100 MEDULLA 



the inspired air may not induce the same result. 105 The 

 hyperglycemia of asphyxia is only partially due to epinephrine 

 discharge for it occurs to some extent after removing the 

 adrenals. 



Hemorrhage. Applying the "cava-pocket" method to dogs 

 under ether, Saito 542 found that it was necessary to deplete the 

 blood about one-fifth of its total volume to elicit an increased 

 secretion of epinephrine by hemorrhage. In the unanesthe- 

 tized dog, on the other hand, the loss of only one-tenth the 

 total blood volume caused the liberation of two to ten times 

 the normal amount of epinephrine. This hypersecretion con- 

 tinued for about three hours. If one-third the total blood 

 volume was lost by hemorrhage, an output of epinephrine 

 10 to 30 times the normal occurred and continued for some 

 hours. 



The hyperglycemia observed after hemorrhage is due in 

 part only to this increased epinephrine discharge. 



Temperature. Hartman and Hartman 277 found an increase 

 in the epinephrine discharge from the adrenals (as measured 

 by the denervated iris) of cats when immersed in cold water 

 as a result not of the fall in body temperature but of the periph- 

 eral stimulation of cooling. Cannon and his collaborators 107 

 working with the denervated heart corroborated Hartman's 

 results and also found an augmentation in epinephrine dis- 

 charge during experimental fever, induced by the injection of 

 killed typhoid bacilli. They therefore inferred that epineph- 

 rine has a calorigenic function which in conjunction with 

 shivering serves to protect the organism against a drop in body 

 temperature. 



Saito, 642 on the other hand, in non-anesthetized dogs detected 

 no increase in the epinephrine discharge from the adrenals of 

 dogs subjected to cold. The application of excessive heat 

 (giving a rectal temperature of 41°C) resulted in an aug- 

 mentation of the epinephrine discharge. 



In man the cardio-vascular responses to cold are not such 



