfBp OOT | Shep OG
JYSIOM
SuluveA | $I 4yoIp pue ured

spaup snoipa paf sab yuasaffip yo syou fo yybvam fipog— 6 WIV J,

19

Calories for maintenance of body weight

BHE rarts.—Although many of the animals
tended to gain weight throughout most of their
lifespan regardless of diet, there were often 50-
to 100-day intervals when weight remained rela-
tively constant. The caloric intake during these
intervals served as a basis for calculating calories
required for maintenance. ‘The results available
are recorded in table 10. The values were ob-
tained for rats varying considerably in weight,
but in general included data for rats on each diet
with a similar weight range. On the basis of the
more extensive data obtained for rats fed SP 8
HVO diet, the calories required for maintenance
appeared to decrease with increasing age and/or
body weight. With rats fed SPE diet, however,
no such relationship appeared to exist. The
tendency for heavy rats on those diets with the
lowest maintenance requirement suggests that
there may be a real difference in the way that
these diets are utilized. The differences observed
in the average calorie requirements with diet,
however, were relatively small considering the
wide range of values observed for individual rats.
More data under controlled conditions of intake
and activity are needed to establish the significance
of these trends.

Tasie 10.—Calories per gram of body weight per
week for maintenance of adult rats fed various diets

Calories per gram of
body weight
Strain and diet Rats
Average Range
BHE rats
Number
SH geil a RAO Bee ee ee 26 0.98 | 0. 82-1. 08
Dik wes oe Re oe 24 95 . 73-1. 14
SPs se ee Eee ee 8 90 . 76—- . 99
le ae 2 ee en 4 96 . 938- .98
SPPRBt.2 22 22ee ts feda. 6 90 . 84— . 95
Seil6é BVO... 222522 8 95 . 85-1. 13
Sie S lard: eee eee 8 92 . 80-1. 05
SPO lard 222.2 6 89 .79- .95
Db So butberve 252.22 8 92 . 89- . 99
SP WG buttere 22325 8 91 . 79-1. 04
Wistar rats
DE SHELLY © tees ace 7 287 . 838- . 96
SP He wie eee 5 . 79 .73- . 85

Wistar RATS.—The lower calorie requirement
for maintenance of the Wistar rats fed SP 8 HVO
or SPE diets when compared with BHE rats
parallels the greater efficiency in their use of these
diets during early growth. In the young rats,
the differences were due in part at least to the
somewhat smaller body weight that was being
maintained during this period by Wistar rats.
A comparison of the weight and intake of the two
strains of rats fed SPE diet (appendix table 80)
shows a lower intake even by older Wistar rats

20

during periods when the weight was as great as or
ereater than that of BHE rats.

Discussion.—Little information is available
on the energy requirements for maintenance of
the adult rat. Fixsen and Jackson (62) estimated
the requirement of the rat at 12.0 metabolizable
Calories per 100 grams per day for animals weigh-
ing 375 grams or less, and 11.5 metabolizable
Calories per 100 grams for those weighing more
than 375 grams. With two strains of rats, Palmer,
Kennedy, Calverley, and others (151) demon-
strated a difference in the utilization of foods for
erowth and in the energy requirement for mainte-
nance. The high-efficiency strain of animals
stored a larger proportion of their food energy and
lost less energy as heat than did the low-efficiency
strain. These authors, using 4.1 Calories per gram
for protein and carbohydrate and 9.3 for fat, ob-
tained a value of 13.2 Calories per gram per day
for maintenance of the high-efficiency rats and
14.6 for the low-efficiency animals. Application
of these factors to the data reported in this
publication for BHE rats fed SP 8 HVO diet re-
sulted in a value of 12.7, similar to that of the
high-efficiency strain. Wistar rats appeared to be
still more efficient in their utilization of this same
diet for maintenance.

Maximum body weight and diet

Average weight curves provide little informa-
tion with regard to the variation in the rate of
gain or in the maximum weight attained by indi-
vidual rats. In table 11 are summarized data on
the average maximum weight and the range of
values observed for rats sacrificed between 300
and 500 days of age and for those that were older
than 500 days. These values include data for
rats scheduled for sacrifice in the age groups indi-
cated, as well as those from longevity studies, and
thus represent a relatively larger group of animals
for some of the diets than are included in table 9.
Data are also summarized for rats fed the various
supplemented SPE diets and for a small group of
rats fed SP 8 HVO and SPE diets from parents
raised on the Wistar stock diet.

Although the average maximum weights ob-
served were generally higher, particularly for the
younger group of rats, than were apparent from
the average weight-age relationships seen in table
9, the results show the same general trend that
has already been discussed. Rats fed SPE diet
with the various supplements were similar in size
to those fed the unsupplemented diet. When
BHE rats were fed the stock diet on which the
Wistar rats had been fed, weanling rats tended to
be small and generally reached a maximum weight
on SP 8 HVO or SPE diet that was less than
that observed with these same diets when the
young were from parents raised on the usual stock
ration.

Dirt AND OBESITY.—Large rats were observed
with all of the experimental diets, particularly
with SPM or SPPB diet. The largest rat was a

TaBLeE 11.—Mazimum weight of rats fed various diets, sacrificed before or after 500 days of age

Strain and diet

Rats | Average
age
Number| Days
BHE rats
Stockman acre sek PRINS ee ee ee ee ee 31 416
SPeSeEVViQ seen tee erie. ne ti ae te 52 380
Protein-fat-containing foods
SR piece ott We Me eae 131 392
SIR Mien he se ed eee ate 20 408
SRB eo tas & are Si SAR 19 410
SIPRBS ite ae Stes cw ee ook ds 26 394
SPE supplemented with—
Choline 0:59. 2 222-225-228 16 419
By, 0.01 mg./100 gm_____-__-------- 6 412
Choline, 0.5%-+ By, 0.01 mg./100 gm_ 6 398
Be, 0.5 mg./100 gm____---_--------- 4 408
Choline, 0.5%-+ Be, 0.5 mg./100 gm_- 9 412
Choline, 0.5%+ Bry, 0.01 mg./100
gm.+ Be, 0.5 mg./100 gm_____--- 8 408
Cholesterol, 0.46%__.------------- 7 416
Cholesterol, 1.88%__..------------ 6 402
Ascorbic acid, ODO jp ities ae 5 377
Ascorbic acid, 0.2%-+ cholesterol,
QUA C per ee ee ol ee RL 8 394
Fat, 8% or 16%:
SRALG REV Ome Als ET 29 409
Sy Siler Be ceieyat a t e s ls 6 429
SIREIGi area eee Wee Ly lady ae 4 416
SPrstbutters22 2 eee os ae ee 2 394
SPelGibutterss se ee ewes 6 409
SP 8 HVO with protein or fat to level
SBRalOveViOes: ewrece 85 sso 4 454
Fell 24 obtoy al UNA © Miah ere apap 3 456
Egg and egg fractions:
SPli(Greshtege) es ess ee Ole 6 429
SRA re Ee ire ek Daeg 1 459
Ry EURO AYA sts oh Spr ea ee 3 407
SIR HYVeuiige inde Were i Pole 5 420
TSB ICO) dc gl ee 8 451
ATMO) Oise a EAD SC Ce ae ee 14 402
Y97+salt mixture, 3%-__---------- 5 430
Diet reversal:
Stock throughout life-___.________-- 1 420
SPE throughout life___._._______-- 2 396
Stock changed to SPE at 250 days__ 0
SPE changed to stock at 250 days____ 1 384
Wistar rats
SRsStEV OMe Okara St oy 1 446
ISIAH eva eee an fe ye! UL oe a 2 355
BHE parents fed Wistar stock diet
BHE young fed—
SIRUSHELV Oe eine ee et Ont erels
SIR Bopanna A ety | ee Mae 3 358

Sacrificed at 300-499 days

Sacrificed at 500 days or over

Weight Weight
Rats | Average
age
Average| Range Average| Range
Grams Grams Number| Days Grams | Grams

470 370-579 57 680 484 | 399-670
602 423-771 57 636 663 | 514-890
626 456-790 65 575 645 | 505-792
684 575-791 21 649 753 | 85-1,020
615 486-800 23 618 690 | 565-902
680 510-976 28 581 715 | 610-908
659 548-756 8 584 670 | 583-790
630 573-713 3 566 713 | 666-780
648 511-764 3 562 730 | 668-767
664 565-790 4 570 666 | 645-713

654 590-735 I 508 623 | 623
661 605-723 2 522 624 | 564, 685
648 568-856 3 552 660 | 544-820
644 536-765 2 578 665 | 627, 703
630 510-740 3 535 596 | 500-769
645 551-781 2 531 689 | 600, 778
663 565-780 27 611 709 | 593-875
613 550-684 4 673 676 | 627-722
686 630-766 6 652 675 | 599-797
600 597, 602 7 662 645 | 564, 732
627 593-662 4 644 624 | 528-700
651 571-736 15 696 725 | 555-982
635 501-845 % 689 674 | 524-870
633 566-729 4 562 687 | 566-788
524 524 6 550 574 | 440-668
598 497-651 7 652 692 | 601-791
668 582-744 5 560 666 | 590-763
541 442-668 17 555 541 | 424-698
522 448-698 6 539 589 | 532-646
555 SV S—5 95 | eee | eee re ee ee tee | eee
537 537 2 675 612 | 528, 697

554 530, 578 1 629 825 | 825
SLES De ees (Ere Coreg eerd |e rer oe 4 686 694 | 608-791
535 535 3 705 680 | 643-709
445 445 9 772 576 | 475-673
538 519, 673 iG 791 758 | 588-970
Bad is Loan oem | had aR achat 9 759 561 | 482-684
533 446-583 5 592 565 | 510-616

No extremely large Wistar

720-day-old animal fed SPM diet that weighed
1,020 grams. Among the rats 500 days and older
that were fed this diet, four reached weights
exceeding 900 grams. On SPPB diet, one rat
reached a maximum weight of 976 grams by 341
days, and three additional animals that were less
than 500 days old reached maximum weights

exceeding 800 grams.
rats were obtained with the semipurified diet, but
with SPE diet one rat weighed 970 grams at 750
days of age, exceeding by “178 grams the largest
BHE rat fed this diet.

No quantitative data on body composition
were obtained for the studies reported in this

21

bulletin, but animals that were obviously obese
were obtained with several of the experimental
diets. Marshall, Hildebrand, Dupont, and Wo-
mack (126) observed for adult rats an apparent
difference in the conversion to body fat of calories
from different diets, even on comparable calorie
intake. Apparent differences in the utilization of
calories by the adult rat fed some of the diets
such as SPM or SPPB may be related to the
extent of the conversion of calories from these
diets to body fat.

Discussion.—Mickelsen, Takahashi, and Craig
(132) observed exceedingly obese rats when the
Osborne and Mendel strain of animals were fed ad
libitum a diet containing 60 percent Crisco. The
largest animal weighed 1,655 grams. Sprague
Dawley rats or NIH black rats fed these high-fat
diets became heavier than stock animals but not
so heavy as the Osborne and Mendel strain.
Obese rats approaching 1,000 grams in weight were
also observed when the Osborne and Mendel strain
were fed the authors’ “best” low-fat regimen for a
period of 60 weeks. The weight curves of these
rats fed the low-fat diet (3 percent) were similar
to those already discussed for BHE rats fed many
of the experimental diets. A reduction in growth
rate occurred at about 15 weeks, with many of the
rats continuing to gain slowly throughout the 60-
week experimental period. Some rats showed a
spurt in body weight gain at the 20th or 30th
week. This ‘best’ low-fat diet of Mickelsen,
Takahashi, and Craig (132) was a relatively simple
diet with casein as the chief source of protein and
with a protein level of 25 percent. Sucrose was
the carbohydrate in this diet, amounting to 66
percent.

The sucrose content of the semipurified diet and
its various modifications discussed in this publica-
tion was high (39 to 52 percent) and may be re-
sponsible for the ready acceptance of these diets
by BHE rats. Food intakes frequently were as
much as 19 or 20 grams daily even at a relatively
early age. The high digestibility and correspond-
ingly low fecal bulk observed by Marshall, Hilde-
brand, Dupont, and Womack (126) with similar
diets make it possible for rats to consume excessive
amounts of these diets without apparent digestive
disturbances. In general, the results obtained
with BHE rats provide further evidence that
obesity in normal male rats may be produced by
diet and that rats may overeat voluntarily if sup-
plied with diets that are sufficiently acceptable and
that can be consumed in relatively large amounts.
The failure to obtain equally large rats when the
stock diet was fed was probably due to a limitation
in the amount of this diet that could be consumed
because of the large fecal bulk and the poor digesti-
bility observed with this diet (126).

Longevity

In table 12 are summarized data dealing with the
survival of rats on all of the experimental regimens
under investigation. In addition to the average

22

results for the more extensive investigations with
SP 8 HVO and SPE diets, data are also presented
for individual series to permit a direct comparison
of the response of littermates to those diets for
which only limited information is available.

SP 8 HVO pier.—A group of 53 rats representing
five experimental series on the semipurified diet
provides data on the influence of this diet on
longevity. The average age of the animals at
death was 629 days, with 50 percent dead by the
end of 616 days. Fourteen rats survived more
than 700 days. Figure 4 shows the percentage of
rats that died within different age intervals on this
diet. The highest death rate occurred between
600 and 700 days.

SPE piet.—Similar data were obtained for 85
rats representing eight experimental series on
SPE diet (table 12). The lifespan of these rats
was considerably shorter than that observed with
the semipurified diet; average age at death was
464 days, with 50 percent dead by 449 days.
Only one of the 85 rats survived more than 700
days. As shown in figure 4, the maximum death
rate for these rats occurred between 400 and 500
days of age.

PROTEIN-FAT-CONTAINING Foops.—Two series
of rats were fed the diets containing milk, beef,
or peanut butter. In addition, comparative data
were obtained on the response of littermates to
SP 8 HVO or SPE diets. The results for the 21
littermates fed SP 8 HVO or SPE diets were, in
general, similar to those already discussed for the
larger number of animals fed these diets. The
shortest lifespan was observed for animals fed
SPE diet. Rats fed the SPPB diet also tended
to die at an early age. Although the average
age at death was approximately the same—about
580 days—for rats fed SP 8 HVO, SPM, or SPB
diets, the number of rats dying within comparable
age intervals was not the same.

Figure 5 presents data for SPM, SPB, and
SPPB diets similar to that seen in figure 4 for
SP 8 HVO and SPE diets. On SPM diet there
were several early deaths but 8 of the 21 rats
survived more than 700 days, in contrast to only
3 of the littermates fed SP 8 HVO diet. On SPB
diet only 1 rat died before reaching 400 days of
age; the maximum death rate occurred between
600 and 700 days; 4 rats survived beyond 700
days. On SPPB diet the maximum death rate
occurred at a somewhat earlier age, between 500
and 600 days, with 5 of the 21 rats dead before
400 days of age.

SPE DIET WITH SELECTED SUPPLEMENTS.—Rats
fed SPE diet supplemented with choline, vitamin
B,, or vitamin By, alone or in combination, were
generally as short lived as on SPE diet alone, and
there was no evidence that any of the supplements
investigated had a measurable effect on the
longevity of these animals. The addition of
cholesterol or ascorbic acid also seemed to exert
little influence on the length of life of rats fed SPE
diet.

TABLE 12.—Age at death and mortality rate of rats fed various diets

Strain and diet

Littermates fed—
SPE supplemented with—

By, 0.01 mg./100 gm______
Choline, 0.5%+By, 0.01
migs/VOOvem 22 ee
Littermates fed—
SPE supplemented with—

@holine;:0:5% =. 2. =
Be, 0.5 mg./100 gm_________
Choline, 0.5% + Bg, 0.5 mg./

Choline, 0.5% + Be, 0.5 mg./
100 gm. + By, 0.01 mg./
NO Of orm se eke eee SS
Littermates fed—
ee supplemented with—

Cholesterol, 0.46%________
Cholesterol, 1.38%_--_-_-_-
Ascorbic acid, 0.2% ______-
Ascorbic acid, 0.2%-+ cho-
lesterol, 0.46%_______.__-
Littermates fed—

Littermates fed—
SPE (fresh egg)___.-________
SPEW

E100

IS GOC Keser aia eye ue cada oy)

Age at death

Rats dying before—

Rats 50 per-| Old-
Aver-| cent est 400 500 600 700
age | died | rat | days | days | days | days
by—
Num- Per- | Per- | Per- | Per-
ber | Days | Days | Days | cent | cent | cent | cent

53 629 616 917 2 17 43 73
85 464 449 705 28 64 88 99
21 579 574 889 5 24 57 86
21 467 419 705 38 57 76 95
21 580 578 903 19 43 57 62
21 589 603 852 5 29 43 81
21 525 541 722 23 37 66 85
8 444 435 581 25 62 1OOR| Sasa
8 441 414 551 38 88 100) |e e
8 475 431 632 25 62 88 100
8 423 400 642 38 75 88 100
9 458 426 626 33 78 89 100
9 432 410 581 22 89 1000 |252—--—
9 464 423 625 33 56 89 100
9 427 418 508 22 79 O08 2e22==
9 443 438 527 22 78 HOO e222
8 415 375 597 50 88 10Q S22" 2
8 477 474 578 25 62 100K See
8 410 406 574 38 88 LO0Mes.22e
8 405 361 533 50 75 TOO} je22 = 2
8 414 358 520 50 88 LOOM ess o=
9 631 643 774 0 22 33 67
9 618 569 775 11 11 44 67
9 524 444 706 11 67 67 89
9 553 506 776 D2, 44 56 78
9 602 610 774 11 22 33 78
9 514 487 707 33 56 67 78
16 618 614 889 6 25 44 69
16 566 518 799 12 44 56 81
8 676 623 917 0 0 25 75
8 582 522 810 0 38 62 75
8 593 505 813 0 38 50 88
18 680 653 917 0 11 28 56
18 654 621 893 0 Live 38 61
10 482 465 604 10 60 90 100
10 578 552 749 10 30 50 70
10 490 441 585 10 50 HOO ass 2 2
10 548 525 696 10 30 70 100
25 559 522 762 8 32 64 92
19 393 381 591 58 74 TOO! | eee
3 590 |e wees 727 0 33 33 67
3 v1 ss Sep 629 67 67 67 100
4 G86s|2 22 2 2 805 0 0 25 25
4 624 Joes 767 25 25 25 50

800
days

900 | 1,000 | 1,100
days | days | days
Per- | Per- | Per-
cent cent cent
96 OOF See ae
LOO} 2 sess | eer
95) 100 |o. -
TOO) 52235 |eeass
UOOs | 2eees | Sean
88 100) 222222
MOOS |Se ae |b eee
LOOW| 22a. |b2ee
89 1007 ===
VOOR see So) eee
OO) | Saas |e

TABLE 12.—Age at death and mortality rate of rats fed various diets—Continued

Age at death Rats dying before—

Strain and diet Rats 50 per-| Old-
Aver- | cent est 400 500 600 700 800 900 | 1,000 | 1,100
age oe rat | days | days | days |; days | days | days | days | days
v=
Wistar rats
Num- Per- | Per- | Per- | Per- | Per- | Per- | Per- | Per-
Littermates fed— ber | Days | Days | Days | cent | cent cent cent | cent cent cent cent
OEE iO tee 28 eee ee ae 10 739 836 876 0 10 20 40 40 LOOM Sense
Dy Boe. See eee ae 10 654 742 888 30 30 40 40 60 LOO 222224 |seeee—
BHE parents fed Wistar stock
diet
Young fed—
Ser VO) 2. 2 0 oe tea 9 703 755 |1, 028 11 11 33 33 78 78 78 160
S124 0 eee eee ee ee eee Pee 9 424 381 762 44 56 89 89 LO Oe) oer = | eee
DIET: SP 8 HVO DIET: SPE
% DYING % DYING
|
30
20
10
NONE
eee 0

Paci® 9 2 Ss 4.” SS C: Hees

AGE (hundred days)

Ficurn 4.—Percentage of total number of rats dying within different age intervals on SP 8 HVO and SPE diets.

KIND AND LEVEL OF FAT.—Data available, al-
though limited, suggest that the lifespan of rats
may be influenced by the kind and/or level of fat
in the semipurified diet. When the dietary fat
was HVO, the average age at death was approxi-
mately the same whether the level of fat was 8 or
16 percent. Although there appeared to be no
difference between the survival of rats fed diets

24

containing 8 or 16 percent lard, the lifespan of
both groups was less than that of animals fed the
diets containing HVO. When butter was the
dietary fat and the level was 8 percent, the average
age at death was close to that observed with
HVO but decreased when the diet contained 16
percent butter to approximately that observed
when lard was the dietary fat.

DIET: SPM

< 4
AGE (hundred days)

Figure 5.—Percentage of total number of rats dying within different age intervals on SPM, SPB, and SPPB diets.

Sait, OO LS

The average length of life of rats fed SP 16
butter diet was less than that observed on SPM
diet. The type and level of protein in these two
diets were the same; mineral content as well as
level of fat was similar. The major differences
between these diets were the presence of 6 percent
HVO and of 5 percent lactose from the dried skim
milk in SPM diet, whereas all of the fat in SP 16
butter was from butter and all of the carbohydrate
was sucrose. The presence of lactose may have
been a factor contributing to the difference in the
survival on the two diets, although the amount
was low in comparison with the 39 percent sucrose
in this diet. No antioxidants were added to
these diets, and the tendency for somewhat re-
duced consumption of the SP 16 butter diet may
be related to lower stability of the fat in this diet.
The content of the low-molecular fatty acids (Cy,
and below) in the SP 16 butter was higher, about
twice that of the SPM diet. Data available pro-
vide no answer as to the cause of the differences
observed.

PRotTEIN LEVEL.—Modification of the semipuri-
fied diet by increasing the protein or the protein
and fat level to that of SPE diet resulted in no
significant change in the lifespan of these rats.
Respiratory infection was responsible for some of
the early deaths of the small group of eight litter-
mates fed SPa 16 HVO and SPb 8 HVO diets;
no difference in survival was apparent for the
larger group of littermates fed SP 8 HVO and

DIET: SPB

DIET: SPPB

6 T> < 4 5 6 1 ?

SPa 16 HVO diets. The results with SPb 8
HVO and SPa 16 HVO were similar, suggesting
again that increasing the level of HVO from 8 to
16 percent was without effect on survival.

EGG AND EGG COMPONENTs.—Rats fed a diet
containing a relatively high level of egg white
(SPEW) and those fed a diet consisting of 100
percent whole egg survived longer than those fed
a diet containing 25 percent egg (SPE) or 30 per-
cent egg yolk (SPEY). The lifespan of rats fed
SPEW was similar to that observed for those fed
the modified semipurified diet (SPa 16 HVO) with
comparable levels of fat and protein, whereas the
average age at death for rats fed SPEY diet was
similar to that obtained for littermates fed the
SPE diet containing cooked fresh egg. The
survival period of rats fed 100 percent egg yolk
was short. No data were obtained on longevity
of rats consuming 97 percent egg yolk and 3 per-
cent salt mixture, but other results obtained with
this diet, to be considered more fully later, suggest
that the lifespan of rats fed this high egg yolk diet
may be increased appreciably when the diet is
supplemented with a suitable salt mixture.
Although some of these data seem to indicate
that it is the yolk of egg that is contributing to
the shortened lifespan of rats fed SPE diet, the
finding that rats tolerate diets containing 100
percent egg better than a diet containing either
25 percent whole egg or 30 percent egg yolk

29

indicates that other dietary ingredients also are
contributing to the response of rats to SPE diet.

Drier REVERSAL.—The number of rats included
in the series to investigate the influence of reversing
stock and SPE diets at 250 days of age was small,
and details for the individual rats are summarized
in table 81 of the appendix. The harmful effects
of the SPE diet appear to have been overcome or
prevented for 3 of the 4 rats that were changed
from SPE to stock diet at 250 days of age. The
4th rat was losing weight before the diet was
changed and died shortly thereafter. This sug-
gests that irreversible damage had already occurred
before the change in dietary y regimen at 250 days.
The average age at death of the 3 animals that
were maintaining their weight at the time of the
change in diet was 705 days, in contrast to a life-
span of 473 days for rats continuing on SPE diet
throughout life. Three of the 4 rats placed on
SPE diet after 250 days of age lived more than 700
days, in marked contrast to 1 out of a total of 85
that reached this age when SPE diet was fed
throughout life. These findings suggest that the
harmful effects of SPE diet are due to a stress
imposed upon the young rat, and that this diet
may be well tolerated by the adult rat.

HEREDITY AND RESPONSE TO SP 8 HVO or
SPE prer.—Wistar rats lived longer on both
SP 8 HVO and SPE diets than did BHE rats.
Over 50 percent of the rats fed these diets lived
more than 700 days, in marked contrast to the
results with BHE rats, particularly those fed
SPE diet. Although the average age of survival
of Wistar rats was somewhat less on SPE than on
SP 8 HVO diet, the difference was of questionable
significance considering that the early death of
two of the rats fed SPE diet was due to respiratory
infections and seemed unrelated to diet.

The shortened lifespan that resulted from
feeding SPE diet to BHE rats when their parents
were raised on our regular stock diet also occurred
when their parents were raised on the stock diet
that had been used for the Wistar animals.
Genetic differences, therefore, and not differences
in dietary history of the parents appear to be
responsible for the short survival of BHE rats
fed SPE diet.

Stock prnT.—No systematic data were collected
to determine the longevity of BHE rats fed the
usual stock diet, but apparently these animals
are relatively long lived. Among the rats that
were sacrificed to provide information on the
characteristics of stock animals at different ages
were 10 rats over 800 days of age. Three of these
were still maintaining their weight and appeared
to be in good health at 820, 916, and 976 days of
age. The remaining 7 animals, from 808 to 897
days old, were losing weight at the time of sacri-
fice. Likewise, BHE rats fed the stock diet that
had been used for raising the Wistar rats were
long lived. Five rats that were continued on
this diet to provide data on older animals were
still maintaining their weight when sacrificed at

26

an average age of 938 days. No information was
obtained with older Wistar rats fed their usual
stock diet.

EARLY WEIGHT GAIN AND SURVIVAL.—Although
the experiments reported in this bulletin were not
designed to determine the influence of food con-
sumption and/or weight on survival, they afford
considerable indirect evidence indicating that ex-
cessive food consumption and the accompanying
rapid gain in body weight were important factors
in determining the lifespan of these rats. In
table 13 are summarized data for gross caloric
intake by rats fed SP 8 HVO and SPE diets during
the first 300 days of life, with the results separated
into groups based on the age at which consistent
weight loss began. The average intake on both
diets tended to be less, particularly during the
200- to 300-day period, for rats with the longer
span of healthy life, although there was consider-
able variation in the food intake of individual rats.
All except 1 of the 9 rats fed SP 8 HVO diet with
a caloric intake of 1,900 Calories or more lost
weight and showed signs of ill health before they
reached 600 days of age. Considering the simi-
larity in the caloric intake of rats fed SP 8 HVO
and SPE diets, however, it was apparent that
differences in the lifespan on these two diets were
not due to differences in the amount of food eaten
by these animals.

The adverse effect of rapid weight gain in the
young adult rat is still more apparent from the
data shown in figure 6. Curves 1 and 2 contrast
the growth curve of a group of rapidly growing

rats fed SP 8 HVO diet with that of rats of rela-

tively long lifespan; curves 3 and 4 represent
similar data for rats fed SPE diet. The 14
rapidly growing rats fed SP 8 HVO diet all had
attained a body weight of 550 grams by the time
they reached 200 days of age; 4 exceeded 600
grams in weight. The average age at death of
these rats was 553 days. Curve 2 shows the
slower growth rate of 14 rats that were fed the
same diet and survived 600 days or more without
weight loss. Most of the rats in this latter group
weighed less than 500 grams at 200 days of age,
and none had reached a weight of 550 grams.
The average age at death was 812 days. The
16 rapidly growing rats fed SPE diet all exceeded
600 grams in weight by 200 days, with an average
age at death of 423 days. By 600 days, most of
the rats fed SPE diet were dead or were losing
weight, regardless of early weight gain. Curve 4,
therefore, represents data for rats maintaining
or gaining weight at 500 days of age. Their
average lifespan of 623 days was oreater than
that of the rapidly growing rats fed the same
diet, but did not equal that of rats growing at a
comparable rate when fed SP 8 HVO diet.

Figure 7 represents similar data for a small
group of rats fed SPM, SPB, and SPPB diets, and
provides further evidence for the harmful effects
of early rapid gain in body weight. The curves
for the most rapidly growing animals fed these

TaBLeE 13.—Mazrimum age of rats before weight loss in relation to caloric intake during the first 300 days
on SP 8 HVO and SPE diets

Intake during—
Diet and age of Average
rats (days) Rats | healthy 0-12 weeks 100-199 days 200-299 days
lifespan
Average Range Average Range Average Range
Number| Days | Calories Calories Calories Calories Calories Calories
SP 8 HVO:
Less than 500__---_- 15 387 6,110] 5, 260-6,860 |} 8, 320 | 7, 190- 9, 780 8, 510 7, 100— 9, 870
HOOEtORD99 Sse 28 | 12 541 6,000 | 5, 220-6,960 |} 8,170 | 7, 280-10, 060 8, 220 7, 280— 9, 780
600 to 699________- 11 624 5,870 | 4, 840-6, 720 | 7,760 | 6, 160- 8, 930 7,900 | 6, 530— 9, 020
a 700 and over___---- 6 757 5,590 | 5, 030-5, 920 7, 890 | 6, 670— 8, 410 7,450 | 6, 720— 7, 990
PE:
Less than 400_____- 20 330 | 6,180 5, 540-7,120 | 8, 260 | 6, 760-10,180 | 8, 610 7, 060-— 9, 290
400 to 499_____.-.. 11 423 | 6,330) 5, 690-6, 820 | 7,940 | 6,170— 9,140 | 8,210] 6, 690-10, 180
500 and over___-_--- 6 533 | 5,610 | 5, 020-6, 340 6, 830 | 5, 500— 8,100 | 6, 950 5, 570— 7, 730
DIET: SP 8 HVO DIET: SPE
GRAMS
800
600
400 ;
r
: | |
I
| =o Obese rats g ox Obese rats |
200-4 (553 days*) i (423 days*)
4—A Long-lived ie A--A Long-lived
rats (812 days*) rats (623 days*)
0

0 150 300 450 600 0 150

DAYS

300 450 600
DAYS

* a vERAGE AGE AT DEATH

FicurE 6.—Comparison of growth curves of obese rats
fed SP 8 HVO and SPE diets with those of long-lived

rats fed the same diets.

diets are all for rats weighing 600 grams or more
by 200 days. Of the 18 rapidly growing rats fed
these three diets, 8 were dead before reaching
400 days of age; only 1 survived 600 days (603
days on SPB diet). The rats that were still
maintaining their weight at 600 days of age grew
slowly on all three diets and survived approxi-
mately 300 days longer than did the rapidly growing
rats fed the corresponding diet. The slowly
growing rats tended to reach maximum weights
comparable to those attained by the rapidly
growing rats but at a much older age.

_ No data were available from this study to
indicate the possible advantage of restricting food

721-631—64——_3

intake to prevent the excessive weight gain of the
older rats fed these diets. ‘The tendency for rats
to become heavy at an early age when fed SPM
and SPPB diets may be a factor in the relatively
large number of early deaths on these diets. Al-
though a rapid gain in weight was generally asso-
ciated with a short lifespan, a slow rate of early
gain did not necessarily result in a long, healthy
life.

The results with other experimental diets show
a similar trend for rapid early growth to be
associated with early death, but are too few to
permit their separation as has been done for the
diets just discussed. The tendency to a shortened

27

DIET: SPM DIET: SPB DIET: SPPB
GRAMS 7
800 =
|
ie pes
ue A- pes
600 PL pane 4a
a
we

i Oo Obese rats

(382 days*)
A--A Long-lived
rats (682 days*)

o—o Obese rats

(437 days*)
A--A Long-lived

rats (775 days*4)

2001-4

o—o Obese rats
(456 days*)
A--A Long-lived

rats (737 days*)

0 150 300 450 600 0
DAYS

150 300 450 600 0

DAYS

*,VERAGE AGE AT DEATH

150

300 450 600
DAYS

Fiaure 7.—Comparison of growth curves of obese rats fed SPM, SPB, and SPPB diets with those of long-lived rats

fed the same diets.

survival period for rats fed lard (SP 8 lard and
SP 16 lard) may be due in whole or in part to
excessive consumption, along with the tendency
to more efficient utilization of these diets.

Discussion.—There have been extensive inves-
tigations on the nutritional requirements of the
rat, but the majority of them have dealt with the
period of early growth. Relatively few have
covered the entire lifespan. Many of the early
experiments concerned with longevity have dealt
with diets deficient in one or more nutrients, result-
ing in retarded growth and in premature death.
Although growth has been the basis for studying
nutritional adequacy of many diets, considerable
evidence has accumulated to indicate that rapid
growth in early life may not insure optimum
health throughout life.

McCay (120) was the first to demonstrate that
lifespan of rats could be extended by severely
restricting caloric intake while maintaining
adequate levels of essential protein, minerals, and
vitamins. With much less restricted intakes (33
and 46 percent) and without severe retardation of
growth and sexual maturity, Berg and Simms (27,
22) showed an extension of life expectancy and a
delay in the onset of major diseases. Ross (166,

28

167), investigating the effect of uniform lifelong
dietary regimens on the mortality pattern of rats,
demonstrated the possibility of modifying life
expectancy not only by quantitative dietary
restriction but also by the ratio of the protein
and carbohydrate components in the diet. Riesen,
Herbst, Walliker, and Elvehjem (158) obtained a
beneficial effect on survival when the caloric
intake of rats fed a synthetic diet was restricted.
Carlson and Hoelzel (41) found that intermittent
fasting tended to increase the lifespan of rats
under conditions that did not result in drastic
retardation of growth. Everitt and Webb (59)
reported for male rats that the faster an animal
reached its maximum weight, the sooner it
deteriorated and died. Callison, Orent-Keiles,
and Makower (40) compared the results of feeding
human-type diets with rats fed a stock ration.
The stock diet which produced the smallest early
weight gains resulted in adult animals with the
lowest maximum weight and in the best
physiological condition. In contrast, the fast-
growing animals which attained the highest
maximum weights were inferior in physical
condition, as judged by bronchiectasis and skin
condition.

McCay, Maynard, Sperling, and Osgood (121)
found that the maximum lifespan of their animals
occurred when rats weighed between 350 and 450
erams. No animal with a body weight exceeding
450 grams at any time in life lived more than 810
days. In considering nutrition during the latter
half of life, these authors reported that the degree
of fatness of the body is the most important
factor as far as lifespan is concerned.

Silberberg and Silberberg (/71) reported the
results of feeding male mice a stock diet containing
5 percent fat with or without an additional 25
percent lard. The mean lifespan of the mice
consuming the fat-enriched diet throughout their
life was 107 days shorter than that of the stock-fed
animals. When the high-fat regimen was initiated
at the age of 6 or 12 months, the lifespan was also
shortened but less so than when this regimen was
started at weaning. When fed for 5-month
intervals, the results varied, depending on the
period of life during which the fat-enriched diet
was consumed. The differences observed were due
to high fat and not to the caloric intake.

French, Ingram, Uram, and others (69) com-
pared the results of ad libitum feeding of a diet
containing 22.7 percent fat, chiefly corn oil (20
percent), with one containing 3.4 percent fat and
20 percent sucrose in place of the corn oil. The
lifespan of male rats fed the high-fat diet was
markedly decreased. Decreased lifespan was cor-
related with increased efficiency of utilization but
not with caloric intake. These authors indicate
that this decrease in longevity may have been due
to the fat as such, or may have been the result of
the improved growth rate conferred by the high-
fat diet.

According to Comfort (42), heredity may be as
important as dietary reduction in determining
lifespan. Although the lifespan of laboratory
animals can be increased by eliminating specific
heritable diseases, inbred stock rats tend to reach a
shorter lifespan than do random-bred animals,
and the author suggests that information on the
mechanism for vigor in hybrids may prove of
significance in studies of aging. Sperling, Loosli,
Barnes, and McCay (176) also reported data im-
plicating inheritance as a factor in survival. Six
and one-half percent of the litters of rats investi-
gated by these authors accounted for 27 percent of
the short-lived rats that died within 500 days; 18
percent of the litters accounted for 47 percent of
the animals dying after 700 days. Lane and
Dickie (111) presented data showing the shortened
lifespan that results from excessive food consump-
tion by genetically obese mice fed ad libitum
and, as the result of long-term restriction of
food intake of these mice, increased their lifespan
by more than 300 days.

Summary

In general, growth was good on all of the experi-
mental diets under investigation, and no evidence
of any dietary deficiency was apparent. Young

rats tended to grow more rapidly when the level
of fat was 17 to 19 percent than when the diet
contained 9 percent fat or less. With some diets,
growth rate was associated with caloric intake;
with others, such as those containing high levels
of egg, milk, beef, or peanut butter, it appeared to
be associated with efficiency of utilization.

Rats fed stock rations generally attained their
maximum weight at a relatively early age and
maintained a constant weight thereafter. On the
semipurified diets and the various modifications of
it, rats tended to continue to gain throughout their
healthy lifespan. Rats exceeding 800 grams in
weight were frequently obtained, especially on the
diets containing milk or peanut butter.

The results reported provide further evidence of
the many factors that need to be considered in
evaluating the effect of diet on the lifespan of the
rat. Survival of rats varied even on diets of simi-
lar fat and protein content. The tendency to
excessive consumption of certain diets may explain
some of the differences in survival observed. The
extent of weight gain and the amount of a diet
that can be tolerated by the adult rat without ad-
verse effects appear to vary with diet. Diets con-
taining high levels of egg or egg yolk resulted in a
shortened lifespan, but the longer life of rats fed
100 percent egg indicates that other dietary in-
eredients were also contributing to the response to
the SPE diet. The results obtained when stock
and SPE diets were reversed at 250 days contribute
further evidence that the age period under study
may be a contributing factor in the response to
diet. The results of feeding the same diets to
BHE and Wistar rats emphasize the importance
of recognizing inherited characteristics in evaluat-
ing dietary response.

Histology and Size of Selected Organs
Histology of kidney

When subjected to gross and to microscopic
examination, the kidneys from 113 rats fed the
stock diet, 99 fed SP 8 HVO diet, and 201 fed
SPE diet, provided information on the influence
of diet, age, fasting, and weight loss on this organ.

Rats MAINTAINING WEIGHT ON sTocK, SP 8
HVO, ano SPE piets.—In table 14 are sum-
marized for different age groups the results of
eross and microscopic examination of the kidneys
from rats that were maintaining weight on these
three diets at the time of sacrifice. The results
for fasted and nonfasted animals have been com-
bined. There appeared to be a tendency toward
somewhat higher ratings for the presence of hyalin
casts when rats were sacrificed without fasting,
but the differences were too small to warrant a
separation of the results without more data to
establish the significance of this trend.

29

Taste 14.—Kidney damage determined microscopically for rats maintaining weight at different ages on
stock, SP 8 HVO, and SPE diets

Diet and age of rats Rats Gross
(days) rating
Hyalin
Stock: Number Score Score
Less than 200_.....-- 19 0
200't0: 29908220525 18 2
300 to 399___________ 11 .6
400 to 499___________ 10 .6 .
HOO tO 690 ras eS ata .8 i
600 and over_____---- 16 1.0 iti:
SP 8 HVO:
Less than 200_______- 5 4
200 to: 299.255. Lecce 12 a3
300 to 399_____-___-- 8 a?
400 to 499___________ 7 <4
500't0:599 222-2 --c 9 .8
SPE:
Less than 200______-- 5 ce? 0
200 to 299__________- 23 :8 1.
300 $0: 399 22cecce ses 12 1.6 1.
400 to 499__________- 14 125 al
HOO t0' 599 2. 2 eis 9 2:2 de

In general, the kidneys of rats under 200 days
of age were normal on all three diets. On stock
or SP 8 HVO diet extensive degenerative changes
in the kidney were rarely seen. A _ gradual
increase occurred with age in the number of rats
fed stock or SP8 HVO diets, with kidneys showing
the presence of eosinophilic albuminous material
or hyalin casts. Kidneys from 81 percent of the
rats fed the stock diet that were over 600 days old
had a hyalin rating of 1 or more, although one of
the oldest rats (916 days) had a kidney that was
apparently normal. Cystic or glomerular damage
was found occasionally and was seen more often
in the kidneys from rats fed the stock diet than
from those fed SP 8 HVO diet.

On SPE diet the results were in marked con-
trast. Of those animals that were fed this diet
and were more than 200 days old, relatively few
had normal kidneys. Kidneys with hyalin ratings
of 2 or 3 were observed even in rats 200 to 300
days old. Cystic or glomerular damage was
occasionally seen but was generally slight.

Calcium deposits were not observed in the
kidneys of rats that were maintaining weight on
any one of these three diets.

RATS LOSING WEIGHT ON stock, SP 8 HVO,
AND SPE prets.—Both age and weight loss were
found to influence the type and extent of kidney
damage observed, and the data summarized in
table 15 have been separated accordingly.

For rats fed the stock diet and with weight loss
less than 100 grams, little damage was observed in
the kidneys from the few animals that were less
than 700 days old; extensive degenerative changes
were observed in kidneys from rats over 700 days
old, with 40 to 75 percent of the kidneys showing
cystic and glomerular damage as well as hyalin

30

NONWH

Histological rating

NUR RDO

Or ar

Kidneys with—

Cystic |Glomerular) Hyalin Cystic |Glomerular
Score Score Percent Percent Percent

(0) 0 0 0

0 0 11 0 0

1 Pee 18 9 9

a 2 50 10 10

4 5) 64 27 18

4 4 81 19 31

0 0 20 0 0

0 0 17 0 0

0 0 38 0 0

0 0 29 0 0

3 0 56 11 sal

0 0 0 0 0

mal . 04 78 0 4

4 wel 92 33 8

al 2 64 14 21

3 3 100 33 33

casts. When weight loss exceeded 100 grams, 86
percent of the kidneys showed all three types of
damage and the extent of the damage observed
bore no relation to age. When cystic damage was
large, there was a tendency for a reduction in
hyalin casts. Fibrosis was generally apparent
when all three types of damage were evident.
Calcium was present in only one of these kidneys.

Animals fed the semipurified diet with weight
loss less than 100 grams presented a somewhat
different picture from that of animals fed the stock
diet. ‘The most extensive damage was found in
kidneys from the small group of rats between 500
and 600 days of age; kidneys from animals sur-
viving over 600 days tended to show progressively
less damage with increasing age. Relatively little
cystic or glomerular damage was observed. When
weight loss exceeded 100 grams, only 2 of the 29
kidneys from rats 400 days of age or older were
normal; no consistent relation between age and
extent of damage was observed. Cystic and glo-
merular damage was found in 65 percent of these
kidneys, a marked increase over that seen in rats
losing less weight but somewhat lower than that
found for comparable groups of rats fed the stock
diet. Calcium deposits were found in the kidneys
of 41 percent of these animals and appeared to be
the heaviest between 400 and 600 days of age.
Calcium was apparent only when all three types of
damage were present. The data for fasted rats
were too few to determine whether or not the
nutritional state of the rat at the time of sacrifice
was a factor in determining the presence of calcium
in the kidneys of these rats.

On SPE diet, relatively few normal kidneys were
observed, regardless of age or weight loss. For
rats under 400 days of age and losing less than 100

TaBLe 15.—Kidney damage determined microscopically for rats losing weight at different ages on stock,
SP 8 HVO, and SPE diets

Weight loss, diet, Histological rating Kidneys with—
and age of rats Rats Gross
(days) damage
Hyalin | Cystic |Glomerular| Calcium | Hyalin | Cystic |Glomerular| Calcium
Rats losing less
than 100
grams:

Stock: Number | Score Score Score Score Score | Percent | Percent | Percent | Percent
400 to 499____ 1 0 0) 0 0 0) 0 0 0
500 to 599__-_- 2 2 9 0) 0) 0 50 0 0) 0
600 to 699____ 2 1. 0 1.0 5 0) 0) 50 50 0 0)
700 to 799____ 4 2.2 2. 0 1.0 1.8 0 75 75 75 0
800 and over__ 5 2. 4 1.8 1.0 1.4 0) 100 40 60 0

SP 8 HVO:

Less than 300_ 4 0 0 0 0 0 0 0 0 0
300 to 399____ De 0 0 0 0 0 ) 0 0 0
400 to 499____ 7 .6 9 0 0 0 57 0 0 0
500 to 599____ 5 2.3 2. 0 1.0 4 0 80 40 40 0)
600 to 699___- 6 14 5 ne, nes 0 33 ile 17 0
700 and over_-_ 3 oh nO 0 0 0) 33 0) 0 0

SPE:

Less than 300_- 6 a) vit 0 2 0 50 0) 17 0
300 to 399____ 21 1.8 1.8 9) er sul 95 29 38 14
400 to 499____ 18 2.7 2. 2 1.8 1.2 3 94 ed 72 17
500 to 599____ 9 3.8 1.9 2. 6 1.3 7 100 89 78 44
600 and over_- 8 Baz 245 2. 0 1.6 4 100 88 62 12
Rats losing more

than 100

grams:

Stock:

300 to 399____ 2 4. 0 2. 0 2.5 3. 0 LO 100 100 100 50
400 to 499____ 2 3.5 2.5 DED 2. 0 0 100 100 100 0
500 to 599____ 3 3.3 20:7, 3. 0 27) 0 100 100 100 0
600 to 699____ if 4.0 4. 0 2.0 3. 0 0 100 100 100 0
700 to 799____ 4 2.0 2. 0 .8 1.5 0 100 50 75 0
800 and over_- 2 3.5 2:5 2.0 3. 0 0 100 100 100 0
SP 8 HVO:
Less than 300_- 2 0 aD 0 0 0 50 0 0 0
EXOD) Troy aH ONS ye | een Ds aca Io sw] DO a Eo | S| en | DSC OE | (a
400 to 499____ 4 3. 5 2.5 2.8 1.8 1S 100 15 75 50
500 to 599___-_ 9 24 251 11 1a, 1.2 100 56 67 44
600 to 699____ {6 2.3 2. 0 1.9 LZ .6 86 el il 43

Spee and over_-_ 9 3. 0 2d 14 1.3 3 89 67 56 22
Less than 300__ 1 4.0 3. 0 1.0 1.0 2.0 100 100 100 100
300 to 399____ 19 3.9 2.50 3. 2 2. 0 2.4 100 95 95 79
400 to 499____ 23 3.8 Qik 3. 0 2.1 19 100 100 100 74
500 to 599____ 21 Sil 20) 3.3 1.9 1.3 100 100 95 62
600 and over_- 12 3.8 PA) 2.9 2.1 .9 100 100 92 42

grams in weight before sacrifice, the extent and
kind of damage found was similar to that already
seen (table 14) for rats that were fed this diet and
were maintaining or gaining weight. In the older
rats, however, there was an increase in the extent
of cystic or glomerular damage. When weight loss
exceeded 100 grams, no normal kidneys were seen
and more than 95 percent showed glomerular and
cystic damage as well as hyalin casts. Degenera-
tive changes were extensive regardless of age, and
the scores for cystic damage tended to exceed those
for glomerular damage, in contrast to the results
with rats fed the stock diet. Calcium was present
more frequently in the kidneys of rats fed SPE
diet than in those fed SP 8 HVO diet ; 18 percent of the
kidneys showed evidence of calcium deposition

when weight loss was less than 100 grams; 62
percent, when the loss exceeded 100 grams.

Data on SPE diet were sufficient to permit a
further evaluation of the factors influencing the
occurrence of calcium deposits in the kidneys. In
table 16, the results of microscopic examination for
calcium are considered in relation to age, weight
loss, and nutritional status of the rat at the time of
sacrifice. Calcium was found occasionally in the
kidneys of rats losing less than 100 grams and was
frequently found in the rats losing more than 100
grams. It was observed more often in kidneys
from nonfasted rats than in those from fasted rats,
regardless of weight loss. When weight loss was
under 100 grams, 9 percent of the kidneys from
fasted rats and 32 percent from nonfasted rats

31

TaBLe 16.—Cailcium determined microscopically in kidneys of fasted and nonfasted rats losing weight at

different ages on SPE diet
Fasted Nonfasted
Weight loss and age of rats (days)
Kidney Rats with Kidney Rats with
Rats calcium calcium in Rats calcium calcium in
kidneys kidneys
Rats losing less than 100 grams: Number Score Percent Number Score Percent
Ness: then 3002 a = ee ee 4 0 0 2 0 0
BOOMO) 699" 2. a4 = ne coun ae as ee eo 12 0 0 9 aS, 33
40010400". 6 coe to ee 13 ae 8 5 .6 40
DOO TOLD OO row ees ae eee a oe 8 .6 38 1 ae A0) 100
OOO MndtoVvier?.2. 3. ee 6 0 0 2 ees, 50
Rats losing more than 100 grams:
Hest Fl aY: Rass) 0,0 So Ne Ae ET ee IO [aCe RE a NEB i | NS See am AMR Es Ne REAL 1 2. 0 100
300 40-690. Se. oe oo oe eee 7 1.4 Lys 12 3. 0 92
BOD tO 4098 oo eet a eee ne Se 10 1.6 60 15 2.0 93
DOOM O99 soos ea ee oe 12 28 50 9 2.0 78
G00sand Over: 5.22 a ee 7 at 43 5 1, 2 40

showed evidence of calcium deposits; when weight
loss was more than 100 grams, the corresponding
percentages were 53 and 83. Calcium was found
most frequently and in the greatest amounts in the
kidneys of nonfasted rats 300 to 600 days of age
that had lost more than 100 grams. Although
fibrosis was not necessarily accompanied by
calcium, calcium was observed only in kidneys
showing extensive damage with evidence of
fibrosis.

Rats FED SPM, SPB, anp SPPB piets.—
In table 17 are summarized data from the micro-
scopic examination of kidneys and livers from
rats fed diets containing milk (SPM), beef (SPB),
or peanut butter (SPPB). The results for rats
that were maintaining weight did not differ mark-

edly from those for rats that had lost less than 100
grams in weight before sacrifice, and the limited
data for these two groups of rats have been com-
bined. No separation by age was necessary
when weight loss exceeded 100 grams.

