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Full text of "Experimental pharmacology, a laboratory guide for the study of the physiological action of drugs"



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CORNELL UNIVERSITY. 



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THE GIFT OF 

ROSWELL p. FLOWER 

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The original of this book is in 
the Cornell University Library. 

There are no known copyright restrictions in 
the United States on the use of the text. 



http://www.archive.org/details/cu31924056948841 



EXPERIMENTAL PHAEMACOLOGY 



GEEENE 



EXPEKIMENTAL PHARMACOLOGY 

A LABOEATOEY GUIDE 



FOE THE STUDY OF 



THE PHYSIOLOGICAL ACTION OF DEUGS 



BY 

CHARLES WILSON gREENE, PH. D. 

PROFESSOR OF PHYSIOLOGY AND PHARMACOLOGY, UNIVERSITY OF MISSOURI. 



THIRD EDITION, REVISED 
WITH 37 NEW ILLUSTRATIONS 



PHILADELPHIA 

P. BLAKISTON'S SON & CO. 

1012 WALNUT STREET 

1909 



Copyright, 1909, by P. Blakiston's Son & Co. 



*- 



Printed by 

The Maple Press 

York, Pa. 



PREFACE. 



Instruction in Piiarmacology should be based on a rigid course of 
required laboratory experiments. The student in the subject must be given 
every opportunity to observe for himself the changes produced by a drug in 
the activities of a tissue, of an organ, and of the entire organism. It is only 
on such intimate personal experience with the facts that one can reach a 
rational understanding of the principles of Pharmacology. 

The directions presented here have been formulated during the growth 
of the course as presented in the University of Missouri. Under each drug 
presented there is given a list of experiments chosen with due consideration 
to the facility with which they may be performed by students. This list 
is followed by detailed yet brief directions for the execution of the experi- 
ments. An occasional type illustration is given to guide the student in his 
efforts. It is assumed that the individual student will have time for only a 
selected number of experiments on each drug, and the plan of the Guide is 
so arranged as to support the instructor in the assignment and execution of 
a number of diversified experiments by the average laboratory class. 

I am indebted to the Department Teaching Staff, especially to Professor 
W. Koch, now of the University of Chicago, to Dr. W. H. Schultz, now of 
the U. S. Public Health and Marine Hospital Service, and to Professor 
R. B. Gibson for numerous suggestions and much assistance. 

I am under special obligation to Mr. G. T. Kline for the drawings of 
apparatus, to Professor Gibson and to my students of the past five years 
for the majority of the new illustrations presented in this edition of the 
Guide. C. W. G. 

University of Missouki, April, 1909. 



CONTENTS. 



THE ACTION OF DRUGS. 



Alcohol 

Ether 

Chloroform . . 

Chloral hydrate . 
The opium series . . 
Caffeine . ... 

Strychnine . . 

Cocaine . . . 

Quinine . . . 

Atropine, scopolamine 
Nicotine 

Curare . . . 

Pilocarpine 
Physostigmine 
Aconite . . 
Veratrine . . 

Digitalis 
Ergot . . . 

Suprarenal gland . . 
Nitroglycerine and the 
Carbolic acid . 
Potassium salts 
Calcium salts 
Barium salts . . . 



nitrites 



PAGE 

I 

6 

II 

14 

IS 
20 

24 

29 

32 

33 
37 
40 
42 

44 
48 
5° 

52 
SS 
56 

59 
61 
61 
62 
63 



OPERATIONS, APPARATUS AND SPECIAL METHODS. 

Physiological solutions . . .64 

Anesthesia for dogs, cats, rabbits, and guinea-pigs . 65 

The preparation of the ventricular muscle .... . 66 

To test the action of drugs on the frog's heart 68 

vii 



VUl CONTENTS. 

PAGB 

Irrigating and perfusing flasks 69 

To test the action of drugs on the blood-pressure, respiration, etc., of 

a mammal . . ... .... 70 

Method of testing the action of drugs on the reflexes of a frog 71 

Method of giving and testing the action of a drug on the frog's gas- 
trocnemius muscle . . 72 

Transfusion buret for mammals . 72 

Apparatus for the study of the isolated mammalian heart .... 73 

List of stock solutions 75 

Report form for experiments on frogs 76 



LIST OF ILLUSTRATIONS. 



FIG. PAGE 

1. Alcohol perfused through the frog's heart 2 

2. Ether on the isolated muscle of the terrapin's ventricle ... . 7 

3. Strong ether solutions on the isolated ventricular muscle. 8 

4. Ether on tone waves of auricular and sinus muscle. . 9 

5. Ether on the irritability of the sciatic nerve 10 

6. Chloroform on the rhythm of heart muscle 12 

7. Chloroform perfusion of the frog's heart . 13 

8. Chloroform on the irritability of nerve . 13 
g. Morphine on the rhythm of terrapin's ventricle . 16 

10. Morphine on the isolated heart of the cat . . . 17 

11. Morphine on the isolated heart of the cat . 17 

12. Caffeine on the ventricular muscle . . 21 

13. Caffeine on the amount of muscular work 22 

14. Strychnine on the ventricular muscle . . . 25 

15. Strychnine on the muscular work . 26 

16. Strychnine on the isolated mammalian heart . . . 27 

17. Cocaine effects on the frog's heart . . 29 

18. Cocaine on the muscular work . . 30 

19. Quinine on the frog's heart 32 

20. Atropine on the heart muscle . . 33 

21. Atropine on the isolated cat's heart . 34 

22. Nicotine on the ventricular muscle . . 38 

23. Nicotine on the isolated cat's heart ... 39 

24. Pilocarpine on the blood-pressure and on the respiration of the dog 42 

25. Physostigmine on the isolated cat's heart . . . 45 

26. Physostigmine followed by atropine on the mammalian blood- 

pressure and respiration . 46 

27. Aconite on the isolated cat's heart. . . . . . 49 

28. Veratrine on the isolated cat's heart . 51 

29. Digitalis on the heart muscle ...... 53 

30. Digitalis on the isolated cat's heart ... 54 

ix 



X LIST OF ILLUSTRATIONS. 

FIG. PAGE 

31. Adrenalin hydrochloride on the isolated cat's heart . . 57 

32. Amyl nitrite on the human pulse .... . . 60 

33. Calcium chloride on the terrapin's heart muscle ... 62 

34. The terrapin's heart, how to cut an apex strip . . 67 

35. Apparatus for the study of heart muscular strips . . 67 

36. Apparatus for the study of drugs on the frog's heart . . 68 

37. Apparatus for the study of the action of drugs on the mamma- 

lian heart 74 



EXPERIMENTAL 
PHARMACOLOGY 



THE ACTION OF DRUGS. 

ALCOHOL. 

List of Experiments Showing the Effects of Alcohol. page. 

1. On the frog .... i 

2. On ventricular muscle . . i 

3. On the frog's heart . . 2 

4. On the isolated mammalian heart. .... 3 

5. On the work of the frog's gastronemius muscle. 3 

6. On voluntary work of human muscle. Demonstration . 4 

7. On the circulatory and respiratory systems of the mammal . 4 

8. On the reaction time of the reflex frog . ... 5 

1. Alcohol on the frog. Inject into the dorsal lymph sacs of two 
frogs doses of 0.3 c.c. (5 minims) and 0.6 c.c, respectively, of 95 percent 
alcohol.' Strong alcohol is quickly absorbed from the lymph sac. The 
larger dose is sufficient to produce temporary complete loss of the reflexes, 
together with the loss of all respiratory movements. A dose of i c.c. 
is toxic for a 40-gram frog. Since the smaller dose is equivalent to 525 c.c. 
for a 7c-kilo man, it is evident that the frog is the more tolerant of alcohol.^ 

2. Alcohol on ventricular muscle. Mount a strip of the ventricle 
of a terrapin in 0.7 percent sodium chloride (see page 66 for the method), 
and when it is contracting with an even and regular rhythm change to a 
solution of 2 percent alcohol in" physiological saline. Return the strip to 

'All doses for frogs given in this book are calculated for an animal weighing 40 grams. 
Each animal used for experiment should be weighed on a "Harvard" platform balance and 
the dose given calculated in proportion to the weight of the animal used. 

"A report blank form for the tabulation of observations on the effect of drugs on frogs is 
given on page 76. 



2 EXPERIMENTAL PHARMACOLOGY. 

pure saline solution after two to five minutes. Record the contractions on a 
drum moving i mm. a second. Repeat the experiment', using successive 
strengths of alcohol of 5 and 10 percent. The alcoholic effect will be dem- 
onstrated rather better on a ventricular strip that is contracting regularly 
in the weaker Ringer's solution, page 64, but the alcohol must be dissolved 
in Ringer's solution of the same composition. 

3. Alcohol on the frog's heart. Destroy the brain and spinal cord 
of a frog, expose the heart by cutting away the ventral wall from directly 
over the ventricle, using care not to lose blood. Do not cut the bridge formed 




Fig. I. — Action of 2 percent alcohol on the frog's heart when perfused through 
the ascending vena cava. The alcohol was dissolved in Ringer's solution. The 
record was taken from the tip of the ventricle by the suspension method. Time in 
seconds and minutes. Perfusion began at the first arrow above the second's record and 
ended at the second arrow. 



by the sternum, but use it as a fixed point to which the heart may be anchored 
by a ligature around one of the aortic arches. Take a direct record of the 
movements of the ventricle, using a light straw lever of the fulcrum-power- 
weight order. Give 1.5 c.c. of 95 percent alcohol in the abdominal 
cavity. Take a continuous record during the time of absorption. This 
method demonstrates the effects on the volume, and on the type of systole 
and diastole. The rate is only slightly changed. 

More satisfactory results are obtained by perfusing the heart through a 
canula in the ascending vena cava. Perfuse the alcohol from four-ounce 
supply flasks provided with constant level tubes. Use a pressure of from 
4 to 6 cm. The perfusion strength to use by this method is 2 to 5 percent 
alcohol made up in Ringer's solution. Perfuse the heart for from two to 



ALCOHOL. 3 

four minutes at a time. Record the contractions of the ventricle. by a thread 
from its tip to the vertical arm of a balanced lever, page 68. In this experi- 
ment, as in all frog's heart perfusion, it is better to use the weaker Ringer 
for the normal solution. The Ringer's solution insures a uniform heart 
rate and strength for long intervals, while the sodium chloride solution 
will sustain the whole heart in regular and strong rhythm for only a few 
minutes. 

4. Alcohol on the isolated mammalian heart. Use a rabbit or a 
cat for this experiment. Anesthetize quickly with ether (do not use chloro- 
form) , insert a canula in the carotid, bleed completely, defibrinate the blood 
and dilute it with nine volumes of Locke's solution. Use this diluted blood 
as a normal solution for perfusing the heart. Reserve enough of the solution 
for making the drug mixtures, pour the remainder into the perfusion appara- 
tus described on page 73, fill the tubes, adjust the apparatus and bring to a 
constant temperature of 36 to 37° C. (a higher temperature is unfavorable). 
Quickly remove the heart, taking care only to preserve enough of the aorta 
for the insertion of the canula without danger of interfering with the semi- 
lunar valves. Mount the heart without catching air in the canula, attach the 
recording lever of the Guthrie cardiograph and start the perfusion. The 
perfusion pressure should be from 80 to 100 cm. of water. 

The heart contracts and a uniform rhythm will be quickly established 
and may be maintained for several hours. Perfuse the heart with 0.2 
percent alcohol in the Locke-blood solution for from 30 to 100 seconds 
at a time, allowing full time for a return to the normal after each drug 
perfusion. Raise the dose successively to 0.4 percent, i percent, and 2 
percent of alcohol. The stronger solutions reduce the amplitude and 
ultimately the rate of the heart; the weaker doses, according to Dixon, in- 
crease the amplitude. 

5. Alcohol on muscular work. Ligate one leg of a frog near the 
thigh to exclude its circulation (a quarter-inch rubber tube makes a fine 
ligature for this purpose). Inject 0.3 c.c. (5 minims) of 95 percent 
alcohol into the dorsal lymph sac. In exactly twenty minutes pith the 
frog, pin it out on the frog-board with the ventral side down, and ligate the 
alcoholized leg. Quickly prepare the tendon of the normal muscle, keeping 
the muscle covered with skin, attach to the muscle lever, and determine the 
work it can do by stimulating the muscle directly with a single induction 
shock once every two seconds until the muscle is completely exhausted. 
Load the muscle with a 30- to 50- gram weight. Record the contractions on 
the lower half of a drum with a speed of i mm. a second. 



4 EXPERIMENTAL PHARMACOLOGY. 

Prepare the second or alcoholized muscle just twenty minutes after it 
has been ligated, mount, load, and stimulate in the same manner. Record 
the second experiment on the upper half of the same smoked papef and 
parallel with the record of the first. Repeat this experiment using a dose 
of 1 CO. of 95 percent alcohol, to demonstrate the injurious effects of 
alcohol on the work of the muscle. (Lee and Salant, Am. Jour. Physiology, 
Volume VIII, p. 6i, 1902.) 

A more difficult but more accurate experiment is obtained as follows: 
Destroying the brain only of a frog, pin it to the frog-board belly down, 
dissect out the right tendon Achilles, and attach to a muscle lever. Isolate 
the lumbar plexus on the right of the urostyle, using care not to interfere 
with the circulation of the gastrocnemius. Stimulate the right muscle as 
above. Now inject alcohol into the abdominal cavity, and after 20 to 30 
minutes of absorption measure the work of the left gastrocnemius. This 
method has the advantage of maintaining the circulation intact for both the 
normal and the alcoholized muscle. 

The effect of alcohol on the speed of the contraction can be determined 
by one of two methods. Que can measure the simple muscle contraction 
before and after alcoholization. Perhaps a better method is to use Lee's 
automatic stimulating device (Am. Jour. Physiol., VIII, p. 61) which auto- 
matically stimulates a muscle at the moment of complete relaxation. Re- 
cord the contractions on a slowly moving drum, 2 mm. per second. 

6. Alcohol on voluntary work of hiunan muscle. Demonstration. 
Measure the voluntary power of the flexors of the middle finger with a load 
of three kilos or more, using Mosso's ergograph. Take two or three normal 
records of voluntary contractions at intervals of 20 minutes. Now take a 
dose of 20 to 40 c.c. of 20 percent alcohol, according to the susceptibility 
of the individual. Remeasure the muscular power after 60, 90, and 120 
minutes, respectively. Compute the work done in kilogrammeters. (Lom- 
bard, Jour. Physiol., Vol. 13, p. 49; Hallsten, Skand. Arch. f. Physiol. Bd. 
16. S. 139.) 

7. Alcohol on the circulatory and respiratory systems of the 
mammal. Anesthetize a dog with morphine and chloroform, p. 70. 
Take the blood-pressure from the carotid artery, and the respiration from a 
side branch of a tracheal canula. Expose the saphenous vein and insert 
a canula for intravenous injections, and attach it to a 50 c.c. buret. 

Students who have attained the requisite skill should take an onkomet- 
ric record with the blood-pressure. To prepare for this record open the 
abdominal cavity of the dog, remove the outer sheath from the left kidney 



ALCOHOL. 5 

and enclose that organ in a renal onkometer. Record the kidney volume 
changes by means of a Brodie's bellows, or Roy's piston recorder, page 71. 

The anesthetic must be given with perfect regularity, 2 to 6 drops of 
chloroform every 30 seconds, the exact amount that will maintain constant 
anesthesia to be quickly ascertained for each animal. 

Take a record on the continuous kymograph and, when all is in good 
working condition and a normal record has been secured, slowly inject 20 
percent wanned alcohol from the buret into the vein imtil some decided 
effect on the blood-pressure is noted, i.e., after a dose of 20 c.c. or more. 
Extreme caution must be observed lest the heart by rapid perfusion be sub- 
jected to an overconcentrated solution. The experiment should be re- 
peated with different doses. 

