90 MEDULLA 



when as little as 1 part of epinephrine is present in 100 million 

 parts of the perfusing fluid. 



Pisemsky's method is similar in principle to the Lawen- 

 Trendelenburg procedure just described. It utilizes the rab- 

 bit's ear as test object. Krawkow 367 finds this method to be 

 sensitive to epinephrine in a dilution of 1 to 10 to 50 million. 



4. The uterine strip method. Epinephrine inhibits the uterus 

 of the rat and stimulates the uterus of the rabbit. Concen- 

 trations of one part in 20 million inhibit uterine movements of 

 the non-pregnant cat. 148 



As shown by Cannon and Hoskins 105 the blood in asphyxia 

 may contain a substance other than epinephrine which inhibits 

 intestinal contractions. This substance inhibits the con- 

 traction of the non-pregnant rabbit's uterus, while epinephrine 

 increases the tone of this preparation. Hence by utilizing 

 both the intestinal strip and uterine contraction methods, one 

 can determine if the observed effect is really due to epinephrine. 



5. The excised-eye method. Epinephrine exerts a mydriatic 

 action on the enucleated eye. 174 A dilution of one part of 

 epinephrine hydrochloride per million causes maximal expan- 

 sion of the pupil. One part in 10 million causes a detectable 

 mydriasis. 451 



6. The anastomotic method of Tournade and Chabrol. 631 In 

 this method the adrenal vein of the experimental animal is 

 anastomosed with the jugular vein of an adrenalectomized dog. 

 The decrease in volume of the spleen of the recipient, as deter- 

 mined by an oncometer, serves to detect an increase in the 

 epinephrine content of the blood of the donor. 



Besides the effect on the splenic volume one can also utilize 

 other pharmacodynamic changes, induced by epinephrine; 

 e.g., the rise in blood pressure, dilatation of the pupil, tachy- 

 cardiac response, etc. 



7. Auto-assay method. 102 Instead of the anastomosis, just 

 described, the animal's blood may be allowed to act on its own 

 organs and the epinephrine determined by its effect on 1) the 