In rats maintaining or losing less than 100 grams
in weight, the chief evidence of degenerative
changes in the kidneys was the presence of hyalin
casts. On all three diets, the kidneys of rats
under 300 days of age were generally normal in
appearance. On SPB diet, little evidence of
kidney damage was observed except in rats 500
days of age or older, whereas hyalin casts were a
frequent finding in the kidneys of rats 300 to
500 days of age fed SPM or SPPB diets.

When weight loss exceeded 100 grams, kidney

TasiLe 17.—Kidney damage determined microscopically for rats maintaining or losing weight at different
ages on SPM, SPB, and SPPB diets

Weight loss, diet, and age of rats (days) Rats
Rats maintaining weight or losing less than 100
grams:
SPM: Number
Wess when 0O2. 2. SS hs SOU eee 16
BOO TO: 499 8. 3 Sa 12
DOO BndsoVer: 2s). fw Re ee 9
SPB:
bess than o002 2-222 2 eo oon ee 16
SOO0M4OvA99) 2 ol ee ee ae es 12
p00 and Over: 25.- 5 es 8
SPPB:
Less than /300 220s se ge es 19
S000 4990 ufo ee ee 21
500: and overs=- 222-5 L224 8 eee 16
Rats losing more than 100 grams:
oH 2A, Ee ee een Sree 14
ae yee 2 ee 15
EB ees a a ne te ne ae 13

Histological rating of kidney
Average
age . ‘
Hyalin Cystie /|Glomerular| Calcium

Days Score Score Score Score
217 0. 4 0 0 0
353 .8 a 32 0
577 raid .2 .2 0
206 mAb 0 Al 0
400 ae) 2 22 0
627 1,2 aD <2 0
217 3 2 Al 0
387 1,2 .6 .6 0
597 0 2 api 0
624 1.4 1,2 aiff .6
556 2.3 2.1 1.3 Beal
512 2.7 2.5 lea wo

32

damage was generally present, regardless of age.
Kidneys from rats fed SPM diet showed the least
evidence of degenerative changes. In spite of
extensive damage, calcium deposits were rarely
seen in the kidneys of rats fed SPPB diet although,
otherwise, these kidneys were similar to those
from comparable animals fed SPE diet. With
regard to calcium deposition, the kidneys from
rats fed SPB diet resembled more closely those
from rats fed SPE diet.

RATS FED OTHER EXPERIMENTAL DIptTs.—In
table 18 are summarized the results of micro-
scopic examination of the kidneys from rats fed
all of the other experimental diets. The data
were obtained chiefly from rats that were sick

or moribund. The influence of weight loss on
the extent of kidney damage was seen consist-
ently in all of the experimental series, but for
most diets the data were too limited to permit a
separation of the results on this basis. The
results reported, therefore, include all available
data, along with the average weight loss for each
group to aid in comparing the results of the
various experimental regimens.

None of the supplements investigated were able
to prevent extensive degenerative changes that
occur in the kidneys of rats fed SPE diet. How-
ever, the data summarized in table 18 do show
some trends suggesting that these supplements
may have influenced the metabolic processes

TABLE 18.—Kidney damage determined microscopically for rats fed all other diets

Strain and diet Rats
BHE rats
SPE supplemented with— Number
@holineQ0i5Y Sos eee oe ee sees 22
By 0-0F met/l00:'¢m_ =~ _ 222-22 Uf
Choline, 0.5%+ By, 0.01 mg./100 gm_________ 10
Be Ocorme. /MOOsemes2 Ue ie SE 8
Choline, 0.5%-+ Bs, 0.5 mg./100 gm__________ 8
Choline, 0.5%+ Bi, 0.01 mg./100 gm.+ Bg,
Oloemes/ OOF emis ool ea ee ee ek ee 1

Cholesterol 0:46 9, 2 ee ee eee
@holesterol#il38 Qe v2 28 fas he Ss ee
Ascorbic acid?:0:2 22 .- 2 2 228 eal ee
Ascorbic acid, 0.2%-+- cholesterol, 0.46%___--
SP 16 HVO

RM
rg
(ee)
—
i)
ied
Q.
!

1

1

1

i)

1

1

1

'

i]

1

1

1

1

'

1

i)

1

'

!

i]

1

1

1

}

'

\

1

1

'

5

'

i]
—

RM
ar)
i)
a
lor)
an)
<I
je)
'

1

'

1

1

1

1

i

1

H

1

1

1

1

1

1

1

i]

1

1

'

'
—

=

—

So

i)

1

'

i]

1

1

i}

'

!

1

1

1

1

1

1

1

1

1

1

'

1

1

1

1

1

1

1

1

i)

'

'

i)

i]

1

i]

'

i]

'

1

!

1
eb

Y97+salt mixture, 3.0% _-.-.---_---_-----
Littermates fed—
Stock

Stock changed to SPE at 250 days_________-
SPE changed to stock at 250 days__._______-

Wistar rats
Littermates fed—
BHE parents fed Wistar stock diet
Young fed—

WPNWW CONSE BPHOVUNGHONOAWMNMIIOCOGOONO

Average Histological rating of kidney
Average| weight
age loss
Hyalin | Cystic |Glomerular} Calcium
Days Grams Score Score Score Score
466 144 2.2 2.8 15 1.0
449 136 2.0 3.0. 1.9 1.3
434 113 2. 4 2.9 2.0 25
472 126 2. 0 2. 0 1.2 4
408 123 1.8 19 1.2 .6
430 139 2. 2 2.6 1.4 no
451 150 2. 2 2.8 1.2 4
406 142 1.8 2.7 1B oud
415 115 L8 2.3 ie sé
434 183 2.2 3. 2 i 7 1.6
547 76 1, 2 a2, 4 0
553 99 1.8 1.4 1,2 .5
547 120 1.8 et 11 0
546 76 1.8 mG .8 .5
519 69 ays each .6 4
638 173 1.6 1.5 12 .5
632 118 ie 1.0 .9 23
530 155 2.5 1.8 1.0 3
474 178 2.3 3.1 1.6 1.9
550 0 .6 0 0 0
535 135 1.5 2.3 1.4 .6
403 77 .6 .9 .2 1.6
428 66 2.4 1.4 1.0 .8
425 35 8 .6 4 2.0
430 5 4 0 0 0
590 195 22 2.7 3. 0 0
396 133 2.0 3. 5 1.5 1.5
686 109 2. 2 1.8 1.0 .8
577 101 2. 0 1.7 7, 3
729 106 4 3 .2 0
664 78 6 6 4 0
886 0 .8 .2 .4 .8
703 75 1, 1.0 .8 .2
500 85 2.4 2.3 1.4 .6

ATCO On

33

involved in the utilization of these diets. Cystic
damage appeared to be somewhat reduced when
vitamin B, was added to the diet, with or without
choline. Calcium ratings were particularly high
for rats fed the diets containing supplements of
ascorbic acid with or without added cholesterol.

When the level or kind of fat, or both, were varied,
the extent of the kidney damage observed was
more like that found with the semipurified diet
than with SPE diet. Damaged kidneys were
seen frequently but no marked differences were
observed in these moribund rats that could be
ascribed to the kind or level of fat. Extensive
degenerative changes, apparent from gross ex-
amination of five kidneys that were not suitable
for microscopic examination, indicate that the
lower rating for the kidneys from rats fed SP 16
HVO was without significance. When the level
of protein was increased, the results were similar
to the results with SP 8 HVO diet when differences
in weight loss before sacrifice were considered.

Microscopically, the kidneys and livers of rats
fed the diet containing 30 percent egg yolk (SPEY)
appeared similar to those from comparable rats
fed SPE diet. The damage observed in the
kidneys from rats fed the diet containing egg
white (SPEW) was less extensive than that ob-
served with SPE diet and resembled that seen in
moribund rats fed the semipurified diet. Less
extensive kidney damage occurred when the diet
contained 100 percent whole egg than when the
diet contained 25 percent egg (SPE), paralleling
the longer survival of rats fed E100 diet.

The microscopic appearance of the kidneys
from rats fed 100 percent ege yolk differed sig-
nificantly from that observed with the other diets
containing whole egg or egg fractions. Cystic or
glomerular damage was small; calcium deposits
were heavy, even in rats showing relatively small
weight loss, and were not necessarily associated
with extensive cystic damage or fibrosis. Most
of the rats fed 100 percent egg yolk were sacrificed
before weight loss exceeded 100 grams, but there
was no evidence of a marked increase in cystic
or glomerular damage with increasing weight loss.
The results from microscopic examination of
tissues from rats fed diets consisting solely of
whole egg or containing high levels of egg yolk
or egg white contrast with those for rats fed 25
percent egg (SPE), and provide further evidence
that ingredients in the SPE diet other than egg
must be contributing to the acceleration of the
degenerative changes that occur on this diet.

Further evidence of this was obtained from a
eroup of 15 rats, 5 fed SPE diet, 5 fed 100 percent
egg yolk, and 5 fed 97 percent egg yolk supple-
mented with 3 percent salt mixture. The rats
were scheduled for sacrifice at 450 days of age.
When a rat on any one of the three diets became
moribund and was sacrificed before 450 days, the
corresponding littermates fed the other diets were
sacrificed at the same time. Two of the rats fed
SPE diet became moribund at 396 and 398 days

34

of age, and 1 rat fed 100 percent egg yolk was
losing weight before reaching 450 days of age.
The 5 rats fed egg yolk supplemented with the
salt mixture appeared healthy at the time they
were sacrificed. The histological findings for the
kidneys from these rats suggest that the shortened
lifespan of rats fed a diet contaiming 100 percent
eg yolk was due, in part at least, to a mineral
imbalance and was not accompanied by marked
degenerative changes such as were seen in the
kidneys of rats fed SPE diet. The kidneys of rats
fed the egg yolk diet supplemented with 3 percent
of a salt mixture containing the mineral elements
considered essential were generally normal in
appearance and showed no evidence of calcium
deposition.

In table 18 are also included the results of
microscopic examination of tissues from rats that
were changed after 250 days from stock to SPE
diet or the reverse. The kidneys from rats that
were maintained throughout life on stock or SPE
diet were typical of those already discussed for
these diets, with the high glomerular damage in
the kidneys from rats fed the stock diet and high
cystic damage and heavy calcium deposits in those
from rats fed SPE diet. When the diet was
reversed, kidney damage was less extensive with
both diets, and these animals lived Jonger than
did the other littermates that were continued on
either stock or SPE diet.

INFLUENCE OF HEREDITY.—Wistar rats were
much less susceptible to kidney damage than were
the BHE strain. Of the nine kidneys examined
from rats fed SP 8 HVO diet, only one from a rat
848 days old was badly damaged; on SPE diet,
two of the nine kidneys showed marked degenera-
tive changes, one from a rat 397 days old and one
from a rat 846 days old. No calcium deposits
were seen on either of these diets, and the marked
difference in the response of BHE rats to SP 8
HVO and SPE diets was not apparent with Wistar
rats. The differences in the response of these two
strains of rats did not appear to be due to the
dietary history of the parent rats. A similar
difference in the response of BHE rats to SP 8
HVO or SPE diets was observed whether the
parents were raised on the usual stock diet or on
the diet that was used to raise the Wistar stock
rats.

Discusston.—A tendency for chronic nephritis
to occur in the older rat has been observed by
many investigators. The extent of the kidney
damage found was generally less than that re-
ported in this publication for BHE rats. Results
reported elsewhere have dealt chiefly with the
occurrence of nephritis in older rats without re-
gard to diet. Saxton and Kimball (168) found
chronic nephrosis in 44 percent of the kidneys from
rats dying naturally, and considered that this condi-
tion occurred spontaneously in the albino rat. De-
generative changes in the kidneys were rarely seen
in young rats, and the incidence of kidney damage
increased with age up to 800 days. There was a

tendency to fewer damaged kidneys in animals
surviving more than 800 days of age. When
erowth was retarded throughout life, nephrosis was
almost nonexistent.

Berg and Harmison (20) and Simms and Berg
(172), investigating a stock colony from which
respiratory infections had practically been elimi-
nated, reported that chronic nephrosis, the
commonest pathological condition observed, was
present in 80 percent of the animals by 700 days.
Kennedy (102) also observed severe renal damage
in rats surviving 2 years or longer with little
evidence of renal abnormalities before they reached
an age of 21 months. Renal damage appeared
earlier, between 12 and 15 months, in obese rats.
Overfeeding or unilateral nephrectomy resulted
in the premature appearance of a type of kidney
lesion common to senile rats. Andrew and Pruett
(10) compared normal kidneys of rats in age groups
300 days and younger with kidneys from rats over
800 days of age. The greatest differences ob-
served were in the tubules rather than in the
glomeruli. Blatherwick and Medlar (30) pre-
sented evidence that functional impairment of
the kidney may exist for some time before
histologic changes indicative of nephritis become
apparent. Gover (77) reported differences in the
type of renal lesions observed in three strains of
mice.

Dietary studies in relation to kidney damage
have dealt chiefly with the influence of protein
level and have yielded somewhat controversial
results. Bischoff (29) reviewed the results of the
early investigations in this field. Casein has been
studied most frequently in experiments dealing
with high levels of dietary protein. There seems
to be considerable evidence that rats under many
conditions can consume relatively high levels of
casein for the greater part of the normal lifespan
without suffering renal lesions characteristic of
nephritis. Saxton and Kimball (168), however,
observed chronic nephrosis more often in animals
receiving casein than in those receiving liver.
Nephrosis was frequently greater in rats that re-
ceived diets high in protein than in those on low
protein diets. Although chronic nephrosis was
more common in animals on high levels of protein
there appeared to be no correlation of lifespan
with the level of dietary protein.

A few reports have also dealt with the possible
role of magnesium in the production of renal dam-
age. <A diet containing cholesterol and cholic acid
and producing atherosclerosis in the rat increases
markedly the magnesium requirement of the ani-
mal (187). Vitale, Hellerstein, Hegsted, and
others (186), in reviewing the present knowledge
of the interrelationship between dietary magne-
sium and calcium in atherosclerosis and renal le-
sions, reported that additional magnesium decreases
or eliminates calcium deposition in the kidney,
regardless of other variables.

SumMary.—Gross examinations of the tissues
at the time of necropsy indicated that the kidney

721-631—64——_4

was the organ most frequently abnormal. Kidney
damage was observed in rats showing no obvious
signs of ill health as well as in sick animals, but
the extent of the damage was considerably greater
in the moribund rats.

Microscopic examination revealed three types
of kidney damage. The most prevalent finding
was the presence of eosinophilic albuminous mate-
rial or hyalin casts in dilated tubules. As evidence
of degenerative changes increased, glomerular
damage became apparent, and in the large, exces-
sively damaged kidneys, extreme dilation of the
tubules resembling cystic degeneration was ob-
served. Calcium deposits were found chiefly in
the kidneys of moribund rats and were rarely seen
except in kidneys showing extensive damage.

The BHE strain of rats seemed to be particularly
susceptible to kidney damage regardless of the diet,
and the results suggest that several factors may
accelerate an inherent weakness in this strain of
rats. Some diets obviously hastened the onset of
lesions and appeared to influence the type and
extent of the degenerative changes observed. The
levels of protein in the stock and experimental
diets were moderate and were similar except for
those diets consisting of 100 percent whole egg or
ege yolk. Level of protein, therefore, does not
explain the excessive kidney damage observed with
rats fed SPE or SPPB diets. Level of dietary fat
also provides no explanation for the results
observed.

The tendency for kidney damage to be less
when the diet consisted solely of whole egg or egg
yolk supplemented with a mineral mixture than
when it contained 25 percent whole egg indicates
that the undesirable effect of this latter diet was
due to the interaction of the various dietary
ingredients rather than to egg alone. The results
with the mineral-supplemented egg-yolk diet
suggest the possibility of a mineral imbalance.

The enlarged and damaged kidneys observed
in some extremely heavy animals, particularly
those fed the diet containing peanut butter, may
be due to an acceleration of degenerative changes
in the kidneys, associated with the stress of
obesity.

The results provide no answer as to why calcium
deposits were present with certain diets but were
absent in equally damaged kidneys from rats fed
other experimental diets. The diets were designed
to supply the animal with adequate amounts of
vitamins and minerals, but the possibility that
certain dietary stresses may increase the need for
some of these nutrients has not been excluded.

Wistar rats proved much less susceptible to
kidney damage than did BHE rats and responded
very differently to the diet containing 25 percent
egg. These results provide further evidence of
the importance of considering inherent charac-
teristics of the strain of animal under investiga-
tion when interpreting the results of nutritional
investigations, and of the need for further research
to discover the biochemical mechanisms involved.

35

Histology of liver

Stock, SP 8 HVO, anp SPE pirets.—Micro-
scopic examination of the livers from 115 rats fed
the stock diet showed very little pathology. Peri-
ductal infiltration and edema were noted occa-
sionally in the older animals. Only one of the
livers examined showed the presence of fat
vacuoles.

The results from examination of 98 livers from
rats fed the SP 8 HVO diet in general were similar
to those for rats fed the stock diet except for the
occasional appearance of small amounts of fat.
Of these livers, 14 showed microscopic evidence
of fat, and 10 of the 14 were from moribund rats
that were more than 600 days old. In no case
were the livers excessively fatty.

In contrast to the results with rats fed stock
or SP 8 HVO diet, microscopic examination indi-
cated that most of the livers from rats fed SPE
diet were fatty. In table 19 are summarized the
results from the histological ratings for fat of 202
livers from rats fed SPE diet. Relatively high
ratings for fat were obtained for livers from rats,
regardless of age, that were maintaining their
weight at the time of sacrifice. In rats over 500
days of age, the score for large vacuoles as well as
for small vacuoles was high. Only 7 of the 58
rats over 200 days of age had livers showing no
evidence of fat. Fat was also seen in two of the
five livers from young nonfasted rats approxi-
mately 150 days old. The presence of glycogen
in livers from nonfasted rats as well as protein
that may be lost during fasting was responsible

for the somewhat lower rating for fat in the livers
of nonfasted rats 200 to 400 days old. There was
a tendency for the scores for liver fat to be lower
for moribund rats, particularly for animals losing
more than 100 grams in weight. No evidence of
fat was observed in livers from 27 of the 78 rats in
this latter group.

SPM, SPB, anp SPPB pints.—The results
from microscopic examination of the livers for fat
in rats fed SPM, SPB, and SPPB diets are sum-
marized in table 20. Excessively fatty livers were
rarely seen with any of these three diets. On
SPM diet, fat was observed most frequently in the
older rats; the larger amounts were seen in the
livers of moribund rats over 700 days old and
losing more than 100 grams. On SPB diet, rela-
tively little fat was apparent regardless of the age
or general health of the rat. On SPPB diet,
small amounts of fat were generally observed in
rats over 400 days of age that were maintaining
weight but, in contrast to the results with SPM
diet, fat was not detected in the livers of the older
moribund rats that were losing over 100 grams.

ALL OTHER DIETS.—In table 21 are summarized
the results of microscopic examination of the livers
from rats, chiefly sick or moribund, fed all of the
other experimental diets. None of the supple-
ments added to SPE diet were able to prevent the
tendency to fatty livers with this diet. Although
interpretation of data on liver fats in moribund
rats is complicated by variable weight losses, there
appears to be evidence for exceedingly fatty livers
in rats fed SPE diet to which cholesterol was

TABLE 19.—Liver fat determined microscopically for fasted and nonfasted rats maintaining or losing weight
at different ages on SPE diet

Fasted Nonfasted
Weight status and age Histological Livers with— Histological Livers with—
of rats (days) Rats rating Rats rating
Small Large Small Large Small Large Small Large
vacuoles|vacuoles|vacuoles|vacuoles vacuoles |vacuoles |vacuoles |vacuoles
Rats maintaining
weight: Number | Score Score Percent | Percent | Number | Score Score Percent | Percent
Tess than, 200 <.-s-epem| Be NE a ene se a a 5 . 6 0. 2 40 20
200: tO 299 so Se 8 7 2.3 0.3 86 29 16 1.8 4 88 44
300 to 399__________ 8 ao) .9 100 87 4 1.2 .8 100 75
400 to 499__________ 14 2.1 9 79 OTe 9 | teehee ee | ae a eee | ee | ee
500 and over________ 9 2.4 221 89 MOO eS | ee ae | Se ee | | ea
Rats losing less than
100 grams:
200 to 299__________ 4 1.0 0 50. 0 2 leas 0 50 0
300 to 899__________ £2 1.4 .8 58 58 8 2. 4 1.0 88 75
400 to 499__________ gs) 1.4 i sg) 62 92 5 2. 0 1.0 80 80
500 and over_______- 14 15) 1.6 vA 93 3 1.3 EAL) 67 100
Rats losing more than |
100 grams:
v1 21! |: a an oS Meme e DOS IeeTeN, SNE cn f 1 0 0 0 0
300 to 399__________ vA ies .9 71 Di 12 e233 .7 17 67
400 to 499__________ 10 .9 1.4 50 90 15 .&9 .8 40 60
500 and over________ 19 | 9 na 47 63 14 nO 1.0 36 aff

36

TaBLE 20.—Liver fat determined microscopically for rats fed SPM, SPB, and SPPB diets

Histological rating
Average of liver fat
Weight status, diet, and age of rats (days) Rats | Average| weight a
age loss
Small Large
vacuoles | vacuoles
Rats maintaining weight:

SPM: Number | Days Grams Score Score
essathane4 QQ ese e eee Bo eee eee ee RR ee 16 240 0 RAZ 0.1
ADORCORS 9 Obes Ae ene Due eee Fe et De ee 5 497 0 “6 12

PB:
essythanv40Qz22 2 au Us ta) 55) eS Wea So be ee 16 241 0 0 al
ANDY) Hay a9 9 fe a a Cede 8 Co ee ee 6 489 0 0 .5

SPPB:

Weesstthank4 0QBEe a) tees be eee Mae ee Fe 15 232 0 0 0
AD OELORS 9 Obras ean Mew oe I ee oe eo 9 516 0 .8 9
Rats losing less than 100 grams:

SHV [pe aaa stan tee ae SRE eee lace SS Ar te eet. St 17 449 47 Bell .1

DB eiieetterwe eS DU ee Oe ee hikes 2 SL ele ek oe 15 446 51 0 wl

RSH BADD Bits 22 lo ety ap A ne ap pe 29 429 52 .3 3

Rats losing more than 100 grams:

SPAN [tei chur see ee eM 2 ee MN ed ae et 14 624 175 ran) .8

SER Gree setey Ae aS eS OMe VA Ne Boon pee il 572 175 sil ail

HSH eo 27) 10 a a a a A 2 13 502 177 0 0

added. There was no evidence that the presence
of fat droplets in the liver was related to the kind
or level of fat in the diet. There was a tendency
to fatty livers with all of the diets containing
whole egg or egg yolk, although the livers of rats
consuming 100 percent egg appeared to contain
less fat than those of rats fed the diet containing
25 percent egg (SPE). Although the addition of
salt mixture to diet Y100 seemed to prevent the
occurrence of extensive kidney damage, the liver
fat of the animals fed this diet, with or without
the mineral supplement, seemed to be similar.
Relatively little fat was apparent microscopically
in the livers of rats changed from stock to SPE
diet at 250 days; when the reverse procedure was
used (SPE to stock at 250 days), liver fat re-
sembled that seen in animals continued on SPE
diet throughout life.

Although there was a tendency for more fat in
the livers of Wistar rats fed SPE diet than for
this same strain of rat fed SP 8 HVO diet, the
amount of fat appeared to be less than that
generally found in BHE rats fed SPE diet.

Quantitative data concerning fat in the liver as
influenced by diet and age are provided by chemi-
cal analyses and are reported in a later section of
this publication in which the problem of liver fat
is considered in greater detail.

Kidney and liver weight

KIDNEY WEIGHT OF ANIMALS MAINTAINING
WEIGHT ON stock, SP 8 HVO, anp SPE pigts.—
In table 22 are summarized for different age
groups the weight of the kidneys from rats that
were consuming stock, SP 8 HVO, or SPE diets
and that were maintaining weight at the time of
sacrifice. Included are data comparing the weights

of kidneys from rats that were fasted for 17 hours
and bled by cardiac puncture,. with those from
rats that were neither fasted nor bled at the time
of sacrifice.

On stock diet, kidney size of fasted rats appar-
ently varied little with age. The average kidney
weight of 1.56 grams represented 0.36 percent of
the body weight. The largest kidney obtained
weighed 2.10 grams, and only 3 of the 38 rats had
kidneys exceeding 2.0 grams in weight. The re-
lation between kidney and body weight was rela-
tively constant for all age groups. In contrast,
kidneys from nonfasted rats tended to increase in
size with age and to represent an increase in rela-
tion to body weight from 0.36 percent in young
rats to 0.47 percent in rats over 600 days old. The
kidneys from these rats tended to be larger than
those from fasted rats of comparable age, exceed-
ing 2.0 grams in 9 of the 11 rats that were over
600 days old.

On the semipurified diet, the kidneys from 200-
to 499-day-old fasted rats were similar in weight
to those from rats fed the stock diet but were some-
what larger in the older rats. Kidneys exceeding
2.0 grams in weight were obtained from 35 percent
of the rats that were between 500 and 600 days
old. In relation to body weight, the kidneys were
significantly smaller (P < 0.01) than those from
rats fed the stock diet. Data for nonfasted rats
fed SP 8 HVO diet were limited to animals less
than 400 days old, but kidneys tended to be large
even in these young rats. Kidney weights for rats
300 to 399 days old were similar to those for rats
under 200 days old, in spite of the increase in body
weight of approximately 100 grams.

On SPE diet, the kidneys of fasted rats tended
to be larger than those from comparable stock or

37

TABLE 21.—Liver fat determined microscopically for rats fed other experimental diets

Strain and diet

SPE supplemented with—

Choline 05S pec. 6 320. ee eee eee
Boe O.Oleme: lOO" sin 2-22 Wace. 2 aee es 2 eee

ig Ozone: COOKS ea aoe ee as Ue ee ana
Choline, 0.5%-+ Bg, 0.5 mg./100 gm__-__-__.-__________-_
Choline, 0.5%-+ Bis, 0.01 mg./100 gm.+ Bg, 0.5 mg./100
Cholesterol, 0. 6% ppl ee ES Eee Rey i ee SS
@nolesterel, 38% 7e ses cro ol a ee

T
Ascorbic acid, 0.2%
0

Ascorbie acid,

62510) 0 ae ieee Seana re Ee oe EE eo eee ee

Y¥9/7--salt mixtute;310-%.< 22-22-22 ee

Littermates fed—

Stock changed to SPE at 250 days_________________-
SPE changed to stock at 250 days___________________

Wistar rats
Littermates fed—

SESE ViOs Se. oe cet a So es et ee
E

BHE parents fed Wistar stock diet
Young fed—

9
2%-+ cholesterol, 0.46%-------_--__-
DR UGA O25 Soe ae ae na ea AD een ns

Histological rating of
Average liver fat
Rats | Average| weight
age loss
Small Large
vacuoles | vacuoles

Number | Days Grams Score Score
Bee 22 466 144 ab 0. 5
ee 7 449 136 JA .6
Ear 10 434 113 4 .6
ees ae 8 472 126 fe .9
eee 8 408 123 .8 70
mie 10 430 139 12 .9
ae ase 8 451 150 1 2.
eee 9 406 142 1.6 2.1
aera 3 9 415 115 .6 .8
meee 9 434 183 v4 1.0

ee eed! 5 547 76 ) 0
eae 15 553 99 fal 23

ae ee 8 547 120 val 0
Seen 6 546 76 an ao
Seer 9 519 69 0 oi
eee cee 17 698 173 .2 155
eer 9 632 118 2 a6
aoe 6 530 155 a2 0. 5
meee 7 474 178 .9 1.23
ee 5 550 0 2 4
Ute s2 20 535 135 ey .8
Sener 16 403 vars .8 2
Se 5 428 66 Te, .4
Se eee 5 425 35 10 .8
[ae ee 5 430 5 1,2 «8

Geer eer 3 590 195 0 0
Reet es ate 3 473 104 (0) pede
ae 4 686 109 1.0 10
ee 3 577 101 0 a5)

ee ae 9 729 106 1 0
eens 9 664 78 4 vi

eee 5 886 0 0 0
ee 9 703 75 2 2
ee if 560 85 14 1.4

SP 8 HVO rats. More than 50 percent of the
kidneys from rats over 300 days of age exceeded
2.0 grams in weight. In nonfasted animals fed
this diet, kidneys tended to increase in size with
age. Two of the rats 300 to 399 days old had
kidneys weighing 8.9 grams.

LIVER WEIGHT OF ANIMALS MAINTAINING WEIGHT
ON stock, SP 8 HVO, anp SPE pizers.—In table
23 are summarized comparable data for the livers
from rats fed stock, SP 8 HVO, or SPE diets. On
the stock diet, there was no indication that age
influenced appreciably the size of the livers from
fasted rats. The average liver weight for these 37
rats was 11.1 grams, representing 2.6 percent of
body weight.

The livers from nonfasted rats tended to increase
in size with age, representing 3.4 percent of body

38

weight in rats less than 200 days old and 3.9
percent in rats 600 days of age and older. The
livers from these nonfasted rats were heavier than
those from the fasted rats, and the extent of the
differences in the weights of this organ between
these two groups of rats depended upon age.
Livers from nonfasted rats less than 300 days
old were approximately 30 percent heavier than
those from fasted rats of comparable age. In
rats over 500 days old, the difference amounted to
approximately 60 percent. The range of values
for liver weights of the nonfasted rats was wide,
even within age groups, with an extremely wide
range of values for rats exceeding 300 days of age.
The results for the distribution seen in table 238,
however, show that the increase in liver size of
nonfasted rats with age was due to the increase in

TABLE 22.—Kidney weights in fasted and nonfasted rats maintaining weight at different ages on stock, SP
& HVO, and SPE diets

Kidney weight Rats with kidneys weighing—
Average
Condition, diet, and Average! weight Kidney
age (days) Rats age at to body | Less | 1.50 to} 2.00 to] 3.00
death ! | Average Range weight | than 1.99 2.99 and
1.50 | grams | grams | over
grams
Fasted rats
Sto Number | Days Grams | Grams Grams Percent | Percent| Percent | Percent | Percent
Less than 200______- 4 160 381 1, 34 1. 12-1. 50 0. 35 165) 25 0 0
200 to 299_________- 15 248 447 1. 58 1. 13-1. 92 . 89 20 73 0 0
300 to 399-22 __-- 6 382 428 1. 58 1. 17-2. 02 . 36 33 50 17 0
400 to 499__________ 5 436 436 1. 54 1. 32-1. 82 . 34 60 40 0 0
500 and over________ 8 727 410 1. 66 1. 21-2. 10 mon 25 62 12 0
SP 8 HVO:
200:t0;299 32 2. 6 252 502 1. 41 1. 24-1. 74 . 28 83 LZ 0 0
300 to 899_________- 8 353 541 1. 57 1, 23-2. 39 . 29 50 38 2 0
400 to 499__________ 7 457 600 1. 63 1. 19-2. 59 . 26 57 29 14 0
500 to 599_________- 14 546 680 yan Wf 1, 43-5. 24 . 82 14 57 29 7
PE:
2007105299258 o df 252 552 1. 69 1. 46-1. 81 .3l 14 86 0 0
3800:t0-399- eee | 8 348 588 2. 44 1. 60-3. 99 . 41 0 38 50 12
400 to 499__________ 14 455 616 2. 29 1. 47-4. 50 Ot 14 36 29 21
500 to 599__________ 11 530 624 2. 34 1. 76-3. 82 36 0 36 54 9
Nonfasted rats
Stock: :
Less than 200______- 15 148 390 1. 41 . 98-1. 86 . 36 73 27 0 0
200° t0:2992> 2-8 == 11 258 466 1. 67 1. 38-2. 01 . 36 27 54 18 0
300 to 399__________ 5 376 482 2.01 1. 34-2. 96 .4l 20 40 40 0
400 to 499__________ 7 465 486 1, 87 1. 07-2. 70 . 88 14 57 29 0
500 to 599__________ 11 538 490 2.15 1. 41-3. 61 . 43 9 54 27 9
600 and over________ 11 679 457 2. 23 1. 45-2. 93 47 9 9 §2 0
SP 8 HVO:
Less than 200______- 5 154 521 2. 08 1. 79-2. 54 . 40 0 60 40 0
200; tOrZ99e Sem ies ae 6 248 532 2. 02 1. 43-3. 32 Sol 17 50 Ale 17
300 to 399__________ 23 332 636 1. 88 1. 41-2. 71 . 80 13 61 26 0
PE:
Less than 200_______ 5 154 520 1. 92 1. 76-2. 17 Nan 0 60 40 0
2005¢0:299 os 18 27. 613 2; 22 1. 49-4. 19 . 37 6 22 67 6
3000 B99n eee 29 330 614 3. 01 1. 69-8. 88 .49 0 38 38 24

1 Weight before 17-hour fast.

the percentage of rats with large livers and not to
an occasional excessively heavy liver.

The increasing difference with age between both
the kidney and the liver weight of fasted and
nonfasted animals suggests that a slowing of the
metabolic processes has occurred in the older rats,
resulting in a temporary enlargement of these
organs, which can still return to normal after a
17-hour fast.

In fasted rats fed SP 8 HVO diet, livers showed
a consistent tendency to increase in size with age,
in contrast to the relatively constant values ob-
served for the weights of livers from comparable
stock rats. The livers represented 2.1 percent of
body weight, with no apparent influence of age
on this relationship. The increase in liver size
with age, therefore, seems to be due chiefly to the
tendency for adult rats fed SP 8 HVO diet to
continue gaining in body weight with age.
Although the livers from these animals weighed

more, on the average, than those from stock rats,
they were significantly smaller in relation to body
weight (P<0.01). There was no evidence that
age was a factor within the limited range for which
data were available.

Livers from nonfasted rats averaged 20.3 grams
in weight, 8 grams heavier than those from fasted
rats of corresponding age. In nonfasted rats
fed this diet, large livers were observed even in
rats less than 200 days old. In contrast to the
stock rats, the livers from these nonfasted SP 8
HVO rats tended to represent a smaller percentage
of the body weight with increasing age, 4.5
percent for rats under 200 days, and 3.1 percent
for those between 300 and 400 days of age.

On SPE diet, the livers from fasted rats were
larger than those from rats fed stock or SP 8 HVO
diets, averaging 21.0 grams in weight and 3.4 per-
cent of body weight. The range of values was
wide, from 12.8 grams for the smallest liver to 31.8

39

TABLE 23.—Liver weights in fasted and nonfasted rats maintaining weight at different ages on stock, SP 8
HVO, and SPE diets

Liver weight Rats with livers weighing—
Average
Condition, diet, and Average| weight Liver to
age (days) Rats age at body Less | 10.0 to] 15.0 to| 20. 0
death ! | Average Range weight | than 14.9 19.9 | grams
10.0 | grams | grams} and
grams over
Fasted rats
Stock: Number | Days Grams | Grams Grams Percent | Percent|Percent| Percent| Percent
Less than 200_-_--_--- 4 160 381 9. 6 8. 3-10. 2 2. 5 50 50 0 0
200 to 299.255 22° 15 248 447 115 8. 3-14. 3 226 20 80 0 0
300 to 399___-_-__--_ 6 382 428 V7 8. 6-16. 1 2.6 33 50 17 0
400 to 499__.-_______ 5 436 436 11. 2 9. 1-12. 2 2.5 20 80 0 i)
500 and over-.===2-.- 7 723 405 10. 7 8. 7-13. 6 2.4 43 57 0 )
SP 8 HVO:
200) t0 299 28 222 6 252 502 L110 9. 1-13. 9 2,2 33 67 0 0
300 to 399___..-_-_-- 8 353 541 12.0 9. 6-14. 1 202 12 88 0 0
400 to 499__________- r 457 600 13. 4 10. 1-18. 2 2. 2 0 ff 29 0
Pais GOVO99 2 eee 14 546 680 14.3 10. 8-17. 9 2.1 0 71 29 0
BOOMtOrA GO emt cs as 7 252 552 18. 2 12-8-24. 3 3.3 0 14 [al 14
300 to 399___-_-_---- 8 348 588 23. 6 18. 2-30. 1 3. 9 0 0 12 88
400 to 499___________ 14 455 616 21. 7 14. 3-31. 8 3.5 0 uh 29 64
500'(0:599-. 226222 1 530 624 20. 0 13. 5-26. 6 3. 1 0 9 46 46
Nonfasted rats
Stock:
Less than 200____---- 15 148 390 13. 3 9. 4-15. 8 3. 4 87 13 0 0
200 t0:299 2 a eae 11 258 466 15.1 12. 0-17. 8 3.2 46 54 0 0
300 to 399___-_______ 5 376 482 16.8 14, 2-21. 7 3. 4 20 60 20 0
400 to 499___________ 6 465 486 a eas 14. 4-25. 9 3. 6 29 57 14 0
D000 599. = a al 538 490 18. 6 13. 0-26. 9 3. 7 18 46 36 0
600 and over__-_---- 11 679 457 18.7 11. 7-21. 7 3.9 9 54 36 0
SP 8 HVO:
Less than 200___----- 5 154 521 23.0 21. 2-30. 7 4.5 0 0 80 20
200 to 2992. 6 248 532 18. 7 14. 3-27. 2 3. 5 17 50 33 0
. 300 to 399___-______- 23 332 636 20. 0 14. 6-26. 3 3. 1 9 39 52 0
Less than 200_.__---- 5 154 520 22. 7 19, 2-27. 1 4.3 0 20 80 0
200 to:2992. 2 2k 18 277 613 28. 4 21. 8-36. 4 4.6 0 0 72 28
300 to 399___-.__-_-- 25 331 GL7 29. 9 20. 0-48. 1 4.8 0 0 60 40

1 Weight before 17-hour fast.

grams for the largest. No consistent trend with
age was noted except for the larger percentage of
rats less than 300 days old with livers weighing
less than 20 grams.

The livers from nonfasted rats fed SPE diet
averaged 28.6 grams in weight and represented 4.7
percent of body weight. For rats less than 200
days old, livers were large in comparison to those
from rats fed the stock diet but similar in size to
those from comparable SP 8 HVO rats. The
largest livers obtained with stock, SP 8 HVO, or
SPE rats were from nonfasted SPE rats 200 to 399
days old.

CoRRELATION COEFFICIENTS.—The data in ta-
bles 22 and 23 show that the factors affecting
kidney weight generally exert a parallel influence
on liver weight. In figure 8 are seen the lines ob-
tained from the regression equation expressing the
relationship between kidney and liver weights of
fasted and nonfasted rats fed stock diet as well as

40

the data for individual rats. Food intake imme-
diately before sacrifice was not controlled for the
nonfasted rats and undoubtedly accounts, in part
at least, for the greater variation in the relationship
observed for these rats.

For any one diet, liver and kidney weights
tended to parallel body weight, and variations in
body weight within age groups seemed to account
in part for the wide range of values observed in the
weight of these organs. Consideration of the indi-
vidual data, however, indicated that the close
parallelism between liver and kidney weights was
not due entirely to the relation of the weight of
these organs to body weight. In table 24 are sum-
marized, for rats fed stock and SP 8 HVO diets,
data relating liver to kidney weight and these
organs to body weight. Correlation coefficients of
0.84 to 0.88 were obtained relating liver and kidney
weights of fasted and of nonfasted rats fed these
two diets. Correlation coefficients relating liver

KIDNEY WEIGHT

Fasted
Regression equation:
y=0.29+0.113x

0 4 8 12

Nonfasted
o Regression equation:

y=0.052+0.109x

16 20 24 26

LIVER WEIGHT (grams)

Fieure 8.—Liver weight in relation to kidney weight in fasted and nonfasted rats fed stock diet.

or kidney weight to body weight tended to be
lower than those for liver and kidney, although for
fasted rats the differences observed were generally
small. The lowest correlation coefficients were
those relating liver or kidney to body weight in
nonfasted rats fed the semipurified diet.

There was little evidence for a quantitative rela-
tionship between liver and kidney weights or be-
tween these organs and body weight in rats fed
SPE diet. Even in fasted rats, ratios for liver to
kidney weight varied from 3.4 to 15.5.

KIDNEY WEIGHT OF ANIMALS LOSING WEIGHT
on stock, SP 8 HVO, anv SPE piets.—In table
25 are summarized data on the kidney weights of
fasted and nonfasted rats that were fed stock, SP 8
HVO, or SPE diets and were losng weight when
sacrificed. The results for rats Josing less than
100 grams have been separated from those for
rats losing over 100 grams in weight.

When weight loss was less than 100 grams,
the kidneys from fasted rats fed stock or SP 8
HVO diets were similar in size to those from rats
of comparable age that were maintaining weight
on these diets. On SPE diet, however, large
kidneys were observed even in young rats, and in
animals 400 to 599 days old 68 percent of the
kidneys weighed more than 4 grams. When weight
loss exceeded 100 grams, the kidneys from fasted
rats tended to be larger with all three diets than
did those from comparable animals with little or

no weight loss. The largest kidneys were from
rats fed SPE diet.

The tendency of the nonfasted rats to have
larger kidneys than the fasted animals was
apparent among those that were losing weight,
as well as among those maintaining weight,
although the differences were small for older SPE
rats when exceedingly large kidneys were found.
In nonfasted rats losing more than 100 grams,
kidneys were large at all ages regardless of diet;
kidneys from SPE rats tended to be larger than
those from animals fed stock or SP 8 HVO diets.

LIVER WEIGHT OF ANIMALS LOSING WEIGHT ON
stock, SP 8 HVO, anp SPE pints.—In table 26
are summarized data for the liver weights of rats
that were losing weight on stock, SP 8 HVO, or
SPE diets. In general, the results for rats losing
less than 100 grams were similar to those for
comparable rats that were maintaining weight
except for the tendency to smaller livers in young
nonfasted rats fed SP 8 HVO diet. When weight
loss exceeded 100 grams, the difference between
the liver weights of fasted and nonfasted rats
became small, reflecting the reduced food intake
of these animals. The livers from SPE rats were
consistently larger than those from rats fed stock
or SP 8 HVO diets. The marked increase in
kidney weight that has been seen to occur with
increasing Joss in body weight was not accom-
panied by a parallel increase in liver weight.

41

TABLE 24.—Correlation of liver, kidney, and body weights in fasted and nonfasted rats fed stock and SP 8

Condition and diet

Fasted rats:

HVO diets
Liver to kidney weight
Rats

Ratio Correlation
coefficient

Number
37 7.2 0. 88
34 7.6 . 85
59 8.9 . 85
33 10. 7 . 84

Liver to body weight

Kidney to body weight

Percent Correlation Percent Correlation
coefficient coefficient

2:5 Oeil 0. 35 0. 72

201 . 80 . 28 . 60

BRD 74 . 40 60

3. 4 49 Rol 45

TaBLE 25.—Kidney weights in fasted and nonfasted rats losing weight at different ages on stock, SP 8 HVO,

and SPE diets

Weight loss, condition,
diet, and age (days)

500 ay over be opts
SP 8H
Less hee DOO s.2'2.- 38
500 and over____------
SPE:
Less than 400______---
400 to 599_______----
600 and over_______---
Nonfasted:
Stock:
Less than 500___-___--
500 and over__--------
SP 8 HVO:
Less than 500_--------
500 and over____------
SPE:
Less than 400_-_..----
400 to 599_________----
600 and overszoce.-.
Rats losing more than 100
grams:
Fasted:
Stock:

Less: than. 500.2222. -s2lewooscse

SPE:
Less than 400___-_-_- aes
400 to 599___________-_-
600 and over____------
Nonfasted:
Stock:
Less than 500___-___--
oe and over..--------
SP 8 HVO:
Less than 500__-_-____-
500 and over____-_----
SPE:

Less than 400.- 2222.
AQO' to 599.2 2222.c0.-
600 and over______-_--

Rats

Kidney weight

Average
age

Average Range

Days Grams Grams
718 1,89 | 1.62— 2
295 1. 30 8i- 1.
644 1. 84 | 1. 46— 2.
296 2.18 85- 7.
489 5. 73 | 1. 85-11.
643 3. 38 | 1. 79- 6.
456 ul 1:
787 2.72 | 2. 17— 3.
375 1.79 | 1. 33- 2.
645 3.28 | 1. 81- 6.
316 4.36 | 1. 51-13
498 5. 30 | 1. 78-12
608 8. 60 | 5. 78, 11
682 2.74 | 2. 09- 3
419 4.90 | 1. 53- 8
654 2.92 | 1. 86- 4
376 7. 74 | 3. 56-13.
504 6. 93 | 3. 37-11
644 4.98 | 2. 79- 7
411 4.50 | 2. 69- 8
695 3. 35 | 1. 65— 5.
426 3.35 | 2.17, 4
685 3. 81 | 1. 27- 7.
339 8.13 | 4. 80-12
486 7.14 | 3. 06-12
643 6. 32 | 3. 50- 8

Rats with

Less 1.50 to
than 1.50} 1.99

grams grams
Percent | Percent
54 0 v1
71 véai 29
59 10 60
79 37 32
2 0 9
22 0 17
48 100 0
70 0 0
21 20 50
32 0 25
3 0 18
4 0 14
0 0
95 0 0
OL 0 33
49 0 50
2 (0) 0
6 0 0
O07 0 0
. 05 0 0
98 0 29
. 53 0 0
. 80 i 19
0 0
0 0
elod: 0 0

kidneys weighing—

2.00 to | 3.00 to More

2.99 3.99 |than 4.00
grams | grams | grams
Percent | Percent | Percent

~ 4 29; #+#O| Oo

0 0 0

30 0 0

21 0 11

18 5 68

50 17 17

0 0 0

62 38 0

30 0 0

25 25 25

36 18 2h

14 29 43

0 0 100

<5 25 0

0 0 67

0 25 25

0 14 86

0 5 95

14 0 86

50 0 50

0 43 29

50 0 50

19 19 38

0 0 100

0 LS 85

0 20 80

42

TABLE 26.—Liver weights in fasted and nonfasted rats losing weight at different ages on stock, SP 8 HVO,

and SPE diets
Liver weight Rats with livers weighing—
Weight loss, condition, diet, Rats | Average Less 10.0 15.0 to | 20.0 to More
and age (days) age Average Range than to 14.9 19.9 29.9 than
10.0 grams grams grams 30.0
grams grams
Rats losing less than 100
grams:
Fasted rats:
tock: Number | Days Grams Grams Percent | Percent | Percent | Percent | Percent
NF Sse Lae Talay) (ecm ee Pape epee (vee eae a |) ee ee ee eee ee ee eee se |e
500 and over___--___- 6 712 12.5 10. 7-15. 5 0 83 74 0 0
SP 8 HVO:
Less than 500_______- 7 295 9.4 6. 5-11. 7 OL 43 0 0 0
B00 andiover:.=2225-- 9 645 12. 4 9. 1-15. 4 11 78 11 0 0
SP
ee than 400________ 19 296 16.1 7. 6-26. 0 16 37 21 26 0
400 to 599___________ 22 489 20. 7 15. 9-27. 0 0 0 50 50 0
600 and over____-___- 6 643 19. 6 16. 5-25. 6 0 0 67 33 0
Nonfasted rats:
Stock:
Less than 500_______- 1 456 10.3 10. 3 0 100 0 0 0
500 and over_____-___- 8 787 19.3 14. 6-24. 1 0 12 50 38 0
SP 8 HVO:
Less than 500_-______ 10 375 14. 3 10. 0-23. 0 0 70 20 10 0
A 500 and over________- 5 619 20. 1 14, 0-24. 7 0 20 20 60 0
PE:
Less than 400_______-_ 11 315 25. 4 15. 0-38. 7 0 0 18 55 27
400 tO: 599 ae a oe 6 489 26. 7 15. 1-388. 9 0 0 33 33 33
600 and over_________ 2, 608 43. 1 33. 6, 52. 6 0 0 0 0 100
Rats losing more than 100
grams:
Fasted rats:
Stock:
Wessathaniys (0 Seeeaete eee |e ee | ee alee ree oan ee ee eee ee loa eee Sole See Le SIL ete
aus and over_____-___-_ 4 682 15. 4 11. 9-18. 2 0 50 50 0 fe)
SP 8 HVO:
Less than 500_______- 3 419 14. 7 13. 1-18. 0 0 67 33 0 0
P 500 and over________- 4 654 13. 8 13. 8-14. 0 0 100 0 0 0
PE:
Less than 400________ vé 376 21.2 14. 0-380. 2 0 14 43 29 14
A000 59 Ours aes 22 504 1OEe 14. 7-27. 5 0 5 55 41 0
600 and over________- 7 644 16. 5 14, 3-19. 8 0 28 72 0 0
Nonfasted rats:
Stock:
Less than 500_______-_ 4 411 19.8 14. 0-23. 1 0 25 0 75 0
poe and over_______--_ 7 695 16. 6 14. 6-19. 4 0 29 (fll 0 0
SP 8 HVO:
Less than 500________ 2 426 14, 7 14. 2,15. 2 0 50 50 0 0
ae andeOveras =. 222 = 20 695 16. 0 10. 8-22. 4 0 35 50 15 0
Less than 400________ 13 339 20. 5 16. 4-24. 1 0 0 38 62 0
ANOKtO2599 zu ee oh sae L 25 482 20. 5 14. 3-40. 1 0) 8 48 40 4
600 and over________- 5 643 20. 2 16. 1-26. 9 0 0 60 40 0
KIDNEY WEIGHT AND DAMAGE.—Table 27 shows __ the presence of a few hyalin casts. When kidneys

the relation of kidney size to the histological find-
ings. Because of the influence of fasting on the
size of this organ, the results of fasted and non-
fasted rats are reported separately. For both
fasted and nonfasted rats, a gradual increase in
kidney damage with increasing kidney weight was
observed with all three diets. Kidneys weighing
less than 1.8 grams were generally normal in
appearance. The only evidence of degenerative
changes in kidneys weighing 1.8 to 2.0 grams was

weighed between 2 and 3 grams, more extensive
damage was apparent, with glomerular damage
occurring in many of the kidneys from stock rats.
Kidneys weighing more than 3 grams generally
showed evidence microscopically of all three types
of damage regardless of diet, but the ratings for
glomerular damage were consistently greater for
rats fed the stock diet.