Since the anesthetics used all depress the irritability of the circulatory 
apparatus, this experiment ought to be demonstrated on a decerebrate ani- 
mal. In such an animal the medulla being intact will maintain natural 
respirations. Any alcoholic stimulation of the medullary centers can easily 
be observed. The recommended intravenous dose of alcohol will produce 
slowing of the heart, a phenomenon which disappears on section of the vagi, 
thus indicating a direct effect on the vagal centers. 

8. Alcohol on the reaction time of the reflex frog. Destroy the 
brain of a frog, including the medulla, and when it has recovered from the 
shock test the normal reaction time to electrical stimuli applied to the toe. 
Measure the time of the reaction with a watch, or record it with a writing- 
point attached to the foot or leg of the suspended frog. Give a dose of 0.3 
c.c. (5 minims) of 95 percent alcohol in the dorsal lymph sac. Retest 
the reaction time at exactly 20 and 40 minutes after the injection. Com- 
pare the results with experiments i and 5 above. 



EXPERIMENTAL PHARMACOLOGY. 



ETHER. 



List of Experiments Illustrating the Effects of Ether. page. 

1. On the frog 6 

2. On the ventricular muscle 6 

3. On the frog's heart 7 

4. On the mammalian heart . 7 

5. On the irritability of voluntary muscle. 7 

6. On the irritability of nerve tissue . . . 9 

7. On the blood-pressure and respiration of a mammal 9 

8. On the germination of seeds 10 

9. On the growth of yeast . . 11 

1. Ether on the frog. Inject 0.2 c.c. (3 1/2 minims) of ether' into 
the dorsal lymph sac or the abdominal cavity of a frog. Give 0.3 c.c. to a 
second frog. The dose can be given more accurately from the hypodermic if 
a 50 percent solution of ether in olive oil is used. The first dose will produce 
anesthesia in about 10 minutes. The stages most readily observed are : ist, 
great excitement shown by rapid respirations, active movements, and 
increased reflex irritability; 2d, slower respirations, very sluggish • response 
to external stimulation; 3d, loss of voluntary muscular control and sometimes 
of respiratory motions. Slight power of reflex response is retained, including 
eye reflexes. The voluntary motions will be regained in from 60 to 90 
minutes if the animal is kept moist (winter frogs), and complete recovery 
in two hours. The frog will recover from the larger dose in from 20 to 24 
hours, or it may even fail of recovery. 

2. Ether on the ventricular muscle. Mount a strip of terrapin's 
ventricle and establish rhythmic contractions in a bath of 0.7 percent saline. 
Record on a drum moving i to 2 mm. per second. Immerse the strip in a 
bath of I percent ether in saline for two to three minutes, then return 
to the physiological saline bath. The sharp decrease in both amplitude 
and rate of contractions is recovered quickly in the saline bath. 

Repeat the experiment using 2, 4, and 6 percent ether solutions. 

The weaker solutions occasionally produce slight but temporary increase 

in the rate, the initial excitation stage. Also use strips of auricle and sinus. 

'The dose is figured for a 40-gram frog. Proportionate doses should be given for other 
weights. In all experiments on frogs that depress their functions, the animal should be retained 
in a moist bell jar for as much as 24 hours, if necessary, in order to test the animal's power of 
recovery. 



ETHER. 7 

3. Ether on the frog's heart. Pith a frog, expose its heart, insert 
a canula in the inferior vena cava and perfuse the heart in place by the 
method described for alcohol, experiment 3. This brings the solution into 
intimate contact with the entire heart and it responds almost instantly to 
any change in the composition of the irrigating fluid. Perfuse the heart 
first with Ringer's solution and follow with i percent ether in Ringer's 
solution. 

4. Ether on the mammalian heart. Use the Roy-Adami method 
(given by Cushny, Jour. Exp. Medicine, Volume II, page 233) or the 




Fig. 2. — The action of ether on isolated heart muscle. In this experiment a strip 
of terrapin's ventricle was mounted in physiological saline until a regular rhythmic 
beat was established. The saline was then drawn off and the strip left suspended in 
moist air. At the point indicated ether vapor was driven through the moist chamber 
until the contractions ceased. The ether vapor was then removed with moist air 
at the second arrow and the recovery of the rhythm took place as shown. 



method described on page 73 and used in experiment 4 of the alcohol 
series. Etherize a cat or rabbit, draw the blood, defibrinate it, and dilute 
it with nine volumes of Locke's solution and use as a standard Locke-Blood 
perfusion fluid. Remove the heart and adjust it in the apparatus, page 74. 
Perfuse with the Locke-Blood solution and when the rhythm is established 
change to i percent ether in Locke-Blood. Use 2 percent ether in a 
later experiment. 

5. Ether on the irritability of voluntary muscle. Mount a gas- 
trocnemius of the frog in the moist chamber, arrange to stimulate the 
muscle directly with a current of medium intensity but which produces a 
maximal contraction. Adjust a vapor apparatus containing saturated 



EXPERIMENTAL PHARMACOLOGY. 




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ETHER. 9 

ether water ready for quick connection with the gas tube of the moist 
chamber. Stimulate the muscle with single induction currents once every 
30 seconds throughout the entire experiment, whether contractions are 
secured each time or not. Record on a drum having a rate of 2 mm. per 
10 seconds. 

Take records, three or four normal contractions, then turn on the ether 
vapor for five minutes. Quickly remove the vapor with a current of fresh 
air. The muscle's irritability will decrease to a point at which the stimulus 
is submaximal or even subminimal, but when the ether vapor is removed 
the contractions quickly reappear and attain their former amplitude. Use 
small muscles for this experiment. 




Fig. 4. — The action of ether on isolated strips from the auricle (upper trace) and 
from the sinus (lower) of the terrapin. The strips were giving tone contraction waves, 
but no fundamental rhythm when bathed with normal sodium chloride solution. At the 
mark "on" the sodium chloride was changed to one percent ether in normal saline 
for seven minutes, then again to the normal. During the ether bath the tone waves 
disappear, a condition which lasts for three minutes after the ether is removed. Fol- 
lowing the ether there is a renewal of the tone waves which are even more rapid than 
in the normal. Time in minutes. 

One may with this preparation also demonstrate that the muscle has a 
diminished power to do work when etherized, method page 72. 

6. Ether on the irritability of nerve tissue. Prepare a muscle 
nerve of the frog, isolating the entire sciatic with a piece of cord, and with the 
skin covering the muscle. Mount the preparation with the nerve in the 
moist chamber and on the electrodes, but with the muscle hanging through 
the hole in the floor of the moist chamber and on the outside so that it will 
not be etherized. Close the hole with a sheet of moist filter-paper. Proceed 
exactly as in experiment 5 above testing the irritability of the nerve through 
its effect on the muscle. 

The influence of ether on nervej irritability may also be demonstrated 
directly from the nerve by the action' current method. For a description of 
the method, see Am. Jour. Physiol., Volume I, p. 104. 

7. Ether on the blood-pressure and on the respiration of the 
mammal. Anesthetize a dog with morphine and ether. Introduce an 



lO EXPERIMENTAL PHARMACOLOGY. 

arterial canida in the carotid for taking the blood-pressure record, see page 
70 for details of method. Insert a tracheal canula and take a record of intra- 
tracheal pressure from a T-tube attached to the canula. Give ether from 
an ether bottle connected to the end of the tracheal tube. Take a continuous 
record and ultimately give excess of ether, then allow partial and guarded 
recovery. Give ether to the point where respirations cease, a point attained 
with difficulty except when the animal has a large dose of morphine. The 
blood-pressure is an index of safety, for it has been shown that respiratory 
impulses are quickly re-established when the blood-pressure remains high. 
Saturated ether in saline as an intravenous injection in doses of 20 c.c. 
and more, given along with a uniform administration of ether by the trachea. 



Fig. 5. — The influence of ether vapor upon the irritability of the sciatic nerve 
in the muscle-nerve preparation of a frog. The muscle-nerve preparation was sus- 
pended in a moist chamber with the muscle hanging through the opening in the cham- 
ber. The first two contractions are normal. The next eight are successive contrac- 
tions at intervals of ten seconds during the passing of ether vapor. At the X the 
ether vapor was removed by a stream of moist air, the nerve being stimulated at inter- 
vals of ten seconds until recovery of the irritability as shown by the contractions at the 
last part of the experiment. A gap of two minutes occurs at X, during which the nerve 
was not irritable. Time in seconds. 

will often demonstrate the characteristic circulatory and respiratory effects 
of the drug. 

The rectal temperature should be recorded at intervals to demonstrate 
the fall of temperature under anesthetics. Note also the state of dilatation 
of the pupil. 

8. Ether on the germination of seeds. Arrange two eight-ounce 
wide-mouth bottles with stoppers each fitted with two glass tubes, letting 
one tube extend to near the bottom of the bottle. Suspend in each, by 
means of cotton, a dozen seeds — corn, wheat, clover, beans, etc. — and in- 
troduce just enough water to maintain a saturated vapor. Set both bottles in 
a window. Twice a day for a week, pass through one saturated ether 



CHLOROFORM. II 

vapor, through the other air. The seeds in both will swell from the ab- 
sorption of the water, but only the seeds in the bottle with pure air intro- 
duced will grow. Reverse the two. The sprouting grain will have its 
growth checked and the etherized seeds will begin to grow. 

9. Ether on the yeast. Take two fermentation tubes of active yeast 
culture, add 2 c.c. pure ether to one. Note the relative rate of gas liberation. 

CHLOROFORM. 

List of Experiments Illustrating the Effect of Chloroform. page. 

1. On the frog. 11 

2. On the heart strip. 11 

3. On the frog's heart. 11 

4. On the mammalian heart. 12 

5. On muscular irritability. . 12 

6. On nerve irritability. 12 

7. On the blood-pressure and respiration of a mammal. 12 

8. On the kidney secretion. 14 

9. On germinating seeds. 14 

1. Chloroform on the frog. Inject 0.06 c.c. of pure chloroform 
or 0.3 c.c. of 20 percent chloroform in oHve oil into the dorsal lymph 
sac or into the abdopiinal cavity of a frog. The anesthesia is more pro- 
found and the reco^'ery less rapid than in the case of ether. Determine the 
relative intensity of action of chloroform and ether by your own experiments. 

2. Chloroform on the heart strip. Proceed as with ether in ex- 
periment 2, page 6, using a 0.05 percent solution of chloroform in 0.7 percent 
saline for one to three minutes. The contractions cease almost at once. 
Recovery in saline takes place very slowly. In comparison with ether the 
period of anesthesia is long. The amplitude of the first contractions to 
reappear is very slight and the recovery rate slow and irregular. The 
original character of activity is not restored within 20 to 40 minutes. Re- 
peat using a solution of o.i percent chloroform. 

An instructive picture is given by parallel records of experiments on 
strips from the same heart showing the effects of 4 percent ether and of 
o.i percent chloroform for two minutes, both in saline. 

3. Chloroform on the frog's heart. Proceed as in the siinilar ex- 
periment with ether, page 7, using 0.5 percent chloroform in physiolog- 
ical saline to irrigate the outer surface of the heart. Or perfuse the heart 



12 



EXPERIMENTAL PHARMACOLOGY. 



bo o <N 

■2 S <„ 



(U <4-( XI 



g g « 



with 0.05 percent chloroform in saline 
through the vena cava. Care must be 
used not to prolong the action of the drug. 
The amplitude is reduced to one-half and 
the rate markedly slovi^ed or entirely sup- 
pressed. Both rate and amplitude are 
recovered, but not so quickly as with ether. 

4. Chloroform on the mammalian 
heart. Determine the action of chloroform 
on the isolated cat's heart, using the method 
described for the alcohol experiment 4, 
page 3. Perfuse the heart with chloro- 
form 0.02 to 0.05 percent in the Locke- 
blood. The chloroform perfusion must be 
for short periods and be guarded closely. 

5. Chloroform on the muscular 
irritability. See ether experiment 5, page 
3. Use o.i percent chloroform water 
in the vapor apparatus. Care must be 
taken to remove the saturated chloroform 
vapor from the vapor apparatus just before 
using, otherwise the muscle, or the nerve 
in the next experiment, will be over anes- 
thetized and will not recover its irritability. 
There is no danger with ether from this 
cause. 

6. Chloroform on the irritability of 
the nerve. Repeat ether experiment 6. 
Use o.i percent chloroform water in the 
vapor apparatus. 

7. Chloroform on the blood- 
pressure and on the respiration of a 
mammal. Proceed as with ether experi- 
ment 7, page 4, using chloroform to anes- 
thetize the dog or cat (rabbits are too 
sensitive to chloroform for use in this ex- 
periment except in practiced hands). Re- 
member that chloroform is said to be 
about forty times as strong as ether in its 



CHLOROFORM. 



13 



general effects on the animal body. If the vagi are intact and the animal 
is anesthetized without tracheotomy there will be marked slowing of the 
heart rate together with a sharp fall of blood-pressure. This effect is 




Fig. 7. — Chloroform perfusion of the frog's heart. Ringer's solution used for the 
normal, o.i percent chloroform between "on" and "off." Perfusion pressure 
4 cm. Record from the suspended apex. Time in seconds. 

eliminated by section of the vagi. With extreme care chloroform anesthesia 
may be pushed to the point where respirations cease, and the animal be 
recovered without artificial respiration. Often, however, in 5 to 10 seconds 



Fig. 8. — The effect of chloroform on the irritability of the nerve in the muscle- 
nerve preparation. The first two contractions represent the normal amplitude upon 
stimulating the nerve of a preparation mounted in a moist chamber. The muscle was 
allowed to hang through the opening in the floor of the moist chamber, so as to protect 
it from chloroform vapor. At the point indicated by the word "on" chloroform vapor 
was driven through the moist chamber. The nerve was stimulated at regular inter- 
vals until no further contractions occurred. The chloroform was next removed 
with moist air and the stimulations continued. After a short interval contractions 
gradually resumed until they reached their normal maximum. 

after respirations cease, the blood-pressure will suddenly sink to a low 
level, and the heart will become weak and slow (see experiment 8 below). 



14 EXPERIMENTAL PHARMACOLOGY. 

a state from which recovery can be secured only by rapid and vigorous 
artificial respiration. 

Give chloroform intravenously in doses of lo to 20 c.c. of 0.5 percent 
solution in saline, allowing plenty of time for recovery in each test. Com- 
pare with alcohol and ether. 

8. Chloroform on the secretion of the kidney. Anesthetize a dog 
with morphine, i c.c. of i percent, and chloroform, avoiding deep anesthesia 
during the preliminary preparations. Insert a ureter canula and connect 
it with a horizontal glass tube mounted on a graduated scale, or see methods, 
page 70. Take a continuous record of the arterial pressure. 

Now determine the normal rate of secretion of urine per 10 minutes 
for at least 40 minutes, keeping the dog under light but constant anesthesia. 
Inject intravenously 10 c.c. of 0.5 percent chloroform solution in saline. 
Double the dose if necessary until profound anesthesia with low blood- 
pressure and weak heart is obtained. Or produce deep anesthesia by means 
of the respiratory inhalations. Recover and maintain light anesthesia for 
an hour or more. The circulation is quickly re-established in good condi- 
tion, hilt the secretion of urine which is suppressed during the stage of 
deep anesthesia is more slowly brought up to the normal with the re-establish- 
ment of good circulation. 

9. Chloroform on germinating seeds. Repeat the experiment 
described for ether, page 11, passing air from saturated chloroform water into 
one bottle of seed, and pure air into the other. After the seeds in air have 
sprouted, reverse the bottles. Both seeds and young growing plants are 
anesthetized by chloroform. The seeds may not grow later, as the drug kills 
plant protoplasm when given beyond a rather narrow limit of both time 
and concentration. 

CHLORAL HYDRATE. 

Experiments Showing the Effects of Chloral Hydrate. page. 

1. On the frog. . 14 

2. On the rabbit or cat. . . 15 

3. On the heart of the frog. . . 15 

4. On the heart muscle. . 15 

I. Chloral hydrate on the frog. Give a hypodermic injection of 
0.5 c.c. of 2 percent chloral hydrate dissolved in 0.7 percent saline. 
Keep the animal in a moist battery jar until complete recovery. Give 
particular attention to the effects on the circulatory and the nervous systems. 



