PHYSIOLOGY OF EPINEPHRINE 93 



which was counteracted by the injection of 0.0007 mgs. of 

 epinephrine per kilo of body weight per minute they concluded 

 that the normal output of epinephrine is about 0.0035 mgs. 

 per kilo per minute which is more than ten times the amount 

 found by Stewart and Rogoff in their more direct measure- 

 ments, and fifty times greater than the results of Satake and 

 his collaborators to be described in a subsequent section. 



10. The "cava-pocket" method. This method originated by 

 Stewart and Rogoff 525 for determining the rate of secretion of 

 epinephrine from the adrenal glands involves the determination 

 of the amount of blood leaving the glands per minute and the 

 concentration of epinephrine in this blood. The veins empty- 

 ing into the vena-cava are ligated or clamped with the excep- 

 tion of the adrenal veins so as to form a pocket by the occlusion 

 of the vena cava beneath the diaphragm and below the entrance 

 of the adrenal veins. Into this "cava-pocket" only blood 

 from the adrenals can enter. By releasing the clamp at the 

 diaphragm the blood enters the general circulation and its 

 epinephrine content may be determined by an auto-assay 

 method. By releasing the lower clamp on the vena cava, 

 through a cannula, the rate of blood flow is measured. The 

 epinephrine content of the blood can also be determined by 

 assay on a segment of rabbit's intestine and confirming, if 

 necessary, on a segment of non-pregnant rabbit's uterus. 



11. The method of Satake, Sugawara, and Watanabe. Si5 

 Since anesthesia, pain, operative manipulations, etc. all may 

 modify the normal rate of secretion of epinephrine from the 

 adrenals, it is obvious that the methods already described are 

 inapplicable for determining the normal resting rate of epi- 

 nephrine discharge. The results obtained by these methods 

 may also be rendered abnormal due to the interference of the 

 above mentioned factors. In order to avoid the effects of these 

 vitiating factors, Satak6, Sugawara, and Watanabe* devised a 

 method whereby the rate of epinephrine secretion in the dog 

 could be determined without necessitating anesthesia, laparot- 