LIVER WEIGHT, LIVER FAT, AND KIDNEY DAM-
AGE.—The weights of livers from rats fed the

43

TaBLE 27.—Kidney weight as related to kind and extent of damage in fasted and nonfasted rats fed stock,
SP 8 HVO, and SPE diets

Condition, diet, and range of kidney weight (grams)

Fasted rats
Stock:

d fst 96,0) a: 0d | 0 pp ee ee ns ppt na. Tien a ges gape
HUSOtO 100 2 ee eo a ee eae
PRL ULE IR ro 16202 | Ne enn ae Seo ed ee Pine ep) en te ety
BOO 00M 90 6 arose oc ke as ee

SP 8 HVO:

Mess: than esOUW oe ae eee a ee eee
SOV BOWLED Oe aie ata als ee a, Dee Be
2 OObO 2. 00 = ed bees ee cei ee ee ee
ay ND ts ae es a
S:00-an dO veres2 2) a ee ee

Less Hany 1 S02 aa eis ee Oe 2 ON eee ee ee eee
ME OER OO pa oe nny hn eee Rene Rae, ee eee eee
POO sO ne OO x nae on RS I a le a ee eee

SPE

Nonfasted rats
Stock:

SPSS day 0 Mn PS | 0 een em a rte Eee usenet ©
TSO) TO OO ret Nok Bo be Pe as en ee ee ee ee Se
OOM 10 Oia oe a se het Pe a a ne
SOON TO AOD am Rete ewe ee ene ee
SO0camMC OVER: 2 yr ht ei coe we eyo a ae ee ee

SP 8 HVO:

Whésoathannd (S00 See Baas ee Dee ee
180 tLOsLOOLct 6a iF eae 8 eee ee ae
FANON GO! DOO) eae rs Eo, atom, at heaping at gets es
OO EONA OD te nok hae ce ae ee

SPE

stock diet also paralleled closely the extent of the
damage observed in the kidneys. In table 28
are summarized data from nonfasted stock rats
that were maintaining their body weight. Little
evidence of kidney damage was observed in these
rats when livers weighed less than 16 grams; ex-
tensive damage was found when livers exceeded
20 grams in weight. ‘There were too few data to
establish a comparable relationship in the fasted
rats, and in moribund rats this relationship was
complicated by variable weight loss.

In nonfasted rats fed SP 8 HVO diet, larger
livers were not necessarily accompanied by
damaged kidneys. No evidence of kidney damage
was apparent in the group of five rats 150 days
of age, although three of the livers from these
rats weighed more than 20 grams.

On SPE diet no consistent relation was found
between kidney damage and liver size or between
size of liver or fat in the liver as seen microscopi-
eally. A liver weighing 13.5 grams showed
evidence of fat in amounts comparable to that

44

Average Histological rating
Rats kidney | _
weight
Hyalin Cystic |Glomerular
Number Grams Score Score Score
25 1. 44 Weal 0 0
2 1. 89 1.0 0 0
7 2231 129 .9 1.4
1 PARTE 4.0 2. 0 3. 0
34 1. 44 2 0 0
7 1. 89 rl ) 0
6 2. 38 ez 2 .2
3 4,12 203 2.0 2.3
1 8. 67 3. 0 4.0 20
23 1455 mG) 0 0
10 1. 87 ileal 0 zo
25 2. 53 2.0 aD 2
16 4, 22 DAs 1.9 1D
43 7. 44 2.4 3. 4 200)
34 1. 47 a 0 0
10 1. 90 ai) aul 0
23 2. 38 1,4 “ial ah
9 Sa0L 3. 0 2.0 2.9
2 W202 2.0 4.0 3.0
12 1. 62 4 0 0
ih 1.90 6 0) 0
12 2. 34 de? 2 .2
1 4.18 2.6 2.2 1.8
5 6. 82 3. 6 3.0 2. 4
iA 1. 70 6 0 0
5 18h 1.0 0 0
Pall 2. 28 Hee, 0 aul
13 OAL 2.5 1.2 1.4
40 8. 52 2.4 wo 2. 2

TABLE 28.—Liver weight as related to kind and extent
of kidney damage in nonfasted rats maintaining
weight on stock diet

Liver Aver- Histological rating
weight age
range Rat liver
grams) weight | Hyalin | Cystic Glo-
merular
Num-
ber Grams | Score | Score Score
Less than 14.0 15 1235, 0 0 0
14.0 to 15.9___ 18 14.9 ai 0 0
16.0 to 17.9 __ 11 17.0 9 0) 0
18.0 to 19.9 __ 6 18. 6 i=5() Bass 3
20.0 and over. 10 22.8 2.1 2 1.6
seen in livers weighing 25 grams. Fat was

apparent at an early age before kidney damage
occurred, and was seen in all but one of the livers
from rats with normal kidneys. As_ kidney

damage increased, liver fat tended to decrease and
often was too small to be apparent microscopically
without special stains for fat.

RATS MAINTAINING WEIGHT ON SPM, SPB,
AND SPPB piets.—In table 29 are summarized
data for the weights of the livers and kidneys
from fasted and nonfasted rats that were main-
taining their weight on diets containing milk,
beef, or peanut butter. For comparison, data are
also included for rats fed SP 8 HVO and SPE
diets from the same experimental series. The
younger fasted or nonfasted rats were littermates
except for an occasional death before the age
scheduled for sacrifice.

The influence of fasting on the size of the kidney
as well as the liver was again apparent in the
results for the young rats. In general, the
results for SPM, SPB, and SPPB diets were
similar to those obtained with the semipurified
diet except for the tendency to large livers in
animals over 400 days old fed SPPB diet. For
all diets except the SPE diet, an increase in liver
weight with age was accompanied by a parallel
increase in body weight, with the liver remaining
a relatively constant percentage of the body
weight. The tendency for certain litters to be
particularly prone to enlarged, damaged kidneys
was apparent in the group of rats 400 to 600 days
of age. One litter accounted for the largest
kidney recorded in table 29 for each of the diets
except SPE. The littermate fed SPE diet was
moribund at the time of sacrifice and had a kidney
weighing 8.7 grams. The kidney weighing 5.57
erams from the littermate fed SPB diet was

responsible for the high average ratio of kidney to
body weight noted for this diet.

RaTs LOSING WEIGHT ON SPM, SPB, anp SPPB
pints.—Differences among these diets became
apparent in rats that were losing weight, as is seen
in table 30. Some extremely large kidneys were
found in young rats fed SPPB diet, particularly
in the nonfasted animals. The largest kidney
observed, weighing 15.8 grams, was from a 341-
day-old nonfasted rat fed this diet. Although
large kidneys were a frequent finding in SPPB
rats, the kidneys of a small group of older non-
fasted rats that had lost less than 100 grams were
normal in size. This group of animals included
the oldest surviving rats on this diet. Enlarged
kidneys were a frequent finding when weight loss
exceeded 100 grams, regardless of diet, although
there were relatively few large kidneys among the
older SPM rats. The relation of kidney size to
the extent and type of damage observed was
similar to that previously discussed for rats fed
SP 8 HVO or SPE diets; hyalin casts were gen-
erally present in kidneys weighing 2 grams or more
and cystic and glomerular damage in those exceed-
ing 3 grams in weight.

The livers from SPPB-fed rats tended to be large
but were generally smaller than those from SPH-
fed rats. In contrast to the results with SPE
diet, the large livers from rats fed SPPB diet
generally showed little microscopic evidence of fat.

Rats FED SPE DIET WITH ADDED NUTRIENTS.—
In table 31 are summarized data for the kidney
and liver weights of rats fed the 10 supplemented
SPE diets. Enlarged kidneys and livers such as

TaBLE 29.—Kidney and liver weights of fasted and nonfasted rats maintaining weight at different ages on
diets with protein-fat-containing foods

Aver- Kidney weight Liver weight Aver- | Kidney| Liver | Liver
Condition, age of rats Rats age age to to to
(days), and diet age body | body | body | kidney
Average Range |Average| Range weight | weight | weight | weight
Fasted rats
200 to 399 days: Number| Days | Grams Grams Grams Grams Grams | Percent| Percent| Ratio
SPISCHViOmene nek 5 313 1.37 | 1. 23-1. 60 10.7 | 9. 1-13. 1 523" 0 0427 al hs
fell Bal end a his ScD Sea peters 5 313 2.09 | 1. 60-2. 91 21.7 | 17. 0-30. 1 578 . 36 ay ff 10. 6
SiIRAVN a Bial aiccnrm fines 6 304 1.38 | 1. 06-1. 85 11.9 | 7. 3-16. 2 580 . 24 2. 0 8. 6
SRA Beene alee atin SS 6 304 1.52 | 1. 16-2. 23 11.9 8. 7-15. 5 540 . 28 Phe ete
RSE 1 BEY Bel re 6 289 1.43 | 1. 12-1. 91 11.8 | 10. 4-14. 3 495 . 29 2, 4 8. 6
400 to 499 days:
SP SHEViOseS toes. 10 523 2.01 | 1. 43-2. 59 14.6 | 11. 9-18. 2 716 . 28 2. 0 7.4
SP hima tesart awh os 6 496 | 2.09 | 1. 55-3. 82 18.9 | 14. 3-24. 4 648 AS2 2.9 9. 9
PHI PAIK Crees an ea a 7 503 1.90 | 1. 438-3. 20 13. 8 | 10. 4-19. 6 659 . 29 2. Tes
SAB ee apoee ee cathe es 8 8 502 2.16 | 1. 33-5. 57 13. 8 9. 4-18. 8 642 . 34 a. I 6. 6
SIPIAB cremains aot 8 509 2.06 | 1. 46-3. 68 16.9 | 13. 0-22. 5 741 . 28 Das 8. 5
Nonfasted rats
150 to 250 days:
SP 8 HVO 10 201 2.08 | 1. 43-3. 32 21.6 | 14. 3-30. 7 530 . 39 4.1 10. 5
10 201 2.04 | 1. 76-2. 22 23.9 | 19. 2-27. 1 540 23o 4.4 11.8
10 202 1.98 | 1. 51-2. 34 21.2 | 16. 5-27. 5 581 . 34 Sy ie LOST,
10 202 1.90 | 1. 55-2. 24 18.6 | 16. 5-21. 9 540 . 35 3. 4 9.8
10 202 1.96 | 1. 59-2. 85 | 20.0 | 15. 0-27. 7 569 . 34 3.5 10. 3

TABLE 30.—Kidney and liver weights of fasted and nonfasted rats losing weight at different ages on SPM,
SPB, and SPPB diets

Kidney weight Liver weight !
Condition, weight loss, age (days), and Rats Average
diet age
Average Range Average Range
Fasted
Losing less than 100 grams:
200 to 499 days old: Number Days Grams Grams Grams Grams
SPM a2. Sc 5 350 1. 63 | 0. 99- 2. 60 13.4 (4) 7.7 -17.2
pgp pte eae ee ie ee 3 268 1.22 . 85- 1. 47 9.9 7.3 -11.9
Nol 2a oe & fees eee eee em ty ee eae eee 17 330 2. 26 . 56- 7. 41 15. 2 5.0 -21.5
500 days and older:
lS Deel of a ee = 5 528 2.50 | 1. 93- 4. 35 16.2 14.7 -18.1
DE Bie ete eee eee ete 4 651 2.52 | 1. 68- 4.53 15. 6 12.7 -20. 2
SPPBe 2225. cece cect enlace 5 586 3. 25 | 1. 38- 7. 09 18.2 11.0 —24. 7
Losing more than 100 grams:
200 to 499 days old:
Db Mi 222i eee sues 1 362 1.10} 1.10 9. 63 9. 6
ii og 2 anne Re ON ciee aha ne eee i 461 fees ae 12.5 12. 5
DEP Ben 28a ec eee aoe e Se ae [teas a eee at a ec a |
500 days and older:
PM m2 oS Soke oe sete cee 3 796 297° | 1e63=25. 53. 13.0 10.1 —15. 6
DP Be Sie ae ee tee See 4 630 2.82 | 1.50—- 3. 48 12.2 11.0 -14.8
DEPP Bs 2222 son ceneweseaeecel 4 531 3.80 | 2.12- 5.78 19.4 (38)} 12.5 -28.8
Nonfasted
Losing less than 100 grams:
200 to 499 days old:
PV Si DE eae ene Sh 7 354 2.67 | 1. 30- 6. 28 18:2 14, 7 -22.3
No fb Rane ee eee ee eee CR oa I 7 312 2. 05 . 96- 3. 70 16.5 (6) 8.7 -27.7
SERB ec leaneee tee es 6 373 5. 50 | 1. 52-15. 8 22. 5 9.8 -33. 1
500 days and older:
DIME 222 oo eee ce ae 2 728 2.23. |) 1.83). 2.63 19. 4 18.0, 20.8
SRDS 22 sec cooceecce sees 3 696 2.53 | 1. 64— 3. 36 22. 8 15, 231.3
NP PBe i522 eede eben ee eee 6 643 1.98 | 1. 77- 2. 28 19. 4 15.2 -25. 8
Losing more than 100 grams
200 to 499 days old:
PIV fae he eh See tesa 5 433 4,46 | 1. 48- 8. 68 16.5 12.0 -21.8
Rs tos ooh ee ee 5 435 4.93 | 3. 01- 6. 40 16.0 13.9 -18. 1
PIP Bis e528 ae one Sie ec ee 5 397 6. 06 | 3. 84- 7.99 22. 2 11. 8 —29, 2
500 days and older:
Vie Ae oe cee ese t 706 2.94 | 1.58- 4. 41 15.1 (5)| 11.4 -18.3
Mii oase tt ee roses caeesee 9 609 5.08 | 2. 00- 8. 03 16. 3 13. 4 -21. 4
RS erat ae eee te 4 606 5. 20 | 3. 89- 6. 25 18. 4 14,2 -21.9

1 Numbers in parentheses indicate when number of livers do not correspond to number of kidneys.

have generally been observed in rats fed SPE diet
were also obtained with all of the supplemented
diets. The kidneys from rats fed the diets supple-
mented with vitamin B, tended to be smaller, on
the average, than those from rats fed the unsup-
plemented diet, paralleling the histological find-
ings. The largest average kidney weights were
obtained when the diets were supplemented with
vitamin By. or with cholesterol. Although these
supplements were without effect on the lifespan
of these animals, there is some indication that they
may have influenced the metabolic processes in-
volved in the utilization of these diets. Consider-
ing the wide range of values obtained in moribund
rats, however, data uncomplicated by excessive
weight loss are needed to establish the significance
of the trends observed.

RATS FED DIETS CONTAINING 8 OR 16 PERCENT
HVO, tarp, oR BUTTER.—The kidney and liver

46

weights for rats fed diets in which the kind and/or
level of fat was varied are summarized in table 32.
Data from animals that were maintaining weight
are limited to a group of five nonfasted rats fed
SP 8 HVO diet and the corresponding results
with the littermates fed SP 8 lard. No significant
differences in the liver or kidney weights of these
young rats were obtained. The results for sick
or moribund rats have been separated on the basis
of weight loss before sacrifice. When weight loss
was less than 100 grams, the kidneys from rats
fed diets containing hydrogenated vegetable oil
at either the 8- or 16-percent level tended to be
smaller than those from rats fed diets containing
8 or 16 percent lard or butter. When weight loss
exceeded 100 grams, the results for fasted and for
nonfasted rats have been combined because of the
small differences usually observed in these two
groups of animals. The kidneys from this latter

0 LE-F FI | 8 ‘0G €8T VET 6 LL -LEG
G 66-8 “CI | 3 ‘6T OST 967 8 v OL-0F @
9 °SE-L ST | G2 al SOF OT 8 GI-L0 %
G "€e-9 “LT | 8 GS EST SSP 6 0 ‘TI-9¢ ‘%
Py “S¢-9 ‘OT | 6 6I 6&§T O87 OT 6 OL-1L %
v ‘9G-2L ET | 9 61 SEI (any 6 8°L -69 'T
6 ‘96-0 ‘9T | € 0G 9GT GLP 8 G GI-ZGI @
0 ‘EF—-0 ‘OT | 6 FG FIL TEP OT L GI-0F %
L°L6-8 “ST | 0 'TG Té1 GOP 8 T “ST-66 @
8 ‘O&-S FI | 6 02 aa LSP 8T 6 ‘OI-06 'T
6 GE-E FL | GTS al SSP 9T 9 ‘TI-82 T

SWDID supp | sun shogq | saqunyy SUDLD

asuBy | oseIOAY osuBy

SSOT ase
qyslem |osvlaay | syey
QYSIOM IOAVT WSBIOAY

spuarunu payfiind pappo Gururpjuos yaip Tdy wo 1ybrvam burso) syou fo sqybran waay pun haupry— Te ATA,

OF ¢
Egg
€8 ‘9
LVL
91 °S

tL YP
€¢ 'P
ST 2
€L 9
9T 9
99
SUWDLED

dSBIOAYV

4ysIom AOUPIST

OLT
ێ1
(Gal
€ST
6ET

8cI
O<T
FIT
681
Gal

al
SUDLD

SSOT

VYSIOM | oSeIOAV

WBVIOAY

CGP
IGP
807
SSP
O€F

aay
vor
ver
LUD
CSP

CSP
shoqg

ose

laQUn yn

8yey

---------- %9F'O ‘Jor9ys9ToyI + %Z'O ‘plow oiqaoosy
Se a ae i See %SO ‘plow siq1oosy
----------------------------- %WSE'T ‘oleysopoyg
----------------------------- %OF'O ‘orlaysetoyD

See ws OOT

[3 G0 “q+ "WS OOT/"Su 100 “gq +%G"'0 ‘eurjoyD
se cca oe wS QOT/3u SO “A+ %S'0 ‘eultouD
[merce ee ae eee a ee ws QOT/ Sut $9 “g
Frere er ks ws 0OT/Su 100 “gq +%¢'o9 ‘aurjoyy
es cates Siete oni gmoney as eee ee ae ws QOT/‘Su To'0 Wg

qyuowelddns qWqg

%F'O ‘euroup

aes ~~~ 9uONy

4]

TasLEe 32.— Kidney and liver weights of fasted and nonfasted rats maintaining or losing weight on diets
containing different kinds and levels of fat

Condition, weight status, and diet Rats | Average
age
Nonfasted rats

Maintaining weight: Number| Days
SP SHV Oe 2 oo eee ee ee 5 184
SPS land oo. ae ao ene eo 5 186

Fasted rats

Losing less than 100 grams:
ol a ct DAY © ‘Pace ane een oc me ene 5 703
Se OME Oe) 46 2 ods hee oe 4 700
Bie Oar ie § Ga eA ta ae eC 6 632
ee Osa at tee eA td 2 695
Deo DUtterea28 es sos Sec eee Se ee 4 605
Ree be Dilttert- ct 2a ee = ee oe 5 554

Fasted and nonfasted rats

Losing more than 100 grams:
S TeV OR 6 2. Sieve ek ee ne ee a 7 587
Re VG Vi), 8 2 2 5 ody ge i 2 636
eS (and ora. eee oa ee 6 493
De CLG irs 5 eS ae 5 ooo
Dee Uber as Se a ee 4 591
SPulG Utter: «282-2 ba. «hae 1 404

Average Kidney weight Liver weight
weight re.
loss
Average Range Average Range
Grams | Grams Grams Grams Grams
1. 95 1. 76-2. 54 22.53 16. 3-30. 7
0 1. 83 1. 64-2. 48 18.9 17. 4-21. 7
53 1.611 1. 46-1. 69 1256 11. 8-15. 0
54 Py Aff 1. 32-3. 45 14. 2 12, 3-15. 5
48 2. 78 1. 70-4. 91 16.3 13. 8-18. 8
94 2. 84 215, 8302 15. 4 15. 1, 15. 6
32 2,15 1. 59-3. 45 14.0 13. 1-15. 4
56 2. 65 1. 67-5. 95 14.6 13. 0-16. 4
151 4. 50 1. 86-8. 67 15.3 11. 3-19. 6
152 4, 94 2. 64, 7. 24 1os2 14. 4, 16. 1
163 5. 12 1. 50-7. 93 15. 6 11. 7-18. 5
138 4. 04 3. 47-4. 99 L5ee 11. 7-18. 0
152 4, 02 1. 80-6. 18 114.4 (8)| 18. 9-15. 0
147 5, £0 capa, 13. 0 13. 0

1 Number in parentheses indicates number of animals when differing from that listed in column 1.

eroup of animals were generally large regardless of
the kind or level of dietary fat.

Rats FED DIETS WITH PROTEIN AND FAT OF SP
8 HVO apsusTED TO LEVEL IN SPE piets.—In
table 33 are summarized data for kidney and liver
size when rats were fed modifications of the semi-
purified diet in which the level of fat was increased
to 16 percent and protein to 30 percent, or the
level of protein alone was increased. Most of
these rats had lost considerable weight before
death. The results obtained were similar to those
observed under comparable conditions with rats
fed SP 8 HVO diet. The smaller kidneys of the
rats fed SPB diet were accompanied by smaller
weight losses. From these data, there appeared
no evidence that an increase in the level of fat or
protein resulted in kidneys and livers comparable
in size to those from rats fed SPE diet, at least as
far as could be ascertained with moribund rats.

RATS FED DIETS CONTAINING WHOLE EGG, EGG
WHITE, OR EGG YOLK.—In table 34 are summarized
data for rats that were fed diets containing whole
egg, egg white, or egg yolk. Included are data
for 10 rats fed SPE diet when the egg in this diet
was dried, cooked fresh egg instead of the com-
mercially dried egg generally used for this diet,
and results for a small group of littermates fed
the diet of egg yolk supplemented with salt mix-
ture. The results for rats fed diets containing
ege white with HVO as the fat (SPW 8 HVO and
SPEW) were similar to those obtained for compar-

48

able rats fed the semipurified diet (tables 22, 23,
25, 26). The results with SPE-fresh egg were
similar to those obtained on the usual SPE diet.
Among the animals that were losing weight, large
kidneys were a frequent finding with all of the
diets, but those from rats fed SPE diet tended to
be the largest. Kidneys and livers were generally
smaller when the diet consisted of 100 percent egg
yolk than when it contained a smaller amount of
ege yolk. The favorable response to supple-
mentation of Y100 with 3 percent salt mixture
discussed under the histological findings was also
apparent in the relatively small kidneys and livers
in these rats.

Stock AND SPE DIETS REVERSED AT 250 DAYS.—
In table 35 are summarized data for kidney and
liver weights when the diet was changed from
stock to SPE or the reverse at 250 days of age.
The kidney and liver weights of the 250-day-old
rats were characteristic of those generally observed
with these two diets. No difference in the size
of these organs was observed whether the rats
ate a constant diet throughout life or had their
diets reversed. It should be remembered, how-
ever, that when the diets were reversed, the age
at death was considerably greater than when either
diet was fed continuously throughout life.

BHE anv Wistar RATS FED SP 8 HVO anpb
SPE piets.—Differences in response to diet of
two strains of rats are seen in table 36, which
summarizes data for kidney and liver weights of

TaBLE 33.—Kidney and liver weights of rats losing weight on SP 8 HVO diet modified to contain the protein
and fat level of SPE diet

Diet Rats | Average

age

Number | Days
SRPSEEDViO eae te: Soe eo. See ee Se 17 679
SPapiGeEnViOe = ss sa eee 18 674
SP biStAyViOs Sera sn Sa 9 632

Average Kidney weight Liver weight
weight |__ ee
loss
Average Range Average Range

Grams | Grams Grams Grams Grams
164 3. 46 1. 57-7. 80 16. 1 10. 8-22. 4
175 3. 78 1. 57-7. 92 17.0 12. 4-24. 9
118 2. 94 1. 46-5. 07 116.3 (8) | 11. 2-21.6

1 Number in parentheses indicates number of animals when differing from that in column 1.

TaBLE 34.—Kidney and liver weights of rats fed various diets containing egg, egg yolk, or egg white

Average Kidney weight Liver weight
Condition, weight status, and diet Rats | Average| weight |__ uae
age loss
Average Range Average Range
Fasted rats
Maintaining weight: Number | Days Grams | Grams Grams Grams Grams
DIRAWiteset osha 018 Leta re 6 550 1.73 | 1.61- 2.18 13. 6 11. 3-18. 0
Fasted and nonfasted rats
Losing less than 100 grams:
ET QQ itiputal ins Pyke ies sail fi Bese es 8 558 48 4,19 | 1. 87-10. 8 129.7 (6) | 16. 8-42. 6
SVP ORS ies tes eb Se alee sted fet re 16 390 59 2. 29 . 93- 5. 99 15.1 (15)} 11. 0-24. 3
Losing more than 100 grams:
SPH freshiepgs oo St eo se 7 492 167 7. 87 | 4. 06-12. 6 23.1 (6) | 15. 8-40. 1
SIRE AW SEP ER RIN EUG, 8 608 184 4.30 | 1. 59- 8. 28 19.4 (5) | 12. 7-29. 9
SIRE RYiet eu piat cote te te 5 9 480 168 5. 89 | 3. 45- 8.13 19.1 (7) | 15. 2-26. 0
a CL 0) 0 Pea ea ON a aS 16 542 156 4. 80 | 1. 52- 8. 68 16.3 12. 0-23. 5
NAL OO SU PS al AAP et gaa I a 3 445 152 3. 36 |, 1. 538- 5. 74 15. 3 14. 1-17. 1
Fasted rats
Littermates:
IRQ a ee Laer es Oe 8 * Now are Dans = 5 428 66 3. 88 | 2. 02- 7. 25 21.5 14, 0-25. 6
NTU) SiS this Cards ER a ee 5 425 35 2.71 | 1. 63- 4. 46 17.3 13. 9-24. 3
Y97-+ salt mixture, 3.0%_______-___ 5 430 5 1.68 | 1. 55- 1.75 14.5 13. 2-16. 5
! Numbers in parentheses indicate number of animals when differing from that listed in column 1.
TaBLE 35.—Kidney and liver weights of rats fed stock or SPE diets reversed at 250 days
Condition and diet of rats Rats Age Weight Kidney Liver
loss weight weight
Sacrificed at approximately 250 days on— Number Days Grams Grams Grams
locke maine eu eA Hay cud vty sues eh 3 250 0 2. O7 17.0
PSHE BUDD cA TE aU Aas Oe er oe PO 3 249 0 2. 74 26. 4
Continued on—
SCO Cksmamir a Wa Ma era irmvonn alee gr ot leh EA TR bt oe his 3 590 195 4, 25 18. 5
HS B71 a= ao de a a pO a i 3 473 104 4.17 22. 2
Diet reversal:
Stock changed to SPE at 250 days__________________- 4 686 109 3. 94 22.3
SPE changed to stock at 250 days____._______________- 4 624 101 3. 48 Pay

BHE and Wistar rats fed SP 8 HVO and SPE
diets. The kidneys were generally small even
with SPE diet, in marked contrast to the large
kidneys from comparable BHE rats. Kidneys

from only two rats of the Wistar strain exceeded
4 grams, one from a rat fed SP 8 HVO diet and
one fed SPE diet. For both diets, livers tended
to be smaller in Wistar than in comparable BHE

49

TABLE 36.—Kidney and liver weights i two strains of rats at terminal age from parents fed two stock diets,

with young fed SP § HVO and SPE diets

Strain and diet Rats | Average
age
BHE rats
Parents fed BHE stock diet:
Offspring fed— Number| Days
DP Osh On 2 ese eae ee £1 571
Bae Le ae ee 14 438
Wistar rats
Parents fed Wistar stock diet:
Offspring fed—
SP SR Oe sous eee sees 10 739
2d 0 eG le ORR eee ReneS aae 9 633
BHE rats
Parents fed Wistar stock diet:
Offspring fed—
Wistar StoGk..iso2 2.5 Js 3 5 886
SP) 8-H Vii 6 eke 9 703
Dien (ah. Ooi ee eee 10 435

Average Kidney weight Liver weight
weight |__ ps
loss
Average Range Average Range
Grams | Grams Grams Grams Grams
136 3. 76 | 1. 70- 7. 80 16.9 10. 0-24. 7
151 8. 24 | 2. 68-13. 3 21.4 15. 3-38. 7
108 2.00 | 1.34- 4.11 113.7 (8) 9. 0-24. 6
80 2.35 | 1. 60— 4. 34 18.9 15. 0-21. 9
Ee toe 1.22 | 1.12- 1. 40 10. 2 9. 6-12. 4
75 2.41 | 1.04 4. 07 12.2 10. 0-15. 7
85 5. 14 . 99-10. 4 121.6 (9) | 13. 7-34. 7

1 Numbers in parentheses indicate the number of animals when differing from that listed in column 1.

rats. The livers from Wistar rats fed SPE diet
tended to be larger than those from the same
strain fed SP 8 HVO diet.

BHE rats from parents raised on the stock diet
of the Wistar rats showed differences in kidney
and liver weights with SP 8 HVO and SPE diets
that were similar to those found when the parents
were raised on regular stock diet. The results
agree with the histological findings, and provide
further evidence that the dietary history of stock
Wistar rats was not responsible for differences in
the response of BHE and Wistar rats to diet.

Discussion.—Much of the information in the
literature on kidney weights in the rat has been
based on studies during the period of rapid growth
or for the young adult rat. There appears to be
a tendency for the right kidney to be somewhat
larger than the left kidney (4, 123), although the
differences observed were small (3 to 5 percent).
There has been general agreement that the weight
of this organ is closely related to body weight,
but the value for this relationship has been found
to vary with the strain of animal under investiga-
tion. The values tabulated in Donaldson’s refer-
ence tables for Wistar rats (50) were obtained
by using the formula of Hatai (86) relating kidney
to body weight. For male rats weighing 450
grams, the value recorded for the weight of two
kidneys was 3.5 grams or 0.78 percent of body
weight. Freudenberger (70) has reported kidney
weights with a similar relationship to body weight
for male Wistar rats 1 year old. For comparable
rats of the Long-Evans hybrid strain of Norway
rats, the average kidney weight represented a
somewhat smaller percentage of the body weight,

30

0.69. Addis and Gray (4), using a log log relation
between body and kidney weight, have developed
an equation for the Slonaker strain of rats and
have presented standards for kidney weights of
rats with body weights up to 400 grams. On
the basis of the standards for the Slonaker strain,
animals weighing 400 grams would have kidneys
weighing 0.54 percent of their body weight.

The results reported in this publication provide
no information on changes in kidney size in the
young growing rat. For fasted adult rats under
300 days of age, kidney weights, when considered
in relation to body weight, were within the range
reported by other investigators.

The influence of feeding various dietary
combinations throughout life on the kidney size
of the rat has received relatively little attention
to date. Many of the available reports relating
diet to kidney size have dealt with short-time
feeding studies, often under extreme conditions
producing acute changes. |The emphasis has been
chiefly on the influence of dietary protein on
kidney size, and there has been genera] agreement
that kidney size is increased with increasing
levels of protein.

Osborne, Mendel, Park, and Winternitz (150)
observed an invariable increment in the size of the
kidney when the casein content of the diet ex-
ceeded 50 percent. This gain in kidney weight
often amounted to 50 percent or more above the
normal weight. When the casein level exceeded
75 percent, unmistakable evidence of kidney
enlargement was found within 8 days. Equally
striking changes were observed when rats were
fed a diet containing 80 percent ‘‘meat residue.”

McCay, Maynard, Sperling, and Osgood (121)
reported a correlation of kidney weight with level
of protein when diets containing 8, 14, and 20
percent casein were fed. These dietary regimens
were initiated during the latter half of life and
did not involve excessively high levels of protein.
The kidney size reflected dietary protein level at
death in spite of the wasting that accompanied
the last diseases of old age. Addis, Lippman,
Lew, and others (5) found that kidney size in-
creased when the level of egg, liver, wheat germ,
or casein was increased from 10 to 60 percent, and
that the extent of the enlargement depended upen
the source of protein. Smith and Moise (174)
reported that, after removal] of one kidney, the
remaining kidney became enlarged and that the
increase was proportional to the level of dietary
casein.

Agreement with regard to the cause of increased
kidney size as the result of feeding high levels of
protein has been less general. Addis, Lippman,
Lew, and others (5) suggested that the differential
effect of dietary protein upon kidney size was not
due to differences in its inherent nutritive value
for the kidney but was secondary to the work
load imposed upon the kidney by urea excretion.
Other investigators (138, 150) conclude that the
load on the kidney from increased urea excretion
is not responsible for kidney enlargement on the
basis of the results of feeding high levels of urea.

In general, the data available on the size of
liver of rats are similar in nature to those reported
for the kidney, and have also indicated a close
relationship between liver and body weight.
Donaldson (50) has reported a value of 18.7 grams
(4.2 percent of body weight) for the liver from
fasted male rats weighing 450 grams. Liver
weights of 12.1 and 16.4 grams have been reported
by Freudenberger (70) for 1-year-old male rats of
the Wistar and Long-Evans strain, respectively.
The Wistar rats weighed 340 grams; the Long-
Evans rats, 458 grams. No strain differences
were apparent, since the livers of both strains
represented the same percentage of body weight
(3.6 percent). Addis and Gray (4) reported still
smaller liver weights for the Slonaker strain, with
the values representing 3.0 to 3.2 percent of the
body weight in animals weighing between 360 and
410 grams. These last-named investigators sug-
gested that a possible explanation for the differ-
ences observed may lie in the higher protein level
of the diets fed the rats with the larger livers.
For rats 1 to 2 years of age, Yiengst, Barrows,
and Shock (191) observed liver weights for the
McCollum strain of rats of 13.3 and 13.0 grams,
representing 2.8 and 3.0 percent of the body
weight, respectively. No significant change with
age was observed.

Several investigators reported results indicating
that liver weight may be influenced by diet without
comparable changes in body weight. Blather-
wick, Medlar, Bradshaw, and others (31) reported
variations in this percentage from 2.8 to 5.2.

Addis, Lippman, Lew, and others (5) obtained an
increase in liver weight of approximately 10
percent, with no comparable increase in body
weight, when rats were fed 60 percent wheat
germ, liver, or egg powder for a period of 20 days.
At the 10-percent level, diets produced no change
in liver weight. Casein was without influence at
either the 10- or 60-percent level. McCay,
Maynard, Sperling, and Osgood (121) reported a
10-percent increase, not accompanied by a com-
parable increase in body weight, when the level
of casein in the diet was increased from 8 to 20
percent and the rats were fed the experimental
diets from middle age until death. Large livers
have been reported in rats fed diets containing
high levels of egg (156) or liver (37).

Even with the stock diet, BHE rats were
relatively large animals, but in spite of their
large body weight the livers of the fasted rats
were generally smaller than those reported by
many investigators. The livers from fasted rats
on the stock diet were similar in size and in
percentage of body weight to those reported by
Yiengst, Barrows, and Shock (1/91). Liver weights
of 10 grams reported by Reussner and Thiessen
(156) for 9-month-old rats fed a diet of cereal,
milk, and sugar or milk alone were similar to
those obtained with BHE rats of comparable
size fed most of the experimental diets. The
average liver weight of 15 grams observed by
these investigators for rats fed a bacon and egg
diet containing 22 percent egg was similar to
that obtained for BHE rats fed SPE diet, when
considered as percent of body weight.

Harrison (85) reported relatively small differ-
ences between the liver weight of young fasted
and nonfasted rats fed stock ration. A search of
the literature has failed to reveal investigations
showing differences in the liver weights of fasted
and nonfasted rats of the magnitude observed
with BHE rats fed the semipurified diet or its
modifications.

Summary.—A kidney weighing less than 1.8
grams was generally normal in appearance.
Degenerative changes were usually apparent when
the kidney weight exceeded 1.8 grams, and cystic
and glomerular damage as well as hyalin casts
were usually observed when the weight exceeded
3 grams.

In fasted rats that were maintaining their weight,
differences in kidney or liver size in relation to
age and to diet were frequently associated with
parallel differences in body weight. Large kidneys
and livers were observed in some of the older
rats fed all diets. Kidneys tended to be large
in rats 300 days and older fed SPE diet, regardless
of body weight. Large livers were found even in
young rats 200 to 300 days of age that were fed
this diet. Although there was a tendency for
kidney or liver weight to parallel body weight, a
somewhat closer relationship was observed between
kidney and liver weights, at least in rats fed stock
or the semipurified diet.

51

In nonfasted rats that were maintaining weight,
both kidneys and livers were larger than those in
comparable fasted rats. The difference between
the size of these organs in fasted and nonfasted
rats varied with diet and age.

In moribund rats, enlarged kidneys were a
frequent finding on all diets, particularly when
weight loss exceeded 100 grams. The extent of
the enlargement observed varied with diet. Some
extremely large kidneys were obtained from rats
fed SPE and SPPB diets. The marked increase
in kidney weight that occurred with increasing
loss of body weight was not accompanied by a
comparable increase in liver weight.

The kidneys and livers from moribund Wistar
rats were generally small, even on SPE diet, in
contrast to the results with comparable BHE
rats fed this diet.

Adrenal weight

RATS MAINTAINING WEIGHT ON stock, SP 8
HVO, anv SPE piets.—In table 37 are sum-
marized data for the weights of the adrenals from
rats in different age groups that had been fed
stock, SP 8 HVO, or SPE diets, and were main-
taining weight at the time of sacrifice. No signif-
icant differences were observed between the adrenal
weights of fasted and nonfasted rats, and the
results recorded are the combined data for both
groups of animals.

The average adrenal weight for 98 rats fed the
stock diet was 19.8 mg., with a wide range of values
from 12.4 to 33.5. No differences were noted with
age, either in the average values or in the distri-

bution within groups, except for a tendency to
larger adrenals in the small group of rats 700 days
and older.

On SP § HVO diet, the average adrenal weight
of 20.2 mg. for 64 rats was similar to that for rats
fed the stock diet, and again, age appeared to have
little effect on the size of this organ. The body
weight of these rats differed on the average by
146 grams so that the relationship of the adrenal
to body weight for these two groups of animals
differed significantly.

On SPE diet, adrenals tended to be larger than
those from rats of comparable age fed stock or SP
8 HVO diets. The largest average adrenal weight
was observed for rats 300 to 399 days of age; seven
of these rats had adrenals exceeding 30 mg. This
age group corresponds to the group previously
shown to have very large and damaged kidneys.

In table 38 are summarized data for adrenal
weights separated according to body weight. Av-
erage adrenal weights tended to increase with body
weight on all three diets. The wide range of values
within groups and the relatively low correlation
coefficients of 0.35, 0.55, and 0.38 for stock, SP 8
HVO, and SPE diets, respectively, indicate that
factors other than body weight were also in-
fluencing the weight of this organ.

Rats LOSING WEIGHT ON stock, SP 8 HVO,
AND SPE pists.—Data for the size of adrenals
from sick or moribund rats fed stock, SP 8 HVO,
or SPE diets are summarized in table 39. The age
groups available differ, depending upon the influ-
ence of these diets on survival. Adrenal size was
influenced appreciably by the extent of weight loss

TABLE 37.—Adrenal weights of rats maintaining weight at different ages on stock, SP 8 HVO, and SPE diets

Average | Average
Diet and age of rats (days) Rats age body
weight
Stock: Number | Days Grams
Less than 200__________ 19 151 390
200' to, 299232 cee 24 249 454
300 to 399_____________ 13 381 452
400 to 499_____________ 13 449 475
500 to 599_.____________ 12 538 493
600't0:690. 2 ee seine 12 652 468
700 and over_____-____- 5 844 468
Average—all_______ 98 389 451

SP 8 HVO:
Less than 200__________ 5 154 524
200 to 299_____________ 12 250 518
S000 S99 ss eee oo Be 31 337 614
400 to 499_____________ 7 457 609
5000599... eee 9 550 677
Average—all_...____ 64 349 597

SPE:

Less than 200__________ 5 154 524
200 to 299_____________ 25 270 599
30060: 39922 22 Soe 34 336 616
400 to 499..........___ 14 455 621
500 to 599_____________ 9 527 637
Average—all_______ 87 345 609

02

Adrenal weight Adrenals weighing—

Average Range Lessthan| 15.0 to | 20.0 to | 30.0 mg.
15.0 mg.}19.9 mg.|/29.9 mg.jand over

Mg. Mg. Percent | Percent | Percent | Percent
18.9 12. 4-23. 6 11 53 37 0
19. 2 14, 0-24. 5 8 50 42 0
19.7 13. 6-24. 4 8 46 46 0
19. 6 15, 4-24. 6 0 46 54 0
20. 1 13. 7-25. 8 ANG 25 58 0
20. 3 14, 5-26. 0 8 58 33 0
25. 6 17. 9-33. 5 () 20 60 20
19.8 12, 4-33. 5 8 46 45 1
19, 2 14, 3-21. 2 20 20 60 0
18.0 13. 8-24. 3 8 67 25 0
21.0 14, 3-32. 7 3 45 48 3
19.9 11, 1-27. 4 14 29 57 0
21.0 15. 4-26. 0 0 33 67 0
20. 2 11. 1-32. 7 6 44 48 2
20. 8 19, 8-21. 8 0 20 80 0
20. 4 14, 8-27. 7 4 40 56 0
27.0 17. 1-55. 3 0 6 74 21
23:3 17. 1-29. 0 0 14 86 0
23. 0 16. 9-28. 4 0 33 67 0
23: 7 14, 8-55. 3 1 21 71 7

TABLE 38.—Adrenal weight in relation to body weight of rats fed stock, SP 8 HVO, and SPE diets

Adrenal weight Adrenals weighing—
Average Adrenal
Diet and body weight of Rats body to body
rats (grams) weight weight Less
Average Range than 15.0 to | 20.0 to |30.0 mg.
15.0 mg.j19.9 mg./29.9 mg.Jand over
Mq.|/

Stock: Number | Grams Mg. Mg. 100g. | Percent | Percent | Percent | Percent
300 to 399____________- 16 372 ibefs Uh 12. 4-22. 6 4.8 19 62 19 0
AQ0 tot 4490s = 2 eae 26 430 10. 6 13. 7-29. 3 4.6 8 46 46 0
450 to 499_____________ 43 471 20. 4 14. 6-25. 9 4.3 i 40 56 0
500 and over____-_____- 12 547 21. 7 16. 3-33. 5 4.0 0 42 50 8

SP 8 HVO:

400 to 499_____________ 10 466 16. 7 11. 1-20. 1 3. 6 30 60 10 0
500 to 599___-_________ 20 547 18.8 14, 3-24. 5 3. 4 5 60 35 0
600 to 699____________- 26 646 21.5 16. 3-32. 7 3.3 0 ol 65 4
seve 700 and over__________- 8 730 23. 2 18. 4-28. 9 3. 2 0 25 75 0
400 to 499_____________ 5 471 19. 1 15. 2-24. 9 4.1 0 60 40 0
500 to 599- ==.) Le 43 560 22, 4 14. 8-47. 8 4.0 2 21 74 2
600 to 699__._________- 30 641 25.3 17. 1-35. 6 4.0 0 10 80 10
MOOMONAOO See ee 8 736 26. 6 17. 1-55. 3 3. 6 0 38 38 25

TaBLeE 39.—Adrenal weights of rats losing weight at different ages on stock, SP 8 HVO, and SPE diets

Adrenal weight Adrenals weighing—

Average |__
Weight loss, diet, and age Rats | Average} weight
of rats (days) age loss Less 20.0 to | 30.0 to | 40.0 mg.
Average Range than 20.0) 29.9 39.9 and
mg. mg. mg. over
Weight loss less than 100
grams:
Stock: Number | Days Grams Mg. M Percent | Percent | Percent | Percent
300 to 699_________ 5 592 56 21.7 18. 4-26. 7 40 60 0 0
700 to 799________- 4 763 65 25.3 15. 1-24. 7 25 50 25 0
800 and over--_--__- 5 853 66 30.0 | 26. 5-36. 3 0 60 40 0
SP 8 HVO:
Less than 400______ 7 245 34 20. 5 17. 1-32. 6 fal 14 14 0
400 to 599_________ 12 491 61 23. 8 14, 4-41-2 33 50 8 8
Bameue CORO OHU ME Bee 9 669 46 25. 8 19. 5-35. 9 11 78 ita 0
Less than 300______ 9 185 23 23. 5 17. 6-33. 5 33 44 22 0
300 to 499_________ 39 401 Hil 28.9 17. 4-44. 5 3 62 28 8
500 to 699_________ 17 590 52 32.8 | 25. 2-63. 6 0 41 47 12
Weight loss more than 100
grams:
Stock:
300 to 699_________ 8 521 125 37. 1 26. 9-53. 1 0 25 50 25
700 to 799_________ 4 776 193 38.0 | 23. 8-47. 3 0 25 25 50
800 and over______ 2 808 161 45. 2 33. 6, 56. 7 0 0 50 50
SP 8 HVO:
Less than 500______ 5 422 155 32.7 26. 3-39. 3 0 40 60 0
500 to 699_________ 15 600 169 35. 7 16. 8-47. 5 13 tf 40 40
sue 700 and over_____- 9 829 205 31.8 18. 0-45. 0 11 33 33 22
Less than 400______ 20 352 150 39. 4 28. 5-58. 4 0 10 55 35
400 to 499_________ 23 443 164 36. 5 18. 0-56. 7 | 17 39 39
500 to 699_________ 32 583 160 35.3 24. 3-57. 7 0 28 47 25

before sacrifice, and the results have been sepa-
rated accordingly. Even when weight loss was
less than 100 grams, adrenal weights tended to be
larger than those found in animals that were main-
taining weight. Adrenals from rats fed SPE diet
were consistently larger than those from rats of

comparable age fed stock or SP 8 HVO diets.
Adrenals tended to increase in size with age, in
contrast to the results for rats that were maintain-
ing weight. When weight loss exceeded 100 grams,
adrenals were large for all age groups and the in-
fluence of diet was no longer apparent.

33

ADRENAL WEIGHT AND KIDNEY DAMAGE.—A
tendency for large adrenals to be associated with
damaged kidneys is seen in table 40. When
adrenals weighed less than 25 mg. there was little
evidence of kidney damage in rats that were main-
taining weight on stock or SP 8 HVO diets. In
the few rats with adrenals exceeding 25 mg., some
kidney damage was generally observed.

In rats fed SPE diet, kidney damage was
apparent in several rats with adrenals weighing
less than 25 mg., and the extent of the damage
tended to increase with the size of this eland.
In rats that were losing weight at the time of
sacrifice, the extent of the degenerative changes in
the kidneys tended to parallel adrenal size.

Large adrenals were observed occasionally on all
diets, accompanied by kidneys showing little or
no damage. These results suggest that adrenal
weights may be reflecting the health of the rat and
that the apparent parallelism with kidney damage
may be the result of the high incidence of renal
disease in these rats.

Rats FED SPM, SPB, anp SPPB piEts.—
Limited data on adrenal size in rats maintaining
weight on SPM, SPB, or SPPB diets are sum-
marized in table 41. The adrenals were similar

in size with all three diets and did not differ
appreciably from those in rats of comparable body
weight fed SP 8 HVO diet. They represented
3.3 mg./100 g. of the body weight, a value con-
siderably lower than that obtained for the smaller
rats fed the stock diet (table 38).

In moribund rats (table 42), adrenals tended to
be large even when weight loss was less than 100
erams. Seventy percent of the adrenals from rats
500 days and older fed SPB or SPPB diets ex-
ceeded 30 mg. When weight loss was more than
100 grams, adrenals were large, regardless of age
or diet, except for the tendency to smaller adrenals
in the rats fed SPM diet that were less than 500
days old.

RaTs FED OTHER EXPERIMENTAL DIETS.—In
table 43 are summarized data for adrenal weights
of rats fed all other experimental diets. The
results are for moribund rats except for a group fed
SPW 8 HVO diet, in which egg white replaced the
casein and lactalbumin of the semipurified diet,
and a group fed egg yolk with or without mineral
supplementation. Because of the limited amount
of data for most of these diets, the results are
recorded as average values without separation by
weight loss. There was considerable variation in

TABLE 40.—Adrenal weight in relation to extent and kind of kidney damage in rats maintaining or losing
weight on stock, SP 8 HVO, or SPE diets

Weight status, diet, and adrenal weight (mg.)