THE OPIUM SERIES. 1 5 

2. Chloral on the rabbit or cat. Give a hypodermic injection of 
2 c.c. of 2 percent chloral hydrate per kilo of body weight in saline. 
Repeat in sixty minutes if necessary to produce the chloral narcosis. Make 
close comparison with the effect of morphine and strychnine. 

3. Chloral hydrate on the frog's heart. Pith a frog and take trac- 
ings of the ventricle when irrigated over the surface with i percent chloral 
hydrate. Or perfuse the heart with 0.2 percent chloral hydrate in 
Ringer's solution and take tracings of the ventricle by the method described 
on page 69. Note that the recovery period is unusually long. 

4. Chloral hydrate on heart muscle. Prepare a ventricular strip 
of the terrapin and establish contraction in a bath of 0.7 percent sodium 
chloride as usual. Change to a bath of o.i percent chloral hydrate 
in sodium chloride. Stronger solutions may suppress the rhythm entirely. 

THE OPIUM SERIES. 

Experiments Illustrating the Effects of Morphine, Codeine and The- 
baine. page. 

1. On the frog. 15 

2. On the mammal. 15 

3. On ventricular muscle. 16 

4. On the frog's heart. 18 

5. On the mammalian heart. 18 

6. On the reflex reaction time. . 18 

7. On the volume of air breathed. ... 18 

8. The morphine group on the circulation and respiration in 

the mammal. 18 

1. Morphine on the frog. Give a dose of i c.c. of 2 percent mor- 
phine acetate in physiological saline in the dorsal lymph sac. Keep the 
animal under observation for two or more hours to secure the later efiects 
in the frog. An instructive comparison is had by giving a dose of 0.5 c.c. 
(8 minims) of o.i percent strychnine nitrate to a second frog at the same 
time. Keep the frog under observation until complete recovery. 

Give a second frog an injection of i c.c. of i percent codeine in phy- 
siological saline. Compare with morphine. 

The dose of thebaine for the frog is i c.c. of i percent. 

2. Morphine on the mammal. Give a hypodermic injection of 1.5 
c.c. of 2 percent morphine under the skin of the shoulder, see anes- 



i6 



EXPERIMENTAL PHARMACOLOGY. 




thesia, p. 65. Keep the animal 
under observation for at least 
two hours and note at intervals 
the temperature, irritability, 
respiratory, ocular, and other 
changes under the influences of 
the drug. If vomiting is pro- 
duced a concentrated watery ex- 
tract of the vomit will show the 
presence of morphine, thus 
demonstrating that excretion of 
morphine takes place into the 
stomach. 

3. Morphine on the ven- 
tricular muscle. Prepare a 
strip of the ventricle of a terrapin 
and get it into regular contrac- 
tions by a bath of 0.7 percent 
sodium chloride. Change the 
strip to a bath' of i percent 
morphine in sodium chloride 
for five minutes, or until a 
marked change in the rate and 
amplitude of the contractions 
occurs, after which the strip 
should be returned to saline. 
Record the contraction on a 
smoked drum moving with a 
speed of I to 2 mm. a second. 
This experiment shows that the 
contractions of cardiac muscle 
are weakened and slowed under 
morphine. Repeat, varying the 
conditions according to the re- 
sults of the previous experiment. 
A stronger solution of morphine 
will inhibit all heart muscle 
activity for many minutes or 
even hours. The proper 
strength of codeine for this 



THE OPIUM SERIES. 



17 




lo EXPERIMENTAL PHARMACOLOGY. 

experiment is, 0.5 percent, in physiological saline, of thebaine about i 
percent soliition. V ' ^ i'" 

4. Morphine on the f fog's heart. PitH at fi-og, expose tKe heart 
and take a record of' its contrafetions, either by the perfusion or by, the sus- 
pension method. Test the irritability of the vagus' t^unk. If the circulation 
is still effective give, a lymph saC injection of 0,5 c.c. of 10 percent mor- 
phine acetate of apply drops ol this solution directjy to the heart from the 
dropping bottle. Retest the effectiveness of thei Vagus stiniulation. - If the 
heart is perfused, the effective solution to use is 0.5 percent of morphine 
acetate in Ringer's solution. ; ' 

5. Morphine on the mammalian heart.— Etherize a cat, collect its 
blood and isolate its heart as described in alcohol experiment 4. Fill the 
tubes of the mammalian heart perfusion apparatus, bring the apparatus to a 
temperature of 36° C, adjust the heart in it and begin the normal perfusion. 
When the heart is contracting with a regular and relatively even rhythm 
perfuse it for two minutes with 0.5 percent morphine in Locke-blood solu- 
tion. Repeat the experiment using i percent solution. If the perfusion 
is too prolonged the heart depression will be removed only with the greatest 
difficulty. 

6. Morphine on the reflex reaction time. Test the reaction time 
in a reflex frog in the usual way, see methods page 71, first on the normal 
animal, then 20 and 40 minutes after a dose of i c.c. of 4 percent morphine 
acetate. 

7. Morphine on the voltmie of air breathed. Anesthetize a rabbit 
(or cat) with two grams urethane and ether, administering the latter at 
perfectly regular intervals and with a constant number of drops. Keep a 
continuous record of the respiration rate per minute either by counting or by 
recording on a smoked drum. Measure the respiration volume as follows: 
Insert a tracheal canula and connect it with an apparatus for measuring the 
volume of expired air. Ether can be given through the open' tube of the 
apparatus except when actually 'measuring the air volume. Fill the grad- 
uated cylinder with water. Then measure the voliime of eight or ten expi- 
rations, according to the volume of the apparatus used, and repeat several 
times to secure reliable averages, of the expiratory volume of the etheriz;ed 
animal. Compute the expiratory volume per minute. Now give i c.c. of 
2 percent morphine hypodermic. Remeasure the respiratory rate and 
expiration volume at intervals of 10 minutes. 

8. The morphine group on the circulation and on respiration in 
the mammal. Anesthetize a dog with chloroform (no morphine), take the 



THE OPIUM SERIES. I9 

blood-pressure from the carotid, insert a tracheal canula and take the 
respiration by the intratracheal method. Insert a canula into the saphen- 
ous vein and connect with a buret for intravenous injections. (One may 
readily insert a canula into the ureter and follow the secretion of urine 
under the morphine. Consult the instructor.) 

Give an intravenous injection of 2 c.c. of 2 percent morphine in saline. 
The injected solution should be about the temperature of the body. Repeat 
after ten minutes, using 4 c.c. When equilibrium is reestablished give 
2 c.c. of I percent codeine. Give 2 c.c. of i percent thebaine. Give 
thebaine first if there is an opportunity to make the test on a second animal. 
Now cut the vagus nerves and repeat the dose of 2 c.c. of 2 percent 
morphine. 

The anesthetic must be gradually diminished according to the amount 
of morphine, etc., that has been injected. Use artificial respiration if 
necessary. 



20 EXPERIMENTAL PHARMACOLOGY. 



CAFFEINE. 

Experiments Illustrating the Effects of Caffeine. page. 

1. On the frog . . .... 20 

2. On the ventricular muscle . . 20 

3. On the frog's heart . . .20 

4. On muscular irritabiUty and on muscular work. . 21 

5. On voluntary work of human muscle . . .21 

6. On the reaction time in man . 22 

7. On the reflex reaction time in the frog. . . 22 

8. On the mammalian heart . . . . . . 23 

9. On the circulation and respiration in the mammal 23 
10. As a diuretic . . 24 

1. Caffeine on the frog. The dose is i,c.c. of 0.5 percent caffeine 

in the dorsal lymph sac. There is usually a great increase in the irritability 
together with muscular cramps in the later stages, and finally paralysis. 
There may be considerable opisthotonus from the direct muscular effects at 
the area of injection. Note the recovery stages when the frog is kept in a 
moist battery jar. 

2. Caffeine on the ventricular muscle. Record the contractions of 
a strip of terrapin's ventricle beating in physiological saline on a slow-speed 
drum. Change the strip from saline to o.i percent caffeine in saline for 
five minutes or less, then back to saline until the contractions become uni- 
form and typical of the saline curve. Repeat, varying the tim'ig of the 
immersion in the drug. Increase the strength of the solution to 0.5 per- 
cent. Ref. — Lingle; Am. Jour. Physiol., VIII, 75. 

3. Caffeine on the frog's heart. Expose the heart of a pithed frog 
and adjust a balanced lever on the ventricle. Irrigate the surface of the 
heart with physiological saline from a dropping bottle for a few minutes, then 
change the irrigating fluid to i percent caffeine in saline for five minutes, 
after which return to saline irrigation. Repeat once or twice, then apply 
caffeine continuously until the maximum effect is obtained. Compare 
especially the auricle with the ventricle in the later stages of the caffeine 
effect. 

When the heart is perfused through one of the veins then the solution 
of caffeine should not be stronger than o.ixto 0.2 percent, and the record 



CAFFEINE. 



21 



should be taken by the apex suspension method. This method yields the 
more accurate results. 

4. Caffeine on muscular irritability and muscular work. Lay 
a tight ligature around the thigh of a frog to close off the circulation in one 
leg. Give a dorsal lymph sac or abdominal injection of i c.c. of 0.5 percent 
caffeine. Allow twenty minutes for absorption, then pith the frog and 
ligate off the caffeinized gastrocnemius. Determine the irritability by 
the minimal stimulus method and, second, determine the amount of 
work the muscle will do when stimulated directly once in two seconds 




Fig. 12. — Action of caffeine on the ventricular muscle of the terrapin. Between 
the marks X-X the strip was immersed in 0.5 percent caffeine in saline. Before and 
after the caffeine the strip contracted in normal saline. 



until completely fatigued. Use a constant load of 50 grams in this experi- 
ment. Prepare first the normal gastrocnemius as quickly as possible and test 
its irritability and the amount of work it will do with uniform load and 
method of stimulation. Repeat the irritability test and the determination 
of work using the caffeinized muscle. If the records are taken on the 
same recording paper, one above the other as in experiment 5, page 3, 
the comparison is very sharp. 

5. Caffeine on the voluntary work of human muscle. Measure 
the amount of work of the flexors of the middle finger by means of a Mosso's 
ergograph while lifting a 3 to 4 kilo weight, one that exhausts the muscle in 
about 50 contractions. Repeat in thirty minutes. Consider these as 
normals. Take two cups of strong coffee or 0.3 gram of caffeine in 
sweetened warm water. Remeasure the work of the flexors as directed 



22 



EXPERIMENTAL PHARMACOLOGY. 



above 60 and 90 minutes after taking the caffeine. The amount of the 
muscular work is usually markedly increased by caffeine. See the next 
experiment. 

6. Caffeine on the reaction time in man. Arrange a tuning fork 
vibrating one hundred times per second and a set of signal keys for measur- 
ing the reaction time to touch. (For details see directions in StirHng's 
Practical Physiology, page 325.) Determine the normal reaction, then the 
reaction time at 30, 60, 90 and 120 minutes after a dose of 0.3 gram 




Fig. 13. 

Fig. 13. — Caffeine effect on the amount of work of the gastrocnemius of the frog. 
The upper tracing is the normal, the lower the opposite muscle after the absorption of 



caffeine in water. This experiment may be performed together with the 
preceding. 

7. Caffeine on the reflex time in a frog. Prepare a reflex frog 
by destroying the brain and the medulla. After the shock has passed away 
determine the reflex reaction time to electrical stimuli applied to the toe of 
the suspended frog. This time is easily recorded by a paper writing point 
attached to some part of the foot itself. Give a dose of i c.c. of 0.5 percent 
caffeine in the dorsal lymph sac. After 30 minutes redetermine the reflex 
time. Draw conclusions from averages here, as the error of procedure is 
high. 



CAFFEINE. 



23 



8. Caffeine on the mammalian heart. Etherize a cat, bleed it, 
and dilute the blood with Locke's solution as in the alcohol experiment 4. 
Prepare the apparatus and raise its temperature to 36° C. Isolate the heart 
and quickly insert it in the cardiograph and start the circulation of the 
Locke-blood solution. When the rhythm is regular, perfuse with o . o 2 to 0.2 
percent caffeine in Locke-blood solution. It is better to begin with a 
weaker perfusion solution of caffeine and increase the strength through two 
or three grades, say from o.i to 0.5 percent. 




Fig. 13 (Continued). 

The stimulus was repeated at regular intervals once in two seconds until exhaustion. 
0.5 c.c. I percent caffeine. 



9. Caffeine on the circulation and respiration of the mammal. 

Give a dog a hypodermic of i c.c. of 2 percent morphine and anesthetize 
with chloroform. Tracheotomize. Take the arterial blood-pressure from 
the carotid and the respiratory pressure from the trachea. Insert a canula 
in the saphenous vein for intravenous injections. Take records on the 
continuous paper kymograph. After securing a normal record of both the 
blood-pressure and the respiration give an intra veous injection of 5 to 10 c.c. 
of 0.5 percent caffeine in physiological saline. Give slowly from a warmed 
buret. This experiment should begin with the small doses and the doses be 
gradually increased. See the next experiment on diuretic action. 



24 EXPERIMENTAL PHARMACOLOGY. 

10. Caffeine as a diuretic. Prepare a dog as in the preceding experi- 
ment. Take the blood-pressure and the respiratory rate. Insert a caiiula 
for venous injections. Open the abdomen in the median line, seek out one 
ureter near its connection with the bladder, ligate and insert a urethral 
canula, taking care to make an unobstructed connection. After the flow 
of secretion has been established, a 2 to 3 mm. rubber tube is connected with 
the canula and the abdominal opening sewed up. Connect the rubber tube 
with a I c.c. pipet graduated in o.i c.c. Mount the buret horizontally. 
Read the rate of secretion by injecting a small bubble of air each five min- 
utes into the rubber tube at its connection with the buret. 

Determine the rate of secretion under constant anesthesia both before 
and after 5 to 10 c.c. of 0.5 percent caffeine. Take readings every five 
minutes for a period of about two hours. 

STRYCHNINE. 

List of Experiments Showing the Effects of Strychnine. page. 

1. On the frog ... . .24 

2. On a mammal, demonstration .... . . 24 

3. On the ventricular strip ... -25 

4. On the frog's heart and cardiac nerves 25 

5. On the irritability and work of voluntary muscle .... 26 

6. On reflex irritability and reaction time. . . . . 26 

7. Local action on the spinal cord . 26 

8. Spasms depend upon cutaneous stimulation 27 

9. Absorbed slowly from the stomach or bladder and readily 

from the intestine or peritoneum . . 27 

10. Stored in the spinal cord 27 

11. On the mammalian heart 28 

12. On the blood-pressure and respiration rate of mammals. 28 

1. Strychnine on the frog. Give a frog a toxic dose of strychnine 
nitrate, 0.3 c.c. (5 minims) of o.i percent. Give in the dorsal lymph sac. 
Note the time of the appearance and the successive stages of increased 
irritability, convulsions, and paralysis. Take fresh frogs and determine the 
limits of the therapeutic or non-toxic dose, i.e., determine the dose per gram 
of body weight that will just fail to produce convulsions. 

2. Strychnine on the mammal. Demonstration. Give a rabbit a 
hypodermic injection of 0.4 c.c. of 0.1 percent strychnine nitrate per 



STRYCHNINE. 25 

kilo of body weight. Consult Cushny's Pharmacology for symptoms. 
Meltzer gives the toxic dose for rabbits as 0.5 mgr. per kilo. Reference, 
Am. Jour. Physiol., Volume IX, page i. 

3 . Strychnine on the ventricular strip. Suspend a strip "of terrapin's 
ventricle in physiological saline and, when it is contracting regularly, subject 
it to a bath of o.i percent strychnine nitrate in saline for five minutes. 
Return the strip to physiological saline until the contractions are unques- 
tionably of the saline type. The rhythm and amplitude are both reduced. 




Fig. 14. — Action of strychnine solution on the ventricular muscle of the terrapin 
In trace a the strip was contracting in physiological saline. At the vertical arrow it 
was transferred to 0.5 percent strychnine. The contractions are gradually slowed and 
weakened. Tracings b to g are successive records around a six-inch drum during the 
recovery which is very prolonged in this experiment. 

