PITUITEIN AND ACOXIT1NE 393 



to ten kilo dog) of pituitrin solution. How does this affect 

 the blood-pressure? What happens to the respiration 1 ? 

 Is this a central or a peripheral action? After the records 

 return to normal (see that all pointers are recording 

 properly) inject a second dose of one cubic centimeter and 

 compare the results produced by this with those obtained 

 from the first injection. As soon as the records again reach 

 the normal (keep the anesthesia regular) inject a third dose 

 of one cubic centimeter. Does the animal become more or 

 less sensitive to the drug! Is the rate of urine flow affected 

 in any way ! If so how do you explain it ? Is the change 

 as great as you expected? How does it compare with caf- 

 feine or sodium sulphate ? Conthme giving pituitrin until 

 five or six (or more) cubic centimeters have been given, 

 watching for changes in the rate of urine flow in the mean- 

 time. Do the intestines show any signs of increased ac- 

 tivity! If so is this a nervous or muscular affair? Inject 

 some adrenaline and see how this affects the urine flow and 

 intestinal records. Do you see any signs of a tolerance 

 being developed for the pituitrin? If so to what is it due . ; 

 Does this occur with any other drugs '! Could you stand- 

 ardize an unknown pituitary extract by comparing the ac- 

 tion of various sized doses of the unknown with a standard 

 dose of a standard pituitary extract on the blood-pressure ? 

 This method is sometimes used to assay pituitary extracts. 

 In that case small sized doses are given and a considerable 

 period of time (fifteen minutes or more) is allowed to elapse 

 between each two injections. 



If the animal is still in fair condition place a solution of 

 aconitine "potent' 1 (ten cubic centimeters equal one iniUi- 

 f/r(U)i) in the burette and determine what is the very least 

 amount of the substance required to kill the animal. The 

 injections must be made cautiously. Watch for postmortem 

 intestinal contractions. Open the chest and see if the heart 

 is fibrillating. 