Rats maintaining weight:
Stock:

Iuess: than 20.02.022.- 2.61222. 5. 5-25 kee ee

20.0 000240. 222 eee eee seme:

25.0 and over_______________________._____.__-

SP 8 HVO:
Less than 20.0___

90,0 t0 24.9 -... os. ae Stee,

25.0 and over______._._____._-____.-___------
SPE:

Less than 20.0.._.__._______........_._.____...
DOOMO 2419: 2 ihe 22 Seon oe es a
29.0 BNG OVele ano Sh nee Bee As Bees

Rats losing weight:
Stock:

Less than 20.0____________________ ee
DOO TO D4 On a 2 ate oe was oats Se ee
DONE OV DOO ten Bea a ae ey
OOOO Osea el an ed te 1 or ee

40.0 and over___-
VO:

Less than 20.0

Ca SoS Se Sasee ee eee ee See Sele ae

DOO TONDO 0 Wie hata i

30.0 to 39.9

34

Mame CUO 3 ee tS ee oe ee
ZOO MO 24,9 Be eo ee eS ek ee ee
D250 TO. 200 tse eet te eee eae
OO NEO a Orie ste St wa ed ft Ts che I
AQ OV AD GOV OTS. 2) xtotne betas hve are Pe

Histological rating for kidney
Average damage
Rats adrenal
weight
Hyalin Cystic |Glomerular
Number Mg. Score Score Score

46 17:2 0.3 0.1 1
Bil 22. 4 .4 ml al
6 26. 4 125 IO 5

22 16. 6 2 0 0
16 21.9 mo .2 .2

2 26. 7 1.0 0 0

16 18.3 .8 0 0

32 22.6 12 2 0
15 2heA 1.6 HO, .3

3 17.6 Riri 3 0
4 22.8 1.0 .8 .8
i 27. 7 2.3 at a
8 34.9 2.0 2.0 2.4
5 48. 6 2.6 2.2 2.8
12 17.7 26 Oo Sil

8 22. 1 8 i) 0
12 27. 6 1.3 .8 10
15 34. 1 2.2 126 5
9 43.9 2.4 1.9 16
3} 18 17, 1.0 aN,
15 22. 5 15 1.0 ath
33 Dine 2.3 1.9 1.3
56 34. 2 2.3 2.9 1.8
28 46. 1 2.4 2.9 2.1

Tas Le 41.—Adrenal weights of rats maintaining weight at drflerent ages on SPM, SPB, and SPPB diets

Adrenal weight Adrenals weighing—
Average | Average
Diet and age of rats (days) Rats age body
weight | Average Range Lessthan| 15.0 to | 20.0 to | 30.0 mg.
15.0 mg.{19.9 mg./29.9 mg.jand over
SPM: Number | Days Grams Mg. Mg. Percent | Percent | Percent | Percent
Less than 300_______--- 13 214 553 17. 4 7. 0-26. 3 23 38 38 0
3000/4992. a ee 6 399 672 21. 4 19. 0-24. 0 0 33 67 (0)
HOOntOr599e2 o = 222 L 2 550 624 22. 4 19. 6, 25. 3 0 50 50 0
PB:
Less than 300________-_- 13 214 520 16.9 11. 5-20. 3 31 38 31 0
300 tor49902 2 = 28 G 413 596 21.2 16. 1-30. 8 0 43 43 14
500 to 599_____-_______- 3 549 673 22, 2 19. 9-23. 6 0 33 67 0
Less than 300_________- 14 217 535 18.7 5. 7-28. 3 21 36 43 0
SO0ttOs4 Ore. os 5 412 644 20. 8 14, 2-26. 7 20 20 60 0
SOOO 99ue sae 6 550 728 23. 7 18. 6-29. 7 0 17 83 0

TaBLeE 42.—Adrenal weights of rats losing weight in two age groups fed SPM, SPB, and SPPB diets

Adrenal weight Adrenals weighing—
Weight loss, age of rats Average | Average
(days), and diet Rats age weight Less | 15.0 to! 20.0 to| 30.0 to| 40.0
loss Average Range than 19.9 29.9 39.9 mg.
15.0 mg. mg. mg. and
mg. ; over
Weight loss less than 100
grams:
Less than 500 days: | Number| Days Grams Mg. Mg. Percent| Percent| Percent | Percent| Percent
SIRI iin Sera ll 358 49 23. 7 17. 7-36. 8 36 45 18 0
SRB Gs ieee un 9 308 46 24. 3 15. 2-32. 1 0 22 56 22 0
SRP Bere sos 22 338 42 26.5 12. 8-50. 2 14 9 55 14 9
500 days and older:
SPMr feels eis if 585 30 28. 9 17. 0-39. 7 0 14 29 57 0
SRBisetsses 5 Fe rf 671 53 34. 6 22. 9-47. 2 0 0 29 29 43
SRP Bid art 4). 10 625 66 33. 4 21. 1-45. 8 0 0 30 40 30
Weight loss more than
100 grams:
Less than 500 days:
SIRI Meine Le 6 421 144 25.1 16. 3-35. 7 0 33 50 16 0
SIRE tenes S 5 450 186 36. 5 25. 5-48. 5 0 0 40 20 40
SRP Bei ma no 5 397 192 36. 9 28. 9-52. 2 0 0 40 20 40
500 days and older:
hey SIA GaN Ree ge 7 775 207 34, 2 26. 8-44. 9 0 0 29 57 14
NIBB sues Wie 13 616 186 36. 4 16. 6-53. 8 0 8 15 46 31
SPBPB es 8 568 168 34. 3 24. 9-44, 4 0 0) 38 38 25
the loss in body weight before sacrifice and many ~— rats. Wistar rats fed SPE diet had generally

of the differences observed seem to be related to
the extent of this loss.

Adrenals tended to be relatively small in rats
fed SPE diet supplemented with vitamin B, with
or without choline, despite the extensive weight
loss of most of these rats. Exceedingly large
adrenals were observed in rats consuming 100
percent egg yolk or whole egg even before weight
loss became excessive. Supplementation of egg
yolk with 3 percent salt mixture resulted in a re-
duction in adrenal size from an average of 33.7 mg.
to 23.0 mg. Wistar rats, except for one with an
exceedingly large adrenal (91.7 mg.), tended to
have smaller adrenals than comparable BHE

larger adrenals than did those rats fed SP 8 HVO
diet, thus showing a dietary response similar to
that observed with BHE rats.
Discussion.—Although data on the weight of
rat adrenals have been reported by several investi-
gators, relatively little information is available
for animals comparable in size to the experimental
animals considered in this publication. As the
result of domestication of the wild Norway rat
(160), a marked decrease in adrenal weight has
occurred. Donaldson (50) reported 49 mg. as the
weight of two adrenals for 340-gram rats of the
Wistar strain. The value recorded by Freuden-
berger (70) for animals of comparable size is

59

Tas ie 43.—Adrenal weights of rats fed other experimental diets

Average Adrenal weight
Strain and diet Rats Average weight
age loss
Average Range
BHE rats
SPE supplemented with— Number Days Grams Mg. Mg.
Choline) 0:59 2 5 kee ee ee eee 22 474 136 33. 9 | 22. 7-53. 3
Bioy 0:00 mig, LOO: emis oe ee ee 8 463 La 32.5 | 21. 5-39. 9
Choline, 0.5% + Bi, 0.01 mg./100 gm______________ 10 434 114 32.6 | 18. 6-47. 2
Bey, Ofo me. / TOO) oma. se 235 ee ee ee 7 465 180 30.1 | 23. 6-35. 5
Choline, 0.56% + Be, 0.5 mg./100 gm_________-__-___ 9 412 128 28.0 | 21. 8-40. 7
Choline, 0.5%+ Bi, 0.01 mg./100 gm.+ Bg, 0.5 mg./

AIC 6) 0k? «ine me ean ee ne eee eee Cine EN eNES 10 430 138 32.1 | 21. 7-42. 9
(Holesterol nOS4 Gp sic at oe naan eee ee eee te < 460 155 32.4 | 24. 0-40. 2
Cholesterol, 1.38% - -~ 2 e e 9 406 142 33.5 | 25. 0-40. 9
IASCORDIG e010, (03 Op = 2-2 ce ee eee eee ee 8 436 129 34. 0 | 19-9-44. 1
Ascorbic acid, 0.2%-+ cholesterol, 0.46%__..__._-__- 9 434 183 36.9 | 30. 2-58. 6

BE TOCEV© 2220S Fea Se ee eee 4 586 cage 30. 8 | 20. 6-42. 1
Nel Edges Hl 62) 0 ap eee ee pan Deg ea ee SRN Pee DO ya 15 553 98 34. 0 | 17. 9-60. 8
RS? UG eared oe SO ee es eee ee 7 514 109 28.9 | 23. 0-35. 2
Der ULC R = <2 te a= eee oe ee 6 545 75 26.3 | 17. 3-40. 9
OP UG Dutbers. See ek. 2 oe eee 10 503 66 29.4 | 11. 7-60. 3
fol efron Gipl oI f @ eeeeaeenen es aan ee Mle eee ew, Ipaeo yee oe 17 637 172 32.8 | 19. 0-44. 2
SPO: SeEly Oi 2a cee Pence See ae eee 9 632 118 31.8 | 22. 0-47. 8
Die bi (ires hte go). 6 ka Bee ee 6 483 166 36.3 | 18. 0-47. 7
No gl 0 nee ee tees ee ei em cr en neces GY Peo te) 6 530 155 33. 2 | 18. 6-47. 0
VA a 2 Se ed «ne es 7 473 178 44.5 | 32. 7-53. 3
DEV SER ViOs2a 3/5 ee he ee eyes 6 550 0 15.0 | 11. 4-19. 3
HL O's Ste oS Sk eS ee eee gc eee ee 21 541 129 37.8 | 23. 1-46. 0
Li 0) | Se Se eee ee ee eee er nee ee ey ee 19 400 73 35. 4 | 20. 2-46. 1
Littermates fed—
| Cao ee RS pe Deen ee Nee ee Re ye 5 428 66 27.6 | 28, 2-32. 4
BY iLO ere Oe Pa 2 Se Ia 2 aes IE le pina ee 5 425 35 33. 7 | 24. 4-50. 1
YO74-saltimixture, 3.0222 Se eee 5 430 5 23.0 | 18. 8-26. 6
Diet reversal:
Sacrificed at approximately 250 days:
Na se el ee 3 250 0 22.9 | 17. 5-27, 4
sil Ed 1 eae ae oe ipeeeieiee Miya Reeesiomeeprte tip teen eee, eer ees a ears 3 249 0 23. 0 | 20. 5-26. 2
Continued on—
BSG be al 2 he a Sr AS ee 2 574 207 25.6 | 25. 3, 26. 0
to} 2g] Sie ene acne nae oan a pee PR Rr Seek Bes ee 2 396 133 30.5 | 22. 8, 38 2
Reversed at 250 days:
Dick changedito Sebo s6o52) 22 6 os ee 4 686 109 33. 4 | 23. 2-40. 2
DEH chanced torstock. 2.2 25622 2S 2 oes ee een Sees 3 577 128 30. 3 | 24. 7-40. 2
Wistar rats
DEES TEL Oe ares: at cee 5 eee ile YO. ek ee eee 9 (20 106 24,2 | 15. 9-41. 1
eee ee ys ane se aS ale ns chs ee, = ed 9 664 80 35.8 | 19.0-91.7

BHE rats from parents fed Wistar stock diet

ol gcd s AAG geeneee Oe OO BEM ne oe Sm Se eyes Rien e 9 703 74 31.1 | 19. 1-48. 3
a ce Oe ee ee oe eo ee a eee ee 9 456 81 32.3 | 17. 8-46. 0

diet on adrenal size have also appeared. High-
protein diets have resulted in larger adrenal
weights than were obtained with high-carbohydrate
diets (32, 97, 181). The response to protein from
the same source may vary, depending upon the
specific combination of dietary ingredients. Fet-
ter and Neidle (60) and Ingle, Ginther, and Neza-
mis (98) observed increased adrenal weights on
high-fat diets, although the differences observed
by Ingle were small.

There is general agreement that many kinds of
shock or stress result in increased adrenal size.
Tepperman, Engel, and Long (180) and Sayers

somewhat smaller, 31 mg. For male rats of the
Slonaker strain weighing 340 grams, Addis and
Gray (4) obtained a value of 37 mg. According
to Freudenberger (70), there was little evidence
for strain differences between Wistar and Long-
Evans rats when weight differences between strains
were considered. Yeakel (190) compared adrenal
weights of rats 700 days of age and older with
those of young rats, and reported consistently
heavier adrenals in old rats whether considered in
terms of absolute weight or in relation to body
weight.

Several reports dealing with the influence of

56

(169) have reviewed the many factors that may
result in adrenal enlargement. Infection generally
causes marked hypertrophy. A long-continued
stress ending in death results in marked hyper-
trophy and hyperplasia, with the degree of hyper-
trophy proportioned to the time which elapses
between the onset of stress and death.

SumMary.—In rats that were maintaining weight
when sacrificed, adrenal weights showed relatively
little variation with diet. The largest adrenals
were found in rats on the diet containing 25 per-
cent egg or consisting of 100 percent egg yolk.
Age also exerted little influence on adrenal size.
The relation of adrenal weight to body weight
varied significantly with diet. For any one diet,
adrenal size tended to parallel body weight but
the relatively low correlation coefficients for this
relationship indicated that the weight of this
organ was reflecting other factors as well.

In rats that were losing weight, adrenals tended
to be large and no differences due to diet were
apparent when weight loss exceeded 100 grams.
When extensive kidney damage was present,
adrenals were generally large. The occasional
occurrence of large adrenals in rats with apparently
normal kidneys, however, suggests that adrenal
weights may be reflecting the general health of
the animal rather than a direct relation to kidney
damage.

A comparison of the results of moribund Wistar
and BHE rats suggests a hereditary difference in
the response to stress, but provides no information
concerning possible differences in the weight of
this gland in normal healthy animals.

Thyroid weight

RATS MAINTAINING WEIGHT ON sTocK, SP 8
HVO, anv SPE pinrs.—Data for the thyroid
weights of rats maintaming weight on stock,
SP 8 HVO, or SPE diets are summarized in table
44. The results for fasted and nonfasted rats
have been combined and the thyroid weights in
all cases include the parathyroids. On stock diet,
thyroid weights tended to increase with age up
to 700 days, but the differences were small con-
sidering the wide range of values observed for
any one age group. No large thyroids were
observed in animals over 700 days old, in contrast
to the relatively large adrenals from these same
rats. For rats fed SP 8 HVO diet, age appeared
to be without influence. The average of 11.8
mg. for the thyroid weights of animals fed this
diet was similar to the average of 11.1 for stock
rats, in spite of the large difference in the body
weights of these two groups. On SPE diet also,
age appeared to exert no consistent influence on
the size of this gland. The average weight of
16.2 mg. for the thyroids from rats fed SPE diet
was significantly more than the average for rats
fed either stock or SP 8 HVO diet (P<0.01).

In table 45 are summarized data for thyroid
weights in relation to body weight. The range
of values for any one group was wide and cor-
relation coefficients were relatively low—0.42,
0.46, and 0.31 for stock, SP 8 HVO, and SPE
diets, respectively. There was, however, a con-
sistent tendency for thyroid weights to increase
with body weight on all three diets, as evidenced

TaBLeE 44.—Thyroid weights of rats maintaining weight at different ages on stock, SP 8 HVO, and SPE diets

Thyroid weight Thyroids weighing—
Average
Diet and age of rats (days)| Rats | Average} body
age weight Less 10.0 to | 15.0 to | 20.0 mg.
Average Range than {14.9 mg.|19.9 mg.Jand over
10.0 mg.

Stock: Number | Days Grams Mg. Mg. Percent | Percent | Percent | Percent
Less than 200_________- 19 151 390 9. 7 6. 5-13. 3 63 30 0
ZOOROH299 Meee ee 24 249 454 10. 2 5. 8-15. 7 42 54 4 0
SOOORSIO Mes 13 381 452 11. 2 5. 6-15. 6 31 54 15 0
400 to 499______._____2 13 449 475 11.9 7. 4-21. 7 23 62 8 8
SOO GOR I9E eee ue 12 538 493 12. 6 9. 2-17. 0 8 75 AL, 0
GOOWGO G99 e soe et 12 652 468 12.8 6. 0-16. 6 25 42 33 0
700 and over_________-_ 8 844 468 10. 4 7. 1-14. 9 40 60 0 0

SP 8 HVO:

Less than 200_..__._-_-- 5 154 524 10.5 8. 5-12. 0 40 60 0 0
200 to 299o te eee tee 12 250 518 10. 2 6. 6-18. 7 58 33 8 0
SOO OPS OE See a ae 31 337 614 12.4 6. 7-17. 5 13 74 13 0
400 to 499_____________ Ul 457 609 10. 1 6. 9-15. 7 el 14 14 0

ears CONDO © sha He oc ort! 9 550 677 13. 8 7. 8-19. 9 11 44 44 0
Less than 200_________- 5 154 524 14.5 11. 9-17. 5 0 60 40 0
200) tor299 se ee 25 270 599 15. 0 9. 1-20. 8 4 44 48 4
SOOKTON SOO I Mh Bee ee | 34 336 616 17.8 10. 6-30. 4 0 29 47 24
400 to 499_____________ 14 455 621 13. 9 6. 1-20. 4 21 50 21 U
500 to 599_________-___ 9 527 637 18. 1 12, 3-23. 6 0 a 56 33

oi
ba |

by the increased proportion of large thyroids

among the heavy animals.
Rats LOSING WEIGHT ON stock, SP 8 HVO,

AND SPE pirets.—The thyroid weights of sick or
moribund rats fed stock, SP 8 HVO, or SPE diet

are summarized in table 46, with the results for

rats that lost less than 100 grams before sacrifice
separated from those for rats with more extensive

weight losses.

On stock diet,

thyroids tended

to be somewhat larger in moribund rats than in

TaBLeE 45.—Thyroid weight in relation to body weight of rats maintaining weight on stock, SP 8 HVO, and

Diet and body weight
(grams)

Stock:
300 to 399__________-
400 to 449___
450 to 499____

500 to 599___________|

SP 8 HVO:
400 to 499___-
500 to 599_.________-

600 to 699___________|
700 and over_________|

PH:
400 to 499
500 to 599____
600 to 699__..__
700 to 799

5

Rats

Number

Average
body
weight

Grams
372
430
471
547

466
547
646
730

471
569
641
736

SPE diets
Thyroid weight
Thyroid
(mg.) to
body

weight | Average Range

(grams)

Percent Mg. Mg
2.5 9, 3 6. 0-13.
2.5 10.8 5. 6-21,
2. 4 P15 58-17.
2.4 13.3 7. 5-18.
2.0 9.4 6. 6-12.
2.1 11.4 6. 7-17.
1.9 12.5 8. 7-19
1.9 13. 6 7. 8-17
3.0 14.0 9, 1-16
2.8 15. 7 10. 3-25.
2.5 16. 3 6. 1-26
2.4 18. 0 9. 5-21.

Thyroids weighing—

Less 10.0 to | 15.0 to |20.0 mg.

than 14.9mg.| 19.9mg. and

10.0mg. over

Percent | Percent | Percent | Percent

2 69 31 0 0
7 38 54 4 4
) 25 65 10 0
4 25 42 33 0
0 60 40 0 0
5 35 50 15 0
.@9 19 69 12 0
ah, 12, 38 50 0
=) 20 40 40 0
4 0 46 46 7
a he 37 37 20
fi 12. 0 50 38

TABLE 46.—Thyroid weights of rats losing weight at different ages on stock, SP 8 HVO, and SPE diets

Weight loss, diet, and
age (days)

Losing less than 100
erams:
Stock:
300 to 699___-
700 to 799
800 and over
SP 8 HVO:
Less than 400
400 to 599
600 to 799
SPE:
Less than 300
300 to 499
500 to 699
Losing more than 100

800 and over______-
SP 8 HVO:
Less than 500

700 and over
SPE:

Less than 400

400 to 499

500 to 699

58

Rats

Number

Average
age

583

Thyroid weight

Average
weight
loss Average Range
Grams MQ. Mq.
56 11. 9 8. 6-17. 5
65 14. 7 9. 4-17. 7
66 1%. 1 14, 2-19. 9
24 9.5 5. 7-12. 5
61 13. 4 7. 2-19. 6
50 13. 0 5. 1-19. 4
23 11.5 7. 5-14. 4
51 19. 8 11. 0-32. 9
52 24. 8 13. 3-36. 7
125 14.5 10. 8-18. 8
193 13: 7 12. 0-14. 8
161 16. 1 14. 4,17. 8
155 20. 1 4, 4-30. 4
169 20. 4 9, 3-32. 4
205 18.9 8. 9-30. 8
150 22. 6 8. 3-37. 4
164 24. 2 7. 6-46. 1
160 25.9 18. 8-36. 2

Less
than
10.0
mg.

Percent

me bo
orRoO FNO COCO

Thyroids weighing—

10.0 to | 15.0 to | 20.0 to! 30.0
14.9 19.9 29.9 mg.
meg. mg. meg. and

over

Percent | Percent | Percent | Percent

60 20 0 0
25 50 0 0
40 60 0 0
50 0) 0 0
50 33 0 0
50 38 (0) 0
67 0 0 0
15 46 31 8
12 18 59 1
62 38 0) 0
100 0 0 0
50 50 0 0

0 0 60 20
13 40 20 20
22 33 11 22

5 35 40 15

0 26 48 22

0 9 69 22

those maintaining weight, but the extent of the
weight loss before sacrifice seemed to have no
influence on the size of this gland. On SP &
HVO diet, thyroids were similar in size to those
observed in rats maintaining weight when the
loss in body weight was less than 100 grams but
were larger when the loss exceeded 100 grams.
On SPE diet, a high proportion of the thyroids
was large, even in rats that lost less than 100
grams. The thyroids of rats fed SPE diet were
consistently larger than those from rats fed stock
or SP 8 HVO diets for all groups as long as com-
parisons were confined to animals of similar
age, taking into consideration extent of weight
loss before sacrifice.

THYROID WEIGHT AND KIDNEY DAMAGE.—In
Table 47 are summarized data relating thyroid
size to the bistological findings in the kidneys from

rats fed stock, SP 8 HVO, or SPE diets. Large
thyroids were often associated with kidneys show-
ing extensive damage. Even in rats that were
maintaining weight, thyroid weight tended to
parallel kidney damage. The extent and kind of
damage in relation to the size of this organ, how-
ever, was influenced by diet and extent of weight
loss. Calcium deposition in the kidneys, seen
only in moribund rats, was frequently associated
with enlarged thyroids. Eighty percent of the
rats with thyroids exceeding 30 mg. had kidneys
containing calcium deposits. Calcium was rarely
found when thyroids weighed less} than 20 mg.
except in moribund SPE rats that had lost more
than 100 grams before sacrifice. No data were
available to establish how much of the weight
recorded as thyroid was due to the parathyroid
gland. Results from microscopic examination of

TaBLe 47.—Thyroid weight in relation to extent and kind of kidney damage for rats maintaining or losing
weight on stock, SP 8 HVO, and SPE diets

Weight status, diet, and thyroid weight (mg.) Rats

Rats maintaining weight:
Stock: Number
essithanelseQue sis = eS ese 65
LB OstO LAL OM MeFi en 10
w W55-{ 0) 0) 199 9 a a ce ge 9
SP 8 HVO:
Messithantls iQue ee ee eee! 32
TUCO} raya 12: a ce Te ee 2,
PROC ONIOEO Bees eee eu ee oN 6
SPE:
Wessithanwlls:Q swiss es 2 ere ee 13
THEA LO) rey Tete ae ne aa are 16
15.0 to 19.9___--_- EEE SL Men] Btn en ee 28
ZOLOEtORLO Oisate ee Be ees ee 6
Rats losing less than 100 grams:
Stock:
Wessithanyl3 Qe) ve. 2 ae See ee
MOT ORC ONAL eres ee eo ae STE Re a LT
A MOSLOM LO seer Ae Series ities ie Ne
SP 8 HVO:
Messithanvi3:0f22 ok ed ls
SORE OAR teas ee nn Post ge SF AS a St
ES OMCOMUGO 2 een Ae

Wessithaniis Oe oe = aie ee eI
Se ONC Om ALO wkend se veny et Me
UP SORGOML OO Beets Se Mar bs Se ete ed
PAULUS) ALS i pe
SONOVANGOVer eases et eS
Rats losing more than 100 grams:
Stock:
Wessuthamiil gs: O cuit Pee) Wei i
SEO COAG wate Lh ee ER I la
PHO MCORUOG OM ie bok Cue ee
SP 8 HVO:
IGessathianet'5 Olu se) se
UP HYOVTOWMEOIO Mcte fo eke he A
PAD) AU) CO) 7-42 49 EO tn a
SOOkan doves au wh eo

_

SPE

nov
CONF OD DPD DW

ONON BOW

SPE:
TFesseb an TOU le Uy en he 3
ORC OMIO ROW Limi Car yo ae ee ol 16
PAULO Oe 748 JA as SU a a 41
SOOkan Govier seh save ey ee 14

721-631—64—_5

Average
thyroid
weight

Histological ratings for kidneys

Hyalin Cystic |Glomerular| Calcium

Score Score Score

Score
0 0 0

1.
1.

Coon
on

—
t laa
OoOorRF WOO Wor
Le a ateaers :
ORCA NOW ONwWbW
WWreb oH
aan (SO . .
ON bo ou
ocoooo ooo oo°

=
mE Ob
—
°
oe
~ eo '’ SO
bo 0

CoOonn
_ ©0 COO ooo

Ore

a
i

NWNN ER IO

NN Er A

OHNEN @OF wan

Co LO Ears

Nope oo

ne

NPN
onw
New
re

BROW COORrwW AWN

i)
= he
Onmo AUNN MPwN
PNNWwW AWwWww ANN
WORO WDONW OO

NNNN SNE
POON NORD e
gooocens NONE,
NNN NE,
Nees

an
oO

these glands have indicated that the large thyroids
from these moribund rats were reflecting, in part
at least, enlarged parathyroid glands. More de-
tails (54) are reported in a separate communication
dealing with the thyroid and parathyroid glands
from these rats as seen from microscopic examina-
tion.

Rats FED SPM, SPB, anp SPPB pints.—The
thyroid weights of rats fed SPM, SPB, and
SPPB diets are summarized in table 48. Thyroids
similar in size to those found in rats fed stock or
SP 8 HVO diets were obtained from rats main-
taining weight on SPM diet; those from rats 300
to 600 days of age fed SPB or SPPB diets tended
to be somewhat larger. Enlarged thyroids were
seen frequently with SPPB diet, even in rats less
than 500 days of age regardless of weight loss.
Thyroids exceeding 20 mg. in weight were found
occasionally in animals that had lost more than
100 grams on each of the three diets, as well as
in older rats with weight loss less than 100 grams.
The thyroids from rats with a relatively long life

span on SPM diet tended to be small in spite of
the large weight loss before sacrifice.

Rats FED OTHER EXPERIMENTAL DIETS.—In
table 49 are summarized data for the thyroid
weights of rats fed the remaining experimental
diets; the results are for rats that were losing
weight, with the few exceptions indicated in
this table. Interpretation of the results in terms
of dietary response is complicated by variation in
weight loss in the different experimental series.
Data on rats maintaining weight or with weight
loss limited before sacrifice might reveal differ-
ences due to diet that are not apparent from the
data available.

Thyroids were consistently large, regardless of
weight loss, for rats fed the various SPE supple-
mented diets, and were similar in size to thyroids
obtained from rats fed the unsupplemented SPE
diet. The kind of fat (HVO, lard, or butter) or
the level of fat (8 or 16 percent) appeared to be
without influence on the size of this gland. Re-
placement of egg white for casein in the semipuri-

TaBLE 48.—Thyroid weights for rats maintaining or losing weight at different ages on SPM, SPB, and

SPPB diets
Thyroid weights Thyroids weighing—
Weight status, diet, and Average | Average | Average
age of rats (days) Rats age body weight Less | 10.0to|15.0to| 20.0
weight loss |Average Range than 14.9 19.9 mg.
10.0 mg. mg. and
mg. over
Rats maintaining weight:
‘ : Number | Days Grams | Grams Mg. Mg. Percent|Percent|Percent|Percent
Less than 300_- 13 214 O09 0 10.5 4. 3-14. 7 46 54 0
300 to 499_____ 6 399 672 0 1. 2 4. 2-16. 7 33 50 aly 0
Soa to 599___-- 2 550 624 0 11.6 7. 8, 15. 5 50 50 0 0
Less than 300_- 13 214 520 0 15 8. 1-15. 1 38 54 8 0
300 to 499____- 7 413 596 0 13.1 7. 0-27. 1 29 on 0 14
500 to 599____- 3 549 673 0 16. 1 14. 1-17. 5 0 33 67 0
SPPB:
Less than 300_- 14 217 535 0 12.5 8. 2-19. 0 21 EYE 21 0
300 to 499____- 5 412 644 0 16. 0 13. 3-19. 8 0 60 40 0
500 to 599____- 6 550 728 0 15. 8 9. 6-22. 0 17 33 17 33
Rats losing less than 100
grams:
SPM:
Less than 500- - 11 358 591 49 13. 6 8. 4-18. 2 18 45 36 0
eaee and over __- 6 599 748 44 19.1 11. 9-34. 7 0 50 17 33
Less than 500- - 9 308 508 46 128 6. 2-19. 9 33 33 33 0
500 and over __- 7 671 628 53 15. 0 5. 7-23. 8 14 29 43 14
SPPB:
Less than 500_- 22 338 576 42 17.2 6. 2-27. 6 5 32 32 32
500 and over __- 10 625 618 66 16. 4 12. 2-20. 5 0 40 40 20
Rats losing more than
100 grams:
SPM:
Less than 500_- 6 421 532 144 22.2 7. 1-46. 5 aliy/ 17 al 50
age and over __-_ 8 776 563 198 15. 7 4. 6-30. 1 12 38 25 25
Less than 500_- 5 450 469 186 221 12. 3-28. 4 0 20 20 60
500 and over __-_ 13 616 505 186 23.1 10. 8-39. 0 0 8 31 62
SPPB:
Less than 500-- 5 397 550 192 18.8 9. 5-29. 0 20 20 20 40
500 and over__-_ 7 570 522 177 24. 4 13. 3-36. 5 0 14 14 (ol

60

TaBLe 49.—Thyroid weights of rats fed other diets

Diet reversal:

fied diet resulted in thyroids similar in size to those
from SP 8 HVO rats. Although large thyroids
were occasionally found in rats fed the diet con-
taining 100 percent egg, the average of 18.0 mg.
for the thyroids from 16 rats losing more than 100
grams on this diet was considerably less than the
24-mg. average observed for comparable SPE rats.
On the basis of the limited data available, there
was no evidence that supplementation of the diet
consisting of 100 percent ege yolk with salt mix-
ture had any marked influence on thyroid weight.
When feeding of SPE diet was initiated at 250

Average Thyroid weights
Strain and diet Rats Average weight
age loss
Average Range
BHE rais
SPE supplemented with— Number Days Grams Mg. Mg.
Choline 015,94 Mew Sea ye eS eee ee 22 474 136 25.4 | 12. 9-42. 5
Bi OOo /1O0 ome se eh eee 8 463 131 23. 4 | 17. 3-33. 5
Choline, 0.5%-+ By, 0.01 mg./100 gm_________ 9 437 96 24,1 | 18. 2-32. 8
Bg cOlomms O08 em 222 a. 22s ee SSS vf 465 180 23. 8 | 18. 0-35. 7
Choline, 0.5%-+ Bs, 0.5 mg./100 gm___________ 9 412 218 21.0 | 9. 7-29.7
Choline, 0.5%+By, 0.01 mg./100 gm.+ Bs,

Ovoumip yl OOfomia se Sas ee ee ee 10 430 138 24,2 | 13. 5-89. 8
@holesterolQi4 G0f8 22 saa een eee 7 460 155 22.2 | 19. 0-29. 8
@holesterol, 138%. 2222-2522 -22 ese se- == 9 406 142 23. 3 | 16. 7-29. 4
ANSCORDIC ACld 022005 sweeney eee oe 8 436 129 23. 2 | 18. 1-28. 6
Ascorbic acid, 0.2%-+ cholesterol, 0.46%-__--_- 9 434 183 25. 4 | 13. 6-36. 0

SMO sEViO ewe hes ec Ce Tae 4 586 Tits 14.2 | 12. 0-15. 7
Dole Sal arecl ee sateces <2 eiagries oy eee LN Rh he it 15 553 98 19.9 | 13. 7-30. 1
SiReliGslar diets et less eS hy PG Pee Eo 7 514 109 18.0 | 11. 2-25. 2
eOMOWGberar a igs ies ee AP oe Ce 5 528 80 17.9 | 10. 6-27. 8
SS bwliGhbpudtteneemn = ees Se ee 10 503 66 15.4 | 10. 0-23. 3
SiawlOBEViOee - 222008 ee 17 637 172 19. 0 8. 7-32. 6
SIRDESteViOwne te ee eo be ee 9 632 118 16. 8 7. 3-26. 9
Siadimeshvege) si 2 Ae ee 8 6 483 166 23.7 7. 6-36. 0
Wisse Mae eb oly seus alana” VE RI 6 530 155 19. 4 9, 2-28. 2
DIN 24 0 ke eS ea ee 7 473 178 24.1 | 18. 1-31. 4
SPW SabVi@ teu ec 8 he one Dee pwr ye 6 550 0 10.3 7. 2-13. 9
TEDL] 8) 6 St R25 neg 21 541 129 19. 5 9. 0-45. 8
RYE: Qpettnettas Mee Nemeth RSLS es te 19 400 73 ‘17.9 9. 5-28. 8
Littermates fed—
DL pai 5 428 66 15.6 | 18. 8-17. 6
BYSI() etter 2 ets ee et 5 425 35 19. 7 | 13. 1-28. 8
VOi-saltimixtures 3.0% <= .225. 52-2. == 22 ---_ 5 430 5 16.6 | 12. 9-19. 5
Sacrificed at approximately 250 days:
OY eS i A rc ee 3 250 0 12.4 | 11. 9-12. 7
SIBBieciivaia mesons wea nca yk Gna CIEL Tg Mi 3 249 0 16.9 | 14. 5-20. 8
Continued on—
LOC kevaeertte erga ee Te Oh in Sle See oe 2 574 207 21.5 | 14. 6, 28. 4
OI Fy eiiea Meni Gilden 2a Boeke as Se 2 396 133 W752 | Li 1 AG 4
Reversed at 250 days:
Stockichanegedcto SPMustle St es eee 4 686 109 19.7 | 18. 0-22. 8
SPH changed to'stocks 222) eo" soi sos 2 tL 3 577 128 22.4 | 21. 3-23. 6
Wistar rats
SIRESWEDV Oitnpisent cus Vai ie Ml) a ee TEEN sh Ut 9 727 106 16. 1 | 11. 3-30. 9
SSI Bib ini east Putue ue GA ed ee ane ee AY 9 664 80 22,2 | 15. 3-34. 1
BHE rats of parents fed Wistar stock diet
DIRAS HEV VQ) Rhuasie. Seonhh tlie et oth ie Se 9 703 74 12.9 5. 8-20. 6
IDWS aes ia VS SSS Pe ee oe 9 456 81 21. 7 9. 9-49. 6

days, thyroids tended to be smaller than when
this diet was fed throughout life, but more data
are needed to establish the significance of this
difference. The thyroids from Wistar rats fed
SP 8 HVO diet and SPE diet were similar in size
to those from comparable BHE rats fed these
diets, and no evidence for strain differences was
apparent from data on moribund rats.
Discuss1on.—Donaldson (50) reported a value
of 60.9 mg. for the total thyroid weight in male
rats weighing 450 grams. A linear relation be-
tween body and thyroid weight was observed.

61

Freudenberger (70) reported still larger thyroid
weights of 83 mg. for the Long-Evans strain of
rats, and observed significant differences between
the Wistar and Long-Evans strains whether
considered in terms of absolute value or in relation
to body size. The thyroid weights reported by
these investigators are considerably larger than
those reported in this publication for BHE or
Wistar rats. The lack of the close correlation
between this gland and body weight such as has
been reported by Donaldson (50) may be due to
the large weights of many of the animals, which
undoubtedly represent, in part at least, fat
deposition rather than growth of active tissues.

Enlargement of the thyroid gland may be asso-
ciated with a low iodine intake. Low iodine
intake, however, did not appear to be responsible
for the enlarged glands observed with SPE diet
which contained 1 p.p.m.iodine. Thompson (182)
reported evidence that the occurrence of hyper-
plasia in the thyroid gland may be influenced by
the relative amount of iodine and calcium in the
diet. Differences in the relative amounts of these
two elements also fail to explain the differences
observed with diet in the size of the thyroids of
BHE rats. The possibility of some other mineral
imbalance in the diets investigated has not been
excluded.

Summary.—Diet appeared to influence the size
of the thyroid more than that of the adrenal gland
in rats that were maintaining weight when sacri-
ficed. The largest thyroids were found in rats fed
SPE diet; on SPPB diet this gland also tended to
be large. The influence of age on thyroid size
varied with the diet. Thyroid size tended to
parallel body weight but, as with the adrenals,
the correlation coefficients were relatively low.

Thyroid size varied with age and extent of
weight loss as well as with diet in rats that were
losing weight when sacrificed. Large thyroids
were often associated with kidneys showing ex-
tensive damage. Although with some diets,
calcium deposition tended to parallel thyroid size,
possibly owing to parathyroid enlargement, cal-
cium deposits in the kidneys of rats fed SPPB diet
occurred rarely in spite of thyroid enlargement.

The thyroid weights for moribund Wistar rats
fed SP 8 HVO or SPE diet were similar to those
for comparable BHE rats, and provide no evidence
for strain differences with regard to thyroid size.

Thymus weight

Data on the thymus weights of BHE rats were
obtained for a limited number of diets, and the
results are summarized in table 50. A marked
decrease occurred in the weight of this gland be-
tween 150 and 250 days of age regardless of the
diet, followed by a relatively small decrease with
age thereafter. Donaldson (50) reported heavier
thymus glands for Wistar rats of comparable age,
with glands weighing 211 mg. at 150 days of age
and 123 mg. at 250 days.

62

Tas ie 50.—Thymus weights of rats at different ages
on stock, SP 8 HVO, SPE, SPM, SPB, and
SPPB diets

Thymus weight
Diet and age of rats Rats |Average =
(days) age
Average| Range
Stock: Number| Days Mg. Mg.
Less than 200_-__-_ Vo 148 106 52-155
200 to: 2992se5 ==) 11 258 66 36-138
300 to 499_______ 8 454 44 28- 58
500 and over_____ 19 586 33 20- 48
SP 8 HVO:
Less than 200__-_- 5 154 151 | 100-196
200 to 299_______ ee 254 65 36- 80
300 to 499_______ 4 417 69 41-— 86
500 and over_____ 10 650 48 28- 72
SPE:
Less than 200____ 6 140 132 92-178
200 to 299__..._- 14 270 71 49-101
300 to 499_______ 13 308 Di 22-113
500 and over_____ abt 510 33 22- 45
SPM:
Less than 200_--_- 5 154 118 64-167
20010 299o ee ces 5 249 58 46- 70
300 to 499_______ 5 441 49 40- 72
500 and over_____ 4 793 44 25- 64
SPB:
Less than 200____ 5 154 125 81-164
200 to 299_______ 5 250 57 38- 82
300 to 499_______ 6 426 45 27-— 83
500 and over_____ ff 633 44 31- 56
SPPB:
Less than 200_-_-_-_ 5 155 152 78-193
200 to 299_______ Gs 250 75 55- 92
300 to 499_______ 2 340 50 33, 66
500 and over_____ 9 634 63 45- 97

Chemical investigations
Kidney

Stock, SP 8 HVO, anv SPE piets.—Data for
moisture, protein, fat, and ash in the kidneys from
rats fed stock, SP 8 HVO, and SPE diets are
summarized in table 51. The results for percent-
age composition on a dry-weight basis and for
total content are included.

The data for rats maintaining weight were from
fasted animals except for the two age groups
indicated for stock rats. The results for young
fasted rats fed stock diet were similar to those
for older nonfasted rats. Neither diet nor age
was found to influence the composition of the
kidneys from these animals. Differences in con-
tent were related chiefly to the size of the kidney.

Separation of the data for moribund rats was
on the basis of weight loss only. The results for
nonfasted and fasted moribund rats have been
combined because there was no apparent difference
in the composition of the kidneys from these two
groups of animals. The kidneys from rats that
had lost less than 100 grams were similar in
composition to the kidneys from rats that were
maintaining their weight at the time of sacrifice.
The large kidneys from rats that lost more than
100 grams tended to have a high percentage of
moisture and protein and a low percentage of fat.

‘SPI poysBJUON |;

08 OTT O9TT LZ 6-2 °€ 9 € 7I-S 9 06 1 '‘06-¥ 62 8 98 I ‘G8 9¢ “2 868 CRW | haiye ain s te aiE RS an vacee ads
a4 82 SIL 08-17% cua G TI-9 @ o OL 0 “€6-% “LL v V8 I G8 18 9 ITL SIP ae erseeme ca), Mek anei OAH 8 d§$
GE 9g €19 te 1 87 L'6 -G'L 0°8 0 ‘06-F ‘98 ¢ 18 6 18 VL € 969 Vga Oe | Glin 5c .ci ne ae 49048
:SUIRIS ONT UBYY o10UL SurIso'T
LE OL 909 G ‘9-8 T 0G & 9I-G 'G LTT 0 68-9 ‘92 1°18 T 62 86 '€ 9G§ OG NW ies te ads
LI 09 OSE L°S-6% oT I ‘81-2 TT 9 FI 9 ‘98-L ‘FL 8 ‘08 OLL F6 T OOF Gee OAH 8 d$
LG 9g LLE ein $4 AG jee) leat LEE € GI 6 ‘C8-6 ‘T8 ¢ C8 T 08 VEG 628 Se cea pret Dorma Per 4909S
ISUIBIS OOT UBY} SSoT SUISOT
0Z 8¢ 19€ § 9-1 € 97 F 9I-S 6 6 GI T ‘28-9 ‘92 G 6L Sy ed 90 I8P AS en So ee eee 669 0% OOF
1G 89 LOP 9°S-7 7 6G & PVI-L CL Suse T ‘98-G ‘PL € 62 G82 It G EGE Leh) | eae set WA 66€ 94 00E
0Z vg 60€ g29-9-6 cS Cp iicalle tall al T ¥8-0 ‘92 F 08 COLL 89 T CSG ju en aan, Cas 00g Wey} dae
93 89 86E VOmce 0°S 8 SI-T ‘OT 0 FI v T8-P 92 F6L L972, &6 % LVG aes See cen 66¢ 94 00G
8I &¢ 966 DROSS Link OOLEAL GL GFL 9 “Z8-L ‘FL 1°82 POL 09 ‘T COP S| | Seer aa ag 667 9F 00E
8T Tg TLZ 9 ‘GS-1 'P Tg SuLL=8 GL 6 FI 118-8 ‘PL G82 g SL Ty T 696 Oe) | aera 00E UY} SsorT
‘OAH 8 dS
9G 9¢ 98E vS-Z 'G Sie T ‘GI-2 ‘OT 9 TL 6 6L-L ‘8L 6 ‘82 G82 83 7% OSG Tn einen poe t 669 94 00¢
GG £9 69€ & G-0'¢ Tg 8 Si-9 eI 6 FI 9 ‘T8-T “62 T ‘08 8 GL bL T GIP Cpa see ee 1 66F °F O0E
OF LY 916 IS SSo5¢ GT 9 ‘€I-0 ‘ET € €T G ‘08-8 “GL G ‘8L €¢L oy T VEG Grom, lst eee O00E UBYy Sso'T
‘by | 4 BY qUaola gq quaa quaola quan quaola quao quad =| supp | shvg Jaq :yooy
“Og lad ~LIq -lad -UN AT [VYUSIOM SULULBJULB IAT
a5e 93U asV
asuvyy -1dAV asUvy -10AV asuvy -I9AV
sv | a | Urey qySToM
-O1g a Aoupry | ase (skep) sper jo
UsV qe uloyOlg IdYeM eyo 93U syey ase pue “Jorp ‘snyeqs FUSION
-IdAVW | -loaAy
4U9}U0d [eyo], yystom AIp WO poseg

S19UP AdS' PU” ‘OAH 8 dS ‘420}8 wo sabp quasaffip yo yybram buiso] 40 Burmnjurpwu syou mouf shaupry ur yso pup ‘yof ‘waj04g— 1G LIEV,

63

Table 52, in which the results are separated on
the basis of kidney weight, shows more clearly
this relationship between kidney size and composi-
tion. The results for kidneys of the same size
were similar regardless of age, diet, or weight
loss. The percentage of fat in the kidney tended
to decrease and the protein to increase with
kidney weight. Although total content of both
protein and fat tended to increase with kidney
size, enlargement of this organ was due in large
part to increased protein. Ash content also
increased consistently with increasing kidney
weight, but no consistent relation between the
percentage of ash and kidney size was observed.
High ash values were found most frequently in
rats fed SPE diet, but values exceeding 6 percent
were obtained occasionally in stock and SP 8
HVO rats. Calcium deposition in the kidney did
not necessarily parallel the percentage of ash in
this organ. Determination of ash in the kidney
was the least accurate of the measurements made,
because of the relatively small samples available
for analysis.

SPM, SPB, anp SPPB piets.—In table 53 are
summarized data for the composition of kidneys
from rats fed SPM, SPB, and SPPB diets. With
these diets, there was little evidence that age or
diet influenced the composition of the kidneys
from rats that were maintaining their weight,
except for the low ash in the kidneys of young
SPPB rats. The higher content of fat, protein,
and ash in rats 400 to 600 days old was a reflection
of the larger kidneys in these older animals. In
the moribund rats with weight loss over 100
grams, the trend for a high percentage of protein
and a low percentage of fat in the large kidneys
of SPB and SPPB rats was again apparent. The
percentage of ash rarely exceeded 6.0 percent
and values for rats fed SPB and SPPB diets

were similar, although calcium deposits were seen
more frequently in kidneys from SPB rats.

OTHER EXPERIMENTAL DIETS.—In table 54 are
summarized protein, fat, and ash data for the
kidneys from rats on additional experimental
diets. Analyses were not made for kidneys from
rats on all of the diets under investigation.
Again, the differences observed tended to parallel
kidney size. The low percentages of fat in
kidneys from rats fed supplemented SPE diets
were similar to those found on the unsupple-
mented diet, and were characteristic of those
observed with large kidneys regardless of diet.
The tendency for ash values to be high in the
kidneys from rats fed the supplemented SPE
diets was comparable to that observed in moribund
rats on the unsupplemented diet.

WIsTAR RATS FED SP 8 HVO anp SPE pirts.—
Kidneys from Wistar rats fed SP 8 HVO diet were
similar in composition to those of the same size
from BHE rats. Kidneys from Wistar rats fed
SPE diet differed from those in moribund BHE
rats fed this diet, as might be expected considering
the differences in kidney size. The relatively
high percentage of fat in the kidneys of Wistar
rats fed SPE diet was of questionable significance
in view of the limited data available. Ash values
were generally low when compared with those
found in the kidneys of BHE rats fed SP 8 HVO
or SPE diets.

Summary.—The influence of diet on the com-
position of the kidney depended chiefly on its
influence on the size of this organ. Enlargement
of the kidney was accompanied by an increase
in percentage of protein on the dry-weight basis
as well as in total protein content, and by a decrease
in the percentage of fat.