4. Strychnine on the heart and cardiac nerves. Pith a frog, expose 
the heart, take a direct tracing of the movements of the ventricle. Test 
the vagus activity by stimulating the vago-sympathetic trunk with a current 
that produces complete inhibition. Next irrigate the surface of the heart 
from a dropping botde with o.i percent strychnine nitrate in physiological 
saline. While continuing the irrigation stimulate the vagus trunk at inter- 
vals of 5 to 10 minutes. Look for a progressive effect on the beat, the rate, 
and on the cardiac nervous mechanism as demonstrated by th€ results of the 
stimulation. 



26 



EXPERIMENTAL PHARMACOLOGY. 



5. Strychnine on the irritability and work of voluntary muscle. 

Ligate the thigh of one leg of a frog to occlude its circulation, give a dose 
of 0.2 c.c. of o.i percent strychnine nitrate. In twenty minutes ligate 
off the other leg, pith the frog (pith immediately if tetanic contractions 
appear earlier), and determine the irritability of the normal and of the 
drugged gastrocnemii by the minimal stimulus method. 

Follow the above test by measurement of the work the muscles will 
do, testing first the normal, and second, the strychnine muscle. Use the 
method described for experiment 5 under alcohol. The irritability and 
the work of voluntary muscle are both greatly increased in the therapeutic 
stage, in sharp contrast to the effect of strychnine on heart muscle. 



St^.l(^r »n, 



m 



iiimaauLiuuuiLi 



I O ,3 C - 0,X.J- H Q 






■ Son -t-Cof/r/r! -J/Zi/oJi 



Fig. 15 — Showing the action of strychnine on the muscular work and on amplitude 
of the single contractions in the frog's gastrocnemius. The lower series is of the normal 
muscle, the upper of the strychninized muscle. The dose was 0.25 c.c. of o.i percent 
strychnine hydrochloride injected into the dorsal lymph sac, after ligation of one leg at 
the thigh. Absorption was allowed until the first spasms when the frog was pithed. 
Weight of frog 40 grams. Load 200 grams. One stimulus in three seconds. 



6. Strychnine on reflex irritability and reaction time. Prepare a 
reflex frog, i. e., destroy only the brain including the medulla. After the 
shock has passed away, one hour or more, determine the reflex reaction time 
to electrical stimulation of the toe by the method given on page 71. Now 
give 0.5 c.c. (8 minims) of 0.02 percent strychnine nitrate. After each 
ten minutes take the reaction time to electrical stimulation until spasms 
appear, which ought to be under 60 minutes. 

7. Local action of strychnine on the spinal cord. Cut the cord of a 
frog at the base of the medulla and destroy the brain. Free the cut end of 
the cord from the surrounding tissue, and carefully paint it with i percent 
strychnine nitrate solution. Muscular spasms will be produced or will 
follow stimulation of the toes of the fore leg. Or stimulate the toe of the 



STRYCHNINE. 



27 



hind leg — reflexes of an orderly nature occur, where no general tetanic con- 
vulsions have been induced by the dose. Pith the cord, all spasms cease. 

8. Strychnine spasms depend also upon cutaneous stimulation. 
Strychninize a frog and when the spasms are strong and continuous paint 
the skin with a 2 percent cocaine solution. The cocaine paralyzes the 
cutaneous sensory apparatus whereupon the convulsions cease. Dip the 
frog in water to remove the excess of cocaine, its local effect will disappear 
in about 10 minutes and the strychnine convulsions will reappear. 

9. Strychnine is absorbed very slowly from the stomach or blad- 
der, but very readily from the intestine and body cavity. Anesthetize 
a half-grown fasting cat. Ligate both the cardiac and the pyloric orifices 



mm\wmi^\ 



m\WMmBW^i^k'^M^mMm^^M^^ 



mmmm 



ton ■OlJ.Sir-ycknins in Locke-Blocl 



I [ I I 1 I I 1 I 



CZC^. -C.i.,4,M. 



Fig. 16. — Strichnine on the isolated mammalian heart. The heart was perfused 
with Locke's solution containing 10 percent of the animal's own blood. Between the 
points marked on and of, a total of 50 seconds, the heart was profused with o.oi percent 
strychnine hydrochloride. The stock solution of the drug had been carefully neutralized 
to eliminate any trace of acid effects. Temperature 34° C. Time in seconds. 



of the stomach. Inject 10 c.c. of o.i percent (10 mgrs.) of strychnine 
nitrate into the stomach. If no spasms occur in 30 minutes then cut the 
pyloric ligature apd run the stomach content into the intestine. Spasms 
may be looked for in two minutes or less. If enough strychnine is absorbed 
from the stomach to produce muscular spasms repeat the second half of the 
experiment on a second animal, injecting the drug directly into a portion of the 
intestine. 

Compare absorption from the urinary bladder and from the abdominal 
cavity in the same manner. 

10. Strychnine is stored in the spinal cord (Lovett, Jour. Physiol., 
Volume I, p. 99). Inject 10 mgs. strychnine nitrate into the dorsal 
lymph sac of a large bull frog. Allow 30 minutes for absorption. Then 
remove the skin and wash away all traces of strychnine that may re- 



28 EXPERIMENTAL PHARMACOLOGY. 

main unabsorbed. Take the cord, also an equal amount of other tissue, 
macerate each in 0.7 percent saline. Inject equal portions of the extracts in 
the dorsal lymph sacs of two frogs. Allow hours, if necessary, for the symp- 
toms to develop. This method will detect traces of strychnine too small for 
chemical identification. 

1 1 . Strychnine on the mammalian heart. Arrange the apparatus 
for the isolated mammalian heart, bring it to a temperature of 34° to 36° C. 
Anesthetize a cat or rabbit with ether, bleed and defibrinate the blood and 
dilute it to ten volumes with Locke's solution. Quickly cut out the heart, 
insert the canula into the aorta and ligature it, attach the cardiograph, and 
start the perfusion of Locke-blood solution. Perfuse with 0.005 percent 
strychnine hydrochloride for 30 secods. The dose may be increased to 
o.oi or even 0.02 percent but recovery from the latter is very slow and 
gradual. 

12. Strychnine on the blood-pressure and on the respiration rate 
of mammals. Anesthetize a lo-kilo dog. Take a continuous record of the 
blood-pressure from the carotid and of the respiration rate from the trachea. 
Give an injection of i c.c. of o.i percent solution of strychnine nitrate 
from a hypodermic into the saphenous vein. One should give close atten- 
tion to the symptoms of this mild dose which will produce little more than 
the therapeutic effects. Repeat this injection until the cumulative dose pro- 
duces convulsions of a mild character. Note that the convulsions may be 
suppressed here by giving more chloroform. Give especial attention to the 
blood-pressure conditions during the tetanic spasm, so as to eliminate the 
strictly passive mechanical factors. 



COCAINE. 



29 



COCAINE. 

List of Experiments Showing the Action of Cocaine. 

1. On the frog. ... 

2. On local sensory surfaces. 
On the heart muscle. 
On the frog's heart. . 
On muscle work. . . 



3- 
4- 

5- 

6. On the circulatory and respiratory systems of the mammal 



PAGE. 

29 
29 

30 
30 
30 
31 



1. Cocaine on the frog. Give a frog a dorsal lymph sac injection 
of 0.4 CO. of 0.5 percent solution of cocaine hydrochlorate in physio- 
logical saline. Observe the symptoms in the usual way. Also examine 
the vifhite corpuscles of the blood for motility ais compared with the unpoisoned 
frog. 

2. Cocaine on local sensory surfaces. Paint one-half the surface 
of your own tongue with a brush wet in 2 percent solution of cocaine 




Fig. 17. — Cocaine effects on the frog's heart when perfused in o.ooi percent 
Ringer's solution. Time in seconds. 

hydrochloride. Use care not to swallow any of the solution. In 8 to 10 
minutes compare the sensitiveness of the two halves of the tongue to electri- 
cal currents by the minimal stimulus method. Test for taste sensations of 
sweet, of salt. Note also the personal sensations of any character result- 
ing from the experiment. 

Give one drop of i percent cocaine in the right eye; repeat in 
three minutes. There is a loss of sensitiveness and the eyeball may be 



30 EXPERIMENTAL PHARMACOLOGY. 

touched without pain. Compare the pupils as to size, as to reaction to 
light. Determine the acuteness of vision of each eye separately at the read- 
ing distance. Cocaine is an analgesic, but not a perfect mydriatic. 

3. Cocaine on the heart muscle. Prepare a strip of terrapin's 
ventricle and vs^hen it is beating in physiological saline in good rhythm 
submit it for from three to five minutes to a bath of o.oi percent cocaine in 
saline. Record the contractions on a slow drum. 




Fig. 18. 
Fig. 18. — Effect of cocaine on the muscular work of the frog's gastrocnemius. 

4. Cocaine on the frog's heart and its nervous mechanism. Pith 
a frog, expose the heart. Take a continuous record of its contractions by 
the usual method. Irrigate its surface with physiological saline. Test the 
irritability of the vagus trunk using a medium strength stimulus. Now 
irrigate the heart for one minute with 0.2 percent cocaine in saline followed 
by saline. When the cocaine contractions have somewhat recovered, retest 
the inhibitory power of the vagus. Repeat the test,using two or three 
drops of I percent solution, and do not wash it off afterward. 

Perfuse the heart with 0.002 percent solution of cocaine in Ringer's 
weaker solution. This method gives more constant results than does the 
irrigation and it is to be preferred. 

5. Cocaine on muscle work. Ligate one leg of a frog at the thigh, or 
use the method described under alcohol. Give a dose of 0.4 c.c. (7 minims) 
of 0.5 percent cocaine in the dorsal lymph sac. Allow 20 minutes for 
absorption then ligate the cocainized leg. Load with a 50-grain weight. 



COCAINE. 31 

Take records of the contractions of the normal muscle on a drum with a 
speed of i mm. per second. Stimulate with single break induction shocks 
once in two seconds until exhausted. Prepare the cocainized gastrocnemius, 
mount and stimulate with the same rate and load. If the two records are 
parallel on the same paper, see figure 18, it will demonstrate the comparative 
difference in work done. Calculate the amount of work per gram of muscle 
in each of the two preparations. 



^ 



Fig. 18 (Continued). 
The endurance of the cocainized muscle is greatly increased. 

6. Cocaine on the circulatory and respiratory systems of the 
mammal. Give morphine and chloroform to a dog. Insert a tracheal 
canula. Take the blood-pressure and respiratory records on the continuous 
paper kymograph. Insert a canula and connect a buret with the saphenous 
vein. Inject 2 c.c. of i percent cocaine very slowly while watching 
the blood-pressure as an indicator. 



32 



EXPERIMENTAL PHARMACOLOGY. 



QUININE. 

Experiments on the Effect of Quinine. 

1. On the frog. . . . . 

2. On the frog's heart. 

3. On the striated muscle . . . 



PAGE. 

32 
32 
32 



1. Quinine on the frog. Inject i c.c. of o.i percent solution of 
hydrochlorate of quinine into the dorsal lymph sac. In addition to the 
usual observations, examine the blood of this frog as regards the motility 
of the white corpuscles. Compare with the blood of a normal frog. 

2. Quinine on the frog's heart. Pith a frog, expose the heart, and 
take a record of its contractions with physiological saline while perfusing 
it from a perfusion bottle. Change the Ringer's fluid to 0.05 percent 
quinine hydrochlorate in Ringer for about one minute. Repeat after 




Fig. 19. — Action of quinine on the frog's heart. The perfusion method was used. 
Normal rate with Ringer's solution. Strength of quinine 0.05 per cent. Timei in 
half minutes. 

recovery, using' i percent quinine. Continue this perfusion until no further 
contractions are secured. Examine the condition of the ventricle at the close 
of the experiment. 

Vary this experiment by pithing the frog, taking care to lose little blood 
and making a record from the ventricle.- Now give a lymph sac injection 
of I c.c. of I percent quinine and take a continuous record through 20 to 
30 minutes. 

3. Quinine on the striated muscle. Ligate one leg of a frog at 
the thigh, inject i c.c. of o.i percent quinine into the dorsal lymph sac. 
In just 20 minutes ligate off the other leg and pith the frog. Determine 
the irritability, first of the normal then of the drugged muscle. Determine 
the work each gastrocnemius will do. 



ATROPINE. 



33 



ATROPINE. 

Experiments Showing the Action of Atropine. page. 

1. On the frog . 33 

2. On the heart muscle 33 

3. On the frog's heart and on the cardiac nervous apparatus . 34 

4. On the secretory nerves of a mammal 34 

5. On the isolated heart of the cat . . -35 

6. On the circulatory and respiratory systems of the mammal . 35 

7. On the eye 36 

8. On man in the therapeutic dose 36 

9. As secreted by the kidney 36 
10. Scopolamine on the frog . 36 

I. Atropine on the frog. Give a frog an injection of i c.c. of i 
percent of atropine sulphate. Keep it under observation in a moist 
battery jar until complete recovery. The toxic dose is i c.c. of 3 percent. 




Atropine -001^ i^^ 



Fig. 20. — Action of atropine on the heart muscle of the terrapin's ventricle. 
The normal solution is sodium chloride, the strength of atropine o.ooi percent. The 
decrease in amplitude is usually not so great as in this tracing, or is even absent entirely 
Time in seconds. 



2. Atropine on the heart muscle. Mount a ventricular strip from 
the terrapin in 0.7 percent sodium chloride, and when it is contracting with a 
uniform amplitude and regular rhythm change to o.ooi percent atropine 
in physiological saline for five minutes, see figure 17. Recover the charac- 
teristic rhythm in saline and repeat using 0.002 percent atropine in saline. 
3 



34 



EXPERIMENTAL PHARMACOLOGY. 



3. Atropine on the frog's heart and cardiac nervous apparatus. 

Pith a frog, expose the heart and take a tracing. Determine an effective 
strength of stimulus for the vagus. Now irrigate the heart for one minute 
from a dropping bottle containing o.i percent atropine in saline. Stimu- 
late the vagus immediately and once every five minutes or less. Atropine 
eliminates the vagus control of the heart by poisoning the peripheral endings. 
The atropine effect is antagonized by physostigmine, page 44, experiment 3, 
and by muscarine. 

4. Atropine on the secretory nerves of a manunaL Anesthetize 
a 10 jkilo dog with morphine and chloroform. Expose and tie a canula in 




Fig. 21. 

I Fig. 2j:. — Action of atropine on the isolated heart of the cat. Locke-blood solution 
the arrows was .001 percent. Temperature 39° C. Pressure 85 cm. of water. The 

the subinaxillary' duct. Expose and stimulate the chorda tympani nerve 
in the hilus of the gland, noting the rate of secretion by the drops of saliva 
per minute from the canula. Give a hypodermic injection of 1.5 c.c. of 
I percent atropine. Stimulate the chorda tympani nerve again. No 
secretion is obtained even though the nerve is stimulated down close to the 
hilys of the gland. 

This demonstration may be made in part as follows: Produce a rapid 
flow of saliva in the dog by a hypodermic of i c.c. of 0.2 percent pilocarpine. 
Observe the .flow by turning out the dog's upper lip. Follow with a hypo- 
dermic dose of I c.c. of I percent atropine. The secretion stops. 



ATROPINE. 



35 



5. Atropine on the isolated heart of the cat. Anesthetize a cat 
with ether. Bleed it and prepare the Locke-blood perfusion fluid. Isolate 
and suspend the heart in the perfusion apparatus. Obtain a normal record 
then perfuse with .001 percent atropine in Locke-blood solution. 

6. Atropine on the circulatory and respiratory systems in the 
mammal. Anesthetize a lo-kilo dog as in experiment 4 preceding. Place 
an arterial canula in the carotid and insert a tracheal canula. Take a con- 
tinuous record of the blood-pressure and of the respiration. Stimulate the 
peripheral end of the sectioned vagus with a stimulus that produces complete 
inhibition of the heart. Stimulate also the central end of the vagus. Now 




was used for the normal perfusion fluid, 
time in seconds. 



