420 EXPERIMENTAL PHARMACOLOGY 



peutic stage of the action of digitoxin ? Discuss the action 

 of the drug; on the heart in detail. 



EXPERIMENT CXXXI. 



Digitoxin, Strophanthin. (Dog: Diuresis, Spleen Volume, 

 Leg 1 Volume, Blood-pressure and Respiration.) 



1. Arrange a dog for recording blood-pressure and leg 

 volume. Then open the abdomen and isolate both ureters 

 near the bladder. Place a cannula in each ureter and ar- 

 range to collect the urine secreted. Now place the spleen 

 in an oncometer and arrange to record the volume changes 

 of the organ. On the drum the spleen volume should be at 

 the top, next below the leg volume, then the blood-pressure 

 and respiration with the time marked on the base line. The 

 rate of urine flow may be recorded with a signal magnet by 

 a hand key and dry cell if desired. The injecting burettes, 

 contain digitoxin (ten cubic centimeters equal one milli- 

 gram) and strophanthin (ten cubic centimeters equal one 

 milligram). 



When all is ready wait a while to get a record of the nor- 

 mal rate of urine secretion. Then take a normal record and 

 inject one cubic centimeter of digitoxin solution. Is the 

 dose too small? Give one cubic centimeter of strophanthin. 

 Which affects the animal the most ? Inject a few more 

 doses very cautiously and then wait for some time to see if 

 the rate of urine flow is changed. If it is how does this com- 

 pare with the action of caffeine or sodium sulphate? 



After time has been given for an action on the kidney to 

 develop (is this certain to occur.') then adjust all writing 

 points and take a normal. Then inject a good sized dose of 

 digitoxin as estimated from your previous experience with 

 the drug and with the animal. How does this affect the 

 spleen and leg? Do the other records show a correspond- 

 ing action? Wait a while and give a similar injection of 

 strophanthin. How does the action of this drug compare 