High ash values were found most frequently in
rats fed SPE diet. Calcium deposition in the

TasuE 52.—Protein, fat, and ash in kidneys of different weights from rats fed stock, SP 8 HVO, and SPE

diets
Average Based on dry weight Total content
Diet and range of kidney Rats kidney | Water
weights (grams) weight
Protein Fat Ash Protein | Fat Ash
Stock: Number | Grams | Percent | Percent | Percent | Percent Mg. Mg. | Mg.
Kidney less than 2.00___________ 20 1. 65 76. 4 79.6 13. 5 4,9 316 52 19
2:00:40 2.99232 ee SS 7 2.74 78.9 Si 7 Adeee yar 465 67 33
3.00 to 4.99___.._...__-__._______ 4 3. 74 81. 2 Odeo 8.0 4.8 613 56 34
SP 8 HVO:
Kidney less than 2.00___________ 40 1. 64 76.5 79.2 14. 6 4.7 304 56 18
D200 tO. 2190 ee td Bo Fe 5 2.37 76.8 80. 2 132% 5. 2 442 75 29
3:00 \t0:4.99... ee 8 4.19 82. 6 85. 5 9. 4 516: 627 64 41
eae COO: 092 252 «sen 2 2 a 6 6. 94 8353 84. 4 9.1 4.5 979 103 53
Kidney less than 2.00___________ 30 1. 59 76.7 80. 1 14. 0 5. 0 297 OL 19
OO SON OO tae, ce CRE ee 10 2. 40 80. 9 79.3 12.6 4.0 400 64 21
S00! G0;4,99 = 1 oho 80. 1 82. 1 1b Ba 4.6 606 82 34
ROO GO: 9:99).2.26 > Bee ood 19 6. 90 82. 5 85. 2 8.5 6.1 1027 102 72
10.0 and! over. =.2-5- 2 Sees 6 i a 82. 7 87.0 Seti Das: 1675 153 96

64

GY ai) 669 Vaz lic T’¢ 6. LE=6:6 Ze OT Fy S8-T ‘92 T G8 6 G8 OLS T9¢ | | rags ek ine ddd8
gE 69 962 Taig Sa a 8 ‘GI-G '€ 9°9 ¢ “L8-9 G8 G8 G G8 08 °¢ 669 cheese ee peer eros rr dds
61 6¢ Ge Go Ger G c'T GeLl=l 6 9 FI T 98-T “82 € ‘08 6 “G8 69% gE9 ea | Ee ce earns ners a Wds
:SUIVIS OOT UBY} V10UL SUISO'T
€& 68 90¢ EeSeG av. GT T “€6-G 6 6 ET € G8-6 TL 997 Q Lh 06 € STP Ose ar | sepia eae Se adds
GG SY 69€ 8 °S-0 7 v'? 6 FI-0 2 @ OT 1 ‘O8-§ “GL G LL € LL 9T % TGV Oty 2a aoe 4 ote aged See aie dds
GG OL VrV 6 77 E vv L ¥I-0°8 0 T & 148-0 TL S Lz 8 82 GL S8P OLA 51 |e ays ees Fe eee Wds
:SULBIS QOT UBY} SST SUISO'T
6T £9 OGE € 9-1 7% & 7 E-81=8 aif ¢ TI 8 “28-0 “22 ¢ 08 GEL, 86 T EGG Cet See en 669 °F OOF
8 8V GLE GS-0 G GG 0 ‘91-6 ‘TI 6 ET 2 “T8-0 82 F 08 6 LL 67 T G66 | Seen Soe nal 668 °F 00%
‘ddds
IG 89 O8E GS-8 E ov G ‘02-0 ‘OT Soa T ‘P8-T “82 8 ‘62 8 LL GEG 867 OSes nae See ee 66¢ °F OOF
ST 0g O8% 6 9-Z 'E S 7 6 LI-8 TT € VI & 18-6 ‘82 0°08 8 92 6G T SOE Oe Sse cr ae se 668 0F 006 £
‘dd
LT €¢ Tés g‘o-T SE cw 6 FI-€ ‘OT 0 ET © G8=poLZ 108 BOLL 18 T 86P ES AA os Paneeentl Shtcat 66 94 OOF
€I eV €9G T 9-9 % 07 8 “STI-T ‘OL G €T & I8-F 82 T 08 T ‘92 LET FOE O beers lie epmpauie ayer 66€ °F 00%
‘by | ‘bn bY JUIIIag | jUaolagd quaola gq qU9ILIT QUAIL g UII |JUIIIg | SWDLD | Shog aq -INdS
-UNN [VUSIOM SULUTGYUIVYL
ule} 93U 93v ase
usy | 3%q -O1L] asuUvyYy -I0AW asuey -IdAV asuvy -IDAW
{USIOM
Aouply | 5B (skvp) syei Jo
UsV YRiy uloJOLg 1048 A 3B 95R SUEDE f ase pur ‘orp ‘snzvys IYSIOM

4u97U0D [RIO T,

4ysIom AIp uO poseg

“LOAY -LIAY

S19 TddS Pv» ‘TdS ‘Wd Vo 1ybram burso7 40 Buvurvpjyurpwu _syou Worf shaupry ur yso pun ‘yof ‘ur1aj01g—' EG AIAV I,

65

TaBLE 54.—Protein, fat, and ash in kidneys from rats fed other experimental diets

Aver- | Aver- Based on dry weight Total content
Aver-| age age ; |
Strain and diet Rats | age |weight\kidney|Water
age loss |weight Pro- | Fat | Ash | Pro- | Fat | Ash
tein tein
BHE rats
Num- Per- | Per- | Per- | Per-

SPE supplemented with— ber | Days |Grams|Grams| cent | cent | cent | cent | Mg. | Mg. Mg.
Choline; 0:5 95222522 eee oe 19 | 492 139 | 6.33 | 82.1 | 85.4] 90] 5.9] 950 95 67
By, 0.01 mg./100 gm_______---_- 8 | 463 181 | 7.11 | 81.8) 788] 96] 52] 954] 105 69
Choline, 0.5%+By, 0.01 mg./

POOQC Si Bo: 2 eee ee 10) 4384 | 114] 7.18 |} 82.3} 825)103)] 58] 963 112 71
‘Bg, .0'o me: /LOOiem=. 22. = 22 ee 7 | 502 129 | 5.13 | 79.5] 820] 93] 56] 824 89 58
Choline, 0.5 %+ Be, 0.6mg./100gm 9 412 127 | 4.74 | 80.5 | 82.8 | 10.2 5. 4 724 80 49
Choline, 0.5%+ By, 0.01 mg./100

em.-+ Bz, 0.5 mg./100 gm______ 10 | 431 | 129 | 5.76 | 81.4|/808]103] 66] 896] 110 72
Cholesterol, 0.46%___________-- 8 451 150 | 7.54 | 81.5 | 83.2 | 11.0 5. 1 |1, 240 155 76
Cholesterol, 1.88% ___..-_____-- 10 409 142 | 6.83 | 81.6 | 85.3 | 10.1 6.8 971 109 78
Ascorbic acid, 0.2%_____------- 9| 415 115 | 5.00 | 80.1 | 83.0] 8&6] 5.2] 802 76 50
Ascorbie acid, 0.2%-+choles-

arly O46) eet 9 434 183 | 5.74 | 80.2 | 85.1 9.9 6. 0 940 109 67

DE 16s Vi Se oe 8 629 84 | 2.76 | 77.9 | 78.9 | 18.4 4.7 446 71 26

Db Sard ses cose ste 11 557 99 | 3.26 | 79.5 | 82.2 | 11.6 4.2 540 7A 26

Seal 6derd: 2 ee. _..@ 2... ee 9 572 LI7 1:3. 31. | 79.7% | :82,2 | 13.2 4.7 529 81 30

SES DUbbeE enc 4i.. eee eee 8 | 601 82 | 2.58 | 79.3 | 80.5 | 12.4) 40] 400 59 20

Se 1G Diernca Sauer 9 486 72. | 2. 74°\ (8:0 | 7953.) 13.5 4.8 459 69 29

12210) | ea eee ee 9 | 559 141 | 4.36 | 82.9 | 82.7] 13.6 | 5.6 | 523 86 35

5 | ean ee eae eee ar 14 | 375 80 | 2.42 | 79.4 | 79.5 | 13.7 | 62] 363 61 31

Littermates fed—

1 el 3) ee le i er es alk em I prem 5 428 66 | 3.88 | 79.5 | 83.5 9.9 6.5 637 70 54
NOOR. a eae ee 4 420 42 | 2.54 | 80.2 | 79.4 | 146 6. 0 383 69 29
Y97-+salt mixture, 3.0%-________- 4} 424 6 | 1.66 | 77.8 | 80.8] 13.5] 5.71] 299 50 21

Diet reversal:
Sacrificed at approx. 250 days:
DbOGWe cn. oes a eee eee 3 | 250 0 | 2.07 | 788 | 79.8] 13.2] 3.0] 3841 56 13
Eee ee oe eee ee 3 249 0 | 2. 74 | $1.3 | 76.8 | 12.8 2.0 375 61 10
Continued on—
DGG s ae Sank ee ee 3 | 590 £95") 4525 Sle Sneeeed | 58-15 ee oee™ 654 63) |2aeee2
Bias eee ee oe eee 2! 396 133 | 464 | 84.5] 788] 9381] 591] 565 67 41
Reversed at 250 days:
Stock changed to SPE__________- 4 686 109 | 3.94 | 80.9 | 842 9. 2 4.9 624 67 35
SPE changed to stock__________-_ 3 STE 116 | 3.55 | 80.6 | 82.4 9.5 3.8 560 63 26
Wistar rats

DE HEY Cheer yet Se 8 762 119 | 2.02 | 80.0 | 82.0 | 13.5 4.3 323 54 18

to] Edo eee ae on ee ee 5 772 103 | 2.80 | 79.6 | 80.9] 164] 43] 446 89 23

kidney and a high percentage of ash did not are grouped by age at which urine collection was

necessarily parallel one another.

Differences between the composition of kidneys
from BHE and Wistar rats were due chiefly to
differences in the kidney weights of these two

strains of animals.
Urinary protein

BHE rats.—Data on urinary protein excretion

were obtained for BHE rats fed 11 of the diets
under investigation, and the results are sum-
marized in table 55. Urine was collected under
two conditions: (1) a 7-hour collection period
without access to food; (2) a 17-hour collection
period with access to food. The conditions of
collection are indicated in the table, and the urinary
protein values recorded are for total protein
excreted during the collection period. Results

66

made; in most cases the age range within groups
was less than 2 weeks. Data for age at death
and size of kidney are included to relate as well as
possible the protein excretion with age at death,
although urine samples were not collected at
this time.

The amount of protein excreted by rats under
200 days of age was generally small regardless of
diet. When urine collections were made for a
7-hour period without access to food, protein
excretion was less than 10 mg. for 67 percent
of the rats. Only 3 of the 61 rats in this group
excreted more than 50 mg. of protein.

When data obtained under comparable con-
ditions were available, a tendency for increased
protein excretion with increasing age was apparent.
Dietary differences were observed in the older

“OATIB [[I]S JI JBI OUTRS OY} IOJ 919M JOIP YOVa WO SdnoIs 93B OA} OY} IOJ VIVE ¢
*S]BI POSRJMOU WO] SINOY LI IOJ ‘s1VA paysvy WIOIJ sIMOY JL OJ poyo[[0o oul 1

0 -----2----]----------] 9 23°% FOL z 81% 9F8 b
ener non| Seeeaeead 0 a oa 80°E SES z 36 'T Fg8 b
pepe Pmen- aes 0 68'€ LOL I Il‘? LPL ion Pt, (een cenernee) |Iaeeaaana 0
a be Saeee | ieaeasnacninan | Seana 0 #0 Pel in | caciaieiie | 0
SSokeeniae | erent 5/10 Lb Geo I 69 '€ Leh SSI a fe ears a| er ocoie ng | 9
0 LP oes T SIF 104 T SF's gg. z
ae Rete silt sos cal 0 G3 629 | nn CaS ech | Seana 0 Eee; | encanta | nena 0
wv 968 z 2'e 629 TE | cama | Gaceaama Q000 [reeecesene|ecessesee a
50" Ozh I 988 S19 AS clasps katy cer iy ee Melee Soe 0
40'S OzF I 96 'F LOL if 9L°% £29 Te. 4 Ulaetesan or | ees 0
86°F RoE To, Ore "| eao | aeeerall 0 6 F ggg g 0S 'F &19 4
S05E Tres |2 00% I 00°2 399 g ge'e 869 é ze 699 I
ojos 0 = tie 1-aai lite ee EO) an 0z¢ z 19° ggg 8
+---------|---------- 0 8o°¢ 00¢ Zz 709 (aG7 z 89g alg 9
~-+-------|---------- 0 scomsncied pareemoncel| 09°6 LOP z 16 °€ Te9 8
ed ee 0 ze'8 Ieb I #901 ehP g 63°9 arg 9
ieee | aera 1) 86 €19 T oF TD 119 P G6 808 g
0 c6°L GPS I 16 € 06¢ z 16 °E ELE, L
19 °¢ oa CS in Geico, |B canes 0 oe'€ $29 9 02% 129 z
Ig ‘F OSF T CPG org F PL'G 88¢ 9 go's GOL g
8 °F Por C= Wiel | Pc cee || ee aioe 0 86% O19 g (age PL9 L
68 ‘TT FIP a 60°2 O6F € &% 9 og¢ 4 68 °L 609 z
S850) oral: Shr. 8 69 II Ch I (ans 629 if 588 08¢ I
OR sent |imipecamere |nanaa nian 0 ¥9'°E 862 8 Sh SG 608 1
LG aieaetoe || Leone I 68% 802 z GL 's £19 L 18:8 969 g
; ONS ee re as | aps cae a 0 8L°E agg g 16° OFL L
Obs oe | OFS aa) I 18 € 688 | es | ee eared beer Oi yo Be ea 0
0 661 CGF I 8g £29 z 29'S POL L
peer | tae os. | 0 be eeeb tes | ha ae So ao | areciew Ons el pig oie hale ee z
Oates | eit eas ca | ae an ge Teh os cee lig One ek Rae G) fa ee Dea en | aes 9
SWUDL}) shog Laqunn | smDip shog daqunn | swDpip shog waqunn | swpsp shog LaQUenny
WY sTOM yyvep qUSsIom yyeop qy3IOM yyeep 4ystom yyeop
Aoupry | yeosy SJB Aoupry | 7B 0sV syey Aoupty | 38 08V $78 y Aoupty, | 4v 03 V Sqey
JOAO PUB “BUI ODT “SUL 66 01 0G “BUI GF 01 OL “SUL OT URYY Ssa’T

—JO WOTJOIOXO UIO}OIg

02-0 6
68-0 IT
#9-$E cy
LI@-LIT 89
F6-08 0g
TL-¢ 1
6¢ 6g
€II-$9 c6
883-88 OFT
80G-F3 lane
SZI-9 ¥G
IST-@ 9g
IIl-@ 9
S6-0 FG
SI-1 9
gs-% ST
&S-F LI
S8-T LI
OIg-p og
I9I-¥ (Gi
€12-@ 62
ELE-S 961
IFI-9 18
La-% Or
FPG FF
It-F 6
02% ‘66 | O9T
€8-T 6r
96-0 9¢
€L-% LT
“ON ‘ON
osuvy | osRI0Ay

ul9}0.1d 9ULIN [8}0.L

P99
#99

93B
asBl0AV

9
1Z

ta
Or
z

Or

g

ai
LaQuunny

S}VY

paras wes poqsBq
‘ads

haa Re cie eam ae pose,
:4004s 0} posueyo Wdsg
isc a ara peyseT

‘Hd 0} posueyd yoo1g
:sABDP 0GZ 1B PISIOADNY

2209S
—u0 panuyjuod $7By
T[BSIOAOI JIC

Cee i dea. mia at pose

‘ddds

a poqsejJuON
‘dds

eGR Seay poqseJUON
‘Wds

Poo pt saa poqsvjJuON

:ads
as ele Oe poJsejJaoON
ee ae ae ee as ee pose y
(OAH 8 ds
ee ea iene po4se
230019

5781 GHE

UWOT}09T[09 oUT.M
JO} SUOT}IPUOD PUB “YyoTp ‘UTeIIg

1 SJ2Up SNOWDA UO Saby qualaffrip yp SDL payspfuou pun pajsvf fo uraqoud fiuwur1t4qQ—'sg AAV,

67

64——_6

721-631

rats. Of the nonfasting rats approximately 375
days old, those fed SPE diet excreted the most
protein. Differences in excretion by rats fed SP
8 HVO, SPM, or SPB diets were small. Rats
fed SPPB diet tended to excrete somewhat more
protein, and the excretion of 3 of the 11 rats
exceeded 100 mg.

WISTAR RATS.—Protein excretion by Wistar rats
was low on SP 8 HVO and SPE diets,in marked
contrast to the results with BHE rats. For
a 7-hour collection period, urinary protein aver-
aged 9 mg. for fasted 614-day-old Wistar rats
fed SPE diet. No data were available for a
comparable age group of BHE rats because of
their short survival on this diet. However, by
approximately 350 days, BHE rats were excreting
87 mg. of protein when urine was collected under
comparable conditions.

URINARY PROTEIN AND KIDNEY DAMAGE.—Most
measurements of urinary protein were made con-
siderably before the age at which the animals
died, and provide little direct evidence to relate
extent of protein excretion to kidney damage or
age of survival. The low urinary protein from
rats less than 200 days old gave little indication
of the extent of kidney damage at death or of the
lifespan of the animals. The only young rat
(180 days) to excrete over 100 mg. of protein had
a 5-gram kidney when he died at the relatively
early age of 358 days. In rats 350 to 400 days of
age, urinary protein appeared to be a fairly good
index of kidney damage and expected survival,
with lfespan generally decreasmg as urinary
protein increased.

Discussion.—The results for BHE and Wistar
rats reported in this publication confirm the find-
ings of other investigators that some protein may
be excreted by animals with kidneys that appear
normal in all respects. Urinary protein for BHE
rats was considerably greater than that generally
reported by other investigators. Gilson (72
found proteinuria to be a usual occurrence in
Wistar and Sprague-Dawley-Holtzman strains of
rats. The average excretion during fasting was
3.0 mg. globulin and 3.3 mg. albumin in 24 hours.
Particularly heavy protein precipitates were ob-
served in the urine of a group of animals main-
tained at a temperature of 4°C. for 3 months.
Saxton and Kimball (168) reported appreciable
excretion of albumin by rats over 300 days old.
Proteinuria was found to increase with age,
although there was somewhat reduced frequency
of protein excretion in rats over 800 days old.
McCay, Maynard, Sperling, and Osgood (121)
obtained an average daily protein excretion of 23
mg. for rats on a low level of dietary protein and
82 mg. for those on a high level. Albumin was
found in the urine of mature rats with normal
kidneys, but with chronic nephrosis increased
amounts were present. There appeared to be a
rough correlation between kidney damage and
increased protein excretion, although the lifespan
of the animals did not appear to be related to the

68

latter. Rather (155) suggests that the thresh-
old of the kidney to protem may be due to tubu-
lar resorption with proteinuria occurring if tubular
resorption capacity is exceeded. Using rabbit
anti-rat kidney serum to produce nephrotic rats,
Drabkin and Marsh (51) observed a marked
increase in labeled urinary protein after injection
of labeled glycine into the nephrotic animals.
Total serum protein decreased and the albumin
moiety almost completely disappeared.

Summary.—Urinary protein excretion in BHE
rats tended to increase with age and to be in-
fluenced by diet. The extent of the proteinuria
observed appeared to parallel the occurrence of
degenerative changes in the kidneys of these
animals. Protein excretion in the urine was con-
siderably greater than has generally been observed
and seemed to be related to the shorter lifespan of
these rats.

Protein excretion by Wistar rats was generally
small and within the range reported by other
investigators.

Liver

RATS MAINTAINING WEIGHT ON stock, SP 8
HVO, anv SPE pirers.—In table 56 are sum-
marized data for protein, fat, and ash in livers of
rats maintaining weight on stock, SP 8 HVO, or
SPE diets, and included are results for per-
centage composition and total content. Most of
the results recorded are for fasted rats. Limited
data were obtained for nonfasted stock rats 300
days of age and older and for a group of young rats
less than 300 days old fed SPE diet.

Age appeared to have little influence on the
composition of livers from rats fed stock diet when
the glycogen content of the livers from nonfasted
rats was taken into consideration. Values of
76.2 percent for protein, 15.8 percent for fat, and
5.0 percent for ash were obtained when the results
for nonfasted rats were calculated on a glycogen-
free basis. The percentage of protein and of ash
in the livers of rats fed SP 8 HVO diet did not differ
with age, but the percentage of fat showed a con-
sistent tendency to increase. With SPE diet,
as with stock diet, the composition of the liver
appeared to be uninfluenced by the age of the ani-
mal. When the data for nonfasted rats fed this
diet were calculated to a glycogen-free basis,’
values for protein, fat, and ash were 55.8, 34.1,
and 3.9 percent, respectively—values differing
greatly from those on the stock diet.

Data comparing the content of the livers from
fasted and nonfasted rats were limited but seemed
to indicate that diet could influence the response of
the liver to fasting. As the result of a 17-hour
fasting period, the protein, fat, and ash content of
the livers of rats fed SP 8 HVO diet were reduced.
Both protein and ash content were smaller in the

8 Assuming a liver glycogen of 8 percent on the dry-
weight basis using a value obtained for comparable rats
(unpublished data).

96 ° 6y € | 624°8 Os a v's P GS-8 “OE T SP € "€9-8 “68 & '6P 9 “09
66° c6 7 | IL P L&-¥ @ TS € ‘€9-0 “66 8 '8P 9 ‘¥9-9 “SE GSP 02g
TS * 0g FV | 88°F T P-G % as 1 ‘OG-T '8& 8 St V PG-8 “OP GLY ¢ 69
9g ° GEE | 93'S G ¥-0'E 9° ¥ Lb-E CLT VTE G 19-3 TV v Ig I ‘G9
GG * ge '€ | 49 € 0 'V-¥ % T's G “GS-0 “LE T 8? € ‘99-T “IP € 1g 9 6S
Was 66 ° &I T ‘$-0 7 97 9 “8E-7 “LT 8 1G 8 EL-8 “9 6 ‘89 £19
OLS 68° | 46% L0-G 'V oT ¢ 'E¢-8 ‘FI 9 ‘6T 6 ‘PL-Z “19 LOL 9 89
81° €L° 62% T 9-2 7 97 ZIG-€ ‘ST 9 ‘8ST G 8L-¥F “19 9 GL L°L9
Ses 09° TG % Te Secey. 9° 9 ‘1é-G ST 6 LT 0 SL-T “L9 612 F 89
LE ° PS ° 0 F Lae Gov, Lv 9 ‘PI-Z FT € FI 6 ZL—-L “99 0 ‘OL 8 TL
GG * €2° OL '€ 6 ‘-0'F vv 0 ‘8I-¥ ‘ET 6 ‘FI v GL-0 “69 GOL T ‘04
tT ‘0 | 89°0 |} 19% So F-SS a LZ '06-G ‘ET 6 ‘OT 8 08-8 “EL 9 ‘92 T 29
SUDLD |SUDLD | SWDLH | quaoiag |yuao1ag Ualag — |\juaowag JUIILI JUIDLAT |\JUIILIT
ulo4 958 938 3B
ysy | 38 -O1g osuByy -1OAVW asUvyYy -I9AV osUuRyy -I9AV
USV ye] ulo}Olg Id4eM

4U9}U0D [BIO J,

4ysiom AIp uo poseg

"S]BI poySBJUON 1

ARPOOD
oS
Nn

8g
ESP
EGE
926
CSG

LUG
LSP
eG
GGG

O8¢
civ
PGS
shoqg

bal

Oro COOrN wPHroeo
al

LaQUnN

058
o5eB
-IDAV

SPBY

Domine ake eoe 66¢ 04 00S
Ge Silane mere 66F 03 OOF
hae Patel teeeanet 66€ 07 00
Saran aetna 1002 Ue} SsorT
he ak Aa 00g UBYY Sso'T
‘dds
ee Sia Cn © eee 66¢ 94 00S
(Pe mee ae od a ee 667 °F OOF
Rect Se 66€ 97 OOE
art am meranty 00 UeYy Sso'T
‘OAH 8 d$8
fo cya ae es , 1OAO pue QOS
el Sas 1 66F 9F 006
Baa, sepes aa 00g UBYy sso'T
:yoo1g

(skep) Syer Jo ose pue JoId

SjUp Ad S| PY” ‘OAH 8 dS ‘2048 uo sabv quasafjp yo yybram bururpyuroun spon WoL Sad UL YsD pup “yoH ‘ULd},0L—' 9G DAV],

69

livers of fasted animals fed SPE diet than in
those of nonfasted rats, but the fat content re-
mained approximately the same whether or not
the rats were fasted prior to sacrifice.

Although the percentage of liver fat among
individual rats varied considerably, the livers from
stock or SP 8 HVO rats were not considered
fatty; those from SPE rats were consistently fatty.
Only two of the animals fed SPE diet had livers
with less than 30 percent fat. The highest per-
centage of fat observed was 63.3 percent in a liver
from a rat fed SPE diet.

With the techniques used, fat was not detected
microscopically unless present in excess of 30
percent. When the concentration of fat was be-
tween 30 and 40 percent, numerous small vacuoles
were observed. When fat exceeded 40 percent,
large as well as small vacuoles were apparent.

Although protein and ash in the livers from SPE
rats were diluted by fat, the total content of each
was equal to or greater ‘than that found for these
components in the livers of stock or SP 8 HVO
rats.

In table 57 are summarized data on the composi-
tion of livers from rats fed stock, SP 8 HVO, and
SPE diets as related to liver weight. There
appeared to be little evidence that the composition

of this organ was influenced by its size. Livers
from stock rats were similar in composition
whether their average weight was 14.9 or 23.1
erams. The percentage of ‘Tat j in livers weighing
less than 16 erams was low in comparison with
the larger livers from rats fed SPE diet. However,
small livers were rarely seen in rats fed this dict.

The increase in liver fat with age that was ob-
served in rats fed SP 8 HVO diet seemed to be
related, in part at least, to the body weight of
these animals. In table 58 are summarized the
results for liver fat as related to body weight.
For animals weighing less than 600 grams, the
increase in the average percentage of fat with age
was small and, considering the range of values
observed, was of questionable sionificance. The
percentage of fat in the livers of rats weighing
between 600 and 700 grams was significantly
higher (P < 0.01) than in the livers of the lighter
animals. Of the 11 rats weighing between 600
and 700 grams, 10 had livers containing more than
20 percent fat. In the larger rats weighing more
than 700 grams, there was some indication that
liver fat was lower when kidneys showed evidence
of damage. The 4 rats in this group with liver
fat less than 20 percent had kidneys showing de-
generative changes; the 2 rats with normal kidneys

TaBie 57.—Protein, fat, and ash in livers of different weights from fasted and nonfasted rats fed stock, SP
8 HVO, and SPE diets

Condition, diet, and range Rats

of liver weights (grams)

Nonfasted rats:
Stock:
Tress ethan 6.0) <2 a ee ee lee
T6sOnton 1 Oi0 et ens ae ee
20.0 andover..-- 22-523 h eee ee
Fasted rats:
SP 8 HVO:
Toess*than’ 12.0228 oe ee
TOGO de 2 tee eee, ee ee ee
i Le: O10 rte al Hs a, ° Rn end ae em eye yee
L6:0 ‘and OVversel kes 6 eee See
SPE:
(béss: than: 16:02) saeco seek ees
LOO) COehO. Oe es a ee ee ee
20:0 SG OVERE 225.6 oe ee ee

a
wocr

a

Number
4

wWnmw

Average Based on dry weight
liver Water
weight
Protein Fat Ash
Grams Percent Percent Percent Percent
14.9 710 70. 4 15; 4. 4.3
16. 6 Ville 74 68. 0 14.3 4.5
2301 69. 9 69. 4 14.8 4.7
10. 7 67.9 72.0 19. 0 4.6
13. 0 68. 4 TAS: 18.1% 4. 6
14. 6 67. 4 68. 2 22. 4 4.6
18. 0 10:2 7022 18. 0 4.7
14.1 64. 6 64. 7 28.9 3.8
18. 2 60. 3 50. 9 42.6 oi
24.1 59. 0 48. 4 45. 6 ono

TABLE 58.—Liver fat and body weight of fasted rats maintaining weight on SP 8 HVO diet

Liver fat on dry-

Body weight range (grams)

70

Rats

Number

6
10
i

6

Average
body
weight

Grams
462
550
653
742

Average weight basis
liver
weight
Average Range

Grams Percent Percent
10. 4 17.1 | 14 8-19. 1
12. 4 18.0 | 15. 5-21. 7
13. 7 22.1 | 19. 4-28. 6
14.6 21.0 | 17. 8-28. 3

had livers containing 24.9 and 28.3 percent fat.
The number of rats with damaged kidneys that
were maintaining their weight on this diet was
small, and more data are needed to establish the
possible significance of this relationship.

On the stock diet, there was relatively small
variation in body weight, and data for rats weigh-
ing more than 600 grams were too limited to deter-
mine whether or not there was any relationship
between body weight and liver fat.

On SPE diet, with high concentrations of fat
in the liver the usual finding, there was no evidence
that the percentage of fat in the liver was related
to body weight. A rat weighing 783 grams had a
liver containing 38.6 percent fat; one weighing 530
grams had a liver containing 51.2 percent fat.

Rats LOSING WEIGHT ON stock, SP 8 HVO, anp
SPE prers.—In table 59 are summarized data for
rats that were losing weight on stock, SP 8 HVO,
and SPE diets. The results are reported for non-
fasted and fasted rats with further separation on
the basis of the extent of weight loss even though
the number of animals in some groups is small.
Most of the results with the stock diet were for
nonfasted rats and were similar to those observed
with animals maintaining weight on this diet.
When weight loss of nonfasted rats was less than
100 grams, the influence of glycogen on the per-
centage composition of the livers was apparent.
Regardless of the extent of weight loss of fasted
moribund rats fed SP 8 HVO diet, the composition
of the liver was similar to that obtained for fasted
rats that were maintaining weight. In nonfasted
rats fed this diet, livers tended to contain a higher
percentage of fat than in the fasted animals, but
again there was little evidence that extent of
weight loss influenced appreciably the composi-
tion of the livers. In contrast, the extent of weight
loss before sacrifice for rats fed SPE diet seemed
to influenced liver composition more than fasting.
The fatty livers characteristic of rats that
were maintaining weight on SPE diet were seen
in many of the moribund rats fed this diet,
although the percentage of fat was generally
somewhat lower than in rats maintaining weight.
When weight loss exceeded 100 grams, there was
a marked decrease in the number of rats with
liver fat exceeding 30 percent.

The wide variation in liver fat of nonfasted rats
that were losing weight on SP 8 HVO diet did not
appear to be merely a reflection of reduced food
intake and extent of weight loss before sacrifice.
Low liver fat in these rats seemed to be associated
with excessively damaged kidneys, whether or not
there had been appreciable weight loss. Data for
liver fat and kidney damage are summarized in
table 60. In the first group are included values for
liver fat when kidney damage did not exceed a
rating of 2 for hyalin casts, with no glomerular or
cystic damage. In the second group are the
results for rats with kidneys showing cystic and
glomerular damage as well as hyalin. Of the 8
rats with kidneys showing little evidence of dam-

age, 6 had livers containing more than 26 percent
fat; only 1 of the 7 rats with extensive kidney
damage had a liver containing more than 20 per-
cent fat (21.5 percent). A similar trend has
already been discussed for fasted SP 8 HVO rats
that were maintaining weight. On SPE diet, high
liver fats were found consistently in rats with
kidneys showing little or no kidney damage; the
highest fat was observed in a rat with small normal
kidneys. However, high liver fats were also ob-
tained frequently in rats with extensively damaged
kidneys, and no consistent relation between fat in
the liver and kidney damage was observed on
this diet.

RATS MAINTAINING WEIGHT ON SPM, SPB, ann
SPPB prers.—In table 61 are summarized the
more limited data for the composition of livers
from rats fed SPM, SPB, and SPPB diets. Data
are presented for two age groups: those 200 to
399 days, and those 400 to 599 days old. No
marked differences were observed in the composi-
tion of the livers of the young rats fed these three
diets, and the results are similar to those already
reported for comparable animals fed SP 8 HVO
diet. In the older rats, the percentage of fat in
the livers was higher and the percentage of protein
correspondingly lower than in 200- to 399-day-old
animals. Liver fat for rats fed SPB diet was
similar to that observed for comparable rats fed
SP 8 HVO diet. Higher liver fats were obtained,
however, for rats fed SPM or SPPB diets. The
percentage of ash in these livers was similar to
that found in the livers of SP 8 HVO rats, and no
differences with age were observed.

The high liver fats for rats fed SPM and SPPB
diets appear to be related to their body weight.
Differences in body weight, however, do not
explain the results for rats fed SPB diet, as seen
in table 62. On the diet containing milk (SPM),
liver fat increased on the average from 16.9 for
rats weighing less than 500 grams to 29.7 for
those weighing 700 grams and more. A similar
trend was seen with rats fed the diet containing
peanut butter (SPPB). On beef (SPB), however,
only 3 of the 13 rats had livers containing more
than 20 percent fat, with one of the highest values
observed in a rat weighing 486 grams.

RATS LOSING WEIGHT ON SPM, SPB, anp SPPB
piets.—No consistent trend with age was apparent
from the data on the composition of the livers
from rats that were losing weight on SPM, SPB,
or SPPB diets. Therefore, the data in table 63
are the results for all age groups combined. The
livers from these moribund rats showed differences
in composition that were similar to those from
rats that were maintaining weight. Liver fat was
consistently low for SPB rats, both fasted and
nonfasted. Liver fat tended to be high in SPM
rats, and again the high fat values seemed to be
related to the large number of heavy animals on
this diet. The highest liver fat with SPM diet
was 47 percent in a rat that lived to be 799 days
old and reached a maximum weight of 1,020 grams.

vA

NOD NOH

mN

aN

6G ° 6h S| GE 6 ¥-0 0 ?T L8S-€ “ST 6 66
IZ ° 60 T | ves 8 PFE & 'v 9 ‘LE-6 TI 9 TS
96 ° tL 66 6 y'S-L PV E'S 9 °ST-9 ‘SI G ‘FI
96 * 64 F | 918 8 E-€ % € 0 09-T ‘8E SP
GS ZEW AeS Sis LvV's Tv 9 ‘9Z-G “LT 8 1G
0s * 16° G9 P GT's? v? T PTL OI 9 ST
62° 8L'T | ol? o S-0 7 9? 6 ‘0G-G ‘FI € 9G
GS * GL° GSE 87-17 87 9 ‘9I-L “ST GOT
&Z * LYS | 99'S 1 G-L 1 8 'E § ‘09-8 “ST 8 TE
Le g9° GGG & G-9 'P 4 ¢ ‘0c-T ‘FI 6 ‘LT
8T 0 c9 ‘0 | 89% ES is 8 LT 8 CLT

SUDID |suDID | SDI | JUuaIIag UIILIT qUIILIT JUIDLIT
ulo4 ose sic)

Usy qe -Olg osuevyy -I9AV oSUvyY -10AV

Usy Ve

4U94U09 [BIO J,

“GL-P GP
‘6Z-T “LS
‘08-9 “GL
‘VS-T “EE
"GL-8 LG
69 ‘2 “89

‘T8-Z GE
"EL-@ 69
PL-G GE
‘LL-6 ‘99

GcLL
quaa1ad

WUIaII | WUawWag

NOOO HHA
uw

“LO
‘69

¥ S9
9 69
9 ‘OL

AY

G 8
I g9L
I 969

G 966
i P8E
G Pgs

NOD WHO

¢ ‘61 CGP 8
0ST 0sg €

¢cLT 168 8T
LTT TOG 9

8 TT LGL T
suDiy | sing |saqunay

dsUByy

uloyolg

yyustiom Ap uo poseg

o8eB
-10AW

TOE M

VUSIOM
IOATT 9B
a08 ase SJVYy

-I9AW | -IoAV

Tie ee OAH 8 d$

3048

‘SUIBIS QOL UBY} A1OUL SuISO'T

9048
‘SUIVIS OO] UYY SSe] Sutso'y

S}V1 poysvjuon

HOS
:SUIBIS NOT UBYY SSeT SuIso'T

s}ei poysey

4oIp pue ‘ssoT VYSIOM ‘uOTIpUOD

Sap Ads PUP ‘OAH 8 dS ‘2038 Uo yybram Burso] syou payspfuow pup pajyspf wodf sua) Ur ysp pup Gof ‘ur9j01g—"6S AAV,

72

Tas LE 60.—Kidney damage and liver fat in nonfasted rats losing weight on SP 8 HVO diet

Kidney damage

o 2.0 hyalin, no cystic or glomerular damage_______- ~~

Ot
2.0 hyalin or more, with cystic and glomerular damage___-__-_

1 Based on maximum rating of 4.

Liver fats tended to be high in nonfasted SPPB
rats.

Rats FED OTHER EXPERIMENTAL DIETS.—In
table 64 are summarized the data available on the
composition of livers from rats fed some of the
other experimental diets. The results are chiefly
for moribund rats, and interpretation is com-
plicated by the variable weight loss of these
animals before death. In spite of the wide range
of values obtained, some differences were observed
that seemed to be related to diet. On the various
diets that consisted of the SPE diet with purified
supplements, liver fats were generally high and
similar to the results with the unsupplemented
diet. When the diet contained cholesterol as the
supplement, however, liver fat tended to be some-
what higher than for the other modifications of
SPE diet, in agreement with the results already
discussed for microscopic examinations of this
organ for fat.

In the series to determine the influence of kind
and/or level of fat, the livers from rats fed SP 16
HVO tended to contain a higher percentage of fat
than those from rats on SP 8 HVO. Livers were
not excessively fatty with any of these diets, and
no consistent differences were observed that related
to the level or kind of dietary fat. When diets of
100 percent whole egg or egg yolk were fed, liver
fats tended to be low and protein correspondingly
high in comparison with the liver fat of rats fed
a diet containing 25 percent whole egg. The
results for rats fed 100 percent whole egg and 100
percent egg yolk were similar to each other. The
results for a small group of littermates showing
little or no weight loss on SPE, Y100, and Y97-+
salt diets confirmed the finding that liver fat was
lower with 100 percent egg yolk than with SPE
diet. Supplementation of the 100 percent egg
yolk with salt mixture was without influence on
liver fat. The livers of Wistar rats fed SP 8 HVO
diet were generally low in fat; 18.4 percent was
the highest value obtained. The only high liver
fat (42 percent) observed in Wistar rats was for a
rat 874 days old that reached a maximum weight
of 970 grams on SPE diet.

Discusston.—Liver fats have been reported to
be susceptible to many factors, including age,
heredity, and diet. Much of the research dealing
with liver lipids has been done on relatively
young animals, and little information is available

Rating for kidney damage ! Liver fat on
Rats dry-weight
basis
Hyalin Cystic Glomerular
Number Score Score Score Percent
8 0. 4 0 25. 6
7 3.0 2.4 a3 18.5

on the liver lipids of the rat throughout life.
Andrew, Shock, Barrows, and Yiengst (/1)
reported the results of histological examination of
the livers from stock animals 1 and 2 years of age.
The two groups of rats were very much alike.
Vacuolation indicating fat storage was observed
occasionally, but no consistent change with age
was apparent. Periportal infiltration of lympho-
cytes was seen in the connective tissue around the
bile ducts, portal vein, and hepatic artery in some
of the older rats. From chemical analysis,
Yiengst, Barrows, and Shock (191) reported no
differences in fat content of the livers from these
two groups of rats. Grunt, Berry, and Knisely
(80), and Grunt and Knisely (S/) reported that
old animals have more hepatic fat than have the
young ones, and that genetic factors appear to
play a significant role in the development of fatty
livers in the rat.

Literature dealing with the many dietary factors
that may produce fatty livers has been exten-
sively reviewed by Deuel (47). Publications on
this subject are numerous, and only a few that seem
closely related to the results under consideration
in this bulletin will be discussed.

Blatherwick, Medlar, Bradshaw, and others
(31) fed rats diets containing 75 percent dried
liver for periods of 30 and 60 days, and obtained
livers of high fat and cholesterol content. Fat
accumulation was well marked by 28 days.
Fractions from liver were fed alone or with various
supplements, including lecithin and cholesterol.
Marked differences in the fat and cholesterol
content of the livers were noted, but changes in
liver fat were not necessarily paralleled by changes
in liver cholesterol. Cholesterol, when added to
a diet containing a 70 percent alcoholic precipitate
of an aqueous extract of liver, resulted in livers of
extremely high fat and cholesterol content.
Feeding certain fractions containing cholesterol,
however, had relatively little effect. The feeding
of cooked egg yolks produced livers with increased
cholesterol content and, to a less degree, increased
fat. More marked increases were observed with
cooked whole eggs.

McCay, Maynard, Sperling, and Osgood (121)
reported higher total lipids, cholesterol, and
phospholipids in the liver of rats fed dried liver
than in those fed milk proteins. The lipid com-
position of the livers of these animals was about

13

&Z° OV 'T | 89 '€ LV SS || Er | 9 66—G ‘0G | 6 FZ § ‘TZ—@ ‘9 | € 99 PLO GLI GGG TE ili eee Ae ek eee 66¢ °F OOF

cI° Gis 88% So Bee | AOE v GC—0 ST | 8 '8T 0 °8Z2—8 19 | 9 EL 8°19 6 GI G63 Cee ee ee ne aa 66€ 94 00Z
‘adds

0% * €8° 90-8 G’c—07|3 7 8 '9Z—8 ‘OT | ¢ ‘0G GoVZ—v 99) | 2. 0% 6 89 6 “ET 60S (RE (a es a ea 669 93 OOF

cT° 149° tL @ G ‘YS '€ | oP L'0@—6 ‘ST | 0°81 6 GZ—9 TL | V PL 6 ‘89 8 IT GOS 1S DY (aie ct es aa 3 66€ 9F 00Z
‘dds

61° 6T ‘I | 80°E GtT—9E | CF G EE—8 ST | 9 FG 8 GL—Z “GG | “19 Z ‘99 6 “ST v0g Se) Nits Biome sere 66¢ °F OOP

110 8Z°0 | 98% OL Vi -Se¥ T ‘96—L ‘9T | 6 61 € ‘92—Z 19 | 8 GL 8 19 6 GL TOS Otel ae = 5 Net aaa re 66€ 97 00G
SUDLD |SUDI | SUDL | Juaag | JuaaLag JUIILI JUIILAT JUIILIT quaaag |jUIIag | supiy | svg |saqunyy -INdg

ulo} o8B ase 5B
sy Very -Olg osuBy -IdAY osuey -IOAY osuey -IdAV
VysIOM
i IOAI] 058
ysy 487 UuldJOI 10ye Bye o0e syey (sdep) syvl Jo ose pue yoiq

-I0AVy | -IaAV

4uo4yUod [BIO],
qyystom AIp uo poseg.

sp TddS' PUP ‘TdS ‘NdS Vo ry bvan Gurwpyurput syou payspf wouf suaar) ur ysp pup “yf ‘urdj04g—" [9 HTAV J,

74

TaBLe 62.—Liwer fat in rats of different body
weight maintaining weight on SPM, SPB, and
SPPB diets

Diet and body weight Average | Liver fat
(grams) Rats body on dry-
weight | weight basis
Number | Grams Percent
SPM:
Less than 500_____- 2 434 16. 9
500 to 599___.__._- 3 575 20. 8
G00=to 6992222 === 4 659 23. 0
700 and over____-_- 2 774 29. 7
SPB:
Less than 500____-- 3 441 19. 6
500 to 599________- 2 549 20. 1
600 to 699________- Uf 654 19. 0
700 and over_-_-__-_- 1 740 19. 0
SPPB:
Less than 500____~- 3 444 17.3
500 to 599_________ 1 550 19. 7
600 to 699_________ 5 667 23. 6
700 and over_____- iG 777 Oso,

the same whether the diets contained 10 or 41
percent liver.

Reussner and Thiessen (156) reported 29.3
percent fat in the large livers from rats fed an
ege and bacon diet, in contrast to 12.5 percent
for a cereal and milk diet and 15.1 percent for a
milk diet. These differences in liver fat were not
related to the level of fat in the diet. In spite of
the high liver fat, the bacon and egg diet resulted
in good survival of rats on long-term feeding.

Okey (140) fed diets containing 1 percent
cholesterol to rats from weaning throughout middle
and old age, and observed no significant differ-
ences in growth, health, and survival between
control and cholesterol-fed rats in spite of the high
fat and cholesterol content of the livers of the
latter. Histological examination of the livers
showed fatty infiltration rather than degeneration
of functioning tissues.

Ridout, Lucas, Patterson, and Best (157) re-
ported a progressive increase with increasing
dietary cholesterol in the accumulation of both
glycerides and cholesterol esters in the livers of
rats.

Okey and Lyman (143) reported the results of
feeding 5, 10, and 15 percent coconut oil or
cottonseed oil with or without added cholesterol.
The response of female rats was occasionally
quite different from males and, for comparison
with the results reported in this publication, only
the results with males will be discussed. In the
absence of dietary cholesterol, elevated liver fats
were observed only when coconut or cottonseed
oil was fed at the 15-percent level. In the
presence of cholesterol, liver lipids and_ total
cholesterol increased with increasing concentra-
tion of dietary fat and were consistently higher
with cottonseed oil than with coconut oil.

Okey, Lyman, Harris, and others (145) also
compared the response of rats to 13 different fats

with iodine numbers varying from 8 to 143, each
fed at the 10-percent level. Liver fat and choles-
terol values in the absence of dietary cholesterol
were not exceedingly high with any of the 13
edible fats investigated. ‘There was a tendency to
relatively low values with the more highly satu-
rated fats. When cholesterol was included in the
diet, liver fat and cholesterol increased; the
increase in cholesterol was generally smallest in
rats fed fats with low iodinenumbers. According to
the author, not one but a number of factors appear
to influence the effect of composition of dietary
fat on liver lipids.

Choline has been found effective in preventing
various types of fatty livers in rats (24). In a
diet free from cholesterol, Best, Lucas, Patterson,
and Ridout (23) reported that regardless of the
kind of fat used, total liver lipids were essentially
normal when the amount of choline chloride pres-
ent was between 0.12 and 0.16 percent. According
to Benton, Harper, and Elvehjem (19), the type of
dietary fat had little effect on the deposition of
liver fat when the diet of the rat contained
adequate amounts of choline and protein. Rid-
out, Lucas, Patterson, and Best (157) found that
the amount of choline needed to maintain liver
glycerides within or slightly above normal when
the diet contains cholesterol does not necessarily
prevent the accumulation of cholesterol esters in
the liver.

Jackson (100) observed a tendency to fatty
livers with degenerative abnormalities when rats
were fed a diet containing 80 percent sucrose.
This diet, however, did not appear detrimental to
growth and general health. On diets containing
45 percent sucrose or starch, no marked differ-
ences were observed in size or histological structure
of livers or kidneys.

Summary.—The results with BHE rats reported
in this publication indicate that age may or may
not be a factor in the percentage of fat in the
liver, depending on the diet under investigation.
The increase that occurred with age on some of
the diets appeared to be related to an increase in
the number of extremely heavy animals on these
diets. Differences in liver fat were not neces-
sarily related to level of dietary fat. The per-
centage of fat in the diet containing beef was
somewhat higher than that in the diets containing
ege, milk, or peanut butter, but liver fat for rats
fed this diet was generally low when compared
with the results for the other diets. Liver fats
were high in rats fed the diet containing 25 per-
cent egg and much higher than were obtained with
the extremely high fat diet consisting of 100 per-
cent ege yolk. The results with rats fed 8 or 16
percent HVO, lard, or butter also showed no
consistent relation between level of dietary fat
and liver fat, although these results were compli-
cated by the weight loss occurring in moribund
rats.

Damaged kidneys were a frequent finding in
BHE rats regardless of diet, and they were not

15

LG OSE ies: & GS-0 7 Gc‘? ¥ 66-6 “ST 8 “ES
oo LOM eS 3s 9 ‘P-8 '€ ov & €6-0 ‘GT 8 ‘8T
06° EV ‘I | 90°E 0 “S-€°G 6:-§ L LAB Si. € GZ
83° ales S076 Pv G-8 '€ 9 ‘PF 8 “€S-0 ‘ST G ‘6
Slew 7 06 °% G ‘P-€ PV GP 6 “81-36 “GT 08ST
610 IG ‘TL | SOE SHG G 9°¢ © tS=0 (26 9 "6%

SUDIL) |SUDLY | SWDLD WWIII — | JUIDMAT UII JUIN
uloy o8e o5V

ysV On ERY | -Olg ODUBYT -1IOAY DDUBYIT -1DAV

Ysy YET

qUoJUOD [RIOT

iL

4yysiom Ap uo poseg

v V9-G99

& GL-T ‘09

I €L-8 ‘PE

vb PL-€ “8S

8 €L-~% “OL

8 “L9-9 '8¢
TUIDI
OSUBY

Uld}O1

qu

ose
~1IDAY

T ‘89
g “G9

IMI | PWIA

JOYE M,

G GG
6 LT
TAT

6ST
8 OT
GPL
SUDA)

VYSIOM
OAT
onde

OAV

IT¢
8GE
OSG

SGP
Lov
866
shog

o3v
asev
-10AW

Se 2 ee ooze ddd$
ET | ar ee Doers San dds
ON at Se See ene Wds
:S7BI poysBjuoN
6 Serene Sie Ae eS ey Adds
| An i ea ee Par eee adds
[re ean ieee! ira 5 Wds
LaQUunny ISYBI poUsByy]
SPBYL §yU1 JO JoIp pus UOl}IPUOL)

S19 TddS PUY ‘TAS ‘IN dS UO ry vam Burso) syou payspfuou pun payspof wowf saucy ur yso pup Gof 129,04 JT—' EY VILV J,

76

HS 61 'T ¥9
OT * vo. L9G
83" 86 G8 T
8S ° 18 T Li '¥
02 G8" G9 “ES
TS ee Gs ° G8 'E
Laue: ZL ‘I (| OF 8
cis 61 T GZS
81° 8ST T 18 €
86° 06 '€ 09 ‘7
1G ° PIT £6 7G
GG * Ot 'T 61
GS Ole FILS
TZ ° 00 ‘T ZO 'E
GG" 56° LE 8
83" va Tg 'S
GG © LET 9G "E
66 09% GG PV
83° G6 'T G6
cE ¥8 € 0G P
AS IZ 8o 7
Se" TE 7% 60 'T
LG" 6G 66'S
0s * IP @ tL Y
eS i 10 @ 86 7
8S" 96 T Ge T
83 0 GZ % GV
SUDLD | SUDI | SWDLD
sy yeq | uloyorg

yuoyUod [VIO],

v? T GS 6 69
&'P [ervey ¢ ‘OL
vv LST 6 89
6S L VG ¢ ‘6S
6 7 TST 0 ‘LL
aan ee 0 91 GTZ
td 8°16 € Fg
8% € GG § 02
9 °E 9 GS 0 FL
9 '€ 8 '8E g ‘6S
co? EWG T 89
& 7 ¥ 1G 0 19
Gv 6 SG G g9
97 6 1G @ ‘99
99 € 61 v 69
Lv 8 GS 6 LO
vv 6 FG 0 “9
& 7 8 LG v F9
8°E 0 GZ 9 °¢9
8 ¢ '6E § Sg
oP 0 96 G 9G
Lv L 6G v 6S
6S Go TE 6 8G
1? 8 66 8 8g
vv 6 SS y G9
(a 8 TG G G9
Gv 9 ‘9G G G9
quawad | qwaaiag | jwaaag
UsV VET ulojJorIg

qystom Alp uo poseg

wo ©
eae
Ke)

MORO OMlro
it
Wo)

G ‘99
quad

JOYR AA

8 LT sor CLL
6IT GOL 8

syed Jest AA

L1G 99T LLG i. Wel ee fre se 4904S 0 posuvyo FdS
"ZS 60T 989 ‘Pe ie f°) 7S Ad8 0} pasuvyo y90Ig
:shVP OCZ 7B pesI9Adzy
LOT ێI 968 (6d earn ee Pa na re ae ae Ads
GST S6I 06¢ Wi al ce ie late eaaeine areca 99048
—uo penur}u0y
7 9G 0 6G S| operates nn es i aHd$
OLE 0 OGG ns | Cini el anne amine Sinuiin fest haa 9098
ishep oez Apoyeutxoidds ye psoyiwoeg
S[BSIOAOL JOT,
I FI 9 VCP Ta | Cae oe ee %O'g ‘orngxtur yes+ 16%
€ LT gE SGP Cy eee er ro See Cr err F OOTA
GIG 99 SGP OE mae ig i a ee ads
—poj soyeurdoqywy
9 FI 08 GLE 7a (EC Cg oe ee en eee OOTA
G LI StI 89¢ :: PEE (deco ea a a: Sg Ge a rena 00TH
8 FI 18 987 GO Seer or een ee tn qoynd 91 d§$
anal L8 €9¢ (PN | he Sas eben Pane art eee 40741nq 8 dS
9 “ST LIT oLG GA a Vege ere ae es pet re plel OT dS
¢ ‘GT T8 87S O18 ieee ag Sat Pee = as cpt wove PIVL8 ds
€ ‘OT v8 669 Sip 5 ola cg ey ae 0 ate ee OAH 9T d$S
8 0Z est ver Gea «| eee naa as net Ie. Sar %9¥'0
‘ForaysopoyI + %ZQ ‘plow oIqtoosy
Z 61 OST 9EP ae IPT as pe oee ere %SO ‘plow siq1oosy
G GS (Gal 607 OP oe Flees Sens %HBE'l ‘Toreysopoup
PES OST Ic? Ses. Malte te nao eae %9F'O “Joreysopouy
6 6T 6G1 T&7 OL Ale ee ws QOT/sut go “g + "urs
ooT/ su To'O0 “gq +%e'o ‘ouroyp
9 ‘61 ral ol 6 “wi3 QOT/‘sut G0 “G+%G"'O ‘ourfouD
€ 02 SZI CLD Saati u sae ecu toile ws QOOT/ su ¢'0 “¢
6 TG FIT PEP a reer | ete i ae, ee eo ee ws
ooT/su 100 ““aA+%so ‘ourjoyp
0 1G T&T e9P Sis Bile Save Gare ws QOT/su 100 “Eg
GIG 681 G6P Oli le ee ee %e'0 “ourpoupn
SsuDiQy | SUDLD shogq | 4aqunn —Y}IM pojyuoulddns qqg
s7@1 WHa
4ySIoM SSO] 938
IdAT] YASIOM | oSVIOAY | Sey yop pus urelyg

ISVIOAY | OSVIOAY

syaup poyuamrsadaa 1ay}0 paf ype WO sua) UL YsD puDd “of “UWI9}0L —FY TTA I,

7]

necessarily accompanied by fatty livers. There
was some indication with other than SPE diets
that large livers tended to be associated with
kidney damage and that changes in the liver with
age might be important in the production of
kidney damage even though the liver itself showed
no evidence microscopically of damage. On SPE
diet alone or with added supplements, liver fat
was high at a relatively early age, often in rats
with apparently normal kidneys. The infiltration
of the liver with fat that was observed with SPE
rats may, however, accelerate kidney changes.
The tendency to enlarged, damaged kidneys on all
diets suggested an inherent kidney weakness in
the BHE strain of rats. It is conceivable that an
excessive load may be placed on the kidneys be-
cause of improper functioning of the liver resulting
from some defect in certain enzyme systems
responsible for the normal activity of this organ.