Fig. 21 (Continued). 

The strength of atropine perfused between 



give an intravenous injection of i c.c. of o.i percent atropine. Note 
the exact time of the injection on the record by a signal pen. When the 
equilibrium is again established, re-stimulate the ends of the sectioned vagus 
with the same strengths of stimulus used before atropine was given. Note 
that the heart rate is no longer slowed on stimulation of the peripheral 
vagus, but that the pupil still actively dilates after this dose when the 
central end of the vagus trunk is stimulated. Atropine also destroys the 
vagus control over the smooth muscle of the alimentary tract thus decreasing 
its motihty. 

Physostigmine is an antagonist to atropine. Try i c.c. of o.i percent 



36 EXPERIMENTAL PHARMACOLOGY. 

intravenous. Use artificial respiration if necessary. Give a second injec- 
tion of atropine later. See figure 23 for a reverse antagonism. 

7. Atropine on the eye. Drop i or 2 drops of i percent atropine 
in the right eye of a dog or cat. The pupil will be widely dilated in a few 
minutes. Keep the animal under observation until the effect entirely dis- 
appears, often only after several days. Atropine destroys the power of 
accommodation and it is used for this clinical purpose in eye practice. 
Students should not use atropine on their own eyes, but a mild dose of hom- 
atropine, 2 or 3 drops of i percent, the effect of which passes off in 24 
to 36 hours, may be tested in one's own eye. In such experiments test the 
accommodation, light reflex, and size of the pupil. 

8. Atropine on man in therapeutic dose. Test on yourself the 
action of a dose of 1/120 to 1/60 grain of atropine by way of the mouth. 
Note the effects on the heart rate, pulse character, respiration, size of pupil, 
light reflex and sensations. 

9. Atropine is secreted by the kidney. — ^This may be demonstrated 
on the rabbit which is very tolerant of the drug. Give a rabbit urethane. 
Collect the urine from a bladder canula. Give a large hypodermic injection, 
2 c.c. of 2 percent atropine, and test the rabbit's urine on the eye of a cat or 
dog. The atropine may be extracted (Binz). Concentrate a large amount 
of urine, add ammonia, shake up with chloroform, evaporate, dissolve the 
residue and test on the eye of a cat or a dog. 

10. Scopolamine on the frog. Give a dose of i c.c. of i percent 
scopolamine in the dorsal lymph sac of a frog. Compare with the effects 
of an equal dose of atropine in experiment i above. 



NICOTINE. 37 



NICOTINE. 



Experiments Illustrating the Action of the Nicotine. page. 

1. On the frog. . . -37 

2. On the ventricular muscle. . 37 

3. On the frog's heart and its nervous apparatus. . . 37 

4. On the nerve fiber and on nerve ganglia. . . -37 

5. On the mammalian heart. 38 

6. On the circulatory system and on the respiratory nervous 

mechanism . .... 38 

7. On muscle irritability . . . 39 

1. Nicotine on the frog. Give an injection of a 0.5 c.c. of 0.2 
percent nicotine into the dorsal lymph sac of a frog. 

2. Nicotine on the ventricular muscle. Prepare a terrapin's heart 
strip and when it is contracting rhythmically in 0.7 percent physiological 
saline, immerse the strip in a 0.05 percent solution of nicotine in saline 
for two minutes, then return to the saline bath. Repeat. If the solution is 
too strong the strip will exhibit a strong tonus with incomplete relaxations. 
The amplitude and the rate are markedly increased. 

3. Nicotine on the frog's heart and its nervous mechanism. 
Pith a frog, expose the heart and take tracings on a drum with a speed of 
2 mm. per second. Stimulate the vago-sympathetic with an interrupted 
current that just causes complete inhibitions. Now irrigate the heart from 
a dropping bottle with o.i percent nicotine in 0.7 percent saline, and 
stimulate the vagus at intervals of two minutes. If the nerve stimulation 
ceases to be effective, then apply the electrodes directly to the sinus. 

To demonstrate the stronger effects on heart muscle prepare a second 
frog. Take a tracing of the heart. Apply a few drops of i percent solu- 
tion of nicotine. 

4. Nicotine on the nerve ganglia and on the nerve fiber. Anes- 
thetize a rabbit (or cat or dog), dissect out the cervical sympathetic and 
the superior cervical ganglion. Stimulations of the nerve or of the ganglion 
lead to vasoconstriction in the ear and dilation of the pupil. Paint the 
nerve below the ganglion with i percent nicotine. Stimulation at a point 
still lower down shows that the nerve impulses still pass undisturbed. 
Now paint the ganglion itself. Stimulate the nerve below the gangUon, also 



38 EXPERIMENTAL PHARMACOLOGY. 

the ganglion directly. What Conclusions ? See also the next experiment. 
(Ref.: Langley and Dickinson, Journal of Physiol., Volume II, page 265.) 
5. Nicotine on the mammalian heart. Prepare the mammalian 
heart perfusion and recording apparatus and bring it to a temperature of 
36° C. Etherize a cat, bleed, defibrinate the blood, and dilute to one-in-ten 
of Locke's solution. Quickly take out the heart, suspend it in the apparatus 
and start the perfusion. When the heart is beating well, perfuse it with 
o.ooi percent of nicotine in Locke-blood solution. There is a constant 




Fig. 22. — Action of nicotine on the ventricular muscle from the terrapin. The 
strip was contracting in physiological saline when transferred to 0.2 percent nicotine in 
saline at the point marked. The solution was too strong and was removed after about 
forty seconds. Time in seconds and half-minutes. 

sharp increase in amphtude with a more slowly developed increase in 
rate. The after amplitude may remain greater than the preceding normal. 
6. Nicotine on the circulatory and respiratory nervous mechan- 
ism. Anesthetize a dog or cat (the animal used in experiment 4 above 
may be used for this experiment also). Take a blood-pressure from the 
carotid and a respiration tracing from the trachea, (i) Determine an effect- 
ive stimulus for the heart and respiration. (2) Now inject 5 c.c. of o.l 
percent solution of nicotine into the saphenous or jugular vein. Repeat 



NICOTINE. 



39 



the dose if necessary, until distinct effects are produced on the heart rate and 
blood-pressure. (3) Stimulate the vagus at first with the strength of stimu- 
lus used before the injection, then with successively stronger stimuli. An 
instructive picture is obtained by dissecting down to and stimulating the 
cardiac branches from the annulus of Vieussens, which may be done in 
the dog on the left side without opening the thorax. 




Fig. 23. — Action of nicotine on the isolated cat's heart. The heart was contract- 
ing in Locke-blood solution when it was perfused with o.ooi percent nicotine between 
the points marked by the arrows. The increase in amplitude is more marked when 
the heart is beating weaker at the time of perfusion. Time in seconds. 



7. Nicotine on muscle irritability. Lay a ligature around the 
thigh of one leg of a frog and then give i c.c. of o.i percent nicotine 
in the dorsal lymph sac. After 20 minutes test the irritability of the normal 
and of the nicotinized gastrocnemius muscles by the minimal and maximal 
stimulus method. 



40 EXPERIMENTAL PHARMACOLOGY. 



CURARE. 

Experiments on the Effect of Curare. page. 

1. On the frog. .... 40 

2. On the motor nerve endings. ... 40 
' 3. On the heart muscle and on the cardiac nervous mechan- 
ism. . 40 

4. Poisons the motor endings before the other portions of the 

reflex arc. . . . . 41 

5. On the mammal. . 41 

1. Curare on the frog. Give a frog a hypodermic of 0.3 c.c. (5 
minims) of 0.2 percent curare. The motor apparatus is paralyzed, but 
the circulation continues and the frog will recover in from one to three days, 
respiration being maintained through the moist skin if the animal is kept in 
a covered jar. 

2. Curare on the motor nerve endings, Bernard's experiment. 
The specific action of curare was demonstrated by Claude Bernard to be on 
the motor nerve end plates. Ligate one leg of a frog to shut off the circula- 
tion, give a hypodermic of 0.3 c.c. of 0.2 percent curare. When general 
paralysis is secured, perform the following tests, interpreting the results 
through the effect on the gastrocnemius muscles: 

a. Stimulate the sciatic nerve on the unligated leg. 

b. Stimulate the gastrocnemius of the unligated side. 

c. Stimulate the sciatic nerve on the ligated side above the ligature. 

d. Below the ligature. 

e. The corresponding muscle. Conclusions. 

3. Curare on the heart muscle and on the cardiac nervous appa- 
ratus. While minimal doses of curare suffice to poison the motor end plates, 
it takes relatively large doses to paralyze the cardiac nervous apparatus. 
The paralysis apparently affects the ganglionic nerve endings first and then 
the cardiac motor endings and muscle. Pith a frog, expose the heart, pre- 
pare the vagus trunk for stimulation and adjust a heart lever for record. 
Allow physiological saline from an irrigating bottle to run over the heart. 
Take a normal record and then stimulate the vagus nerve. Now irrigate 
slowly with 0.2 percent curare in saline and stimulate the nerve 10 seconds 
at a time at intervals of 10 minutes for several tests. 



CURARE. 41 

4. Curare poisons the motor endings before the other portions 
of the reflex arc. Tie a ligature on a frog's leg at the thigh, inject 0.3 
c.c. of 0.2 percent curare. Just as voluntary activity ceases stimulate the 
skin of the poisoned leg. The unpoisoned gastrocnemius will contract. 
Rapidly expose and stimulate the poisoned sciatic. The poisoned gastroc- 
nemius will not contract, while the unpoisoned one will, owing to reflex 
stimulation through the cord. 

5. Curare on the mammal. Morphinize and chloroform a dog. 
Take blood-pressure. Introduce a tracheal canula and take the respiratory 
record by the intra-tracheal method. Arrange the apparatus for artificial 
respiration when needed. Inject into a vein 5 c.c. of i percent curare. 
All movements of voluntary muscles will quickly cease including respiratory 
movements. The heart rate and the blood-pressure remain good, and if 
artificial respiration is applied the circulation can be maintained for several 
hours, or until the drug is eliminated and recovery occurs. 



42 



EXPERIMENTAL PHARMACOLOGY. 



PILOCARPINE. 

Experiments Showing the Action of Pilocarpine. 

1. On the frog 

2. On the mammal 

On the ventricular muscle . .... 



3- 
4- 

5- 



PAGE. 
... 42 
. 42 

43 

On the frog's heart 43 

On the circulatory and respiratory systems of the mammal . 43 



I. Pilocarpine on the frog. Give a frog a hypodermic injection 
of 0.6 c.c. of 10 percent solution of pilocarpine nitrate. Keep the 
frog in a moist battery jar until normal again. The toxic dose is I c.c. of 
10 percent solution of pilocarpine. 



on off 



UjUULjUULIjU 




ir~tnnmrV~nmr- 



nr~nrnnnrir~nr 



Fig. 24. — Blood-pressure and respiratory effects of an intravenous injection of i 
c.c. of I percent pilocarpine in the dog. Injection between the points "on" and 
"off." Time in seconds. Pressure in mercury. Reduced to four-fifths the original size. 

2. Pilocarpine on the mammal. Give a dog a hypodermic injection 
of 0.3 c.c. (5 minims) i percent pilocarpine. This dose produces a 
marked secretion by glandular structures. Examine the flow of saliva by 
turning back the upper lip, drying it and noting the accumulation of drops 



PILOCARPINE. 43 

at the mouth of the salivary duct. An injection of i c.c. of o.i percent 
atropine in a vein antagonizes pilocarpine and stops the secretion. 

Give additional drops of i percent pilocarpine in the eye. Drops 
of I percent atropine on the eye will overcome the action. 

3. Pilocarpine on the ventricular muscle. Mount a strip of the 
terrapin's ventricle in physiological saline. When the contractions are 
regular transfer to a o.i percent pilocarpine solution in saline. Allow it 
to act only i minute then renew the physiological saline bath. As a final 
test give the strip a continuous bath of 0.1 percent pilocarpine and note 
the successive effects. 

4. Pilocarpine on the frog's heart. Pith a frog, expose the heart 
and take tracings of the ventricle. Test the activity of the vagus with a 
strong interrupted current. Now irrigate the surface of the heart with 
drops of I percent pilocarpine for two minutes. Stimulate the vagus trunk 
one minute after pilocarpine and at successive intervals of five minutes. If 
the drug is strongly active the heart will beat slower. In the early stages 
the stimulation will result in acceleration, but in no inhibition as in the 
normal. Applying the electrodes directly to the sinus gives no inhibition 
showing that the pilocarpine has acted on the vagus endings and not on the 
ganglionic connections. Drops of i percent atropine sulphate will restore 
the heart beat after pilocarpine, these two drugs being antagonists. 

5. Pilocarpine on the circulatory and respiratory system of the 
mammal. Anesthetize a dog with morphine and chloroform. Introduce a 
tracheal canula and be prepared to use artificial respiration if necessary. 
Take blood-pressure and respiration records on a continuous paper kymo- 
graph. Test the activity of the vagus. Give an intravenous injection of 
I c.c. of I percent pilocarpine nitrate. Retest the activity of the vagus 
after the pilocarpine. Atropine antagonizes the pilocarpine effect. Ex- 
amine the pupils from time to time. Also note the increased rate of salivary 
secretion. 



44 EXPERIMENTAL PHARMACOLOGY. 



PHYSOSTIGMINE. 

Experiments on the Action of Physostigmine. page. 

1. On the frog ... . . 44 

2. On cardiac muscle . . 44 

3. On the frog's heart and its nervous apparatus . . . . 44 

4. On the heart of the cat ... 44 

5. On the respiratory medullary center and on the circulatory 

system of the mammal . . .... 44 

6. On the eye . . . . 47 

1. Physostigmine on the frog. Give a frog a dorsal lymph sac 
injection of i c.c. (17 minims) i percent physostigmine. The effects 
produced are diminished irritability, loss of muscular tone, paralysis of the 
respiratory center, loss of reflexes, and death, or, at best, a very slow and 
prolonged recovery. 

2. Physostigmine on cardiac muscle. After a ventricular strip 
from the terrapin has begun beating regularly in physiological saline, transfer 
it to o.i percent physostigmine in saline for two to three minutes. Physi- 
ological saline recovers the normal contractions after several minutes. 
Compare the results with those from pilocarpine and muscarine. A bath of 
0.002 percent atropine antagonies the physostigmine effects. 

3. Physostigmine on the frog's heart and its nervous apparatus. 
Pith a frog and take a record of the heart beat. Determine the minimal 
effective stimulus of the vagus trunk for inhibition of the heart rate. Now 
irrigate the surface of the heart with drops of o.i percent physostigmine 
from an irrigating bottle for two minutes. Redetermine the minimal stimulus 
for the vagus trunk beginning with a very weak induction current. If 
the contractions are at a slow rate or have ceased, irrigate the surface of the 
heart with i percent atropine. Atropine antagonizes physostigmine. 
Compare with pilocarpine. If the perfusion method is used then 0.0 1 
percent physostigmine is the proper solution strength for the frog's heart. 

4. Physostigmine on the isolated heart of the cat. Prepare an 
isolated cat's heart by the method used in the nicotine experiment 5. When 
it gives regular contractions, perfuse it with o.oi percent physostigmine 
in Locke-blood solution. 

5. Physostigmine on the respiratory medullary center and on 
the circulatory system of the mammal. Anesthetize a dog, insert a trach- 



PHYSOSTIGMINE. 



45 




46 



EXPERIMENTAL PHARMACOLOGY. 



eal canula and be prepared for artificial respiration. Take a continuous 
record of the blood-pressure and of the respiratory movements. Insert a 
canula in the saphenous vein and connect it with a buret containing the drug. 
Give an intravenous injection of o.i percent physostigmine slowly until the 
first effects are noticed on blood-pressure. Note the amount and mark 
the time of the dose on the record by a signal pen. Usually there is a pro- 





lljUUUlJUUlJUlJUUUUUUJJlJlJUlJUlJUlJlJUUlJlJ^ 

XT 

Fig. 26. 

Fig. 26. — Action of physostigmine and its antagonism by atropine in the mammal, 
showing the effects of an injection of 8 mgr. of physostigmine just before the part of 
of respiration and the circulation effects upon the injection of 2 mgr. of atropme be- 
At a, b and c are shown portions of the trace at 30-second intervals. Time in seconds. 

gressive paralysis of the respiratory center accompeinied by a great slowing 
of the heart and a fall of blood-pressure by one-half or more. The heart 
continues to beat long after respiration ceases. Use artificial respiration 
until the blood-pressure improves' and the anesthesia becomes Hght. This 
will not restore automatic respiratory movements as it does after heavy 
anesthesia. If at this time a venous injection of 0.5 c.c. of i percent 



PHYSOSTIGMINE. 



47 



atropine be given from a hypodermic syringe the respiratory movements 
will be quickly established and the slow heart and low pressure will give 
way to the rapid heart and strong pressure following primary injection of 
atropine, experiment 6, page 35. The vagus inhibitory apparatus is effective 
under physostigmine, but not after atropine. Repeat the experiment. It 
takes a larger dose of physostigmine to overcome the atropine and pro- 



j|||KWij|^^ 








I ' I j^ i 



> 1 1 1 1 1 1 1 



3 b 



Fig. 26 (Continued). 

Parts I, iX and iT give the respiration trace, blood-pressure and time, respectively, 
the trace shown. The parts of the trace numbered 2, 2X and 2T show the recovery 
tween the arrows. A few second's gap intervenes between the two parts of the figure. 



duce the characteristic effects. Examine the pupil before and after the 
physostigmine. 

6. Physostigmine on the eye. Give 2 drops of i percent phy- 
sostigmine in one eye of a dog or a rabbit, at intervals of five minutes. It 
is better to use one of the experimeter's own eyes. Strong contraction of 
the pupil follows. A decrease in intraocular pressure has also been proven, 



48 EXPERIMENTAL PHARMACOLOGY. 

and to produce this effect is the chief therapeutic use of the drug. A strik- 
ing comparison is obtained by dropping i percent atropine in the unused 
eye of the dog after the physostigmine effect has come on in the other eye. 
Physostigmine will overcome the atropine dilation of the pupil. The experi- 
menter may show the antagonism between homatropine and physostigmine 
on his own eyes, but it is recommended that one eye always be reserved. 



ACONITE. 

Experiments on the Action of Aconite. page. 

1. On the frog 48 

2. On the circulatory system of a mammal. 48 

3. On the frog's heart 48 

4. On the mammalian heart. . . . 48 

1. Aconite on the frog. The dose is 0.5 c.c. of o.i percent aconite. 

Compare with digitalis. 

2. Aconite on the circulatory system of the mammal. Take a 
continuous tracing of the blood-pressure of a dog. Give i c.c. of o.i 
percent aconitine crystals. Note particularly the progressive effects on 
the nervous and muscular elements of the circulatory apparatus. 

3. Aconite on the frog's heart. Destroy the cerebrum and optic 
lobes only of a frog, -expose the ventricle and take a tracing. Give an in- 
jection of 0.5 c.c. of O.I percent aconitine in the lymph sac. One may 
expect a progressive stimulation of the accelerator and vagus nervous 
apparatus followed by paralysis of nerves and muscle. 

4. Aconite on the mammalian heart. Prepare an isolated heart 
as described for the nicotine experiment 5. When the heart is contracting 
regularly with the Locke-blood perfusion then perfuse for 10 seconds with a 
0.0002 percent aconite solution. A prolonged perfusion or perfusion 
with a stronger concentration of aconite will quickly set up incoordinate 
contractions and fibrillation. 



ACONITE. 



49 




XI 



S 



a, 
a 
o 






50 EXPERIMENTAL PHARMACOLOGY. 



VERATRINE. 



Experiments on the Action of Veratrine. page. 

1. On the frog. . .' . . -5° 

2. On the mammal. . .... 50 

3. Veratrine on heart strip. . . . 50 

4. On the frog's heart. . . . 50 

5. On the isolated mammalian heart. ... 50 

6. On the form of the simple muscle contraction 50 

7. On the circulatory and respiratory systems of the mammal. . 50 

1. Veratrine on the frog. The dose for a frog is about 0.5 c.c. 
of a I percent solution of the fluid extract veratrum viride or 0.3 c.c. of 
o . 1 percent veratrine . Compare with the effects of aconite and of barium. 
See experiment 4. 

2. Veratrine on the mammal. Give a cat or rabbit i c.c. of o.i 
percent veratrine hypodermically, or i c.c. of i percent for a dog. Keep 
under observation for a considerable time. 

3. Veratrine on the heart strip. Subject the contracting strip of 
ventricle to 0.005 to 0-05 percent vera tine in sahne. 

4. Veratrine on the frog's heart. Pith a frog, expose the heart and 
take a tracing when perfused with 0.005 percent veratrine in Ringer's 
solution (o.oi percent destroys coordination). 

5. Aconite on the isolated mammalian heart. Prepare the appara- 
tus for the isolated heart experiment, isolate a cat's heart and perfuse with 
0.0002 percent veratrine in Locke-blood solution. See Fig. 25. 

6. Veratrine on the simple muscle contraction of the frog. Ligate 
one leg of a frog and give a hypodermic of 0.5 c.c. of o.i percent vera- 
trine. After 15 minutes prepare the veratrinized muscle and take simple 
muscle contractions to show the form of the contraction wave, using a 
tuning fork to record the drum speed. Compare this curve with that of 
the undrugged muscle. 

The frog of experiment i may be used to show the veratrine effect on 
muscle work. Stimulate once in three seconds in this experiment, since the 
relaxation may not be complete in an interval of two seconds. 

7. Veratrine on the circulation and respiration of a mammal. 
Take a record of the blood-pressure from the carotid of an anesthetized dog. 
Tracheotomize and take respiratory tracings. Give i c.c. of i percent 
veratrine in the abdominal cavity. When marked cardiac slowing appears 
cut the vagi and note the effects on the heart. 



VERATRINE. 



51 




52 EXPERIMENTAL PHARMACOLOGY. 



DIGITALIS. 

Experiments Showing the Action of Digitalis. page. 

1. On the frog. ... 52 

2. On the ventricular muscle. ... . . . 52 

3. On the frog's heart. . . 52 

4. On the atropinized frog's heart. . 52 

5. On the mammalian heart . . . 52 

6. On the circulatory and respiratory systems of the mammal. 53 

7. Digitalis as a diuretic 53 

1. Digitalis on the frog. Give a dose of 0.5 c.c. of 0.2 percent 
of soluble digitalis. The digitalis effects develop slowly. Note the heart 
rate, and particularly the circulation in the web. Keep in a moist battery 
jar for at least two hours. Examine the heart if death occurs. 

2. Digitalis on the ventricular muscle. Treat a strip of terrapin's 
ventricle contracting in saline to a bath of 0.002 percent digitalis in saline. 
Follow with pure saline. Repeat with a 0.005 percent digitalis. Still 
stronger solutions may be used, but a marked tone will result as shown in 
Figure 26. 

Digitalis solutions may be used made up in the weaker Ringer, but 
as the rate is slower and the amplitude much greater than that in sodium 
chloride solutions the picture will be quite different, though the same in 
kind. Delirium cordis of the strip is produced by the stronger solutions act- 
ing for several minutes. 

3. Digitalis on the frog's heart. Pith a frog and take a record of 
the contractions of the ventricle when irrigated with physiological saline. 
Irrigate slowly with drops of 0.2 percent digitalis for two minutes, then 
wash off with saline. 

A more effective method is to perfuse the heart from a canula in the 
vena cava. Use a much weaker solution for perfusion, i.e., 0.0005 to 
o.ooi percent digitalis in Ringer. These effects should be compared with 
the effects on cardiac muscle above. 

4. Digitalis on the atropinized frog's heart. Atropinize the frog's 
heart to eliminate the car'diaic nervous control, then repeat experiment 3 
above. 

5. Digitalis on the mammal heart. Use the method described 
on page 70. Isolate and perfuse the cat's heart with the normal solution 



DIGITALIS. 



53 



of Locke-blood, then with o.oooi percent digitalis (soluble digitalis) 
in Locke-blood. Increase the strength to 0.0005 percent. The stronger 
solution will usually produce a great increase in amplitude followed by 
fibrillation. The weaker solution, see figure 30, produces a typical mild 
therapeutic effect on the heart. Compare with the results of experiment 6. 
6. Digitalis on the circulatory and respiratory systems of the 
mammal. Anesthetize a dog and take continuous kymographic records 
of the blood-pressure and of the respiration. Slowly inject into the saphe- 
nous vein 2 c.c. doses of 0.5 percent digitalis at five-minute intervals 




Digitalis o.oe^ 



Fig. 29. — Experiment showing the action of digitalis on the rhythm and tone of a 
strip of terrapin's ventricle. The strip was contracting in physiological saline. Between 
the words "on" and "off" it was subjected to 0.06 percent of digitalis in saline. 



until the three stages of digitalis effect on the heart and blood-pressure are 
obtained. The anesthetic must be perfectly constant. One may give the 
maximal dose of 4 c.c. of i percent digitalis at once. In this instance the 
three stages are passed through rapidly and the animal will usually die in 
10 to 20 minutes. Read Cushny's Pharmacology, pp. 430-435. 

7. Digitalis as a diuretic. Morphinize and chloroform a dog. 
Take the blood-pressure. Isolate the ureters near the bladder and insert 
canulas, using care not to occlude the ureters by twisting or otherwise. Con- 
nect the ureters by means of a T-tube with a horizontal 2 c.c. pipet graduated 



54 



EXPERIMENTAL PHARMACOLOGY. 




ERGOT. 55 

to 1/50 c.c. Close the abdomen with sutures. Insert a venous canula and 
connect with a transfusion buret. Establish the normal secretion per 10 
minutes, cutting off the column of secreted urine by injecting a bubble of air 
into the mouth of the buret by inserting a hypodermic needle through the 
rubber connecting tube. Now inject 5 c.c. of o.i percent digitalis or 
strophanthin into a vein and take the secretion in successive 10 minute 
periods until the flow is constant. Repeat the dose once or twice at long in- 
tervals. Mark the secretion intervals on the blood-pressure record. 

Compare these results with those observed on other diuretic drugs — 
caffeine, urea, inorganic salts, etc. 



ERGOT. 

Experiments on the Action of Ergot. page. 

1. On the frog 55 

2. On the heart muscle. 55 

3. On the arterioles of the frog. 55 

4. On the blood-pressure and heart rate of a mammal. 55 

1. Ergot on the frog. Give 0.5 c.c. of the fluid extract. 

2. Ergot on the heart muscle. Change a contracting heart strip 
from saline to a i o percent solution of Squibbs' fluid extract of ergot in saline 
solution. Allow it to act for five minutes. Take a continuous record. 

3. Ergot on the arterioles of the frog's web. Wrap a frog in 
a wet cloth and fasten to a frog-board for examining the web. Give a 
lymph sac injection of 0.5 c.c. fluid extract of ergot. Select a good field 
of small arterioles and measure their diameter at once. The relative 
change in diameter of small vessels can be determined by selecting a field 
in which pigment spots mark the borders of the vessels. Sketch such a 
vessel and spots for the normal. Re-sketch after the drug. Re-measure at 
intervals of five minutes as the ergot is absorbed. 

4. Ergot on the blood-pressure of a mammal. Give an intravenous 
dose of 0.5 c.c. fluid extract of ergot to a mammal while taking a record 
of the blood-pressure. 



56 EXPERIMENTAL PHARMACOLOGY. 



SUPRARENAL GLAND. 

The commercial preparation of the active principle of suprarenal gland, 
adrenalin hydrochloride, presents the same physiological action as the gland 
extract and has the special advantage of preparation in definite and known 
strengths. It has come into general use for therapeutic purposes and is, 
therefore, used in these experiments. 

Experiments Showing the Action of Adrenalin Hydrochloride, page. 

1. On the frog. 56 

2. On the ventricular strip 56 

3. On the frog's heart 56 

4. On the isolated mammalian heart .... -56 

5. On the simple muscle contraction . 58 

6. On muscle work . . • 58 

7. On the local mucous surfaces . . 58 

8. On the size of the blood-vessels in the frog's web 58 

9. On general blood-pressure and peripheral vaso-constriction 58 

1. Adrenalin on the frog. Give 0.5 c.c. o.i percent in the dorsal 
lymph sac. 

2. Adrenalin on the ventricular muscle. Transfer a terrapin's 
ventricular strip contracting in physiological saline to o.oi percent adren- 
alin in saline. Change after two to five minutes. The drum speed should 
be I cm. per minute. Suprarenal extract has also been shown to increase 
the amplitude and the rate of the ganglion free ventricular muscle of the 
dog. Cleghorn, Amer. Jour. Physiol., Volume III, p. 273. 

3. Adrenalin on the frog's heart. Use the perfusion method, page 
68, with the heart in place and the inflow canula in the ascending vena cava. 
Follow physiological Ringer perfusion with o.ooi percent adrenalin 
hydrochloride in Ringer. The drum speed should be 2 mm. per second. 
Direct application to the surface of the heart requires a strength of at least 
0.05 percent adrenalin hydrochloride. 

4. Adrenalin on the isolated heart. Perfuse a cat's heart in the 
usual way with Locke-blood solution for a normal, then change to a o.oooi 
percent adrenalin hydrochloride in Locke-blood. If the heart be beating 
feebly it often happens that the contractions will increase in amplitude by 
200 percent and more. 



SUPRARENAL GLAND. 



57 




.B c 
■t 8 



wj 



tn 






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V oi 

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^ CO 

<u o 

-^ J-- 

o '^ 

o ^ 

'S '^ 

O cj 

O l^ 

T3 CL, 

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58 EXPERIMENTAL PHARMACOLOGY. 

5. Adrenalin on the simple muscle contraction. Ligate one leg 
of a frog and give 0.5 c.c. of 0.05 percent adrenalin. Allow ten minutes 
for absorption. Compare the simple muscle contractions of the two gastroc- 
nemii as repards a, amplitude, and b, the time of the simple contraction. 
The muscular power of patients with Addison's disease has also been shown 
to be greatly improved by giving the extract of suprarenal gland. 

6. Adrenalin on muscle work in the frog. Prepare a frog as in 
experiment 5 above and test the work performed by the two muscles. For 
details of procedure see alcohol experiment 5. 

7. Adrenalin on mucous surfaces. Paint one-half the tongue with 
0.1 percent adrenalin hydrochloride. At intervals of five minutes drop 
0.0 1 percent in saline (sterilize by boiling) in one eye. Compare the two 
halves of the tongue and the two eyes as to vascular condition. Examine 
the size of the pupils. Test for possible differences as to the sensitiveness 
of the conjunctiva. Try the effect in the eye of a cat or dog. 

8. Adrenalin on the size of the blood-vessels of the frog's web. 
Use a dose of 0.5 c.c. of o.i percent as a hypodermic. See ergot experi- 
ment 3, page 55; nitroglycerine experiment 3, page 59. Or apply drops of 
o.i percent directly to the web under the microscope. 

9. Adrenalin on general blood-pressure and on vaso-constriction 
in a manunal. Prepare a dog for blood-pressure. Adjust an onkometer 
to the left kidney and record the change in volume with a Brodie's bellows 
or Roy's piston recorder. Give 2 to 4 c.c. of o.oi percent adrenalin 
hydrochloride slowly in a vein. Give 2 c.c. of 0.1 percent atropine to 
eliminate the vagus action on the heart and repeat the adrenalin. Compare 
with digitalis, page 53; ergot, page 55; veratrine, page 50. Drugs of 
antagonistic action are nitrites and potash salts. 



NITROGLYCERINE AND THE NITRITES. 59 

NITROGLYCERINE AND THE NITRITES, 

Experiments on the Action of Nitroglycerine and the 

Nitrites. page. 