Differences in the accumulation of fat in the
livers of BHE and Wistar rats when fed SPE diet
under identical conditions provide evidence sug-
gesting inherent differences in the metabolic proc-
esses involved in the utilization of this diet by
these two strains of rats.

Serum cholesterol

Serum cholesterol measurements were usually
made on the blood from fasted rats, and only the

results with fasted animals are included in this
section.

RaTs MAINTAINING WEIGHT ON sTocK, SP 8
HVO, anv SPE piets.—The influence of age and
diet on cholesterol levels in the sera from rats
maintaining weight on stock, SP 8 HVO, and SPE
diets is summarized in table 65. Age appeared
to exert no influence on the serum cholesterol levels
or rats fed stock diet. A cholesterol level of 114
mg./100 ml. was obtained for a 976-day-old rat fed
this diet. Cholesterol values were below 150 mg./
100 ml. in 80 percent of the sera analyzed. On
SP 8 HVO diet, serum cholesterol levels were
similar to those on stock diet when the age of the
rats was less than 500 days. In rats more than
500 days old, however, only 43 percent of the
cholesterol values were below 150 mg./100 ml. and
3 of the animals in this group had sera containing
more than 200 mg./100 ml. On SPE diet, serum
cholesterol levels were high even in the youngest
eroup of rats, and were consistently higher than
150 mg./100 ml. for all age groups. Values ex-
ceeding 200 mg./100 ml. were a frequent finding,
and 9 of these SPE rats had serum levels exceeding
300 mg./100 ml. The high serum cholesterol levels
in rats 300 to 399 days of age seem to be another
indication that this period is a critical one in the
response of rats to SPE diet.

TABLE 65.—Influence of diet and age on serum cholesterol levels in rats maintaining weight on stock, SP 8
HAVO, SPE, SPM, SPB, and SPPB diets

Serum cholesterol

eee EEE EE EE EE ee

Diet and age of rats Rats | Average
(days) | age
Average
= as) ae eee ee
Number | Days | Mg./100 ml.

Stock:

Less than 300___-__- 19 229 120

300 to 499_________ 5 410 ila by

500 and over______- 6 691 127
SP 8 HVO:

Less than 300_____- 6 252 103

300 to 899________- 8 353 12

400 to 499_________ 6 457 131

500 t0:599- 2 2s2222- 14 546 166
SPE:

Less than 300_____-_ 7 252 199

300 to 399__._-__-- 7 353 351

400 to 499_________ 14 455 232

500 16599. ..-22. 11 530 287
SPM:

Less than 400_____-_ 6 304 118

400 to 599________- 6 512 164
SPB:

Less than 400______ 6 304 103

400 to 599________-_ 6 angst 163
Sees

Less than 400_____- 6 289 135

400 to 599________-_ 11 530 221

78

Rats with cholesterol levels of—
Range

Less than | 150 to 199 | 200 to 299| 300 mg./

150 mg./ | mg./100 mg./100 100 ml.

100 ml. ml. ml. and over

Mg./100 ml.

79-217 79 16 iss 0
97-151 80 20 0 0
107-179 83 17 0 0
90-117 100 0 0 0
81-185 15 25 0 0
112-154 83 U7 0 0
99-270 43 36 21 0)
157-240 0 57 43 0
178-670 0 14 43 43
152-402 0 43 43 14
197-432 0 9 55 36
102-128 100 0 0 0
87-265 50 Uy 33 0
80-152 83 17 0 0
79-243 50 ie 33 0
95-236 83 0) Ur 0
129-343 9 36 36 18

0 ee

RATS MAINTAINING WEIGHT ON SPM, SPB, anp
SPPB pirts.—The limited data for rats fed diets
containing high levels of milk, beef, or peanut
butter are reported in table 65. The results for
rats fed SPM and SPB diets were similar to those
for SP 8 HVO rats. In general, serum cholesterol
levels were low in rats under 400 days of age, and
tended to be higher in rats 400 to 599 days of age.
The slightly higher value for rats under 400 days
of age on SPPB diet was due to inclusion of one
rat with a value of 236 mg./100 ml., and is of
questionable significance considering the limited
data available. In the older rats fed this diet,
however, cholesterol values were significantly
higher (P<0.01) than those for rats of comparable
age fed stock, SP 8 HVO, SPM, or SPB diets,
with 54 percent exceeding 200 mg./100 ml.

RATS LOSING WEIGHT ON sTock, SP 8 HVO,
SPE, SPM, SPB, anp SPPB priers.—In table 66
are summarized similar data for rats that were
losing weight on these same diets. The results
are reported without regard to weight loss before
sacrifice. Although there seemed to be a trend
toward somewhat higher cholesterol values when
weight loss exceeded 100 grams, the data available
were too few to warrant separation on this basis.
Differences in serum cholesterol with age and with
diet were still apparent in the moribund rats.
Cholesterol levels exceeding 150 mg./100 ml. were
rarely seen in rats less than 400 days old on SP

8 HVO, SPM, and SPB diets. In the intermedi-
ate age group, elevated cholesterol values were
found with all diets, although the proportion of
rats with high serum levels and the extent of the
elevation depended upon the dietary regimen of
the rats. Except with SPPB diet, rats with a
relatively long lifespan tended to have lower
cholesterol levels than did those in the intermedi-
ate age croup. Rats fed stock or SP 8 HVO diets
generally had lower levels than did those fed the
other diets. One exceedingly high value of 1,813
mg./100 ml. has been omitted from the average
value recorded for stock rats. In this animal the
thyroid gland was almost entirely replaced by
tumor. On SPE and SPPB diets, the proportion
of elevated cholesterol values was high in compari-
son with those obtained in rats fed the other diets
investigated.

CHOLESTEROL AND KIDNEY DAMAGE.—The in-
crease in serum cholesterol with age appeared to
be associated, in part at least, with an increase
in the number of rats with enlarged and damaged
kidneys. In table 67 are summarized data relat-
ing kidney size to serum cholesterol level. On
stock, SP 8 HVO, SPM, or SPB diets, levels
exceeding 150 mg./100 ml. were rarely found in
healthy or moribund rats with kidneys weighing
less than 1.8 grams. Kidneys in this weight
range showed little evidence of degenerative change.
Somewhat higher serum cholesterol levels tended

TABLE 66.—Influence of diet and age on serum cholesterol levels in rats losing weight on stock, SP & HVO,
SPE, SPM, SPB, and SPPB diets

Diet and age of rats Rats | Average
(days) age
Average

Number | Days | Mg./100 ml.

Stock:

500 and over____-_-_- 9 PR 166
SP 8 HVO:

Less than 400______ 5 264 91

400 to 699_________ 12 570 182

700 and over______-_ 3 743 113
SPE:

Less than 300______ if 189 153

SOOMOVS99 Sots 2 ee | 16 367 386

400 'to15992 222 2 40 497 346

600 to 699________- 12 640 218
SPM:

Less than 400______ 4 340 184

AQOtOTD99 22S] 5 501 258

600 and over______-_ 1 600 175
SPB:

Less than 400______ 33 268 118

400 to 599-222! 3 535 348

600 and over______- 5 704 162
SPPB:

Less than 400______ 12 306 163

AQOtoOjO99s = 22% Set 10 520 276

600 and over______- 2; 663 315

Serum cholesterol

Rats with cholesterol levels of —
Range
Less than | 150 to 199 | 200 to 299] 300 mg./
150 mg./ | mg./100 mg./100 100 ml.
100 ml. ml. ml. and over
Mg./100 ml.

101-235 56 22 22 0
80-103 100 0 0 0
84-385 42 33 8 17
96-129 100 0 0 0
90-248 57 0 43 0

121-904 6 6 19 69

132-932 5 2 35 58

115-290 17 0 83 0

103-419 75 0 0 25

122-573 20 20 40 20

175 0 100 0 0
98-134 100 0 0 0

155-620 0 33 33 33

105-220 40 20 40 0
51-298 67 8 25 0

138-654 30 10 30 30

289, 341 0 0 0 100

TaBLE 67.—Serum cholesterol levels of rats with kidneys of different weights on stock, SP 8 HVO, SPE,
SPM, SPB, and SPPB diets

Kidneys less than
1.80 grams
Diet Rats Rats
Average Average
weight | cholesterol

Number | Grams | Mg./100 ml. | Number
Stock 232-2532 = 31 1. 49 108 6
oy egret) s yd 6 Male ee 34 1. 47 114 10
Si es eee SS 27 1. 52 192 10
Oe Mies ee 13 1. 33 115 a
oll eee 15 1. 44 113 1
Sila ef: a eee 18 1. 46 147 13

to accompany the small normal kidneys from rats
fed SPPB diet. The highest levels to accompany
kidneys in this weight range were those from rats
fed SPE diet. Kidneys weighing between 1.8
to 2.2 grams frequently showed some signs of
damage, chiefly evidenced by the presence of
hyalin casts. Cholesterol levels accompanying
kidneys in this weight range were consistently
higher than those found in rats with small kidneys.
Cholesterol values in rats with badly damaged
kidneys exceeding 3.0 grams in weight were
generally high, but neither kidney size nor the
types of kidney damage observed showed any
quantitative relationship to the extent that the
serum cholesterol was elevated.

A further consideration of the cholesterol data
suggests that the influence of age on serum levels
may be related chiefly to the increase with age in
the number of rats with enlarged damaged kidneys.
Evidence for this is seen in the data summarized
in table 68 for rats fed the semipurified diet,
where the results for rats with damaged kidneys
have been excluded. The main difference between
the results in this table and in table 65 lies in the
results for rats 500 days and older. The 5 animals
in this age group with small normal kidneys had
an average cholesterol value of 120 mg./100 ml.
similar to that found for younger rats, in contrast
to 166 mg./100 ml. (table 66) for all 14 animals in
this age group.

TasiE 68.—Serum cholesterol levels of rats with
normal kidneys at different ages on SP 8 HVO
diet

Cholesterol
Average age (days) Rats
Average Range
Number |Mg./100ml.|Mg./100ml.
75 ae ee ae ee 6 103 90-117
5 ie ees ee ee eee 6 119 84-164
7.16) 0 eee eee ene 5 133 112-154
DO tee es oes eee 5 120 99-150

Kidneys 1.80 to 2.19 Kidneys 2.20 grams
grams and over
Rats pets
Average Average Average Average

weight | cholesterol weight | cholesterol
Grams | Mg./100 ml. | Number | Grams | Mg./100 ml.
1. 94 142 4 2.78 225
1.95 157 10 3. 88 228
1.91 280 76 5. 51 343
1.95 187 3 3. 06 397
1. 86 241 8 3. 32 302
1. 99 222 10 4.45 304

SERUM CHOLESTEROL IN LITTERMATES.—No con-
sistent relation of serum cholesterol to liver size,
liver fat, and adrenal or thyroid size was observed.
There was some indirect evidence that the wide
range of serum cholesterol levels was due in part
to differences in inherited characteristics in the
mixed strain of rats under investigation. Litter-
mates were used in each of the experimental series
for comparison of the various dietary regimens,
but relatively few data were available to compare
the response of littermates fed the same experimen-
tal diet. One series with SPE diet provided some
data that permitted a direct comparison of the
response of littermates to this diet under strictly
comparable conditions. In table 69 are sum-
marized the findings for two littermates from each
of four litters. All were sacrificed at about 550
days of age. Data are included not only for serum
cholesterol levels but also for the organ weights of
these rats. Only one of the animals had lost more
than 100 grams when sacrificed. Although the
range of serum cholesterol values for the individual
rats in the four litters was wide, varying from 152
to 432 mg./100 ml., the serum levels for littermates
were relatively close. In contrast, organ weights
of individual rats varied considerably even for
littermates.

Rats FED OTHER EXPERIMENTAL DIETS.—In
table 70 are summarized limited data on serum
cholesterol levels in rats fed the other experimental
diets. Most of the data were for sick or moribund
rats that were losing weight at the time of sacrifice.

The wide range of values and the tendency to
elevated serum cholesterol values observed in
SPE rats were also apparent in rats fed the various
supplemented SPE diets. No significant differences
were observed in the serum cholesterol levels on
any of these diets. Most of these rats had lost
more than 100 grams before sacrifice and had large
damaged kidneys. A comparison of the serum
levels in rats that were maintaining weight might
show differences not apparent in these moribund
animals.

When the level of HVO was increased from 8 to
16 percent, the average serum cholesterol level

TABLE 69.—Serum cholesterol levels and organ weights for rat littermates fed SPE diet

Weight Organ weights
Litter No. Identifica-| Age | Maximum at Serum
tion No. weight death cholesterol
Liver | Kidney | Adrenal} Thyroid
Days Grams Grams | Mg./100 ml. | Grams | Grams Mg. Mg.

7 5 513 714 611 267 19. 1 4, 73 46 26
rete gpa ahr Sark alec dRE eRe 2 513 675 657 275 26. 6 2. 58 27 21
8 e 510 530 516 285 16. 9 1. 76 18 15
MGM LM Nar eG 2 511 590 585 220 13.5 2.32 24 20
10 i 504 580 560 432 25. 0 2. 32 18 18
Tae a ee i 2 504 535 500 362 18. 6 1. 88 17 15
13 ‘3 494 563 542 154 16. 4 4, 50 27 19
EU Te aed 2 494 566 511 152 16.8 6. 37 29 27

TasiE 70.—Serum cholesterol levels in rats fed other experimental diets

Weight status and diet of rat

Losing weight on—
SPE supplemented with—

@holinepOM pac see ee eee
Bro sOOlsme yO ORM 1 te Fe ee

Choline, 0.6%+ By, 0.01 mg./100 gm________-____________-
Be Oroame lO Oem See etait ee Se coe eos ees
Choline, 0.56%+ Bs, 0.5 mg./100 gm______________-_______-
Choline, 0.5%+ By, 0.01 mg./100 gm.+ Bs, 0.5 mg./100 gm__

@holesterol0:46.07 sos. os sous fe Ee
Cholesterol WSS pe wees se Dike ase fo eae Ee
NSCOR DIGHACIO WONZ On sus Nae Sa
Ascorbic acid, 0.2%-+ cholesterol, 0.46%___--___-

MOG saltiamixiures 3:02 82 oe oe os Se

SPW 8 HVO

(138 mg./100 ml.) was similar to that observed
on the lower level of this fat. With butter or lard
there was no evidence that increasing the level of
the fats caused any appreciable change in serum
cholesterol. Serum cholesterol values, however,
tended to be much higher when the dietary fat was
lard than when it was HVO.

Serum cholesterol values were obtained for
rats on only two of the diets investigated to de-
termine the influence of egg or egg fractions—
SPW 8 HVO and E100. On SPW 8 HVO diet,
cholesterol levels were similar to those for com-
parable SP 8 HVO rats. On the diet consisting
solely of egg yolk, serum values were significantly
lower than when the diet contained 25 percent
whole egg. Supplementation of egg yolk with
salt mixture had little influence on serum
cholesterol.

Serum cholesterol
Rats Average
age
Average Range
Number Days Mg./100 ml. | Mg./100 ml.

Ee ene eer 11 483 365 264-700
a Src titen: Li 4 549 296 221-440
3 562 291 204-382

5 512 346 252-510

6 431 334 257-457

u 447 344 196-549

Fern tein ss 8 451 351 261-452
ite TEES 7 422 370 210-470
eps eer ee 5 460 425 224-930
ee eee vi 431 421 164-840
wade a 6 679 138 96-209
Bee a sat 10 548 282 137-674
sa Oe 6 591 285 198-455
ee nas 6 626 204 156-294
rer eae 6 529 168 118-209
Spe eee 10 420 186 115-311
Pattern ee 4 461 213 176-252
Bed yen 2 5 430 190 169-218
clears ies i 6 550 110 80-158

Discussion.—The results reported in this publi-
cation as well as those reported by other investi-
gators have shown that many factors influence
cholesterol levels in the blood, and that the inter-
actions between dietary factors and other factors
such as heredity, age, and sex make the problem of
interpreting serum values a difficult one. Many
review articles have appeared dealing with various
aspects of cholesterol metabolism. Kritchevsky’s
(109) book provides information on the biological
significance and function of cholesterol. Portman
and Stare (153) reviewed the many factors im-
portant in the dietary regulation of serum choles-
terol levels. Deuel (46) covered many phases of
lipid metabolism in relation to blood cholesterol
levels.

Discussion of the literature dealing with serum
cholesterol will be limited to those investigations

81

that seem most closely related to the results
reported in this bulletin. Blood cholesterol levels
vary considerably among species and only reports
dealing with rat as the experimental animal will
be considered, along with a few of the reports
dealing with humans because of interest in the
possible application to humans of the results
obtained with rats. The results for rats will be
confined to those reported for male rats.

The response of serum cholesterol levels to
diet often differs, depending upon the absence or
presence of cholesterol in the diet. Comparison
of serum cholesterol values, therefore, must take
into account whether we are dealing with en-
dogenous cholesterol or with serum cholesterol
levels that may be reflecting both endogenous and
exogenous cholesterol.

The liver is the chief source of endogenous cho-
lesterol and not only is able to synthesize this
sterol but also is active in its breakdown and
excretion. Serum cholesterol values in the ab-
sence of dietary cholesterol generally reflect the
balance of activity in the liver with regard to these
two processes.

With humans, serum cholesterol levels reflect
lifetime dietary habits which generally include
the consumption of cholesterol-containing foods.
With the rat, however, many investigations deal
with diets that contain little or no cholesterol so
that blood cholesterol is strictly endogenous in
origin. Even in the absence of dietary cholesterol,
the results relating the kind and/or level of fat to
serum cholesterol levels of rats are not entirely
consistent.

In the absence of dietary cholesterol, several in-
vestigators report a tendency for blood cholesterol
levels in rats to increase with increasing unsatura-
tion of dietary fat. Klein (105), feeding diets
containing 5- and 30-percent levels of Crisco or
corn oil found plasma cholesterol levels to increase
as the intake of linoleic acid increased. Swell,
Flick, Field, and Treadwell (179) reported in-
creased levels with increasing unsaturation of fat
when rats were fed diets containing soybean fat
hydrogenated to different iodine values. Nath,
Wiener, Harper, and Elvehjem (136) reported
little effect on serum cholesterol levels in rats as
the result of feeding increasing quantities of hy-
drogenated coconut oil but a slight increase when
1 percent corn oil was added to the diet. Sun-
flower seed oil (79) has also been reported to
elevate blood cholesterol.

With diets in which sucrose was the carbo-
hydrate, Marshall, Hildebrand, Dupont, and
Womack (126) obtained significantly higher cho-
lesterol levels with 15 percent corn oil than with
3 percent corn oil or with 15 percent lard or HVO.
In contrast, no significant differences in serum
levels were observed when the carbohydrate was
starch. Okey, Lyman, Harris, and others (144)
reported that the degree of saturation of dietary
fat exerted little influence on serum cholesterol
levels when 10 percent of fat was added to a nutri-

82

tionally adequate synthetic diet. Best, Lucas

Patterson, and Ridout (23) also reported that the
kind of fat had little effect on serum cholesterol
when the diet contained sufficient choline to pre-
vent fatty livers.

Aftergood, Deuel, and Alfin-Slater (6) found no
significant difference in the plasma cholesterol
levels of rats fed a diet containing 15 percent
cottonseed oil or lard after a 12-week feeding
period. After 24 weeks, however, plasma choles-
terol levels were significantly lower in rats fed
cottonseed oil than in those receiving lard. Avigan
and Steinberg (15) reported an increase in serum
cholesterol when either coconut oil or corn oil was
added to a Purina chow diet, but the increase was
ean greater with coconut oil than with corn
oil.

There is at present no satisfactory explanation
for these divergent findings. The results for BHE
rats reported in this publication indicate that, in
the absence of dietary cholesterol, serum levels
change slowly with diet, and suggest that some of
the discrepancies in the literature may be due to
the relatively short feeding periods generally
studied. Another factor that may be responsible
for some of the differences observed is the hered-
ity of the strain of rats under investigation.
Kohn (106) reported evidence for considerable
variation among strains of rats in their average
serum cholesterol values which varied from 65
to 132 mg./100 ml.

Investigations of the influence of dietary cho-
lesterol on the serum cholesterol levels in the rat
have dealt chiefly with the addition of cholesterol
per se rather than with the use of cholesterol-
containing foods. The response to feeding these
cholesterol-containing diets is apparently in-
fluenced by accompanying dietary components.
Dietary cholesterol may be absorbed by the rat
in the absence of dietary fat, but the presence of
fat in the diet results in an appreciable increase in
serum cholesterol levels (33). The fatty acid
component, not glycerol, is reported to be the
important factor (179, 189). Dietary cholesterol
may result in elevated values in the blood in the
absence of fat if sufficient bile salts are fed (179).
Wilgram, Lewis, and Best (189) reported increased
cholesterol levels when choline was added to a diet
containing cholesterol.

Unsaturated fats tended to lower serum cho-
lesterol levels of rats fed cholesterol in contrast to
the elevated values reported by several investi-
gators when this sterol was absent from the diet.
Okey and Stone (147) and Aftergood, Deuel, and
Alfin-Slater (6) reported lower serum values with
cottonseed oil than with lard, and small but com-
parable differences in liver lipids. The latter
investigators report that the differences in serum
levels observed were not due to differences in the
absorption of these two fats. The addition of
large amounts of vitamin E to the lard diet eli-
minated the differences observed in the liver lipid
but did not influence blood cholesterol levels.

Nath, Wiener, Harper, and Elvehjem (136) demon-
strated a marked accumulation of cholesterol in
the blood and livers of rats fed 1 percent cholesterol
and 10 percent hydrogenated coconut oil, although
no accumulation was observed with cholesterol or
coconut oil when fed alone. Replacement of 1
percent of the coconut oil with an equivalent
amount of corn oil resulted in a marked decrease
in blood and liver cholesterol and in a proportion-
ately greater decrease in total liver lipids. Shapiro
and Freedman (1/70) found that the addition of
safflower oil and methionine to a cholesterol-
containing and sulfur-deficient diet was more
effective in reducing hypercholesterolemia than a
supplement of methionine with a hydrogenated
fat (Crisco). No exceedingly high levels of
cholesterol were observed with the 13 fats in-
vestigated by Okey, Lyman, Harris, and others
(145) even where cholesterol was included in the
diet. The highest value for male rats was 96
mg./100 ml. when coconut oil was fed. Lower
values were associated with the more highly un-
saturated fats, but there was no consistent trend
relating serum levels to the degree of saturation
of the dietary fat.

The influence of the unsaturated fats on serum
cholesterol levels does not appear to be related to
absorption of the sterol. Lin, Karvinen, and Ivy
(117) and Ivy, Lin, and Karvinen (99) reported a
limited capacity for cholesterol absorption based
on measurements of fecal excretion. Byers and
Friedman (37) compared the immediate response
of rats to cholesterol added to the diet in soybean
oil, corn oil, lard, or coconut oil as determined by
measurements in intestinal lymph, and found
absorption to be greater with the unsaturated than
with the saturated fats.

Okey and Lyman (143) observed a difference in
response to dietary cholesterol depending on the
level as well as the kind of dietary fat. Choles-
terol levels tended to be higher when cholesterol
was fed with 10 percent coconut oil than when fed
with an equivalent amount of cottonseed oil.
At the 5- and 15-percent levels of these two fats,
however, no significant differences were observed.

Very little has been reported on the serum lipids
of rats fed cholesterol-containing foods. Blather-
wick, Medlar, Bradshaw, and others (31) reported
high plasma cholesterol as well as fatty livers of
high cholesterol content as the result of feeding
diets containing large amounts of beef liver.
Reussner and Thiessen (156) did not determine
blood cholesterol values for rats on the cereal and
milk or egg and bacon diets, but did obtain evidence
of differences in the serum lipid components based
on flotation rate measurments that showed a
much higher value for the S; 12-400 class for the
bacon and egg diet than for the cereal and milk
diet. Rosenkrantz and Bruger (162) found that
the feeding of egg yolk resulted in an elevation of
the cholesterol content in blood and liver.

Although there has been some evidence that
dietary cholesterol has little influence on the serum

cholesterol of human _ subjects, evidence has
increased indicating that under some circum-
stances dietary cholesterol may be an important
factor in determining serum cholesterol levels.

A single dose of 10 grams of cholesterol fed in a
meal with ample fat caused only a small and
transient change in the serum cholesterol of young
men (1/04). Serum cholesterol levels may be
elevated, however, as the result of consuming
cholesterol-containing foods such as ege (34) or
butter (25, 26). From investigations of the re-
sponse to various fractions from butter with and
without various supplements, Beveridge, Connell,
Haust, and Mayer (25) showed that relatively
small amounts of cholesterol, depending on the
dietary fat with which it is associated, may effect
highly significant increases in plasma cholesterol
in man. Beveridge, Connell, Mayer, and Haust
(27) fed varying levels of cholesterol with a
homogenized diet containing 30 percent of the
calories as a butter-fat fraction low in cholesterol
to a group of university students for a period of
16 days. Between intakes of 13 and 634 mg. of
cholesterol daily, serum cholesterol levels increased
sharply, but no further significant increases were
obtained with daily intakes of 1,300 to 4,500 mg.
Cook, Edwards, and Riddell (43) reported 15
percent absorption of crystalline cholesterol by one
subject (male) in contrast to 60 percent when
ege was the source of the sterol. <A transient
elevation in cholesterol was observed, with serum
levels returning to normal within 24 hours. For
patients with normal fasting serum cholesterol
levels, Messenger, Porosowska, and Steele (130)
observed an elevation in these levels after feeding
ege for a period of 48 days. Okey and Stewart
(146) and Okey (141) demonstrated a slight but
consistent rise in the cholesterol level of normal
women taking four egg yolks daily for 1 month.

No attempt will be made to review the extensive
literature now available on the influence of the
degree of saturation of the dietary fat in controlling
the level of serum cholesterol in humans. Al-
though many factors complicate interpretation of
these studies, such as the short duration of the
experimental period, the influence of previous
dietary history, and heredity, there is considerable
evidence that serum cholesterol levels in humans
may be reduced by increasing the proportion of
unsaturated fat in the diet (109).

The cholesterol level in rats’ blood is generally
lower than that observed in humans. This
relatively low cholesterol level may be due to a
species difference or may be a reflection of the
lifelong feeding of diets low in fat and cholesterol.
The results reported for BHE rats in this publica-
tion indicate that elevated cholesterol levels may
occur in rats consuming throughout life diets
containing relatively high levels of sucrose and
higher levels of fat than are usual for this species.
The response of the rat to cholesterol-containing
diets does not differ markedly from that of humans
to comparable diets.

83

Considerable interest has been evidenced in the
plant sterols, such as are present in peanut butter,
and their role in lipid metabolism, because of
their possible value in reducing blood cholesterol
levels. Although there is evidence that plant
sterols do result in reduced blood cholesterol under
many conditions, the findings on this subject have
not been entirely consistent. Here again, the
presence or absence of dietary cholesterol seems to
be a factor in determining the response to these
sterols.

Several recent reports (76, 99, 178) indicate
that plant sterols are absorbed by the rat. Swell,
Boiter, Field, and Treadwell (178) investigated
some of the factors influencing the absorption of
these sterols and have suggested that they are
absorbed through the same mechanism as cho-
lesterol. A maximum absorption of 22.9 percent
was observed when soybean sterols were fed with
25 percent oleic acid and 1 percent sodium
taurocholate. Ivy, Lin, and Karvinen (99)
reported a comparable value for the absorption
of soybean sterols and a decrease in absorption of
Se eile when a mixture of the two sterols was
ed.

There appears to be little evidence for a decrease
in serum cholesterol values when plant sterols
are fed to rats on cholesterol-free diets. Swell,
Boiter, Field, and Treadwell (178) obtained an
appreciable elevation in the serum level as the
result of including 2 percent soybean sterol in a
diet containing oleic acid and bile salts. Liver
sterols tended to be lowered when plant sterols
were included in the diet. Chromatographic
analysis provided no evidence of appreciable
amounts of plant sterols in either blood or liver,
and the rise in the sterol concentration in blood
appeared to be due to cholesterol or to a sterol
with the same R, as cholesterol.

When soybean sterols were added to a diet
containing cholesterol, Swell, Boiter, Field, and
Treadwell (177) obtained a reduction in blood
cholesterol values in comparison with those
observed in the absence of the plant sterol. Serum
cholesterol levels were found to decrease with
increasing concentrations of the plant sterol.
Alfin-Slater, Wells, Aftergood, and others (7) and
Ivy, Lin, and Karvinen (99), however, found no
appreciable change as the result of adding soybean
sterols to a cholesterol-containing diet. The basic
diet used by Swell was one that resulted in a
marked hypercholesteremia in the absence of
plant sterols, whereas the diets used by Alfin-
Slater, Wells, Aftergood, and others (7), and Ivy,
Lin, and Karvinen (99) produced blood cholesterol
levels only slightly higher than normal.

In view of the results reported for plant sterols
fed in the absence of cholesterol, it is possible that
phytosterol as well as the unsaturated fat present
in peanut butter may be a factor in the elevated
serum cholesterol levels reported in this publica-
tion for BHE rats fed SPPB diet.

The kind and level of dietary protein (61, 134,

84

185, 142, 144, 147) and the type of dietary carbohy-
drate (3, 82, 103, 152, 153) have been implicated as
factors of importance in determining serum choles-
terol levels in the rat. The investigations reported
in this publication were not planned to determine
the role of either of these dietary components.

The level of protein was relatively constant in
the diets of BHE rats except for the diets consist-
ing of 100 percent whole egg or egg yolk. The data
available were insufficient to determine whether
the high level of protein in Y100 diet was a factor
in lowering the serum cholesterol of these rats.
The possible effect of specific proteins in combina-
tion with other dietary ingredients as factors in-
fluencing serum cholesterol levels has not been
excluded.

Sucrose was the dietary carbohydrate for most
of the diets fed to BHE rats. The only diets with-
out high levels of sucrose were the stock diet,
E106, and Y100 diets. Differences in the response
of rats to diets containing 25 percent whole egg
(SPE) and those containing 100 percent egg (2100)
or 100 percent egg yolk (Y10G) may be related to
the lack of sucrose in these last two diets.

The thyroid gland has long been recognized as
exerting appreciable influence on lipid metabolism
and is the most important of the endocrine glands
as regards the control of cholesterol metabolism.
Handler (54) reported a marked increase in the
cholesterol concentration of the liver and serum of
the rat in the hypothyroid state. Thyroid feeding
resulted in a decrease in the cholesterol concentra-
tion of the liver and effected a relatively small
decrease in serum levels. Although cholesterol
synthesis and absorption have been found to in-
crease in the hyperthyroid rat, it appears that the
excretory or destructive processes concerned with
cholesterol dominate in the hyperthyroid state
(36).

However, as the result of injecting anti-rat kid-
ney serum (AKS) into rats previously fed with
thyroid to produce hyperthyroidism, Rosenman
and Smith (165) reported a marked increase in
plasma cholesterol. Under these conditions the
hypothyroid rat showed a lowering of the plasma
cholesterol when compared with the control ani-
mal. It appears that this effect on the hyperthy-
roid rat was due to a metabolic block to lipid
egress resulting from the anti-rat kidney serum
which permitted the accumulation of cholesterol
in the blood and not to any change in the hyper-
thyroid state.

The enlarged thyroids here reported for BHE
rats fed SPE and SPPB diets were generally ac-
companied by elevated serum cholesterol levels.
There was no evidence microscopically of any
abnormality in the thyroids of the rats that were
maintaining weight, and no data were available to
determine the possible influence of these diets on
the excretion of this sterol.

There has been considerable evidence associating
hypercholesterolemia with nephrosis in man and
in animals. Hyperlipemia has also been observed

to accompany the nephrotic state. Moribund
BHE rats, regardless of diet, frequently exhibited
a hypercholesterolemia generally associated with
damaged kidneys. Blood sera from these rats
were often obviously lipemic. In many ways the
picture seen in these moribund rats was similar
to that observed in experimentally induced
nephrotic rats.

Heymann and Lund (90) showed that a con-
dition simulating the nephrotic syndrome of
childhood can be produced in rats by the in-
jection of rabbit anti-rat kidney serum (AKS)
prepared by immunizing rabbits against rat
kidney. This procedure has been used rather
extensively to study the factors involved in
chronic nephrosis in this animal. Heymann,
Matthews, Lemm, and others (91) observed no
evidence of a disturbed clearance of fat from blood
when intravenous injections of C labeled tri-
laurin were given to nephrotic rats. Rosenman,
Friedman, and Byers (163) reported that the
hypercholesterolemia observed was not due to
increased intestinal absorption, to decreased rate
of excretion, nor to increased cholesterol synthesis.
The elevated blood cholesterol present in these
rats was endogenous in origin, and the authors
have suggested biliary obstruction as the cause.
Friedman, Rosenman, and Byers (71) found that
the nephrotic rat was unable to remove either
endogenously or exogenously derived lipid from
plasma with its usual efficiency. A progressive
fall in plasma albumin was found to follow the
injection of AKS and was associated with a rise
in plasma triglycerides, phospholipids, and total
cholesterol. Heymann and Hackel (88, 89) in-
dicated a possible involvement of both the kidney
and liver in the mechanism eliciting hyper-
lipemia. Buateral nephrectomy (88) prevented
the development of hyperlipemia, and it was
suggested that a “hyperlipemia inducing” agent
may be secreted by the nephrotic kidney. Sub-
total hepatectomy (89) resulted in reduced hyper-
lipemia. Ehrich, Forman, and Seifer (55) re-
ported an increased kidney weight, an increased
adrenal weight, and extensive proteinuria in
rats receiving a large dosage of AKS.

Lewis and Heymann (/1/5) analyzed the serum
lipoproteins in these rats and found the greatest
increment in the low density fractions. They
were similar in type to those of nephrotic children.
Heymann, Matthews, Lemm, and others (9/) sug-
gested that the hyperlipemia observed was due to
increased mobilization of lipid rather than to a
deposit of lipid in tissues. Marsh and Drabkin
(124) provided evidence indicating that fat was
mobilized from body stores.

There appears to be little information on the
production by dietary means of hypercholester-
olemia and hyperlipemia in rats associated with
kidney damage. According to Blatherwick and
Medlar (30), diet alone will produce nephritis and
will also determine its severity. They observed
marked involvement of the kidney when rats were

fed a diet containing 75 percent liver. Some kid-
ney damage was also found when the level of liver
fed was 30 percent. Fatty infiltration of the liver,
high liver and plasma cholesterol, and increased
urinary protein were observed. An average
plasma cholesterol of 88 mg./100 ml. was observed
in stock rats without nephritis. Values over 146
mg./100 ml. were considered hypercholesteremic.
On liver diet, the mean value was 126 mg./100 ml.
without nephritis and 219 mg./100 ml. was con-
sidered the upper level for normal rats. Higher
values were associated with extensive kidney dam-
age. Fatty infiltration of the liver was observed
even though kidneys still appeared normal in rats
fed the high level of liver.

The fatty infiltration of the liver, the high
plasma cholesterol, and the increased urinary pro-
tein obtained by Blatherwick and Medlar (30)
when rats were fed a diet containing high levels of
liver were strikingly similar to the results reported
here for BHE rats fed diets containing 25 percent
ege.

SummMary.—The results of the investigations re-
ported in this bulletin provide further evidence
that many factors influence blood cholesterol levels,
and emphasize the statement made by Portman
and Stare (153) that it is unwise to place too much
emphasis on the effect of a single factor in the con-
trol of serum cholesterol unless that factor is
evaluated under a wide range of conditions.

From the long-term studies with BHE rats, the
relation of serum cholesterol levels to age was
found to differ with diet. High levels were rarely
seen in healthy BHE rats that were maintaining
their weight on the stock diet and there was little
evidence that cholesterol levels were influenced by
age. Cholesterol levels were generally low in rats
under 400 days old that were maintaining their
weight on the semipurified diet or on modifications
of this diet, SPM, SPB, and SPPB, containing
milk, beef, or peanut butter. In the sera of older
rats, elevated cholesterol levels were observed on
all of these diets except the stock diet; the highest
value observed in the absence of dietary cholesterol
was for rats fed SPPB diet. The increased serum
cholesterol in the older rats was generally accom-
panied by kidneys showing evidence of degenera-
tive changes even in rats that appeared healthy at
the time of sacrifice.

Although serum cholesterol values tended to
be high in moribund rats, relatively low cholesterol
levels were found in several rats that survived
over 700 days. Cholesterol values obtained for
individual rats at intervals throughout life are
needed to determine whether we are measuring
changes in cholesterol level that are due to aging
processes or whether these changes may be the
result of the development of some pathological
condition.

In the presence of dietary cholesterol, with
ege as the source, elevated cholesterol values
were observed in relatively young BHE rats.
The values for rats between 200 and 400 days

85

of age were significantly higher than those observed
on the other experimental diets. Exceedingly high
values were observed for rats 300 to 400 days of
age. Elevated serum cholesterol values were seen
before there was evidence of kidney damage, and
showed no relation to the amount of liver fat.
The addition of cholesterol to the SPE diet already
high in cholesterol appeared to exert little influ-
ence on the serum level of this sterol, indicating
that a saturation level had been reached with
the diet containing 25 percent egg. Dietary
cholesterol alone was not responsible for the high
serum cholesterol levels in SPE rats; the values
for rats fed the exceedingly high cholesterol-
containing diet Y100 were significantly lower than
those with SPE diet. In the levels fed, there
was no evidence that supplementation with
choline, vitamin B,, vitamin By, or ascorbic
acid exerted asignificant influence on the cholesterol
levels found in moribund rats fed SPE diet. A
serum cholesterol level of 160 mg./100 ml. appeared
to be the upper limit for serum levels associated
with normal kidneys in stock or SP 8 HVO rats;
the upper limit for rats fed SPE diet was 250
mg./100 ml.

Serum protein components

RATS MAINTAINING WEIGHT ON sTOCcK, SP 8
HVO, anv SPE prers.—In table 71 are sum-
marized data from electrophoretic analysis of
blood serum from rats maintaining weight on
stock, SP 8 HVO, and SPE diets. The data
reported are for fasted rats. The results are
reported as percentage of total protein; no data
were available for total serum protein. Values
for albumin and alpha, globulin have been com-
bined because of difficulty encountered in obtain-
ing a clear-cut separation of these components
for some of the serum samples analyzed. The
presence of one or more components with an
electrophoretic mobility faster than that of
albumin (PA) was of particular interest. Because
of the influence of this prealbumin component
on the relative percentage of the other serum
proteins, data for serum samples with no PA
present are reported separately from those with
The usual serum protein components with a
normal distribution were found in the serum of
rats less than 300 days old that were maintaining
their weight on the stock diet. In rats over 300
days of age, serum proteins contained smaller
concentrations of albumin and alpha, globulin
and higher concentrations of the other components
than those in the younger rats. In some rats
small amounts of a fast-moving component were
found, generally represented by a diffuse band
rather than by a clear-cut peak or peaks. The
highest value observed for this fast-moving
component was 2.4 percent of the total serum
proteis.

The results with SP 8 HVO diet were in general
similar to those with stock diet except for the

86

greater proportion of rats with PA in their sera.
This component was present in the sera from
some of the rats that were less than 300 days old,
and was found in 67 percent of the animals more
than 300 days old. Some relatively high con-
centrations of this component were found in sera
from the oldest group of rats. The relative con-
centration of alpha, globulin also tended to in-
crease with age.

On SPE diet, the fast-moving component was
present at all ages, generally showing a more
distinct separation, and evidence of more than
one fast-moving component was frequently ob-
tained. Between 300 and 400 days, the propor-
tion of animals with sera containing PA was large
and the amounts of PA tended to be high. This
component was absent from all but one of the
sera from rats 400 to 499 days old but again was
seen in a high percentage of the rats 500 days old.
The significance of this decrease in PA in the
400- to 499-day-old group was not apparent but
may be related to the ability of these rats to
survive the critical 300- to 399-day period. The
relative concentration of the other protein com-
ponents varied and showed no consistent trend
with age. The concentration of gamma globulin
in the sera of SPE rats tended to be low whether
or not PA was present.

Rats LOSING WEIGHT ON stock, SP 8 HVO, anp
SPE piets.—In table 72 are summarized data for
rats that were losing weight on these same diets.
The data available for moribund or sick rats fed
stock diet were limited in number and were for
older rats. Except for a higher concentration of
PA, the results were similar to those obtained for
rats of comparable age that were maintaining
weight on this diet.

The relative concentration of albumin and
alpha, globulin tended to be lower in rats that
were losing weight than in those maintaining
weight on SP 8 HVO diet, and difficulty was
encountered, in the older rats, in obtaining a
separation of these components from alpha, globu-
lin. PA was absent from the sera of rats under
300 days old and was low when present in the
sera of rats over 600 days of age. Of interest was
the exceedingly high PA value of 41.8 percent in
one rat with a liver tumor. This value has been
excluded from the results in table 72.

On SPE diet, large amounts of PA were found
in the sera of moribund rats of all age groups 300
days and over, including the 400- to 499-day-old
animals. There were too few data to assess
accurately the influence of the extent of weight
loss on the serum proteins, but it may be of
significance that the three rats over 300 days old
showing no PA had all lost over 100 grams.

SERUM CHOLESTEROL, KIDNEY SIZE, AND DAMAGE
IN RELATION TO PA.—In table 73 are summarized
data on cholesterol levels and kidney size and dam-
age as related to increasing amounts of the fast-
moving component in the sera of rats fed SP 8
HVO and SPE diets. On SP 8 HVO diet, when

na
mao

KO NOrwd otis

ai
re

© 19 CO GO

CONANT HHA
Co 19
Sr

quaalag | juaLag

aT Oy
—nqols | -nqojs
suey) | vjog

‘uIUN|s UBYY A[pIdei oLoul Sutaow syuouodurod 10 yuouodWM09 ulUING[Berid syussoIdel Wqy

T 6 9°¢ 8 Slats | Led
GL & G9 SESAlecas
9) 49 CeO arn So i6
6 °L 8 “99 Vil Soo Gy
0 OT ERS Oe TsO eGale ORS
€ 6 T ‘79 69 GT | 8 'E
gL G 69 8'§ S| EE
GV vvL 6€ 66,08
G6 TE 19 Ve Gees eis One
ee ee TT | tT
JUIILIT | JUAWAT | quawag | quaa1agq
uly
uly —nqols esuey =f esRIOAY
—nqo[s Ieydye
‘eydiy | + ur
“diy Wd

Vd UPA szer ‘sutoyord windes Jo uoryptsodwoy

06S
FOP
ets
£96

97g
9ST

shoqg

ase
IDVIOAY

moO NNMO NWR

$7BY

see O

re

eT

KSA SDOON 2WI91GH

neo

Oto NOTE

1U9ILAT

uly
—nqojs
BUIUIBL)

0 61 GUL 21°19 GEG Vanna ee eee 66¢ 97 00S

6 ST 0'8 6 ‘OL GGT 1° I ge ogc og 66F 91 OOF

te Als Gel PEL 8S Chan |e ee 66€ 94 O00E

8 FI Lp, FOL GZ CP a eee OO UY} sso'T
‘HdS

9 IG GOTT PPS SPS oh. || Se ms 66¢ 94 00¢

€ OT 0°8 € °L9 or ee Shwe ee 0c 66F 93 OOF

021 F'8 & F9 &Gé S| iS eaeat 66€ 94 008

Grizal 8G 9 ‘89 OGG Tle Hen Saas O0€E UBY} Sso'T
‘OAH 8 dS

I ‘GS 02 0 '8¢ TOL Conny | eanein T9AO PUB OOG

9 IG T'8 6 ‘FS OGF Poaal\boe es te 66F 93 00E

6 ST ¢°9 € “OL c6I 4 Pia s 00g UY Sso'T
WMaWdId | (WAI | 1UI9LIT shog aq 2y004g

-UNN
ull
uly ull —nqoys
—nqols —nqo[s Teyd[e
Bog eeydly + utur ose (s£ep)
“nq[y |oesev10Ay | sey | Sper Jo ose pus yoIq

Vd Moy sper

‘suiojoid wimdes Jo uorpisodurog

S91p WdS' PU» ‘OAH 8 dS ‘49038 vo sabp quasaffip yo yybrvam burwpyurpw syou wou dsas fo syuauodwos wi9}01J— 1), LAV,

87

‘sun qos *eydye pus 'eydye pus urumay]e pourquios syuosoidor onye A suoryeredos 100g z
‘unde uvyy A[pides o10w Suraour syusuodurod 10 yuouUodu09 urumnq[eaid syuosoidod Wd 1

Vv? & GI 6 G G9
OL OST 68 6 G9
6% | 81.08 | P29
€ Ol 0 "GS 0 '99 2
a L1G SUE 0 ‘0S
OTT 9 ST GL T ‘09
Warley | Waa | Wala | jUIIsI I
uly
uly ull ul] —nqoys
—nqoys | -nqojs | -nqops | teydye
vuuey | BIg eeydyy | + Uru
“nq Vv

0 ZI-8 @ | 88

€ ‘OI-8 0) 49

VEIL 7% | OL

9-61 | 4T

6°L 6°

L8-¢e| oS
1UdAMMIT JUNI”
asuey =| aseloAy

Wd

Wd UPA szer ‘surojoid umass Jo uorpisodui0y

66S 9 GST
OF 8 6 ¢
£96 8 VS
eoeee healeceaes 9°G
eoL & Go LT
ESP I QUEL
pics Can aa VTL
6L9 & 9 6
shivg 1aq QUIDLIT
-WNNT
ur
-nqoys
ase BUIWIBY)
OSBIOAYV | $}BY

FIG 68 G 9G €Tg
I GI 0'8 74 PLY
v ‘OT PST 8 F9 GPE
0 GI 8 °L 0'SL 183
G 0G € 69c OTL
9 TG G8 € GG PSP
6 61 LTT 6 ‘9S LIE
GTS 8h stag) 89
quaalag | qualia | qua1ag | svg
uly
ull ull —nqors
-nqgojs | -nqops | !eydye
Bypog ceydy | + ulur 3B
nly

Vd JNOYPM $71
‘gurojord umndes Jo uorsodu0y)

SUP AdS PU ‘OAH 8 dS ‘49038 wo

be oe oe

I
1aq

“UN AT

66¢ 93 00S

‘aes: 66F 04 OOF

Gees 668 °F 0OE

Berea OO UY} ssoT
“HdS

waa nnn- IIAO PUB QI

eae 66S 0% OOF

Seehee OOF UR Sso'T
‘OAH 8 dS

aaanace JOAO PUB QE
>Y9049

aSBIDAY | S}BY

(sfep)
Syel Jo ode pus JIC

sabn quasaffrp yo yybran Burso) syou wouf dias fo spuawod wos Ur9},01q— EL ATAV J,

88

TaBLE 73.—PA,!' serum cholesterol, kidney weight, and kind and extent of kidney damage in rats fed SP
8 HVO and SPE diets

Serum cholesterol ? Kidney weight Rating of kidney damage
Diet and PA Rats | Average} Average
range age PA?
Average| Range | Average} Range Hyalin | Cystic | Glomer-
ular
Mqg./100| Mg./100
SP 8 HVO: Number | Days | Percent mi. ml, Grams Grams Score Score Score
PA, none_______- 25 426 117 81-185 Wal .2- 3.4 0. 3 0 0
Less than 4.0___- 10 493 PT 129 112-192 1.5] 1.2- 2.0 .3 0 0
AnORtor (es == 2 6 520 6.8 188 108-278 2.5 | 1.8- 4.5 1.5 0. 5 0.5
a SO and over-_-__-- 1 544 17. 6 270 270 5. 2 5. 2 2.0 3. 0 2.0
SPE:
PAS Nome. =.= 2- = 20 405 0 225 152-326 $2.2 | 1.5- 4.7 1.2 4 se
Less than 4.0__-- 8 419 2. 6 286 132-434 2.1 | 1. 8- 3.6 Lee, 0 0
AO. COnG9 a6 22 - 15 426 Beak 314 152-437 4.8 | 1. 6-10. 1 1.8 1.5 .9
8.0 and over___-- 12 434 11.7 488 237-743 6.1 | 1. 8-11. 2 2.1 2. 7 1.2

1PA represents prealbumin component or components moving more rapidly than albumin.

2 PA values represent relative percentage of serum protein components.

per 100 milliliters in serum.