1. On the frog. 59 

2. On the heart muscle. . 59 

3. On the arterioles of the frog 59 

4. On the circulation volume 59 

5. Amyl nitrite on the pulse . 59 

6. Nitrites on mammalian blood-pressure . 60 
Nitroglycerine and the nitrites affect primarily the peripheral circu- 
lation, causing vaso-dilation with fall of blood-pressure. The specific action 
is on the muscular tissue. 

1. Nitroglycerine on the frog. Give a frog a dose of 0.5 c.c. of 
o.i percent nitroglycerine in the dorsal lymph sac. 

2. Sodium nitrite on the heart muscle. Test the action of 0.02 
percent sodium nitrite on the contracting ventricular strip. 

3. Nitroglycerine on the arterioles of a frog. Bind a frog for the 
microscopic examination of the web circulation. Then give i c.c. of o.i 
percent nitroglycerine in the lymph sac. Immediately measure the 
smaller arterioles in a favorable field and re-examine every two minutes as 
absorption progresses. Try direct application of drops of 0.1 percent to the 
web. 

4. Sodium nitrite on the circulation volume. Pith a frog or small 
terrapin. Insert a canula in the aorta or one of its branches, snip the 
veins with the scissors to allow free perfusion, set the frog-board at an angle 
to facilitate drainage of liquid. Perfuse the blood-vessels with a weaker 
Ringer's solution for a normal. Follow with o.oi percent soditun nitrite 
in the weaker Ringer, keeping a uniform pressure of the perfusion liquids 
of from 6 to 10 cm. Measure the perfusion rate in drops per minute, or 
collect the outflow in a 25 c.c. graduate. 

Test the amount of outflow when irrigated with 0.0005 percent of 
soluble digitalis, then follow with o.oooi percent sodium nitrite, both in the 
weaker Ringer. 

5. Amyl nitrite on the pulse. Take normal pulse records with one of 
the standard sphygmographs. Break an amyl nitrite pearl on a handkerchief 
and breathe deeply the fumes. Pulse tracings taken 5 and 10 minutes later 
will show the usual signs of dilated blood-vessels with accompanying low 
pressure. Slight headaches sometimes follow the use of amyl nitrite. 



6o 



EXPERIMENTAL PHARMACOLOGY. 



6. Nitrites on mammalian blood-pressure. Anesthetize a lo kilo 
dog and take the blood-pressure. Give intravenous doses of nitrites in the 
following order, repeating with larger doses if necessary and always allowing 
full time for recovery: i c.c. of o.i percent nitroglycerine, 3 c.c. of o.i 
percent; 2 c.c. of 0.1 percent amyl nitrite; 6 c.c. of 0.1 percent 






Fig. 32. — Action of amyl nitrite on the human pulse. One amyl nitrite pearl was 
crushed on a handkerchief and the fumes inhaled deeply. Trace i is the normal pulse. 
Trace 2 immediately after amyl nitrite fumes. Traces 3 and 4 are stages of recovery. 
Time in seconds. 



sodium nitrite. The blood-pressure remains low for a long time after 
sodium nitrite. A dose of 2 c.c. to 5 c.c. of 0.2 percent digitalis or 2 c.c. 
of o.oi percent adrenalin hydrochloride will antagonize this effect. 

Give 2 c.c. of O.I percent atropine to eliminate the action of the car- 
diac nervous apparatus and repeat the above doses of nitroglycerine and 
sodium nitrite. 



CARBOLIC ACID. 6l 



CARBOLIC ACID. 

Experiments on the Action of Carbolic Acid. page. 

1. On the frog. . . 6i 

2. On the growth of yeast and bacteria . . . . . 6i 

3. On the circulatory and respiratory systems of a mammal 61 

1. Carbolic acid on the frog. Give a dose of i c.c. of i percent. 

2. Carbolic acid on the growth of yeast and of bacteria. Prepare 
six fermentation tubes of active yeast culture and as many test-tubes of 
inoculated bouillon. Keep one tube of each for a normal and to the others 
add enough 10 percent carbolic acid to make a series of o.i, 0.5, i, 2, and 
4 percent solutions. Keep at laboratory temperature and observe through a 
period of several days. 

3. Carbolic acid on the circulatory and respiratory systems of the 
mammal. While taking records of blood-pressure and respiration by the 
usual method give an intravenous injection of 10 c.c. of 0.5 percent carbolic 
acid. When the collapse stage is far advanced inject i percent soditmi 
sulphate slowly. Judge the amount required by the action in overcoming 
the carbolic acid depression of the respiratory apparatus. 

POTASSIUM SALTS. 

Experiments Showing the Action of Potassixmi Salts. page. 

1. On the heart muscle ,61 

2. On the reaction time in the reflex frog. . . 61 

3. On muscle irritability and muscle work in the frog . . 61 

1. Potassium chloride on the heart muscle, A ventricular strip 
contracting in physiological saline solution is transferred to 0.06 percent 
potassium chloride in saline for two to five minutes. Contractions return 
in saline even after stronger doses of potash. 

2. Potassium bromide on the reaction time in the reflex frog. 
Compare the reaction time of a reflex frog before and 20 to 40 minutes after 
0.3 c.c. of 5 percent potassium bromide in the dorsal lymph sac. 

3. Potassitxm chloride on muscle irritability and muscle work 
in the frog. Compare the two gastrocnemii as to irritability and as to 
amount of muscular work done. Dose 0.3 c.c. of 5 percent solution given 
hypodermic after one leg is ligatured. 



62 



EXPERIMENTAL PHARMACOLOGY. 



CALCIUM SALTS. 

Experiments Illustrating the Action of Calcium Salts. p'Age. 

1. On heart muscle 62 

2. On the frog's heart . . 62 

3. On the blood-pressure and the respiration in the mammal. 63 

I. Calcium chloride on heart muscle. Transfer a ventricular strip 
from physiological saline to 0.03 percent calcium chloride in saline for 
three to five minutes. Record on a drum speed of 2 cm. per minute. 
Repeat, using 0.06 percent. The rate is increased and the amplitude often 




Fig. 33. — Terrapin's heart muscle as influenced by a solution of 0.06 percent cal- 
cium chloride in physiological saline. A weaker solution produces much less tone. 
Time in seconds. 



doubled. The stronger solution produces great increase in tone which 
sometimes passes into delirium cordis. Potash salts antagonize. Read 
Ringer, Jour. Physiology, 1883. 

2. Calcium chloride on the frog's heart. Perfuse the frog's heart 
through the vena cava with 0.7 percent sodium chloride and follow with 
0.03 percent calcium chloride in 0.7 percent sodium chloride. Recover 



BARIUM SALTS. 63 

the sodium chloride type of contractions, then perfuse with o.oi percent 
barium in sodium chloride. 

3. Calcium chloride on the blood-pressure and the respiration 
in the mammal. Give an intravenous dose of lo c.c. of i percent for a 
dog. Cut the vagi and repeat the dose. Alternate the dose with potassium, 
2 to 4 c.c. of I percent. 



BARIUM SALTS. 

Experiments on the Action of Barium Salts. page. 

1. On the frog . . 63 

2. On the heart muscle 63 

3. On the circulation and on the respiration movements in 

mammals . . ..... 63 

1. Barium on the frog. Dose, i c.c. of i percent barium chloride. 

2. Bariimi chloride on the heart muscle. Transfer a contracting 
ventricular strip from 0.7 percent sodium chloride to o.oi percent bariiun 
chloride in saline. Short immersions increase the rate, but long baths show 
that this salt does not sustain contractions as do calcium salts. A o.i percent 
solution in saline delays contractions with prevention of relaxation. Con- 
tractions still take place in i percent barium chloride. Compare with 
digitalis. 

3. Baritmi chloride on the circulation and on respiratory move- 
ments in mammals. The effect on the heart and blood-pressure and on 
respiration in a mammal is demonstrated by an intravenous dose of 5 c.c. 
of 0.2 percent given slowly. This dose should be repeated several times 
both before and after section of the vagi. Barium salts act as strong poisons 
to the nerve centers, especially those in the medulla. 



OPERATIONS, APPARATUS AND SPECIAL 
METHODS. 

PHYSIOLOGICAL SOLUTIONS. 

The lymph and blood plasma in which the tissues develop are the true 
physiological solutions. 

Artificial solutions imitate lymph in its isotonicity — ^its physical character, 
and in its composition — its chemical character. Sodium chloride in 0.6 per- 
cent solution, used first by Nasse in 1869 on frog's muscle, and by Bow- 
ditch in 1871 on the frog's heart, was supposed to prevent injurious changes 
in the tissue by virtue of its isotonicity. Ringer in 1883 and Locke in 1885 
introduced the solutions which bear their names. They showed that the 
chemical factors play a fundamental part in the effects of these solutions 
on the tissues. At the present time we recognize that exact isotonicity is not 
nearly so fundamental as at first supposed, and that these solutions are 
chemically active in relation to the living protoplasm. 

At the present time much attention 'is being given to the effects of 
asphyxiation on the physiological activity of living tissues that are isolated 
from the normal circulation. The artificial solutions can be made more 
efficient by shaking with air before using, or by shaking with pure oxygen. 
Isolated mammalian hearts give much more constant characters in their 
response to artificial solutions which contain defibrinated blood, prefer- 
ably from the animal supplying the heart. Even with five to ten percent of 
blood such solutions are strikingly more efficient, supposedly because they 
are much better oxygen carriers. For cats' hearts Locke-blood solutions 
aerated by a stream of oxygen are very efficient indeed. 

1. Physiological salt solution or normal saline. Sodium chloride 
in distilled water 0.7 percent. More exact isotonicity is secured by 0.6 
percent for frogs, 0.7 percent for terrapin and 0.9 percent for mammals. 

2. Ringer's solution. The Ringer's solution that imitates the blood 
serum in its effects on heart tissue is made up in this laboratory in the 
following proportions: 

Sodium chloride, 0.7 percent. 
Potassium chloride, 0.03 percent. 

64 



ANESTHESIA. 65 

\ Calcium chloride (cryst. computed water free), 0.026 percent. 
For heart work where a more rapid rate is desired the amount of potas- 
sium must be reduced to that in Ringer's original formula. 
Sodium chloride, 0.7 percent. 
Potassium chloride, o.oi percent. 
Calcium chloride (cryst. computed water free), 0.026 percent. 

3. Locke's solution. Locke's solution is a mixture of the salts in 
Ringer's solution with dextrose added to make o.i percent. 

Sodium chloride, 0.7 percent. 
Potassium chloride, 0.03 (or o.oi) percent. 
Calcium chloride (cryst), 0.026 percent. 
Dextrose, o.i percent. 

4. Locke-blood solution. . Add 5 to 10 percent of defibrinated whole 
blood to the above Locke's solution. 

ANESTHESIA. 

The mammals usually available for laboratory experimental purposes 
are dogs, cats, rabbits and guinea-pigs, each of which can best be anesthe- 
tized by a special treatment of its own. 

Dogs. Give a lo-kilo dog i c.c. (17 minims) of 2 percent mor- 
phine under the skin of the shoulder, holding its head firmly between the 
operator's legs while the hypodermic injection is being given. Allow 15 
minutes or more for the morphine to take effect. The morphine should be 
followed by chloroform or chloroform and ether in equal parts. Give it 
by means of a small nose hood made by sewing a cheese-cloth, that has been 
folded in the form of a blunt cone, to a wire ring, or use a Senn's inhaler 
mask. When the voluntary movements have about ceased, tie the dog to a 
holder and take it to the experimental table. The tests of good anesthesia 
are: i, loss of voluntary movements; 2, no cutaneous reflexes; 3, slight 
corneal reflexes or none in deep anesthesia ; 4, even and fairly deep respira- 
tion; 5, medium blood-pressure and pulse. This condition of anesthesia 
is maintained by giving chloroform from a dropping-bottle at abso- 
lutely regular intervals of 30 seconds by the watch. The number of 
drops necessary for each animal will quickly be found by trial. In the 
experience of this laboratory it is from 3 to 6 drops per 30 seconds. The 
success of most pharmacological experiments on dogs depends upon main- 
taining an absolutely even anesthesia. 

Cats. A mixture of equal parts of chloroform and ether is the most 
5 



66 EXPERIMENTAL PHARMACOLOGY. 

practical anesthetics for cats. These animals are anesthetized most conven- 
iently by putting them in a box of about two cubic feet in dimension and 
provided with a close cover. A very convenient box is the tin display 
cracker box with glass window obtained of the grocer. Drop in the box with 
the cat a small strip of cheese-cloth saturated with chloroform-ether mix- 
ture, ID c.c. in broken doses will anesthetize a cat in lo minutes. As 
soon as the animal falls down under the influence of the anesthetic it 
should be taken from the box, fixed in the holder, and the anesthetic given 
from a cloth in the manner and with care prescribed above for the dog. 
Cats do not survive pure chloroform in the hands of the ordinary student 
anesthetist. 

Rabbits. Give rabbits 2 grains of urethane by the mouth. Follow 
with light and careful use of ether. Or pure ether may be given without the 
urethane. Give the ether in the manner and with the regularity recom- 
mended above for giving chloroform to dogs. Do not use chloroform or 
even chloroform mixtures with rabbits. 

Guinea-pigs. These little animals when they must be used for 
pharmacological purposes are anesthetized best with pure ether or ether 
followed with a little morphine. 

THE PREPARATION OF THE VENTRICULAR MUSCLE. 

Destroy the brain of a terrapin, remove the plastron and open the peri- 
cardium. Grasp the left angle of the base of the exposed ventricle with a 
forceps and cut with a scissors from this point around the apex to the oppo- 
site side, thus removing a piece about one inch long and the size of the half 
of a small lead pencil. Split this strip into two or three smaller ones for 
class use. 

To mount the heart strip tie silk threads to each end, one with a loop 
one-half inch long and the other with a loop about four inches long. Place 
the short loop on the hook of the glass-rod support provided for the purpose, 
and the long loop over the recording lever. Use a straw lever of the power- 
fulcrum-weight order mounted in a muscle lever holder. A total tension of 
one gram is best for developing the contractions of the ventricular strip. 

The holder mentioned above is made of a glass rod 4 to 5 mm. diameter 
and 15 cm. long. Bend it at a right angle in the middle and then draw out 
and turn a hook on one end, the hook being turned back on the rod. The 
apparatus set up complete consists of a single iron stand with three clamps, 
the top one to support the lever holder, the middle the glass rod, and the bot- 



THE PREPARATION OF THE VENTRICULAR MUSCLE. 



67 




Fig. 34. — The terrapin's heart, ventral view, showing how to cut an apex strip 
for experimental purposes and how to split this apex into smaller pieces. 




Fig. 35. — Apparatus as set up to demonstrate the contractions of the apex muscle 
of terrapin's ventricle. The glass L-shaped holder should be set on the stand high 
enough to allow of easy change of solution tubes. The figure shows the tube of physio- 
logical saline and other details for the better illustration of the mounting of the heart strip 



68 



EXPERIMENTAL PHARMACOLOGY. 



torn one a platform on which rests the footed test-tube (1x3 inch specimen 
tube) to contain the solution surrounding the strip. The ventricular strip 
mounted in this apparatus with a tension of one gram and bathed in a solu- 
tion of 0.7 percent sodium chloride will begin rhythmic contractions in from 
10 to 40 minutes. These contractions will continue about two hours, 
growing constantly smaller for the entire time. The strip may then be 
revived by a bath of Ringer's solution or by serum, and may again be used 
in the sodium chloride bath. 



TO TEST THE ACTION OF DRUGS ON THE FROG'S OR 
TERRAPIN'S HEART. 

Two methods are used in this laboratory for the study of the action of 
drugs on the frog's heart, both permitting of permanent records. The 




Fig. 36. — Showing the method of recording the action of the frog's heart in place 
n the body cavity. If the perfusion method is used the canula can be inserted with 
greater ease if the frog is reversed on the support. 

most convenient method is to pith the frog, open the thorax and expose 
the heart, adjust the foot of a delicately poised heart lever on the venticle 
and, while the record is being taken, irrigate the surface of the heart with the 



IRRIGATING AND PERFUSING FLASKS. 69 

drug. Dissolve the drug in physiological saline and always take a previous 
normal record under saline irrigation. This method requires the use of 
relati\'ely strong solutions. The most convenient irrigating bottles are four- 
or eight-ounce aspirator bottles with tubed foot for rubber connector. These 
are each provided with a small-mouthed canula attached by a short rubber 
connection, and the flow is regulated by a screw compress. Fit these 
flasks with Marriotte stoppers and support them on a stand by a universal 
buret clamp about the neck. 