Cholesterol values represent milligrams

3 Omitting one rat with kidney weight of 13.2 grams—no PA and cholesterol 202 mg./100 ml.

PA was absent from the sera, cholesterol levels
were generally low and the kidney small with
little evidence of damage. Only 3 of the 25 rats
in this group had kidneys exceeding 2.0 grams
in weight, and only 5 had serum cholesterol levels
exceeding 150 mg./100 ml. When the PA level
in the serum was less than 4 percent of the serum
proteins, cholesterol levels and kidney weights were
similar to those for rats with no PA in their sera.
When the PA level was above 4.0 percent, kidneys
were generally enlarged and cholesterol levels
exceeded 150 mg./100 ml. in all but 1 rat.

On SPE diet a similar trend was observed,
although the range of values was wide for each
group. In the group of 20 rats with no PA in
their serum protein, only 1 had a serum cholesterol
level in excess of 300 mg./100 ml. and 2 of the
kidneys exceeded 3.0 grams in weight. Excluded
from the data was 1 rat with a very large kidney
weighing 13.2 grams. This rat had no PA in the
serum and a serum cholesterol of 202 mg./100 ml.
In the group of 12 rats with PA levels 8 percent
and over, only 1 had a serum cholesterol value of
less than 300 mg./100 ml.; the others had values
exceeding 400 mg./100 ml. Three of the kidneys
weighed less than 3 grams; eight exceeded 6.0
grams. In general, high concentrations of PA in
serum proteins tended to parallel serum cholesterol
levels somewhat more closely than kidney size.

Rats rep SPM, SPB, anp SPPB pirts.—In
table 74 are summarized limited data from
electrophoresis of the sera from rats fed SPM,
SPB, and SPPB diets. There were insufficient
data to establish the influence of age. With each
of these diets the fast-moving component was
present in the sera of some of the rats, even among
the relatively young animals. The highest level
observed was for a rat fed SPM diet, with the
fast-moving component representing 20 percent
of the serum proteins. The other serum proteins

were present in amounts that were similar to
those found in rats fed SP 8 HVO or stock diets.

Discusston.—Many factors have been shown
to influence the results of electrophoretic studies
of blood proteins, and hence to complicate com-
parisons of the results of such studies (28, 49, 133).
Concentration and kind of buffer, optical devices
used to resolve the protein concentration gradients,
and species, strain, sex, and age of the experi-
mental animals may all be determining factors.
Many of the investigations have dealt with at-
tempts to characterize certain pathological condi-
tions by means of the electrophoretic pattern of
the blood proteins. There appear to be no
reports of investigations comparable to those
included in this bulletin dealing with the electro-
phoretic pattern of the blood proteins of rats on
various dietary regimens throughout their lifespan.

In 1945, Deutsch and Goodloe (49) investigated
the plasma proteins of 20 species of animals and
obtained evidence of a small amount of protein
migrating more rapidly than albumin in certain
species, including the rat. These authors reported
poor electrophoretic separation for some of the
proteins in the blood plasma of rats. Halliday
and Kekwick (83) reported, in the blood of young
rats, a component moving ahead of albumin,
possibly a second albumin, which varied in con-
centration from 8.6 percent at 12 days of age to
4.2 percent at 90 days. Total albumin increased
from 60 to 70 percent of the total protein during
this period. <A preliminary report (38) from this
laboratory indicated the presence of high levels of
rapidly migrating proteins in the blood serum of
rats receiving a diet containing 25 percent cooked
dried whole ege.

Although data on rapidly moving components
in the sera of rats are limited, considerable atten-
tion has been given to their occurrence in the sera
of humans, variously designated as PA (prealbu-

89

9°¢ 9 °ST TEL e VS S86 S
ZL 9 Vv ‘0G P'99¢e 0 ‘ST-0'T
T¢ 6 “GT L719 ¢ T ‘06-4 9
GL 0 FT 0'8 9 ‘P9 GL “8 iS
G'8 ¢ SI €°9 0 ‘F9 ON 2a)
69 G ‘FI v9 € “69 6%
GL PST LZ 9°99 6 Y =0 1
T ‘06 z CEL teeatet) GG ‘8b
89 9 ‘ST 9°S 6°19 v9 7%
quaalag | JUdILag | JUAdLId | JUIILIg JUIDLIT
uly
ull ull uly -nqord osUuByYy
—nqols —nqos —nqo[s 'eydye
BUIUIBY) Byog Seydly + Ulu
Nqly 1Vd

N BRO ON WTOP

re
<i

1UaIlag

OBVIOAY

1Vd UA szer ‘sutojord uindes Jo uolyisodwog

‘suI[NqO[Ss *eyd[e pue leydye pue uruinaq[e pourquioo syuosoidad onTeA :uoryeiedas 100g ¢
“SUI[NGO[S BVUITILS PUB BJBq POUIGUMIOD Syudsoidod ONTBA :UOTZBIKdaS LOO z
‘uluindye uByy A[prder e1ow Sutaow syusuoduroo a0 yuouodui0s urtuingeeid syussoidet Wg 1

VE
869
GPs

61g
60S

ESP
OIE

EPG
906

shoq

ase
ASVIOAY

HN MR NH OOM OD

Jaq
“UNA

8} BY

1Vd WOGPM s}VI
‘suroqyoid uindos jo uorisoduog

9°IT GST G OLe
near LZ °8T 4°9 &L9
6 IT G ‘GS RAY 0 '8¢
F 6 PST Gh 0 “S9
yd t I ‘13 9 ‘OL 9 "ES
Loe 6 OT Or T “€9
LOL 8 ‘ST G9 Py F9
8 6 GLI 69 T ‘99
qualad | quaotag | quaalag | quaasag
uly
ul] uly uly —nqoys
—nqojs | -nqoTs -nqoys Teydye
Bulwer Byogd eeydiy ++ Ulu
-uqly

LOV G
9S G
LoS G
16Z €
S87 G
06Z €
aad G
008 a
4aq
shoq |-wnyy
osu SHREDS |
aSBIOAY