The second method, that of perfusion, is carried out best as described 
by Walden in the American Journal of Physiology, Volume III, page 123. 
Insert a canula into the inferior vena cava for an inflow and one in the aorta 
for an outflow, or merely cut one aortic branch and let the outflow go free. 
The canula is connected with two supply bottles, one for physiological saline, 
the other for the drug in solution. The Marriotte stoppers should be set 
at exactly the same pressure levels. Connect the two flasks with the inflow 
canula by a T-tube brought as close as possible to the heart in order that 
the solutions may be changed quickly with only a short connecting tube to be 
washed out. Very weak solutions of drugs are required by this method of 
perfusion. The frog's heart is quickly exhausted in pure saline solutions, 
so, for certain prolonged experiments it is better to use the weaker Ringer's 
solution for dissolving the drug. 

Record the contractions of the ventricle by a thread from its apex to 
the ventrical arm on a balanced horizontal lever. A flexible paper or 
celluloid writing point will add to the accuracy and beauty of the records. 
These writing points should be 2 to 3 cm. long by 0.5 cm. wide and made 
of Hght-weight but hard note paper. 

IRRIGATING AND PERFUSING FLASKS. 

The quarter- and half-pint aspirator bottles manufactured by Whitall, 
Tatum & Co., with tubed foot for attaching a rubber tube are particularly 
adapted to both irrigation and perfusion of the heart. For use in irrigation 
these bottles are clamped to a heavy based stand by a universal buret clamp 
on the neck. Insert a tight-fitting rubber stopper with a 2 mm. glass tube, 
to give a constant pressure level. A short heavy rubber connector provided 
with a small screw compress and a glass dropper serves to regulate the speed 
of the outflow. Such a flask attached to an independent stand and set at a 
level so that the fluid drops only a few millimeters is an exceptionally satis- 
factory method of applying solutions directly to the surface of the heart. 



70 EXPERIMENTAL PHARMACOLOGY. 

Two perfusion bottles may be connected together by a T-tube for per- 
fusion work. In this case the inflow canula is connected by a very short 
(6 to lo cm.) tube of small caliber and is supported firmly by a clamp on 
the T-tube. Or a Y-canula can be used and the flasks attached directly to 
its limbs. In either case it is better to insert a small T-tube with light 
spring clamp in order to wash out any drugs in the tubing. This canula, 
when provided with an overflow, as shown by Gibson and Schultz in an 
article now in manuscript, permits change from one solution to another 
without a break in the pressure of the fluids. The connecting tubes for 
the flasks should be 25 to 30 cm. long to permit adjusting. Set screw or 
spring compresses near the bottle. Fill one flask with the normal solution, 
the other with the drug. A very small amount of the fluid can be applied 
by means of these perfusion flasks. 

TO TEST THE ACTION OF DRUGS ON THE BLOOD-PRESSURE, 
RESPIRATION, ETC., OF A MAMMAL. 

1. The anesthetic. For anesthesia methods see page 65. 

2. The operations. Blood-pressure is taken from one of two arteries, 
the right common carotid, or the femoral artery. The femoral is practical 
only for the dog. To expose the common carotid make a three-inch cut 
over the trachea from the proximity of the larynx to the manubrium. Sepa- 
rate the muscles down to the trachea, and then along the side of the trachea 
till the common carotid artery and vagus come into view. Use the scalpel 
handle and tear rather than cut the facias and muscles involved. Avoid 
the veins and the laryngeal arteries. No blood need be lost after the skin is 
cut. Separate the fascia binding the artery and vagus, using care not to injure 
the latter. Place a bulldog forceps on the artery well toward the thorax. 
Ligate the cephalic end. Lay and tie a ligature loosely about the intervening 
stretch of artery for the canula. Grasp the artery at the cephalic ligature 
and use the tip of the scissors to make a V-shaped cut two-thirds through 
the artery wall and directed toward the heart. Insert the canula and ligate 
it firmly with the ligature already laid. 

The femoral artery is exposed by a 5 cm. cut over the artery where 
the pulse can be felt near Poupart's ligament. The artery is prepared and 
the canula inserted as described for the carotid. 

The saphenous vein or the jugular are used for injecting drugs. 
Insert a small washout canula toward the heart choosing the vein exposed 
by the previous operation. Keep the vein closed with a bulldog forceps in 



ACTION OF DRUGS ON THE REFLEXES OF A FROG. 7 1 

order to prevent small clots in the mouth of the canula, except when in- 
jections are to be made. 

Tracheotomy should generally be performed for all student work on 
the mammals used in blood-pressure experiments in pharmacology. Free 
the trachea immediately below the thyroid cartilage and insert a metal 
canula made especially for the dog, or insert one limb of a glass T-tube of 
as large size as the trachea will take. Tie it firmly with small stout twine. 

The apparatus consists of a continuous paper kymograph (Ludwig's 
weight-driven pattern arranged to run the paper in the right-handed direction 
is the most satisfactory instrument) ; mercury manometer for measuring the 
blood-pressure; respiration tambour (Marey's form); signal pen to record 
stimulations, injections and other events; time signal; stimulating coil and 
accessories complete; and a jacketed buret for transfusing warm solutions 
into the vein. The recording pens of the manometer, tambour, signals, etc., 
must all be adjusted to the kymograph in an exact vertical line. Fill the 
lead tube of the manometer with lo percent magnesium sulphate from a 
pressure bottle, take the zero level of the manometer, set the time signal to 
write on this level, connect with the canula, and fill to a pressure of 130 mm. 
mercury. Connect the respiration tambour directly with the side branch of 
the tracheal tube. Start the kymograph, ink all the pens, remove the arterial 
bulldog clamp, and the experiment is ready to begin. 

A renal onkometric record should be taken with blood-pressure in the 
investigations on certain drugs. Open the abdomen along the entire median 
line, cut the wall transversely for two to three inches over the left kidney. 
Strip the kidney of its fat and looser coverings and enclose it in a renal 
onkometer. Adjust the overflow from the onkometer to the exact kidney 
level and take a record of the variations with a small sized Brodie's bellows 
recorder adjusted in line with the recorders mentioned abo\'e. 

METHOD OF TESTING THE ACTION OF DRUGS ON THE . 
REFLEXES OF A FROG. 

Carefully destroy the brain and the medulla, but not the cord. Pre- 
vent the loss of blood. Suspend the frog to a horizontal rod on a stand, 
using a card hanger or a loop of string on the upper jaw. Stimulate the tip 
of the toe with acid or with platinum electrodes and measure the reaction 
time by counting seconds until the foot is withdrawn. The reaction time 
may be recorded on a kymograph. Attach a horizontal writing point of 
mucilaged paper to the leg above the foot. Take the speed of the drum with 



72 EXPERIMENTAL PHARMACOLOGY. 

one magnet beating seconds, and record the instant of stimulation with a 
second and independent magnet controlled by a contact key. 

Take the normal reaction time first, then give the drug as an injection 
in the dorsal lymph sac and allow about 20 minutes for absorption. Re- 
measure the reaction time and repeat at intervals of 10 minutes to get the 
progressive effects of the drug. 

METHOD OF GIVING AND TESTING THE ACTION OF A DRUG 
ON THE FROG'S GASTROCNEMIUS MUSCLE. 

One should always compare the drugged muscle with a normal or un- 
drugged muscle from the same frog. This may be done in one of two ways. 
I St. With the circulation undisturbed. Pin the frog face down on a frog- 
board, isolate and attach the tendon Achilles to a muscle lever, isolate and 
stimulate the sciatic at its origin in the lumbar plexus using care not to dis- 
turb the circulation, or stimulate the muscle directly. After a normal record 
is secured then give the drug in the usual way and take a record of the other 
or drugged muscle. 2d. Lay a ligature about one leg near the thigh tight 
enough to stop its circulation. Give the drug by injection into the dorsal 
lymph sac, or abdominal cavity, and after absorption is complete and the 
tissues have been acted on by the drug (20 to 30 minutes) dissect out the 
gastrocnemii and test. Always use the undrugged muscle first and the 
drugged one immediately following. While the normal muscle work is being 
• tested the drugged leg should have its circulation stopped by ligature. This 
leaves the two muscles in more nearly the same state of nutrition and 
asphyxiation. It is usually best to stimulate the muscle directly. There 
are three tests that can be applied: i. Irritability, by the minimal stimu- 
lus method; 2, Rapidity of the simple muscle contraction; 3, The amount 
of work a muscle will do with simple contractions at constantly repeated 
intervals. In this latter test stimulate once in two seconds, record on a 
drum with speed of i mm. per second. 

TRANSFUSION BURET FOR MAMMALS. 

Transfusions of several cubic centimeters of liquid should be warmed 
to body temperature. Inclose a 50 c.c. buret in an ordinary Liebig's con- 
denser jacket and mount vertically on a heavy base stand. Mount and 
connect a 6-inch funnel with the upper side tube of the condenser. Attach 
a rubber tube fitted with a spring compress clamp on the lower side tube to 



ARRARATUS FOR THE STUDY OF THE ISOLATED MAMMALIAN HEART. 73 

regulate the outflow of the warm water introduced by the funnel to keep the 
perfusion liquid at the proper temperature. Mount a thermometer inside 
the condenser with its bulb near the lower end of the apparatus. The buret 
connections with the transfusion canula should be as short as possible and 
their tubes should be provided with light screw-compresses. Where only 
I or 2 c.c. of liquid is to be introduced it is unnecessary to warm it. In fact 
a hypodermic syringe is most convenient where the volume of the injection 
does not exceed 1.5 c.c. 

APPARATUS FOR THE STUDY OF THE ISOLATED MAMMALIAN 

HEART. 

The mammalian heart isolated completely from the body can be 
maintained in constant activity for several hours. It gives constant responses 
to drugs in solution in the perfusion liquid best adapted to maintain its 
life, i.e., Locke's solution with a small quantity of the animal's defibrinated 
blood. Cats and rabbits are especially well adapted to this experiment. 
The smaller size of the cat's or rabbit's heart makes it preferable to that of 
a dog. 

The points to be secured in the isolated heart apparatus are: i. A 
uniform temperature of about 37° Centigrade. 2. An adjustable pressure 
for the perfusion fluid. 3. A device for quickly shifting from the normal 
perfusion to the drugged perfusion fluid without change in temperature, 
pressure or any other factor than the presence of the drug. 4. An accurate 
recording device. 

The apparatus shown assembled in Fig. 37 accomplishes all of the 
above points. The gas water heater connected as shown will maintain a 
uniform temperature in the water jacket through which the perfusion tubes 
run to the heart canula. The overflow from the water jacket is conducted 
into a pan in which the perfusion fluid reservoirs receive preliminary warm- 
ing. The heart is attached to a very short canula beneath the warming 
jacket and the overflow of perfusion fluid maintains a temperature of the 
heart only slightly below that of the warming jacket. 

The pressure on the heart, i.e., on the perfusion fluid, is accomplished by 
connecting the perfusion bottle with an air or oxygen reservoir, and this in 
turn with a water reservoir which can be raised or lowered. The flow of 
water from the pressure bottle into the closed system produces the desired 
pressure on the perfusion system. At the same time the perfusion fluids 
are aerated by the air (or oxygen) as it is forced into the reservoir, a result 



74 



EXPERIMENTAL PHARMACOLOGY. 



accomplished by conducting the perfusion bottle inlet tubes to the bottom 
of the containers. 

A uniform pressure is secured on both the normal and the drugged per- 
fusion fluids by the system of tubes shown. If the clamp is removed from 



K>= 



Gulhne Cariiograph 





Fig. 37. — Illustrating the assembly of apparatus for the pharmacological study of 
the isolated heart of a mammal. The legends on the apparatus are self-explanatory. 



the outflow tube of the drugged perfusion fluid at the exact moment a second 
clamp is placed on the tube from the normal fluid reservoir (or vice versa) , 
the shift will be accomphshed without change of pressure on the heart. The 
tubes run independently to the canula which is itself so short that the time 



LIST or STOCK SOLUTIONS. 75 

from the moment of turning a perfusion fluid on or off is reduced to a mini- 
mum. The canula is provided with a side washout tube. 

The Guthrie cardiograph shown is very adjustable in all essential fea- 
tures. It gives satisfactory and accurate records, if care is used in inserting 
the lever tips into the walls of the heart. This apparatus permits a direct 
record on the ordinary kymograph. It also permits one to surround the 
heart with a warm cup or jacket where greater constancy of temperature is 
desired, as in research work. 



LIST OF STOCK SOLUTIONS. 

Make the solution up in 0.7 percent sodium chloride solution and in Ringer's 
solution. Special solutions must be prepared for the mammalian heart experiments. 

Aconite o.i percent. 

Adrenalin hydrochloride o.ooi percent, o.oi percent, 0.05 percent, o.i percent. 

Alcohol 95 percent, 2 percent, 5 percent, 10 percent, 20 percent. 

Amyl nitrite 0.1 percent, pearls. 

Atropine o.ooi percent, 0.002 percent, 0.1 percent, 0.2 percent, i percent, 2 per- 
cent, 5 percent, and 1/120 grain tablets. 

Barium chloride o.oi percent, 0.1 percent, 0.2 percent, i percent. 

Caffeine 0.1 percent, 0.2 percent, 0.5 percent, e percent. 

Calcium chloride 0.03 percent, 0.06 percent, i percent. 

Carbolic acid 0.5 percent, i percent, 10 percent. 

Chloral hydrate 0.1 percent, i percent, 2 percent. 

Chloroform 0.05 percent, 0.1 percent, 0.5 percent, 20 percent in oil, pure. 

Cocaine hydrochlorate o.oi percent, 0.2 percent, 0.5 percent, i percent, 2 percent. 

Codeine 0.5 percent, i percent. 

Curare 0.2 percent, i percent. 

Digitalis 0.0005 percent, o.ooi percent, 0.002 percent, 0.1 percent, 0.2 percent, 
0.5 percent, i percent. 

Ether i percent, 2 percent, 4 percent, 6 percent, 8 percent, pure. 

Ergot Squibb's fluid extract, 10 percent of fluid extract. 

Hyoscyamine i percent. 

Locke's solution. 

Morphine acetate i percent, 2 percent, 10 percent. 

Nicotine 0.02 percent, 0.1 percent, 0.2 percent, i percent. 

Nitroglycerine 0.1 percent. 

Physiological saline 0.7 percent. 

Physostigmine 0.1 percent, i percent. 

Pilocarpine nitrate 0.1 percent, i percent, 10 percent. 

Potassium chloride 0.03 percent, i percent, 5 percent. 

Potassium bromide 5 percent. 

Quinine hydrochlorate 0.1 percent, i percent. 

Ringer's solution, weak, strong. 

Sodium nitrate o.oi percent, 0.02 percent. 

Sodium sulphate i percent. 

Strychnine nitrate i percent, 0.1 percent, .02 percent. 

Thebaine 0.5 percent, i percent. 

Veratrine 0.05 percent, 0.1 percent, i percent, i percent of fluid extract. 



76 EXPERIMENTAL PHARMACOLOGY. 

REPORT FORM FOR EXPERIMENTS ON FROGS. 

Animal Name 

Weight Date 

Experiment 

I. Normal Reactions. 

3. Respiration 4. Reflexes 5. Eye 



I. Position, Activity, 
etc. 



2. Circulation, Heart, 
Skin, Mucous Mem. 



II. Action or the Drug. 

Time Dose How given Dose per kilo. 

Observations on: 
h. m .s. ■ Apfjyijipg 2. Circulation 3. Respiration 4. Reflexes, etc. 5. Eye 



III. Summary. 



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