ie a Sage Wd
[JUSIOM SUISO'T
669 °F OOF
~~" "OOP UBYY Sso'T
‘adds
Sat 669 94 00F
~-""QOF Uv} ssoryT
‘dds
669 °F OOP
~~~" QOF UBY} Sso'T
‘Wd8
[VYSIOM SUIULEYUIBIY

(sep)
sje Jo ode pus

‘qorp ‘snyeqs JUSTO M

SIP TddS PY? ‘TdS Wd V0 sabo yuasaffip yw sys wouf pias fo syuauodwuos w9j01g-—F), ATAV J,

90

min), FC (fast moving) or Rho (rapid). Azerod,
Lewin, and Ghata (16) obtained evidence of two
prealbumin protein fractions in normal human
serum, an electrophoretically homogeneous frac-
tion migrating slightly faster than albumin and a
heterogeneous fraction spread over a large area
in front of the albumin. A change in the mobility
of the blood proteins and the presence of a rapidly
moving prealbumin fraction as the result of the
administration of heparin to lipemic individuals
was noted by Nikkilé (139), Lever, Smith, and
Hurley (1/3, 114), and Herbst and Hurley (87).

The influence of heparin on the blood proteins
appears to be attributable to the liberation of a
lipoprotein lipase (107) into the blood and to the
production of more rapidly migrating fractions
due to the association of the fatty acids with some
of the blood proteins (75). Interest in this
heparin clearing reaction has been evidenced
because of its possible role in fat transport. The
concentration of this clearing factor in blood
serum is normally low, and the physiological im-
portance of the reaction has not been definitely
established. Many of the investigations have
dealt with measurements of enzyme activity as
determined by clearing of lipemic sera or liberation
of free fatty acids, and have not included electro-
phoretic measurements of the blood proteins. ‘The
present status of our knowledge of clearing factor
has been reviewed by Robinson (159) and
Engelberg (57).

The data available from electrophoretic studies
of sera from BHE rats have provided no informa-
tion concerning the chemical nature of these fast-
moving components and no proof that these com-
ponents were the same as those resulting from the
administration of heparin. There seemed to be
considerable indirect evidence linking high level
of this component to the lipid metabolism of these
rats. Elevated serum cholesterol values were
obtained for the majority of the rats with high

levels of PA in their sera. The lipemic sera that
were encountered frequently, even after the usual
17-hour fast, were associated generally with high
levels of one or more fast-moving components.
Rosenman and Smith (164) indicated a possible
causal relationship between deficiency of albumin
and increased lipid content of nephrotic plasma.
Whether or not the albumin content of the blood
of BHE rats was a factor in the results obtained
could not be determined from the data available.
The relative values for the various protein com-
ponents in serum protein provide no information
on the actual concentration of these fractions in
the serum. Further investigations are underway
to determine the possible physiological significance
of PA and the relation of these components to
lipid metabolism.

Summary.—With the BHE strain of rats, age
and diet were found to influence the relative
amount of the various protein components. Of
particular interest was the frequent occurrence of
a component or components moving more rapidly
than albumin (PA).

In stock rats 300 days or younger, there was no
evidence of the fast-moving component and, except
in the sera of a few moribund rats, the amounts of
PA were relatively small even in the older animals.
PA was present in the sera of some of the younger
rats fed the semipurified diet or SPM, SPB, or
SPPB diets, with a tendency for high levels in the
older rats. On SPE diet, levels of PA tended to
be high at all ages, with the largest proportion of
rats with serum containing this component in the
300- to 399-day-old group.

Small amounts of PA were observed in approxi-
mately 50 percent of the rats with normal kidneys
and serum cholesterol levels, irrespective of the
experimental diet. When serum levels of PA were
high, they were often associated with enlarged
and damaged kidneys and with high cholesterol
levels.

General Summary and Implications for Future Research

Results are reported from long-term studies
with male rats dealing with the influence of diet
on length of life and changes that occur with age
in blood serum and in livers, kidneys, adrenals,
and thyroids. The diets investigated were mod-
ifications of a relatively simple semipurified diet.
Keg, beef, milk, or peanut butter were substituted
for 20 to 25 percent of the semipurified diet in one
series of experimental diets; the kind and level
of fat in the semipurified diet was varied in the
second series of diets. The fats included a
hydrogenated vegetable oil, lard, and butter, and
the levels used were 8 and 16 percent. For com-
parative purposes, data were obtained for animals

721-631—64—_7

raised on the diet routinely used for maintaining
the laboratory stock colony. Results showing the
influence of fasting and of weight loss before
sacrifice have also been included. Most of the
data reported are for BHE rats, a mixed strain
of animals bred in our stock colony, but also
included are the results of feeding a group of
Wistar rats the semipurified diet and the diet
containing 25 percent cooked dried egg.

The animals grew well on all of the experimental
diets and generally attained a maximum weight
greater than that observed with rats on the stock
diet. During the period of early growth, rats
fed the diets containing egg, milk, beef, or peanut

91

butter grew more rapidly and used their diet more
efficiently for growth than did those fed the
semipurified diet. Many of the rats continued to
gain in weight as long as they remained healthy
and some became extremely large, particularly
when the diets contained milk or peanut butter.
The differences in body weight observed were not
consistently related to food intake or to level of
dietary fat.

The lifespan of BHE rats fed the various experi-
mental diets differed widely. At death, kidney
damage was a frequent finding regardless of diet.
The extent of the damage varied among diets and
generally paralleled the length of survival. The
shortest average lifespan and the most extensive
kidney damage were observed with diets contain-
ing 25 percent ege. When rats fed the egeg-
containing diet, SPE, during the first 250 days of
life were then placed on stock ration, their lifespan
was significantly longer than when the SPE diet
was fed throughout life. When the feeding of this
diet was delayed until the rats reached 250 days
of age, length of life was also prolonged. Survival
was longer with a diet consisting of 100 percent
whole egg than with one containing 25 percent
ezge. Some extremely long-lived rats were ob-
tained when the milk-containing diet was fed.
When the dietary fat was HVO, animals tended
to live longer than when the fat was lard or butter.

No evidence was obtained of any nutritional
deficiency in the diets under investigation.
Neither level of fat nor level of protein explained
the differences observed. The results, particu-
larly those with 100 percent whole egg or egg
yolk in contrast to those with 25 percent egg,
suggest that the rate of the development of
untoward changes in the tissues was related to
the particular combination of nutrients under in-
vestigation rather than to any one dietary in-
eredient.

Research is needed to determine the specific
combination of nutrients responsible for acceler-
ating changes in the tissues which result in early
death, and to establish whether or not the age
span during which the diets are fed is a critical
factor in determining the resporse to such diets.
The possibility also should be explored of estab-
lishing criteria that would detect at an early age
possible adverse effects of specific nutrient
combinations.

A factor that appears to complicate interpre-
tation of the longevity data is the tendency for
some rats to eat excessively and to gain at a very
rapid rate. Animals weighing 600 grams or more
by the time they reached 200 days of age died at
an early age regardless of diet.

Comparative studies of rats fed controlled as
well as ad libitum amounts of food are needed to
permit a more accurate assessment of the data
on longevity in relation to diet, as well as to deter-
mine the possible adverse effect of excessive
food consumption at various stages in the life
cycle.

92

Microscopic examination of the tissues indicated
that the kidney was the organ most frequently
found to appear abnormal, and that kidney damage
was observed in rats showing no obvious signs of
ill health, as well as in moribund rats. Some diets
obviously hastened the onset of lesions and also
appeared to influence the type of degenerative
changes observed. A kidney weighing more than
1.8 grams usually showed evidence of degenerative
change, and extensive damage was apparent in
kidneys weighing more than 3 grams. The in-
fluence of diet on the composition of the kidney
depended chiefly on its influence on the size of this
organ. Enlarged kidneys generally contained a
relatively high percentage of protein and a low
percentage of fat. Although high ash values were
also found frequently, calcium deposition as deter-
mined microscopically did not necessarily parallel
the percentage of ash in the kidney.

Microscopic examination of the livers revealed
little evidence of degenerative changes in this
organ, although both histological and chemical
measurements showed a high fat content in the
livers of rats on diets containing high levels of egg.

The kidneys as well as the livers from rats
subjected to a 17-hour fast before sacrifice were
generally smaller than those from nonfasted rats.
The increasing difference with age between the
weight of these organs from fasted and nonfasted
rats fed stock diet suggests that the physiological
activity of these organs is decreasing with age.
Calcium deposits in the kidney also appeared to
depend upon the fasting state of the rat at the
time of sacrifice.

Comparative data on the tissues of fasted and
nonfasted rats at different intervals throughout life
might well contribute information on the aging
processes.

The size of the adrenal and thyroid glands
seemed to be influenced by diet when comparisons
were made for animals that were maintaining weight
when sacrificed. The influence of diet on the
thyroid weight was apparent even in relatively
young rats, whereas the influence of diet on the
adrenal was seen chiefly in older rats. In mori-
bund rats, large adrenals and thyroids were a
frequent finding regardless of diet.

In rats that were maintaining weight at the
time of sacrifice, serum cholesterol levels varied
with age and with diet and appeared to bear no
consistent relation to level of dietary cholesterol
or fat. With the stock diet, serum levels were
generally low at all ages. With the various
modifications of the semipurified diet, serum
cholesterol levels tended to be high in older rats.
Some extremely high levels were observed, even
at a relatively early age, in rats fed the cholesterol-
containing egg diets. Cholesterol levels also
tended to be high in rats fed the diet containing
20 percent peanut butter, although the cholesterol
content of this diet was low. In moribund rats,
serum cholesterol levels exceeding 200 mg./100
ml. were observed frequently regardless of diet,

and generally were accompanied by enlarged and
damaged kidneys.

A rapidly moving protein component in the
blood serum of rats was observed occasionally
at all ages and on all diets. The percentage of
rats with this component in their sera, as well as
the amount present, varied with age and with diet.
The presence of small amounts of PA observed
occasionally in young rats seemed to bear little
relation to diet. When high levels of this compo-
nent were observed, they were usually associated
with extensively damaged kidneys and elevated
serum cholesterol levels.

Histological and biochemical investigations of
the tissues of moribund rats measure only terminal
stages and provide little information concerning
the intermediate steps leading to death and the
effect of diet thereon.

More extensive studies dealing with the
changes that occur at different stages of the life
cycle are needed to establish the role of diet in the
sequence of events that determine length of life.

The limited data for Wistar rats fed the semi-
purified diet and the diet containing 25 percent
egg indicate that the response to diet may differ
markedly with the strain of rats under investiga-
tion. Wistar rats lived longer than BHE rats fed
both diets, with greater differences observed when
the ege-containing diet was fed. Even in older
rats of the Wistar strain, kidney damage was
rarely seen and appeared to be unrelated to the
diet.

To explain such differences in the response to
diet, comparative data for different strains of
animals should include measurements to detect
basic differences in tissue enzymes and in the
metabolic pathways controlling the utilization of
various experimental diets. The possibility of
detecting inherent differences at an early age
and of controlling or preventing by dietary means
the adverse effects due to heredity also warrants
further consideration.

Literature Cited

(1) AaES-JORGENSEN, E., and Dam, H.
1954. THE ROLE OF FAT IN THE DIET OF RATS.
4, INFLUENCE OF SUPPLEMENTATION WITH
RAW SKIM MILK, LINOLEIC ACID OR BOTH ON

GRowTH. Brit. Jour. Nutr. 8: 296-301.
(2) and Dam, H.
4, THE ROLE OF FAT IN THE DIET OF RATS.

5. INFLUENCE OF SUPPLEMENTATION WITH
RAW SKIM MILK, LINOLEIC ACID OR BOTH ON
FOOD AND FLUID CONSUMPTION AND URINE
PRODUCTION. Brit. Jour. Nutr. 8: 302-
306.
(3) Apams, M., Fisner, M., and Kovat,|G. J.
1959. THE INFLUENCE OF DIETARY CARBOHYDRATE
ON KIDNEY AND LIVER DAMAGE AND SERUM
CHOLESTEROL IN THE RAT. (Abstract)
Fed. Proc. 18: 178.
(4) Appis, T., and Gray, H.
1950. BODY SIZE AND ORGAN WEIGHT.
14: 49-80, illus.
Lippman, R. W., Lew, W., and others.
51. EFFECT OF DIETARY PROTEIN CONSUMPTION
UPON BODY GROWTH AND ORGAN SIZE IN
THE RAT. Amer. Jour. Physiol. 165:
491-496, illus.
(6) Arreraoop, L., Dunn, H. J., Jr., and ALrin—
SLATER,
1957. THE COMPARATIVE EFFECTS OF COTTONSEED
OIL AND LARD ON CHOLESTEROL LEVELS IN

Growth

(5)

THE TISSUES OF RaTS. Jour. Nutr. 62:
129-142.
(7) Aurin-SuaterR, R. B., Wewis, A. F., Arrercoop, L.,
and others.

1954. THE EFFECT OF PLANT STEROLS ON CHOLES-
TEROL LEVELS IN THE RAT. Circulation
Res. 2: 471-475.

(8) Aumauist, H. J.

1956. THE REQUIREMENTS FOR AMINO acips. In
Block, R. J., Amino Acid Handbook—
Methods and Results of Protein Analysis,
See aa illus. Charles C. Thomas, Spring-
e

(9) ANDERSON, W. E., and Smiru, A. H.
1932. FURTHER OBSERVATIONS OF RAPID GROWTH
OF THE ALBINO RAT. Amer. Jour. Physiol.
100: 511-518.
(10) AnpREw, W., and Prusrt, D.

1957. SENILE CHANGES IN THE KIDNEYS OF WISTAR
INSTITUTE RATS. Amer. Jour. Anat. 100:
51-79, illus.

Suock, N. W., Barrows, C. H., Jr., and
Yrenest, M. J.
1959. CORRELATION OF AGE CHANGES IN HISTO-
LOGICAL AND CHEMICAL CHARACTERISTICS
IN SOME TISSUES OF THE RAT. Jour.
Gerontology 14: 405-414, illus.
(12) AssocraTION oF OrriciIaL AGRICULTURAL CHEMISTS.
1950. KJELDAHL-WILFARTH-GUNNING METHOD-
OFFICIAL. Ed.7, 2.24,p.13. Washington.

(11)

(13)
1960. FAT (ACID HYDROLYSIS METHOD) IN OFFI-
CIAL METHODS OF ANALYSIS. Ed. 9, 13.119,
p. 176. Washington.
(14) Arwatser, W. O., and Bryant, A. P.
1906. THE CHEMICAL COMPOSITION OF AMERICAN
FOOD MATERIALS. U.S. Dept. Agr. Off.
Expt. Stas. Bul. 28 (rev. ed.), 87 pp.,
illus.
(15) AvicaAn, J., and StrinspeEre, D.
1958. EFFECTS OF SATURATED AND UNSATURATED
FAT ON CHOLESTEROL METABOLISM IN THE
RAT. Soc. Expt. Biol. and Med. Proc. 97:
814-816.
(16) AzErop, E., Lewin, J., and Guava, J.
1958. PRE-ALBUMIN PROTEIN FRACTIONS IN NOR-
MAL AND PATHOLOGICAL SERUM. In PRo-
TIDES OF THE Biological Fluids, Proc.
Fifth Coll., Bruges, 1957, H. Peeters, ed.,
pp. 197-202, illus. D. Van Nostrand Co.,
Inc., New York.
(17) Barr, V. H., Couuins, R. A., EL.vensem, C. A.,
and Hart, E. ’B.
1950. THE IMPORTANCE OF THE DIETARY LEVEL
OF FATS ON THEIR NUTRITIONAL EVALUA-
TION. Jour. Nutr. 40: 383-392.

93

(18)

(19)

(24)

(28)

(29)

(30)

(33)

(34)

94

Beatriz, W. R.
1936. MAKING AND USING PEANUT BUTTER. U.S.
Dept. Agr. Cir. 384, 14 pp., illus.
Benton, D. A., Harprer, A. E., and ELvEHJEM,
CEO
1956. THE EFFECT OF DIFFERENT DIETARY FATS
ON LIVER FAT DEPOSITION. Jour. Biol.
Chem, 218: 693-700.
Bere, B. N., and Harmison, C. R.
1957. GROWTH, DISEASE AND AGING IN THE RAT.
Jour. Gerontology 12: 370-377, illus.
— and Simms, H. 8.
1960. NUTRITION AND LONGEVITY IN THE RAT.
II. LONGEVITY AND ONSET OF DISEASE
WITH DIFFERENT LEVELS OF FOOD INTAK®.
Jour. Nutr. 71: 255-263.
——— and Simms, H. S.
1961. NUTRITION AND LONGEVITY IN THE RAT.
III. FOOD RESTRICTION BEYOND 800 DAYS.
Jour. Nutr. 74: 23-32.
Bsst, C. H., Lucas, C. C., Parrerson, J. M., and
Ripout, J. H.
1958. EFFECTS OF DIFFERENT DIETARY FATS AND
OF CHOLINE ON HEPATIC AND SERUM LIPIDS
OF RATS. Canad. Jour. Biochem. and
Physiol. 36: 613-623, illus.
—-—— and Ripotrt, J. H.
1933. THE EFFECTS OF CHOLESTEROL AND CHOLINE
ON DEPOSITION OF LIVER FAT. Jour.
Physiol. 78: 415-418.
BEvERIDGE, J. M. R., Connetyt, W. F., Haust,
H.1L., and Mayer, G. A.
1959. DIETARY CHOLESTEROL AND PLASMA
CHOLESTEROL LEVELS IN MAN. Canad,
Jour. Biochem. and Physiol. 37: 575-582,
illus.

ConnELL, W. F., and Mayer, G. A.

1957. THE NATURE OF THE SUBSTANCES IN
DIETARY FAT AFFECTING THE LEVEL OF
PLASMA CHOLESTEROL IN HUMANS. Canad.
Jour. Biochem. and Physiol. 35: 257-270,
illus.

— ConneELL, W. F., Mayer, G. A., and Haust,
15 bea Bp

1960. THE RESPONSE OF MAN TO DIETARY CHO-

LESTEROL. Jour. Nutr. 71: 61-65, illus.
Brier, M.

1959. ELECTROPHORESIS; THEORY, METHODS AND
APPLICATIONS. 563 pp., illus. Edited by
Academic Press, Ine., New York, N.Y.

BiscHorr, F.

1932. THE INFLUENCE OF DIET ON RENAL AND
BLOOD VESSEL CHANGES. Jour. Nutr.
5: 431-450.

BLATHERWICK, N. R., and Mxepuar, E. M.

1937. CHRONIC NEPHRITIS IN RATS FED HIGH
PROTEIN bDiETs. Arch. Int. Med. 59:
572-596, illus.

Mepuiar, E. M., BrapsHaw, P. J., and
others.

1933. THE DIETARY PRODUCTION OF FATTY LIVERS
IN RATS. Jour. Biol. Chem. 103: 93-106.

BLUMENFELD, C. M.
1934. WEIGHT CHANGES IN THE SUPRARENAL
GLANDS OF ALBINO RATS ON VITAMIN E

DEFICIENT AND FAT DEFICIENT DIETS.
Endocrinology 18: 367-381, illus.
BoutmaNn, J. L., and Fiock, E. V.
1951. CHOLESTEROL IN INTESTINAL AND HEPATIC
LYMPH IN THE RAT. Amer. Jour. Physiol.
164: 480-485, illus.
Bronte-Stewart, B., Antonis, A., EHEauszs, L.,
and Brock, J. F.
1956. EFFECTS OF FEEDING DIFFERENT FATS ON
SERUM-CHOLESTEROL LEVEL. Lancet
CCLXX: 521-526, illus.

(35) Brown, R. A., and Sturtevant, M.
1949. THE VITAMIN REQUIREMENTS OF THE
GROWING RAT. Vitamins and Hormones
7: 171-199, illus.
(36) Byzrs, S. O.
1958. THE MECHANISM FOR CHANGES IN BLOOD
CHOLESTEROL IN DERANGED THYROID
sTATEs. Amer. Jour. Clin. Nutr. 6:
642-643.
(37) ——— and Frizpman, M.
1958. BILE ACID METABOLISM, DIETARY FATS, AND
PLASMA CHOLESTEROL LEVELS. Soc. Expt.
Biol. and Med. Proce. 98: 523-5286.
(38) Cauutson, E. C., and Fisumr, M.
1955. ALTERATION OF RATS’ SERUM PROTEIN
PRODUCED BY DIET. (Abstract) Fed. Proc.
14: 429.
(39) ——— Fisumr, M., and OrENT-KEiLEs, EF.
1952. DIET AS A FACTOR IN THE PRODUCTION OF
DEGENERATIVE CHANGES IN TISSUES OF
RAT. (Abstract) Fed. Proc. 11: 487.
(40) ——— Orent—Kuitss, E., and Maxownr, R. U.
1951. THE EFFECT OF SOME COMBINATIONS OF
HUMAN FOODS ON THE GROWTH AND HEALTH
OF THE LABORATORY RAT. Jour. Nutr. 43:
131-152.
(41) Cartuson, A. J.. and Horuzsu, F.
1946. APPARENT PROLONGATION OF THE LIFE
SPAN OF RATS BY INTERMITTENT FASTING.
Jour. Nutr. 31: 363-375, illus.
(42) Comrort, A.
1956. THE BIOLOGY OF OLD ace. Nature 178:
291-294.
(43) Coox, R. P., Epwarps, D. C., and RippE.t, C.
1956. CHOLESTEROL METABOLISM. 7. CHOLES-
TEROL ABSORPTION AND EXCRETION IN
MAN. Biochem. Jour. 62: 225-234.
(44) Corrine, A. M., Crows, P. J., and Ponp, V. R. G.
1951. THE GROWTH RESPONSE OF RATS TO PURI-
FIED DIETS. Brit. Jour. Nutr. 5: 68-74,
illus.
(45) Dex Veccuio, A., Keys, A., and AnpEeRson, J. T.
1955. CONCENTRATION AND DISTRIBUTION OF
CHOLESTEROL IN MUSCLE AND ADIPOSE
TISSUE. Soc. Expt. Biol. and Med. Proc.
90 (2): 449-451.
(46) Devet., H. J., JR.
1955. BLoop uipIps. In The Lipids. II. Bio-
chemistry, Digestion, Absorption, Trans-
port, and Storage. Ch. 5, pp. 349-520,
illus. Interscience Publishers, Inc., New

York.

4) ==

1955. THE OCCURRENCE OF LIPIDS IN THE ANIMAL

AS A wHOLE. In The Lipids. II. Bio-
chemistry, Digestion, Absorption, Trans-
port, and Storage. Ch. 6, pp. 521-706,
illus. Interscience Publishers, Inc., New
York.

(48)

1957. THE NUTRITIONAL VALUE OF Fats. In
The Lipids. III. Biochemistry, Biosyn-
thesis, Oxidation, Metabolism, and Nutri-
tional Value. Ch. 14, pp. 835-933, illus.
Interscience Publishers, Inc., New York.

(49) Drurscu, H. F., and Gooptog, M. B.
1945. AN ELECTROPHORETIC SURVEY OF VARIOUS
ANIMAL PLASMAS. Jour. Biol. Chem. 161:
1-20, illus.
(50) Donaupson, H. H.
1924. THE RAT, DATA AND REFERENCE TABLES FOR
THE ALBINO RAT (MUS NORVEGICUS ABIy-
CUS) AND THE NORWAY RAT (MUS NORVE-
Gicus). Memoirs of the Wistar Institute of
Anatomy and Biology, No. 6. Ed. 2, 469
pp., illus. Philadelphia.

(51)

(52)

(56)

(57)

(58)

(59)

(60)

(61)

(62)

(63)

(64)

(65)

(66)

(67)

Drapxin, D. L., and Marsa, J. B.
1955. METABOLIC CHANNELING IN EXPERIMENTAL
NEPHROSIS. I. PROTEIN AND CARBOHY-
DRATE METABOLISM. Jour. Biol. Chem. 212:
623-631, illus.
DreyvEN, L. P., Remsen, G. H., and Hartman,
A. M.
1956. COMPARATIVE ASSAY FOR VITAMIN Bj IN
CERTAIN MILK PRODUCTS BY VARIOUS RAT
GROWTH METHODS. Jour. Nutr. 59: 89-102.
Dunn, M.S., Murpuy, E. A., and Rockuanp, L. B.
1947. OPTIMAL GROWTH OF THE RAT. Physiol.
Revs. 27: 72-94, illus.
Douranp, A. M. A., FisHpr, M., and Apams, M.

1964. HISTOLOGY IN RATS AS INFLUENCED BY AGE
AND DIET. I. RENAL AND CARDIOVASCULAR
systems. Arch. Path. 77: 268-277, illus.

Exuricu, W. E., Forman, C. W., and Szeirmr, J.

1952. DIFFUSE GLOMERULAR NEPHRITIS AND LIPID

NEPHROSIS. CORRELATION OF CLINICAL,
MORPHOLOGICAL, AND EXPERIMENTAL OB-
sERvATIONS. Arch. Path. 54: 463-503, illus.

Ence., R. W.
1943. THE CHOLINE CONTENT OF ANIMAL AND
PLANT PRODUCTS. Jour. Nutr. 25: 441-446.

ENGELBERG, H.

1960. HEPARIN LIPEMIA CLEARING REACTION AND
FAT TRANSPORT IN MAN. SUMMARY OF
AVAILABLE KNOWLEDGE. Amer. Jour. Clin.
Nutr. 8: 21-38.

Everitt, A. V.

1957. THE SENESCENT LOSS OF BODY WEIGHT IN
MALE RATS. Jour. Gerontology 12: 382-
387, illus.

— and Wess, C.
1957. THE RELATION BETWEEN BODY WEIGHT

CHANGES AND LIFE DURATION IN MALE
Rats. Jour. Gerontology 12: 128-135,
illus.

Fetter, D., and Nerp.ie, E. A.

1959. EFFECT OF A HIGH-FAT DIET ON GROWTH
AND BLOOD SUGAR OF THE RAT. Metab-
olism 8: 762-768, illus.

Finuros, L. C., AnpRus, 8. B., Mann, G. V., and
Stare, F. J

1956. EXPERIMENTAL PRODUCTION OF GROSS
ATHEROSCLEROSIS IN THE RAT. Jour. Expt.
Med. 104: 539-554, illus.
Frxsen, M. A. B., and Jackson, H. J.
1932. CCXXVIII. THE BIOLOGICAL VALUE OF
PROTEINS. III. A FURTHER NOTE ON

THE METHOD USED TO MEASURE THE NITROG-
ENOUS EXCHANGE OF RATS. Biochem.
Jour. 26: 1919-1922.

Foun, O., and Dents, W.

1914. THE QUANTITATIVE DETERMINATION OF
ALBUMIN IN URINE. Jour. Biol. Chem.
18: 273-276.

Forsss, E. B., and Swirt, R. W.
1944, ASSOCIATIVE DYNAMIC EFFECTS OF PROTEIN,
CARBOHYDRATE. AND FAT. Jour. Nutr.
27: 453-468, illus.
—— S8wirt, R. W., Evurorr, R. F., and Jamgs,
W. 4H.
1946. RELATION OF FAT TO ECONOMY OF FOOD
UTILIZATION. I. BY THE GROWING AL-
BINO RAT. Jour. Nutr. 31: 203-212.

—— Swirt, R. W., Evurorr, R. F., and JAmzs,
We cEe
1946. RELATION OF FAT TO ECONOMY OF FOOD
UTILIZATION. Il. BY THE MATURE ALBINO
RAT. Jour. Nutr. 31: 213-227.
—— Swirt, R. W., Jamzs, W. H., and others.
1946. FURTHER EXPERIMENTS ON THE RELATION

OF FAT TO ECONOMY OF FOOD UTILIZATION.
I. BY THE GROWING ALBINO RAT. Jour.
Nutr. 32: 387-396.

721-631—_64——_8

(68)

(69)

(70)

(71)

(72)

(73)

(74)

(75)

(76)

(77)

(78)

(79)

(80)

(81)

(82)

(83)

(84)

Forses, E. B., and Swirt, R. W., Taacksr, E. J., and
1946. others. FURTHER EXPERIMENTS ON THE RE-
LATION OF FAT TO ECONOMY OF FOOD UTILI-
ZATION. II, BY THE MATURE ALBINO RAT,

Jour. Nutr. 32: 397-403.
Frencu, C. E., Incram, R. H., Uram, J. A., and
others.

1953. THE INFLUENCE OF DIETARY FAT AND

CARBOHYDRATE ON GROWTH AND LONGEVITY
In RATS. Jour. Nutr. 51: 329-339, illus.
FREUDENBERGER, C. B.

1932. A COMPARISON OF THE WISTAR ALBINO AND
THE LONG-EVANS HYBRID STRAIN OF THE
NORWAY RAT. Amer. Jour. Anat. 50:
293-349, illus.

Frrepman, M., Rosenman, R. H., and Bygrs, S. O.

1954. THE ROLE OF EXOGENOUS LIPIDS IN THE
HYPERLIPEMIA AND HYPERCHOLESTEREMIA
OF NEPHROTIC RATS. Jour. Clin. Invest.
33: 1103-1105.
Giuson, 8. B.
1949. STUDIES ON PROTEINURIA IN THE RAT.

Soc. Expt. Biol. and Med. Proc. 72:
608-618, illus.

Gopparp, V. R., and Goopat, L.

1959. FATTY ACIDS IN Foop Fats. U.S. Dept.
Agr. Home Econ. Res. Rpt. 7, 4 pp.
(March 1959.)
and Goopat., L.
1959. FATTY ACIDS IN ANIMAL AND PLANT PROD-
UCTS. COMPILATION OF ANALYTICAL DATA
AND BIBLIOGRAPHY. U.S. Dept. Agr., Agr.
Res. Serv., Human Nutr. Res. Div., 34
pp. [Processed.]
Gorpon, R. 8.
1955. INTERACTION BETWEEN OLEATE AND THE
LIPOPROTEINS OF HUMAN SERUM. Jour.
Clin. Invest. 34: 477-484, illus.
GouLp, R. G.
1954. ABSORBABILITY OF DIHYDROCHOLESTEROL
AND siTostEROL. (Abstract) Circulation
Res. 10: 589.
Gover, P. A.
1940. RENAL LESIONS FOUND IN PURE LINES OF

mick. Jour. Path. and Bact. 50: 25-30,
illus.
Gray, H., and Appis, T.
1948. RAT COLONY TESTING BY ZUCKER’S WEIGHT-
AGE RELATION. Amer. Jour. Physiol. 153:
35-40, illus.
GrunpauM, B. W., Geary, J. R., Jr., GRANDE, F.,
and others.
1957. EFFECT OF DIETARY LIPID ON RAT SERUM
AND LIVER CHOLESTEROL AND TISSUE MAST
cELLS. Soc. Expt. Biol. and Med. Proc. 94:
613-617, illus.
Grunt, J. A., Berry, R. J., and Knisexy, W. H.

1958. AGE AND CASTRATION IN RELATION TO FATTY
LIVER IN THE MALE RAT. Endocrinology

62: 822-827, illus.

——— and Kniszty, W. H.
1960. STRAIN DIFFERENCES AND THE DEVELOP-

MENT OF FATTY LIVER IN THE AGED RAT.
Jour. Gerontology 15: 184-1385.
GuGcENHEIM, K., Inan, J., and Peretz, EH.

1960. EFFECT OF DIETARY CARBOHYDRATES AND
AUREOMYCIN ON SERUM AND LIVER CHO-
LESTEROLIN RATS. Jour. Nutr. 72: 93-98.

Hauurpay, R., and Kexwicr, R. A.

1957. ELECTROPHORETIC ANALYSIS OF THE SERA
OF youNG RATS. Roy. Soc. London Proc.,
Ser. B. 146: 4381-487, illus.

HANDLER, P.

1948. THE INCIDENCE OF THYROID ACTIVITY ON
THE LIVER AND PLASMA LIPIDES OF CHOLINE-
AND CYSTINE-DEFICIENT RATS. Jour. Biol.
Chem. 173: 295-303.

95

(85)

(86)

(87)

(88)

(89)

(90)

(91)

(92)

(93)

(94)

(95)

(96)

(97)

(98)

(99)

(100)

(101)

(102)

96

Harrison, M. F.

1953. EFFECT OF STARVATION ON THE COMPOSI-
TION OF THE LIVER CELL. Biochem. Jour.
55: 204-211, illus.
Harat, 8.
1913. ON THE WEIGHT OF THE ABDOMINAL AND

THORACIC VISCERA, THE SEX GLANDS,

DUCTLESS GLANDS AND THE EYEBALLS OF

THE ALBINO RAT (MUS NORVEGICUS

ALBINUS) ACCORDING TO BODY WEIGHT.

Amer. Jour. Anat. 15: 87-119, illus.
Hersst, F.S. M., and Hugtey, N. A.

1954. EFFECTS OF HEPARIN ON ALIMENTARY
HYPERLIPEMIA. AN ELECTROPHORETIC
stupy. Jour. Clin. Invest. 33: 907-911,
illus.

HEYMANN, W., and HackeEt, D. B.

1955. ROLE OF KIDNEY IN PATHOGENESIS OF
EXPERIMENTAL NEPHROTIC HYPERLIPEMIA
In RATS. Soc. Expt. Biol. and Med. Proce.
89: 329-332, illus.

— and HackEt, D. B.

1955. ROLE OF LIVER IN PATHOGENESIS OF
EXPERIMENTAL NEPHROTIC HYPERLIPEMIA.
Metabolism 4: 258-263, illus.

— and Lunp, H. Z.

1951. NEPHROTIC SYNDROME IN RATS. Pediatrics
7: 691-706, illus.

— Marruews, L. W., Lemn, J., and others.

1954. FAT METABOLISM IN NEPHROTIC HYPER-

LIPEMIA. Metabolism 3: 27-81, illus.
HoaAGLAND, R., and Snipmr, G. G.

1940. NUTRITIVE PROPERTIES OF CERTAIN ANIMAL
AND VEGETABLE Fats. U.S. Dept. Agr.
Tech. Bul. 725, 12 pp.
— and Snip_mr, G. G.
1941. NUTRITITIVE PROPERTIES OF STEAM-REN-
DERED LARD AND HYDROGENATED COTTON-
SEED o1L. Jour. Nutr. 22: 65-76.
— Sniper, G. G., and Swirr, C. E.
1952. NUTRITIVE VALUE OF LARD AS AFFECTED

BY THE PROPORTION OF FAT IN THE DIET,
Jour. Nutr. 47: 399-409.
Hopson, A. Z.

1945, THE NICOTINIC ACID, PANTOTHENIC ACID,
CHOLINE AND BIOTIN CONTENT OF FRESH,
IRRADIATED EVAPORATED AND DRY MILK,
Jour. Nutr. 29: 137-142.

Horowitz, N. H., and Brapiz, G. W.

1943. A MICROBIOLOGICAL METHOD FOR THE DE-
TERMINATION OF CHOLINE BY USE OF A
MUTANT OF NEUROSPORA. Jour. Biol.
Chem. 150: 325-3383, illus.

Inez, D. J.

1945. A FURTHER STUDY OF EFFECT OF DIET ON
ADRENAL WEIGHTS IN RATS. Endocrinol-
ogy 37: 7-14, illus.

GinTHER, G. B., and NeEzamtis, J.
1943. EFFECT OF DIET IN RATS ON ADRENAL

WEIGHTS AND ON SURVIVAL FOLLOWING
ADRENALECTOMY. Endocrinology 32: 410-
414, illus.

Ivy, A. C., Lin, T. M., and Karvinen, E.

1955. ABSORPTION OF DIHYDROCHOLESTEROL AND

SOYA STEROLS BY THE RAT’S INTESTINE.
Amer. Jour. Physiol. 183: 79-85, illus.

Jackson, C. M.

1930. THE EFFECTS OF HIGH SUGAR DIETS ON THE
GROWTH AND STRUCTURE OF THE RAT.
Jour. Nutr. 3: 61-77, illus.
Jonzs, D. B.
1931. FACTORS FOR CONVERTING PERCENTAGES OF

NITROGEN IN FOODS AND FEEDS INTO PER-
CENTAGES OF PROTEINS. U.S. Dept. Agr.
Cir. 183, 22 pp.
KENNEDY, G. C.
1957. EFFECTS OF OLD AGE AND OVER-NUTRITION
ON THE KIDNEY. Brit. Med. Bul. 13: 67-
70, illus.

(103)

(104)

(105)

(106)

(107)

(108)

(109)

(110)

(111)

(112)

(113)

(114)

(115)

(116)

(117)

Keys, A., ANpERsoN, J. T., and Granpz, F.

1960, DIET-TYPE (FATS CONSTANT) AND BLOOD
LIPIDS IN MAN. Jour. Nutr. 70: 257-266.
MicKketsEN, O., Miuuer, E. V. O., and

CuHapmMaN, C. B.

1950. RELATION IN MAN BETWEEN CHOLESTEROL
LEVELS IN THE DIET AND IN THE BLOOD.
Science 112: 79-81, illus.

Kuttn, P. D.

1958. LINOLEIC ACID AND CHOLESTEROL METABO-
LISM IN THE RAT. I. THE EFFECT OF DIE-
TARY FAT AND LINOLEIC ACID LEVELS ON
THE CONTENT AND COMPOSITION OF CHO-
LESTEROL ESTERS IN LIVER AND PLASMA.
Arch. Biochem. and Biophys. 76: 56-64‘
illus.

Koun, H. I.

1950. CHANGES IN PLASMA OF THE RAT DURING
FASTING AND INFLUENCE OF GENETIC FAC-
TORS UPON SUGAR AND CHOLESTEROL
LEVELS. Amer. Jour. Physiol. 163: 410-
417, illus.

Korn, E. D.

1955. CLEARING FACTOR, A HEPARIN-ACTIVATED
LIPOPROTEIN LIPASE. I. ISOLATION AND
CHARACTERIZATION OF THE ENZYME FROM
NORMAL RAT HEART. Jour. Biol. Chem.
215: 1-14, illus.

Kovat, G. J.

1961. CHOLESTEROL MEASUREMENT IN NORMAL
AND LIPEMIC SERA! ELIMINATION OF AN
EXTRANEOUS CHROMOGEN. Jour. Lipid
Res. 2: 419-420, illus.

KritcHevsry, D.

1958. CHOLESTEROL. 291 pp., illus.

and Sons, Inc., New York.
Lampen, J. O., BAHLER, G. P., and Peterson, W. H.

John Wiley

1942. THE OCCURRENCE OF FREE AND BOUND

BIOTIN. Jour. Nutr. 23: 11-21, illus.
Lang, P. W., and Dicxin, M. M.

1958. THE EFFECT OF RESTRICTED FOOD INTAKE
ON THE LIFE SPAN OF GENETICALLY OBESE
mick. Jour. Nutr. 64: 549-554, illus.

Lanes, W.
1950. CHOLESTEROL, PHYTOSTEROL, AND TOCOPH-

EROL CONTENT OF FOOD PRODUCTS AND
ANIMAL TIssUES. Jour. Amer. Oil Chem.
Soe. 27: 414-422.

Lever, W. F., Smiru, P. A. J., and Hurury, N. A.

1953. EFFECTS OF INTRAVENOUS HEPARIN ON THE
PLASMA LIPOPROTEINS IN PRIMARY HYPER-
CHOLESTEREMIC XANTHOMATOSIS AND IDIO-
PATHIC HYPERLIPEMIA. Science 118: 653-
654, illus.

——— Smriru, P. A. J., and Hutey, N. A.

1954. IDIOPATHIC HYPERLIPEMIA AND PRIMARY
HYPERCHOLESTEREMIC XANTHOMATOSIS.
Ill. EFFECTS OF INTRAVENOUSLY ADMINIS-
TERED HEPARIN ON THE PLASMA PROTEINS
AND uipips. Jour. Invest. Dermat. 22:
71-87, illus.

Lewis, L. A., and Heymann, W.

1954. ULTRACENTRIFUGAL ANALYSIS OF SERUM
LIPOPROTEINS IN NEPHROTIC SYNDROME OF
rats. Soc. Expt. Biol. and Med. Proce.
86: 766-767.

LIcHTENSTEIN, H., Benoran, A., and Reyno.ps, H.

1959. COMPARATIVE VITAMIN By. ASSAY OF FOODS
OF ANIMAL ORIGIN BY LACTOBACILLUS
LEICHMANNIL AND OCHROMONAS MALHA-
MENSIs. Jour. Agr. and Food Chem. 7:
771-774.

Lin, T. M., Karvinen, E., and Ivy, A. C.

1955. CAPACITY OF THE RAT INTESTINE TO ABSORB
CHOLESTEROL. Soc. Expt. Biol. and Med.
Proc. 89: 422-423, illus.

(118) Loneswortn, L. G., and JAcossEn, C. F.
1949. AN ELECTROPHORETIC STUDY OF THE BIND-
ING OF SALT IONS BY (-LACTOGLOBULIN
AND BOVINE SERUM ALBUMIN. Jour. Phys.

Colloid Chem. 53: 126-135, illus.

(119) LunpBack, K., and Stevenson, J. A. F.

1947. REDUCED CARBOHYDRATE INTAKE AFTER
FAT FEEDING IN NORMAL RATS AND RATS
WITH HYPOTHALAMIC HYPERPHAGIA. Amer.
Jour. Physiol. 151: 5380-537, illus.

(120) McCay, C. M.

1952. CHEMICAL ASPECTS OF AGEING AND THE
EFFECT OF DIET UPON AGEING. In Cow-
dry’s Problems of Ageing—Biological and
Medical Aspects. Ch. 6, . 139-202,
illus. Albert I. Lansing, ed. The Wil-
liams and Wilkins Company, Baltimore.

(121) 5 Maynarp, L. A., SPERLING, G., and Oscoop,
H. 8.
1941. NUTRITIONAL REQUIREMENTS DURING THE

LATTER HALF OF LIFE. Jour. Nutr. 21:
45-60, illus.
(122) McCoy, R. H.
1949. DIETARY REQUIREMENTS OF THE RAT. In
The Rat in Laboratory Investigation.
Ed. 2, Ch. 5, pp. 68-103. Farris, E. J.,
and Griffith, J. Q., ed. J. Lippincott Co.,
Philadelphia.

(123) Mackay, L. L., and Mackay, E. M.
1937. THE DIFFERENCE IN THE WEIGHT OF THE
LEFT AND RIGHT KIDNEYS. Growth 1:
309-311.
(124) Marsu, J. B., and Drasxin, D. L.
1955. METABOLIC CHANNELING IN EXPERIMENTAL
NEPHROSIS. II. LIPIDE METABOLISM.
Jour. Biol. Chem. 212: 633-639, illus.
(125) MarsHatu, M. W., and HILDEBRAND, H. E.
1963. DIFFERENCES IN RAT STRAIN RESPONSE TO
THREE DIETS OF DIFFERENT COMPOSITION.
Jour. Nutr. 79: 227-288, illus.
(126) HitpDEBRAND, H. E., Dupont, J. L., and
Womack, M.
1959. EFFECT OF DIETARY FATS AND CARBOHY-
DRATES ON DIGESTIBILITY OF NITROGEN AND
ENERGY SUPPLY, AND ON GROWTH, BODY
COMPOSITION AND SERUM CHOLESTEROL OF
rats. Jour. Nutr. 69: 371-382, illus.
(127) Maver, J.

1948. GROWTH CHARACTERISTICS OF RATS FED A
SYNTHETIC DIET. Growth 12: 341-349.
(128) Menpet, L. B., and Hupsstu, R. B.
1985. THE RELATION OF THE RATE OF GROWTH TO
DIET. III. A COMPARISON OF STOCK RA-
TIONS USED IN THE BREEDING COLONY AT
THE CONNECTICUT AGRICULTURAL EXPERI-
MENT STATION. Jour. Nutr. 10: 557-563,
illus.

(129) Merriut, A. L., and Wart, B. K.

1955. ENERGY VALUE OF FOODS—BASIS AND
DERIVATION. U.S. Dept. Agr. Handb. 74,

105 pp.
(130) MUsgeNGHE, W. J., Porosowska, Y., and STEELE,
"1950. EFFECT OF FEEDING EGG YOLK AND CHO-

LESTEROL ON SERUM CHOLESTEROL LEVELS.
Arch. Int. Med. 86: 189-195, illus.
(131) Merra, V. C., and Mircuenn, H. H.
1954. DETERMINATION OF THE METABOLIZABLE
ENERGY OF ORGANIC NUTRIENTS FOR THE

RAT. Jour. Nutr. 52: 601-611.
(132) Micxetsen, O., Taxanasut, S., and Craia, C.
1955. EXPERIMENTAL OBESITY. I. PRODUCTION
OF OBESITY IN RATS BY FEEDING HIGH FAT
birts. Jour. Nutr. 57: 541-554, illus.
(133) Moors, D. H.
1945, SPECIES DIFFERENCES IN SERUM PROTEIN

PATTERNS.

Jour. Biol. Chem. 161: 21-32,
illus.

(134)

(135)

(136)
C

(137)

(138)

(139)

(140)

(141)

(142)

(143)

(144)

(145)

(146)

(147)

(148)

(149)

(150)

Moyer, A. W., Krircurvskry, D., Logan, J. B., and

Cox, H. R.

1956. DIETARY PROTEIN AND SERUM CHOLESTEROL
IN RATS. Soc. Expt. Biol. and Med. Proc.
92: 736-737.

Natu, N., Harper, A. E., and E.vensem, C. A,
1958. DIETARY PROTEIN AND SERUM CHOLESTEROL.
Arch. Biochem. and Biophys. 77: 234-236.

Wiener, R., Harper, A. E., and E:vensem,

2 AS

1959. DIET AND CHOLESTEREMIA. I. DEVELOP-

MENT OF A DIET FOR THE STUDY OF NUTRI-

TIONAL FACTORS AFFECTING CHOLES-

TEREMIA IN THE RAT. Jour. Nutr. 67:

289-307.

Nervurkar, M. K., and SanasraBupue, M. B.

1956. METABOLISM OF CALCIUM, PHOSPHORUS, AND
NITROGEN IN HYPERVITAMINOSIS A _ IN
YOUNG RATS. Biochem. Jour. 63: 344—
349, illus.

Newsureu, L. H., and Curtis, A. C.

1928. PRODUCTION OF RENAL INJURY IN THE
WHITE RAT BY THE PROTEIN OF THE DIET.
DEPENDENCE OF THE INJURY ON THE DURA-
TION OF FEEDING AND ON THE AMOUNT AND
KIND OF PROTEIN. Arch. Int. Med. 42:
801-821, illus.

NIKKILA, E. A.

1952. THE EFFECT OF HEPARIN ON SERUM LIPO-
PROTEINS. Scand. Jour. Clin. and Lab.
Invest. 4: 369-370.

Oxey, R.

1941. MIDDLE AND OLD AGE IN CHOLESTEROL-FED
RAts. Soc. Expt. Biol. and Med. Proc.
46: 466-470. ;

1945. CHOLESTEROL CONTENT OF FOODS. Jour.
Amer. Diet. Assoc. 21: 341-344.

and Lyman, M. M.

1956. PROTEIN INTAKE AND LIVER CHOLESTEROL:
EFFECTS OF AGE AND GROWTH OF THE TEST
ANIMAL. Jour. Nutr. 58: 471-482, illus.

and Lyman, M. M.

1957. DIETARY FAT AND CHOLESTEROL METABO-
LISM. I. COMPARATIVE EFFECTS OF COCO-
NUT AND COTTONSEED OILS AT THREE
LEVELS OF INTAKE. Jour. Nutr. 61:
523-533.

Lyman, M. M., and Ernset, B. M.

1959. EFFECT OF FOOD RESTRICTION ON CHOLES-
TEROL METABOLISM. 1. MODERATE LIMI-
TATION DURING LATE ADOLESCENCE. Jour
Amer. Diet. Assoc. 35: 115-118.

Lyman, M. M., Harris, A. G., and others.

1959. DIETARY FAT AND CHOLESTEROL METABO-
LISM: EFFECTS OF UNSATURATION OF
DIFTARY FATS ON LIVER AND SERUM
Lipips. Metabolism 8: 241-255, illus.

and Stewart, D.

1933. DIET AND BLOOD CHOLESTEROL IN NORMAL

WoMEN. Jour. Biol. Chem. 99: 717—727.
and Strong, M. M.

1956. LARD VS. A VEGETABLE FAT IN RELATION
TO LIVER AND SERUM CHOLESTEROL. Jour.
Amer. Diet. Assoc. 32: 807-809.

Orr, M. L., and Wart, B. K.
1957. AMINO ACID CONTENT OF FoopDs. U.S.

Dept. Agr. Home Econ. Res. Rpt. 4,
82 pp.

Osporne, T. B., and MENDEL, L. B.
1919. THE NUTRITIVE VALUE OF THE WHEAT
KERNEL AND ITS MILLING PRODUCTS.

Jour. Biol. Chem. 37: 557-601, illus.
Menpet, L. B., Park, E. A., and WINTER-
nitz, M. C

1927. PHYSIOLOGICAL EFFECTS OF DIETS UN-

USUALLY RICH IN PROTEIN OR INORGANIC
saLts. Jour. Biol. Chem. 71: 317-350,
illus.

97

(151) Paumer, L. S., Kennepy, C., CALVERLEY, C. E.,
and others.

1946. GENETIC DIFFERENCES IN THE BIOCHEMIS-
TRY AND PHYSIOLOGY INFLUENCING FOOD
UTILIZATION FOR GROWTH IN RATs. Minn.
Agr. Expt. Sta. Tech. Bul. 176, 54 pp.,
illus.

Portman, O. W., Lawry, E. Y., and Bruno, D.

1956. EFFECT OF DIETARY CARBOHYDRATE ON
EXPERIMENTALLY INDUCED HYPERCHOLES-
TEREMIA AND HYPERBETALIPOPROTEIN-
EMIA IN RATS. Soc. Expt. Biol. and Med.
Proe. 91: 321-323.

(152)

(153) and Stars, F. J.
1959. DIETARY REGULATION OF SERUM CHOLES-
TEROL LEVELS. Physiol. Revs. 39: 407—
442.
(154) Rapinowitz, J. C., and SNELL, E. E.
1948. THE VITAMIN Be GROUP. XIV. DISTRIBU-
TION OF PYRIDOXAL, PYRIDOXAMINE, AND
PYRIDOXINE IN SOME NATURAL PRODUCTS.
Jour. Biol. Chem. 176: 1157-1167.
(155) Ratunmr, L. J.
1952. FILTRATION, RESORPTION, AND EXCRETION
OF PROTEIN BY THE KIDNEY. Medicine
31: 357-380.

(156) Reussner, G. H., Jr., and Tuisssen, R., JR.
1958. NUTRITIVE VALUE STUDIES OF A WHEAT
FLAKES, DRIED WHOLE MILK AND SUGAR
MIXTURE. Food Res. 23: 244-253.
Rivovut, J. H., Lucas, C. C., Parrerson, J. M.,
and Best, C. H.
1952. THE EFFECT OF VARYING AMOUNTS OF
DIETARY CHOLESTEROL AND OF CHOLINE
UPON LIVER LIPIDS. Biochem. Jour. 52:
79-83, illus.
RiesEen, W. H., Hersst, E. J.. WALLIKER, C., and
ELVEHJEM, C. A.
1947. THE EFFECT OF RESTRICTED CALORIC
INTAKE ON THE LONGEVITY OF RATS.
Amer. Jour. Physiol. 148: 614-617, illus.
Rosinson, D. 8.
1960. THE HEPARIN CLEARING REACTION.
Jour. Clin. Nutr. 8: 7-19, illus.

(157)

(158)

(159)
Amer.

(160) Rocsrs, P. V., and Ricutsr, C. P.
1948. ANATOMICAL COMPARISON BETWEEN THE
ADRENAL GLANDS OF WILD NORWAY,
WILD ALEXANDRINE AND DOMESTIC NORWAY
rats. Endocrinology 42: 46-55, illus.
(161) RosmnseEre, H. R.
1942. CHEMISTRY AND PHYSIOLOGY OF THE
VITAMINS. 674 pp., illus. Interscience
Publishers, Ine., New York.
(162) RosENKRANTZ, J. A., and Brueer, M.

1946. EXPERIMENTAL ATHEROSCLEROSIS. IX.
THE EFFECT OF PROLONGED FEEDING
OF EGG YOLK POWDER IN RATS. Arch.
Pathol. 42: 81-87, illus.
(163) aaa R. H., Frrepman, M., and Byrzrs,
Ss. O.
1955. THE DISTRIBUTION OF CHOLESTEROL AND
TOTAL LIPIDS IN THE NEPHROTIC RAT.
Jour. Clin. Invest. 34: 700-703.
and Situ, M. K.
RELATIONSHIP BETWEEN CONCENTRATIONS
OF ALBUMIN AND LIPIDS IN PLASMA OF
EXPERIMENTALLY NEPHROTIC RATS. Amer.
Jour. Physiol. 191: 40-44, illus.
and Situ, M. K.
EFFECTS OF ALTERED THYROID FUNCTION ON
PLASMA LIPIDS OF EXPERIMENTALLY NE-
PHROTIC RATS. Soc. Expt. Biol. and Med.
Proc. 98: 444-448.
Ross, M. H.
1959. PROTEIN, CALORIES AND LIFE EXPECTANCY.
Fed. Proc. 18: 1190-1207, illus.

(164)
1957.

(165)
1958.

(166)

(167) ———
1961. LENGTH OF LIFE AND NUTRITION IN THE RAT.

Jour. Nutr. 75: 197-210, illus.
98

(168)

(169)

(170)

(171)

(172)

(173)

(174)

(175)

(176)

(177)

(178)

(179)

(180)

(181)

(182)

(183)

Saxton, J. H., and Kimpatt, G. C.

1941. RELATION OF NEPHROSIS AND OTHER DIs-
EASES OF ALBINO RATS TO AGE AND TO
MODIFICATIONS OF DIET. Arch. Path. 32:
951-965, illus.

Sayers, G.
1950. THE ADRENAL CORTEX AND HOMEOSTASIS.

Physiol. Revs. 30: 241-320, illus.
SHapiro, 8. L., and Freepman, L.

1955. EFFECT OF ESSENTIAL UNSATURATED FATTY
ACIDS AND METHIONINE ON HYPERCHOLES-
TEREMIA. Amer. Jour. Physiol. 181: 441-
445,

SILBERBERG, R., and SrnpeRBERG, M.

1955. LIFE SPAN OF MICE FED A HIGH FAT DIET AT
VARIOUS AGES. Canad. Jour. Biochem.
and Physiol. 33: 167-173, illus.

Stus, H. S., and Brere, B. N.

1957. LONGEVITY AND THE ONSET OF LESIONS IN
MALE RATS. Jour. Gerontology 12: 244~
252, illus.

SLANETzZ, C. A.

1943. THE ADEQUACY OF IMPROVED STOCK DIETS
FOR LABORATORY ANIMALS. Amer. Jour.
Vet. Res. 4: 182-189.

SmitH, A. H., and Morss, T. S.

1927. DIET AND TISSUE GROWTH. IV. THE RATE
OF COMPENSATORY RENAL ENLARGEMENT
AFTER UNILATERAL NEPHRECTOMY IN THE
WHITE RAT. Jour. Expt. Med. 45: 263-
276, illus.

Sope., A. E., YusKa, H., and Couen, J.

1937. A CONVENIENT METHOD OF DETERMINING
SMALL AMOUNTS OF AMMONIA AND OTHER
BASES BY THE USE OF BORIC ACID. Jour.
Biol. Chem. 118: 443-446.

Spreruine, G. A., Loosui, J. K., Barnes, L. L., and
McCay, C. M.

1946. THE EFFECT OF COFFEE, HUMAN DIETS, AND
INHERITANCE UPON THE LIFESPAN OF RATS.
Jour. Gerontology 1: 426-432, illus.

Swe.., L., Borrer, T. A., Fietp, H., Jr., and
TREADWELL, C. R.

1954. ESTERIFICATION OF SOYBEAN STEROLS IN
VITRO AND THEIR INFLUENCE ON BLOOD
CHOLESTEROL LEVEL. Soc. Expt. Biol. and
Med. Proc. 86: 295-298.

Borrer, T. A., Frevp, H., Jr., and Treap-
WELL, C. R.

1956. THE ABSORPTION OF PLANT STEROLS AND

THEIR EFFECT ON SERUM AND LIVER STEROL

LEVELS. Jour. Nutr. 58: 385-398.
Fuick, D. F., Freup, H., Jr., and TReap-
WELL, C. R.
1955. ROLE OF FAT AND FATTY ACID IN ABSORP-

TION OF DIETARY CHOLESTEROL. Amer,
Jour. Physiol. 180: 124-128, illus.
TEPPERMAN, J., ENGEL, F. L., and Lone, C. N. H.

1943. A REVIEW OF ADRENAL CORTICAL HYPERTRO-
pHy. Endocrinology 32: 373-402, illus.
—— Encet, F. L., and Lone, C. N. H.
19438. EFFECT OF HIGH PROTEIN DIETS ON SIZE
AND ACTIVITY OF THE ADRENAL CORTEX IN
THE ALBINO RAT. Endocrinology 32: 403-
409, illus.
TuHompson, J.
1933. INFLUENCE OF THE INTAKE OF CALCIUM ON
THE THYROID GLAND OF THE ALBINO RAT.
Arch. Path. 16: 211-225, illus.
TIsELIus, A.
1937. A NEW APPARATUS FOR ELECTROPHORETIC
ANALYSIS OF COLLOIDAL MIXTURES. Fara-
day Soc. Trans, 33: 524-531, illus.

(184) Torprer, E. W., MacArruur, M. J., and LEHMANN,
J

1960. CHROMATOGRAPHIC SEPARATION OF VITA-

MIN Bs COMPONENTS IN FOOD EXTRACTS.

Assoc. Official Agr. Chem. Jour. 43: 57-59.

(185) Zook, E. G., Orr, M. L., and Ricwarpson,
L. R.

1951. FOLIC ACID CONTENT OF rFoops. U.S.

Dept. Agr. Handb. 29, 116 pp., illus.

(186) Viraue, J. J., HELLerstTsIN, E. E., Heastep, D. M.,

and others.

1959. sTUDIES ON THE INTERRELATIONSHIPS BE-
TWEEN DIETARY MAGNESIUM AND CALCIUM
IN ATHEROGENESIS AND RENAL LESIONS.
Amer. Jour. Clin. Nutr. 7: 13-22.

Wuirtst, P. L., Nakamura, M., and others.
INTERRELATIONSHIPS BETWEEN ©EXPERI-
MENTAL HYPERCHOLESTEREMIA, MAGNESIUM
REQUIREMENT, AND EXPERIMENTAL ATHER-
oscLEROsIs. Jour. Expt. Med. 106: 757-
766, illus.

(188) Wart, B. K., and Merritt, A. L.

(187)

1950. COMPOSITION OF FOODS—RAW, PROCESSED,
PREPARED. U.S. Dept. Agr. Handb. 8,
147 pp.

(189)

(190)

(191)

(192)

(193)

(194)

Wiueram, G. F., Lewis, L. A., and Bust, C. H.

1957. EFFECT OF CHOLINE AND CHOLESTEROL ON
LIPOPROTEIN PATTERNS OF RATS. Circula-
tion Res. 5: 111-114.

YEAKEL, E. H.

1946. CHANGES WITH AGE IN THE ADRENAL GLANDS
OF WISTAR ALBINO AND GRAY NORWAY RATS.
(Abstract) Anat. Rec. 96: 525.

Ree M. J., Barrows, C. H., Jr., and Sock,

1959. AGE CHANGES IN THE CHEMICAL COMPOSI-

TION OF MUSCLE AND LIVER IN THE RAT,
Jour. Gerontology 14: 400-404.
ZuaTKis, A., Zak, B., and Boyue, A. J.

1953. A NEW METHOD FOR THE DIRECT DETERMI-
NATION OF SERUM CHOLESTEROL. Jour,
Lab, and Clin. Med. 41: 486-492, illus.

FO Gss E. G., MacArtnur, M. J., and Torprmr,
1956. PANTOTHENIC ACID IN Foops. U.S. Dept.
Agr. Handb. 97, 23 pp., illus.
ee T. F., Hau, L., Youne, M., and Zucker,
1941. THE GROWTH CURVE OF THE ALBINO RAT
IN RELATION TO DIET. Jour. Nutr. 22:
123-138, illus.

99

:
:

Appendix

The tables in the appendix supply additional
data not included in the text.

In tables 75 through 78 are summarized the
data for the ingredients used in making the
experimental diets. These tables serve as a basis
for the calculated values recorded in tables 2
through 6.

In tables 79 and 80 are presented data on weight
and intake of individual series of rats, showing the

general agreement among different experimenta-
series of animals when fed the same diet.

In table 81 are presented data for individual
animals when a change in dietary regimen was
made at 250 days of age. Although the data for
this group of rats were extremely limited, the
individual data show that consistent differences
were observed for all of the rats as the result of
this change.

101

‘son[va pozA[Cuy ¢
*(871) ‘sa0yyo [1B f(p °d “6%7) ‘(JOT) ‘Poye[Noywo sv UJOJOId YOIYM UOT] 10}OVJ UTOJOId PUB WOSOIZ{U OJ SON[BA JO OOANOS |

66°T ¥9 'T 89'T £8 °G GSP L0°T bL* ¥'E 09 'T 80°T €9'T i) LZ° 80°T $8 ‘I tT 18° €g° v'9% 9F 9 Bh 1oyyng ynUuveg
02 8 9L'E CLP Go'It | os lt? 99% 26 'F te 'b 69'S PLS 96 * 68 °T 19°9 G2 9 66 '°E LE °E 68° €'9L G% ‘9 TGcGk. Witte ee eet Jog
OL % 968 OL 0€ ‘8 69% £2 'T ¥6° 08 ‘T bP S 18 ‘I CLT (Ate 18° 9L 6F'E L6G $9 'T og 9°Se 88 °9 £9"Q SPT[OS ALU WPS
$e 9 90 °E 20 °E 98 ‘IT | SEO 609 PLT tL ‘9 62 9 98 °E 91 "9 96°T TLS v8 'F OL'L Go 9 99 “g £6 'T L°08 GZ 9 T6%6E |so2o- OPYAM B50 PO
69'S et 60 T 79S CONE. Ie 4 29° 90 °% £0°% Let 08 'T og* 9L° 96 'T 6h % 18 ‘1 09 'T &P' G 6% 9% 9 Cle ie yoA 330 poli,
£6 °E 86 'T 99 ‘T 6L°9 Soe | ar T L0°E 8h 'E 10% OLS 60'T L¥'T 00 °€ (4m7 IL'€ £8 '% LL” 8 ‘OF GZ 9 GRke We ee 390 pod
66 °% aK tL °% PIL 06° 68 '€ Tit Po L0°€ tL % FL @ 69° +6" L'E 79'S OLS G9 '% 08 * Tag GZ 9 an | Rk Dees ees 4svox
08 '€ OSACamr aa eet G8 CI | 26° 10 °9 eo 'T 61% $9 'F 40'E 8h 'e CLG 08 'T FL 98 6 96 ‘FP 61 9L'T 6 6L 6h 9 ISGh Woe UyOING]eypow'T
8L°9 eo 'OL =| el‘ 60°02 | &h'9 26 £9 '% $9 '€ er 9 90° 69°F ee 0 89% 146 °9 bL'8 0L°¢ GL 'é OTT 0°28 629 SOC ps em 2 = ec UpOsED)
sUvipD | suds | smDLD | SUD | sULDLD | SULDLD | SUDID | SUDI | SUDLH | SUDLH | SUDID | SULDID | SDI | sUDI | SUDID | SULDIY | SUDI | SULDIY | SULDL SUD

ppe ppe 1040By
eUpIOS JouypOIg|oupoATH} opurey 014) «jouyuBTy} oulp ouju | ouleA | ous jouyUR[elouTyssO]} oujUO | oUTSAT JoupONoT] oUfONoy,}| oUTU | oULYd jupoJOIg| Ufo} , uod poo

nO | -redsy “StH | -131y -o1AJ, |-[Au0y “10 -OST | -0o1UT, |-09d AAT, -O1g | -O1IN

1 SU poyuauiuadxa Ut spuaipaubur fo supub QQ] 4ad Uorpsodwod prop OUD pud WI9}04J—"GL ATAV

102

“8 QLT Wj] o “8 1g WL9}] p

“8 61 U9] o

*@ 88 W0}T q

“eyep poystiqnduy) g
“4e] JO MOT}ISOdUI0D TAO’ poye[NIeVO ,

"4BJ.19}4Nq JO MOT {sSOdu0) Y4IM 4B] SUIUINSSB poze[NI[VO 9
“(97) \L’¢ ‘Wosiapuy pue “y ‘shox “VY ‘oIqo00A Taq :00IN0g ¢
(84) "I ‘TIepoop pur “yz “A ‘prepoop ‘0.109 +
“(@I1T) “MA ‘0BUBT :00IN0S ¢

"8 0G WIT &

(74) ‘T'‘T8poop pure “yz “A ‘preppoy :eoInog
“son[va pozA[euy 1

paeieas 0 EvocP lla ost sdes|: 6°90 , | 96c8h 9T'SE | 28°€ 187% 89 °¢
paaatel LST 9 manne nampa on OG: Tg ‘9 Reem onal ESO | 8S tL PF
haa 08 8 90vlL 10° $0° &h" €0° og ° Peer "2 €¢"
Sart 082 ‘Ze GPT 18° coh LLG | 618 Br4e | =| PS 0 FI
teas $cc O88 ‘T 1 L0°T 09° £8 FOZ | SEZ 8°26 [7-7] Bas £01
Rae scp aa aaa c0°0 90° £3" o9 % 9I° ol '€ pee ie Lie 40% €9° 66° II 90° tT Fo"
SETESSsS 99 e evn, | 100 | #00 | 030 | 200 6g'0 |---| SEO | BEO | ZI; «| 90:0 =| 20 | 100 | ¢00 | G00
9°&& (hatha emcee oe 6 69 9°L L°9 Lora
G in mee, EP Sa = 61 8Z
4 8°L 8°lP ¢’¢ 6D es | teeta 6° GF
8 6% gee 07% PGS irteeiees 0-CT 8°Sa
9 o°OT Cor [Sry 2.95 saan o'L 8 OE
OND Lewes che Raper |i Pane af Z'0 GL FS9 £°0 0€L 9'T €°9 T $I
‘ON SUWDIY | SUDID | SUDID | SUDIY | SMDIN | SUDID | SWDIDH | SWDIDH | SWDID | SUDID | SWdID | SWDLDH | sMUDID | suDID | SUDID
ife) 81D 8Ig sI1)-01
B08)
Ilv 1®10.L Ze) Life) sD Lave) Lave) dig &D 1D 10D
ony[eA yo109 Thy Id -OU0y
euIpoy | -sopoyO
sploe £448] poyeinyesuy, Sploe £448} poyeinyes

€°0¢
8°71
82 T
0°8¢
LGP
oh P G62
g8'0 1ST
L°G6 OOT
08h 00T
¢'0E OO
99 OOr
G '8E OOr
9 GS OOT
supp | susp
12101
148}
T2IOL

9 SPILOS XT

Pa

wu}

UL WIS

1 Y[OA 380 polidg
1 839 Pop oO M

p Jons Joog

qey 339

sprp jojuaunsadxa ur syuarpasbur fo pun yof apna fo swoib Oot sad uorpsodwoa pridvJ—9), HAV,

103

(887) OFS ‘2 ho ee, wciaks | imscia wins aie Gir ‘Sutaes GAMA PARMPRMGR Ge DT) TAIN) ELT | (ie eee sl (SR aad nea as (ain Alaa
A(z
siete decay @| Oe a apqey Ore OF (99) 921 cae aay oat] | Smet nas | ((CO19) TIS Tottoe errs s ees = gaqgng ynUBod
“(Z
Ne i 21489 OTT) 1 ee 18Z (911) 002 (S61) 9L°T Soo ee ee Jjoog
(88T) 00S SP Ti eae ese as a ce a 99) OOUL | eae ep salen ee smeo te 5 ane eae ppevenr tat ae nee ae 19990
(887) OV (1 91489 ae Ge (99) SEI (91T) 91° (S6T) (0 <i iam ei aa ar SplOS YIU WES
“(%
an (real aay 91qRy oe» SF (99) a0BLI, aieerercaatialel) tanec acsiaae (11 2 FLT wooo a aan maa -"—pjatp PYM SIT
6
(887) OFS ‘G ) eh oP) bP (99) OrL ‘2 (911) LPI ($67) Ce i) Cacia aad as penp ‘xjoA s5qy
(Z
(881) OFL ‘S So) L) ‘om GP (92) £98 ‘T (911) 0 OL ($61) 5 Ne eae eens pop “Ssiy
Z “(288
Peer a | ae ee. 91484 OTT) €8 ‘d ‘96) | 29% Seog esos | a | AAI C ZI Soe eee SC Boras LLY,
aah sm electri | mmm nim |b ia ee one oe ee ee oe ee ee ae ULUUIN [BpIB'T
“(16 =
aed Sein |e an “IN 0% (99) ooBI I, ‘d‘%g) | 9°9 IN ZrO ‘0 Se Sa ee me UIOBE 6)
—ulody —ulodj —wmodj —wodj —ulodj
Bye aT eyed “si Byeqd ‘SIN Byeqd ‘Sn Bye ‘SIN
qyuolpois uy
V Urey A Ulporg, auljoup ley UTUIBILA, plow o1uoyyoy UB
ie ee (887) 0% (881) 9% (881) OT Sie te oe oe
(78T) Or" (98T) 20 ° (88T) 291 |(88T) i (887) ie Ae ee dee Joyyng yNUBod
(781) e¢ ‘1 (987) L10 * (887) € I = |(887) 6h" (887) 81 Coe eee oe ee pod
| Ghee i la Wk] (ae aa ie ane eg SS (881) OL’ (88T) 10 ies eo aaa Pee ee a eke eee a miags, acct dh a |
(781) re OF0 * (981) £00 * (887) Or 'T (887) 96 T (887) Co ie ee SpHOs AVA WAS
ea ee. 860° (98T) £00 * (88T) OL¢ (881) CQege wpe Sees Sess tress ess gps polip ‘oy SAT
“(AI
jee Sik (98T) 920 ° (887) OL’ (887) 99 ° (88T) OG! [lResee rosters polp ‘xJox Saoy
“(AI
a1qey ‘¥G7) | PFS" (G8T) Z10* (88T) 02° (881) 90 ‘T (881) pote ser ea sara ee ee pep 33q1
“IIA GO % (98T) 10 °% “TIN 0 0S “IJIN 0'2 “IJIN OO9s Wegatesss te ete at 4svo
peysl] peysl]
eee asa aoe ost ate to ee ee eee ee ee ee -qndug | ¢F° -qndug | 1F0 eaeas eres nciana el ere = EA
“TAL 910 0 “IA G10 0 “IN GOT 0 “TAL GL ‘0 “IA CZ0cQ) va 8 see ee ee ulosed)
—woly —ulody —ulody —ulod} —ulodj
ByVd SIN Byeqd “SIN Bye “SIN ByeEqd “BIN Byeqd ‘STN
quolporsuy
ourxopiudg plow [OW UIOBINT UIABHOqIy OUITUBIY J,

spoup poyusunsadra Ur syuarpasbur fo sumib Qo, 4ad uorpsodmos uwopA—LL ATAVY,

104

“SUIvIS QOT Jod E00 UUNIsseqod JOJ APIATPISMOS Jo 4IUUTT {9TqQeID0,0p 40 Nz
“PIN ‘OT[ASyog ‘oolAdog yorvosay [BIMy[NOISY ‘UOISIAIG, YOIeasaY UOTyeAIOSUOD, Jd}JWM PUB [Og ‘AMOIUSOY “MQ “fF pus
qypoodg "M ‘VY Aq 4NO poliiwo s[esJOUTU Joj sasATeue [voTMMoyDooedg = *syueTparSut WOdJ PopE[NOTV ‘oINZXTIUT WBS ydooxa ‘Son[VA pouTulJoyop AT[BOTZATCUR ITY 1

09° 9'T 00€ OI8 et SF ° GS 00€ VG (ibs “ee wet tees qoyng ynuvsg
GI ° 20° 88 000 ‘T 0&% LE ° 0 ‘ST 069 OrT GG=S) zen inns 08° o tee pelp ‘joog
OT * F0° 99 099 ‘T O&? 90 ° T€ OL9 OOT ‘T Weis |e SPHOS H[FUL ULyAS
80° GO ° G6 006 088 GG ° bg 66 48 ih) lar ete pelp ‘oy 83
Or’ SI ° 91 Ost Ort ST ° ¢'8 O%L OFZ ton) eae ¢ perp ‘Hos 334
LT 8T GP 00g OOF LE GL 029 OIG Vance | ee nnn Pelp ‘93
Or 8 iT 002 OOT ‘% &% 9°S T'8 OOT ‘T OIT Ay tiple ae ak Oe ee ae eS 4Seox
€1 c0 9T 00d O9T L% 0’? OLT 08 Oi ee | meen nen UMINg[eyoe'T
9T ‘0 10° Il aNz 8'E LG 69 OP 16... OVD «sna ureser)
See ats oe L°9 0rS ‘T 008 ‘8T ge ‘E v9 062 08g 2 00L ST BEES SS OANGXTUL YTBG
by ‘ON by by 5b “BIN 5b BN by SULDL)
uolog esouvsuvy, | WNIsousey, | wnIssejiog winIpog riaddog uoly snioydsoyg | wintoe9 ysy poo

Sip JDUamisadxa Ur syuarpasbur fo suDsb QQT Lad Uoyrsod wos pouaurU PUD , YSP-—'S) a1avy,

105

*(9z 0} 12) SABP ZZ—OBV BuPULOM IFVIOAY 1

0z1 ‘9 6G 'T | ZIP o1g SIT 8I 199 PIT 0% 899 PIT a LLG gIT td aLg SIT 6 029 PIL £8 ae
OFT ‘9 8I‘T | OOF 999 601 91 99g 601 8 189 eI £% P89 aa 9% 689 ell 62 o8S aa Peon slietio es ec enue ads
008 ‘9 L121 | GOP 666 IZ1 81 266 0Z1 1Z 609 i74l G 09 eal 9% 669 Tal 1€ 66S ral Cor. ities 7 Nd
002 ‘9 cOL‘T | $Or 619 IIl gt P89 raul 0% 689 SIL a 269 PIL ¥% 269 PII 08 619 II | a a aren ads
ge ‘9 DEEL Cele 989 Gol GT P89 iva’ LI P69 921 02 069 921 (a6 609 OgT 8% 669 La 6 OAH 8 ds
80) vu} HEL
008 ‘¢ 0z0'T | P98 TLh 16 LI oSh 18 a 6LP 26 91 OLP 26 02 OLD 26 ike PLP 16 6% ueeceT s-Oue ads
OLT‘g OOL‘T | Pe OPP 96 ra oh 96 ial 8oP 86 9T oP 16 61 LLP 101 £% ILP O01 8% OAH 8 dS
S}UI ICSI AA
OzT ‘9 LLU‘T | 00F g9g 601 8ST 699 601 02 819 IIT tad 819 aa! 9% 819 III 6% oLg OIT (43 TTT eseoAy
06 ‘¢ OPL‘T | Le org 86 ST 1g¢ 901 GT LLg Ill LI og 201 02 gag LOL £% 19g 901 Coan || Melos ee a
026 ‘9 SPL‘T | 98 99 801 0% 1g¢ 901 02 OFS SOL 02 969 LOL 7 OPS GOL 9% 199 601 CCrew. || Rok ae es ical
0cz‘9 | 20z‘L | f%F z99 801 8I LLG III rad LLG TIT 1% 809 LIT 1g £69 vIL 08 TLg Orr rh | (le Si ara ee -
002 ‘9 G6 ‘T | 90b 88¢ aa Lt 89 IL IZ 869 SII £% £69 FIT ¥ 869 SIT (a3 LLG ian! rad hae
06 ‘¢ L9Z‘T | &9€ z9¢ OZT GT GPS a ST GHG OT 8I ggg SIT ad £99 021 1% gag SIT 8% “777 Trodvi0A Vy
0s2 ‘¢ b2e'T | O98 €1¢ rea 9T £99 SII 81 ta] PIT 61 erg 601 a PES PIL G Z08 LOL CG* (ine mas fae. at
088 ‘¢ OFS ‘T | GPE peg PIT ial Org 801 ra 929 raat ST 6E9 SIL (a Bho LIL 1G ogg SII SO., |etes ee i |
016 ‘¢ 196 'T |} &S8 699 611 91 EG OIL GT 1¢¢ SIL a 199 IZI G Z99 LIT 6% Pro OTT oe Lo NS oe eas
022 ‘9 ee ‘T | ZOE 9L¢ £21 €1 g9¢ 0ZI 9L 89g ita LT 189 ral tad 109 821 8% 109 821 6% I
SULDIP) | SUDA) SULDIP) | SULDLD SULDI | SUD SULDIP) | SULDLP) SUDIY | SWDLD SULDI | SWDI SUDIp) | SULDLD ‘OAH 8 dS
SA ECee rs!
soTo[VO| oyeqUy | upey |soporeg| oyBJUT | ulepH |soTsojRO| oyeyUT | UeH jsoqopeD]) oyLJUT | UIVH [soo[VH] oyeUT | UTC) |Soo[VH| OYVJUT | UlCH jsoTopep| oyejUyT | UIC)
Solos
pues “orp ‘Uye14g
SYOOM ZT IOJ [CIOL GE HOOM IT YOM. OT 390M 6 YOOM 8 OOM 2 00M
01g FIT Ip OFS OIT 6F 68P 86 LP CGF 16 Gp LOE PL oF 19% 9 8&8 LP vg
1gg LOL 1g Tbs £01 tb PSP £6 ag Shp 98 oF 698 TL OF GLZ £9 8 Lb %
£89 SII OF 09g ran oP Ania O01 P €PP 06 eh 198 €L CP £9 eg 98 LP 4
Pog ZOL 1g LPS GOL Lp 86h 96 LP Shh G8 oP 898 TL 9F 18 gg 1g Lb ZG
LLG £21 98 oLg (eat oF org 801 oP 8S 16 bP gle 08 oF 81% 6g 8 Lb iva
S8P 6 98 OLP 06 Ip bo 18 eh beh #8 SF 98 OL bP £92 19 0g 8P OL
P8P £01 ve GPP 6 PE L&h £6 88 O@P 68 Ip 098 LL 68 99% 9¢ 1G SP Or
PPS GOL 68 £01 OF I8P 26 oP LbP 98 ag 188 PL ag 682 99 1 oF 88
9F9 SOL 8 101 eh 89F 06 IF 8oP 88 &P 068 GL Gb 162 99 68 rag g
GTg 66 8 86 Ip CGP 18 OP aay G8 OF OIF 08 +P L08 69 OF 8P Or
199 601 eh FOL SF org 86 oF eLP 16 tp 06g GL & 182 ia bE ap 8
199 901 hy OIL 8P 88P 6 LP ag £8 PP $98 OL oF 18% 9 1g LP oT
geg PIT ae #29 rags 68 ESP £01 68 SEP 6 OF Gos 8L Ip G82 19 oe GP tPF
61g OIL ae 1g 601 68 ILP 00r OF 80F 18 6£ PPE &L 88 P8Z 09 88 oP OL
Lo OIL 08 LIg OIL OF 8LP ZOr 68 OPP 6 OF 198 LL &P i244 89 1g oF OL
£29 IIL oe £6h GOL rhs £8P £01 98 ag 26 88 BLE 08 18 £68 29 23 bP Or
ggg SIL ina 09g 6IT 7 GOP GOT Ip ooh 96 &P OLE 08 FP 882 19 rE oF ial
SULDIF) | SULDLD SUDA | SUDID Sudip | sMDup SULDIP | SWDID SULDI) | SUDID SULDI | SULDI | SUD LIQUNAT “OAH 8d8
s7¥1 HE
solo[eg| oyequy | ule |solsojeO| oyeyuy | UTeH |sopO[VO] oyVUT | UTC |sopso[VeH] oyeJUT | UPVH |sofso[VO| oxVJUT | UIC) |Soo[VO} oyeVjUT | UTC
1dq3IoM
SUIUBIM $70 Solas pus ‘yorp ‘UPeyS
9 H0OM g YOO b HOOM € HOOM 3 H00M T 00M

syaon BT Iuif sof spp TIdS Pp“ ‘TIS ‘WdS ‘AdS ‘OAH 8 dS paf sys fo ayopur poof pun ub yyhram hipyoa M—6L TAY,

106

“QU SToM SUTUTCS IO SUTUILIUTLUT [TTS S}LI 9 VOIPUT SosoyMored UT sIOqUINN ‘PopNpoUy yOu 4YsToM SUTSOT A[}U4STSMOD SyeY 1

cgah tas be cee aa fee ee (aca peel 018 082 ‘6 $98 ‘T (Z) LI 822 Og ‘6 88 ‘T (¢) 6¢ | #99 099 ‘8 682 ‘T (9) 2) Gan | ee eae eeerennn Gemma cls
SP Ears] SnieeTaoA| Te haate = soe ee ey 9GL Og ‘6 g18 ‘T (Z) 19 199 OFE 6 L6L ‘T (p) 2% ¢99 022 ‘6 GLL ‘T (OQ) ECC | names ames tak ae ares: ads
ree telge | es epee noer| Raa eRe] |e eB aR GLL 062 ‘6 G88 ‘T (9) eb | Zee 018 ‘6 106 ‘T (9) OL 699 00 °6 ES ‘T ((h) Ue ena eee eens Wds
iaiaaetaai ties al ec ee ede |e eee | EM gaa | Oa os 082 ‘L 00F ‘T (1) 9g ‘| STS OFS ‘2 OSF ‘T (Zab... *|Postaae see ads
e69 OST ‘8 OFL‘T (1) 9 PLg O6T ‘8 ChL ‘T (Z) #1 FS O3T ‘8 81 ‘T (g) 0g | 999 019 ‘8 $28 ‘T D) LA) ae OAH 8 ds
—poj soyvuloyyy
sel GAA
TLL 088 ‘8 119 ‘T (g) 12 | 902 O19 ‘2 £9F ‘T (9) SI 889 O8P ‘2 88F ‘T (9) #9 | 999 062 ‘2 OL ‘T C2) IS)y | Gemeens ee neiratee eis hme ads
668 O6T ‘2 0g¢ ‘T (2) ce | #99 028 ‘9 ISh ‘T (¢) 9— | 8Fo - OLL ‘9 IP ‘T (4) 48 | 8Tg ore ‘9 6FE ‘T (S) 207i semen nena ae eens OAH 8 d8
—po9jJ soyBUreggTT
SyeL IBISTAL
Cages | esata Space a Res ey ee! See | RES ESS Se a| Cae ee os¢ 082 ‘2 O0F ‘T (1) 9g | 819 028 ‘2 0S ‘T (8) 8 Sf gipoacea eee ote asvloAV
eS hae agen ease am cei hee Re Nesta or ected eaten ae US e.g CE a pm anole acre
Sse Sin |Geusraenes eee eeaetal cos al (ena eae (eae =| Ina 1] MG Cee [a NEC cae ese as bs aera LL9 066 ‘8 602 ‘T (2) 56 1s | beens ene LS
7a oa 7 ae ee ime eras ween ere SERS LCT wy Saas ee ae pa ee ose 082 ‘2 OOF ‘T (1) 9g | ST¢ OFS ‘2 OSF ‘T COV BN
9¢9 ore ‘8 892 ‘T (Z) St | g6¢ OL ‘8 182 ‘T (4) 9% | 829 029 ‘8 Ces ‘T (61) ze | -809 OFZ ‘8 E94 ‘T (82). 0G.. lsuiaeieee coast OBVIOAV
capaaiinel| Uaaear sl Lens a ae at 88g OgT ‘8 SCL 'T (g) $¢ | a2¢ 08S ‘8 928 ‘T (F) OF | 89g 092 ‘2 099 ‘T (Q)R0te || Resin nanan meas M
ea aS cannes || Nanaia || ioe eire ay ormemens ||) trig | ae acumen |r 699 026 ‘8 668 ‘T (9) 6g | 029 062 ‘8 e9L ‘T (2) G20) | Gagan aaeatn ea eameemenenes Cl
819 OFF ‘8 G62 ‘T (1) 0g | 8z9 06 ‘8 006 ‘T (2) 08 | #29 088 ‘8 82 ‘T (9) 0& | 999 01Z'8 692 ‘T (Q) SP x. ges seer ene Sepennee sae Vv
£69 OST ‘8 OFL ‘T (1) 9 FLg O6I ‘8 CPL T (Z) $1 OPS 021 ‘8 SL ‘T (g) 0g | 99¢ OLS ‘8 P28 ‘T (Oytqu | ae seta ime sees Barris
SULDLY SULDLY) SULDLY SULDLY SULDLY) SULDLY) SULDLY) SULDLY SULDLED SULDLY) SULDLE) SULDLY) ‘OAH 8 dS
s}®l GHA
solloyjeg | oyejUy uley sollojeg | oye,Uy urey sollojeg | oyxeJUT ures Ssollojeg | oye UT uyey
skep sep skep
00s 38 |~ 002 38 og 38 SopIOs PUB “JoTp “UPeIPS
JUSTO s&Vp 008-004 FUSTOM sep 002-009 s&ep 009-002 qUS}OM sep 00%-00F
es9 002 ‘8 9F9 ‘T (6) te | 8I9 026 ‘8 099‘T | (ZI) £9 | 89g OST '8 9e9'T | (G1) 82T | OFF #1 Wee enc ege Or aneaee aeasgee eel ‘iiiessddds
rast) 068 ‘8 P19 ‘T (ol) #& | 609 098 '8 809 ‘T TZ | 9¢¢ OST ‘8 PLS ‘T 801 | O&F FI Geeks Cen ean apt pean ome mats
699 089 ‘8 OFL 'T (TI) 9% | %9 066 ‘8 TOL ‘T OO en 2998, 0s6 ‘8 g69'T | (eI) PET | 6aF Pie) 3. cee aes ema Aiaaals "77" Wds
FLg 029 °2 oLF T (F) 02 | 869 099 '8 L¥9 ‘T 1g | 24g 09 ‘8 109 ‘T 601 | 8eF a. ie cae aeseees Si Gos GER eOEE Pee ees
$89 063 ‘8 F9L‘T (OT) €8 gg OFF ‘8 962 ‘T (eI) co | FOF 09T ‘8 92 ‘T 6 668 TE Wee Ao ligactetas ier ae vara a. ~~ OAHSidS
—povj soyeur19}qVT
siti FH
189 086 ‘9 gee ‘T (2) 48 | ogg 069 ‘9 986 ‘I (8) og | ST¢ 098 ‘9 61€ ‘T LIT | 86€ OT iiss os Se dS
e6F 022 ‘9 gce ‘T 12 | GLP 006 ‘¢ GS ‘T LT ap ose ‘9 ce ‘T Z| 898 Ot Sanii ceases eo eee eee O MESS
—poj SoyeUlle}yT
s}el IePSTAA
629 022 ‘8 oss‘t =| (41) 0& | 809 02 ‘8 wso‘t = | (ze) 6S | LFS 086 ‘2 See ‘T el | Fh ge idee Pon tad Galil ae sa nen e ROMBIDAY,
129 090 *2 g9¢ T (b) & 129 OLE 'L SIFT % | 629 06 ‘9 988 ‘T SZ | t0F g iStimet pasted
889 O6P ‘8 £69 ‘T (g) 8 | 609 082 ‘8 769 ‘T GL | $89 09L ‘2 6F ‘T 6IL_ | SIF Or
£89 Osh ‘6 L18 ‘T (g) 09 | $09 006 °2 £29 ‘T (1) 9% | 899 028 ‘2 P19 ‘T OOT | 89F 8
GLE OSL ‘L O6F ‘T (S$) 2 | S09 009 ‘8 $99 ‘T eg | zg¢ 00F ‘8 919 ‘T GIL | 68h GT
169 090 ‘8 STL ‘T (6g) ¢& | 09¢ OT ‘8 LL ‘T (gt) #2 | FOS 00 ‘8 eIL‘T LIL | 288 +P
699 OBL ‘L oso ‘T (6) 6— | 189 026 ‘2 $89 ‘T 09 | T2¢ 008 ‘8 COL ‘T GI | BLE or
209 010 ‘8 FOL 'T yo | eg? OFT '8 SeL ‘T 99 | 18% 080 ‘8 SIL ‘T 60T | 828 or
09 020 ‘8 LOL ‘T SF | gee O28 ‘2 $19 ‘T oF | 9T¢ 029 ‘2 C29 ‘T 62 | 288 or
$89 062 ‘8 $92 ‘T (OL) 8 1g¢ OFF ‘8 962 ‘T (eI) 2o1 | F6F O9T ‘8 9@2 ‘T c6 | 668 at
SULDLYD SUDLD SULDLD SULDLY SWDLD SWDLYD SULDLYD SULDLYD SULDLY SUDLY LIQULNAT [OAH8 dS
sje1 GH
SOLIO[BO oyequy uley) Sollo[eg, oyeqUuy Ulery Ssollo[eg ayequy uley
sfep skep skvep skep
OOF 38 oog 48 002 98 | OOT 38 Sqyey solos pue “Jorp ‘UPB
JUSTO sAep 00-008 JUSTO M SABP 008-00 YUSTOM. sABp 002-001 qUSIOM

sj TddS Pu» ‘Td ‘WdS ‘AdS ‘OAH 8 dS Vo spoaayur hop-goy Hof syou fo aynyur poof pun ‘urnb qybraa Gybvayj— ‘08 HIGV I,

107

be £08
£°2% 19%
are ALL
£12 L¥e
L°6L Pee
£12 28%
8 ZS 8°28
0°eI ZF
9°12 £LE
Th 9°08
FLT 8°
Toa Z'8e
9'TZ 9°9Z
#82 £°9Z
oF —_—-| 0'9%
6°91 0°¢%
9 FL FZ
€°91 Z 9G
8°02 9°02
FUL 6°22
Leal ad
ade 9°21
6 II 6°€%
“OW ‘OW

DWOONMWDOSARO
CHrANAMIN DM HM
A ied sod od ai od

SCOMOournnAr

Dorrnr~ roonsnsNnr
FNNKHAN AHHH

eoorrecm
~

oL‘T

SULDLD

GL 1G
861%
¥6 ‘ST
VG FS
92
80 TE
89°LT
$8 “0%
29 61

G6 GS
82 €8
TL ‘61
GL ST
TG “8T
8P 06
LE 0%
89 FT

SULDLD

Prous yy,

[euoipy | Aoupry

IOAYT

SUBBIO POJDOOS JO YY BIOM

bP9
60L
£9
889
geo
¥69
T6L
809
89
LOL

v9
928
819
Of
189
169
LEQ
829

SULDLE)

q{UusTOM
munuL
“XRT

yyrop yw
UBT AA

qyeop
4e o3V

A

----------]---------------- ODBIOAY

yoojs 0} posuvyo wads

Pa gee ig ote beatae ae ~--9SBIDAV

Ads 04 posurya yo09g

‘SABP 09Z JV POSIOADY

Ba age ee a ere OdTIOAY

—uo ponuyyu09

Ril oe aa|oo se ee OdVIOAY

O16 ‘€ 022 ‘F 616 ZI8 So— OF 169 919 OLg
OLL'S OIL‘ PPG 906 9t— £01 $89 602 909 g
OLL'F OFZ 'F PF ‘T S18 9T— if a19 829 289 P
060 'F 086‘ ¥20'T 992 ST bP €19 869 pgg §
019 ‘€ 096 ‘8 $06 T9Z bL— c= ooh ogg geo 4
089 ‘Fb 088 ‘F 068 860 ‘T 06 81 O19 02g £09
019 ‘F O8b ‘fb 868 ZT ‘T 18 9% oho ggg eee g
O19 'F OIL 't 188 620 ‘T COT 8 T6¢ 68h 18h b
029 ‘F 089 ‘b 868 SLI ‘T 08 81 9F9 99¢ 8h £
099 ‘F 092 LL8 990 ‘T 16 61 09g 69F OSF a
008 ‘ OLL ‘ES PCL 922 67 bP 669 gsg $19
OOF 'F 020 ‘F 928 PLL €8 98 269 FI9 629 g
092 '¢ 018‘ ToL SPhL 1% ST 82¢ 199 ore g
092 ‘8 O2F ‘& 929 8o9 61 €1 God £09 OLY i
OLT'F OST 'F 960 ‘T L¥0'T 0g (63 ggg L0G 98h
062 ‘F 0F8 ‘F 002 ‘T £12 ‘T OF Lg €£9 289 ogg g
O10 ‘F 0£8 ‘8 $00 'T 696 8& ral 629 16h 6LP €
0ZL'E 0L8 ‘€ ££6 696 L 9g IIg¢ p09 8hP E
a el 060‘ pelea ana), OBA Spee 1106 mae 74) ogg
Sao ee ore ‘F Pio. vars sas, fo eee LG Cie. eee S19 ¥
ate <a OOI ‘F seers Tt 68h ie emer | Nee re ll Led ggg 4
ea oe 098 ‘¢ R tacoe sl LP Pirtdee Sesh OS ie all) SPS PSP T
ween 016‘ TTTTTT T=") O66 brah n cae £09 L8h
ages: OF0‘b Reet aS LOE ears 4 ee!) 3") 629 ¥
ee wee OFS ‘E haa Peden tL) tre re Ok ~ | OSF OFF z
Pie eat 080 ‘F Fes ea | O00 7 ee AOS Bo LOLS L8P i
$9140] | $aisojnQ | suns) SULDLEY) SULDL SuDLy) | SWDLDH | swDLD | SWDLD
séup skup ssep sfup sAvp skup skep skup skep
008-096 | 092-002 | OOF-0GZ | 082-002 | O0E-08% | 08z-002 008 092 008 me
10991'T
—j A3.10U0 SSO.UD —}8 OYCJUL POO —4e UTCS ISOM —Je JYSIOM

Shop OGE 1D passaaas LO afr)
moybnowyy spaip Td pun yoojs pof syoe pajspfuou ATT yonpurpur fo syybrom unbso pun ‘waraans ‘aynyur poof qybran fipog— 18 a1av yy,

:SABP 09Z IV PodyLWOVG

JOIP puv UOT}IPUoH

108

U.S. GOVERNMENT PRINTING OFFICE:1964

,

4

Ul

TE