SIGNIFICANCE OF THE SUPRARENAL GLANDS 159 



iter by Waterman (c), that after piqiire epinephrin can be demonstrated in 

 general venous blood is erroneous. The Meltzer-Ehrmann (frog's 

 all) reaction employed by these observers is useless for this purpose, 

 is has been well pointed out by Schultz(6). Even in the arterial blood and 

 dth a much more sensitive method (the frog perfusion preparation) no 

 epinephrin has been detected after piqiire (Kahn(c), v. Briicke, Negrin y 

 Lopez). 



The proper way to settle this question is to collect blood from the 

 suprarenal veins and to assay its concentration in epinephrin by a reliable 

 method. This has been attempted by Kahn(d) (1912) and by Quinquaud, 

 (1915), who convinced themselves that there was some increase in the con- 

 centration of epinephrin in the blood of the suprarenal veins after piqiire. 

 But the experiments were few and not very consistent, and in the absence of 

 exact measurements of the rate of blood flow they cannot be accepted as 

 proof of an increased output. A diminished blood flow would be not 

 unlikely to be present some hours after piqiire and this of itself would entail 

 an increased epinephrin concentration if the output had remained un- 

 altered. There is in any case no proof and little probability that if an 

 increase had been demonstrated in the epinephrin output, it could ever be 

 great enough to cause a demonstrable increase in the blood sugar content. 

 By an indirect and not very satisfactory method Trendelenburg and 

 Fleischhauer reached the conclusion that the rate of discharge of epi- 

 nephrin is not increased by the diabetic piqure. 



The second method of testing the question, inducing the conditions 

 associated with hyperglycemia (or glycosuria) after the suprarenals have 

 been interfered with so as to render an increase in the epinephrin output 

 impossible, has been much more extensively employed. Although many 

 observers have come to the conclusion that in the absence of the suprarenals 

 the experimental hyperglycemias in question do not occur, this is due 

 solely to the fact that essential conditions were neglected. Of these the 

 most important are : 1. An increase in the sugar content of the blood and 

 not the appearance of sugar in the urine should be the test. It is well 

 known that little or no urine may be secreted in acute experiments, after 

 such operations as epinephrectomy and piqure, and the absence of gly- 

 cosuria has then no value. 2. The glycogen store must be adequate to 

 permit of a decided hyperglycemia. Negative results cannot otherwise be 

 accepted. The only sure way is to estimate the liver glycogen. 8. Only 

 animals which have completely recovered from the effects of the operation 

 practiced to eliminate the epinephrin output of the suprarenals should 

 be used, e.g., rabbits which have survived double epinephrectomy, and cats 

 after removal of one suprarenal and section of the nerves of the other. 4. 

 At least one major splanchnic nerve should be left intact. It is quite 

 unphysiological to sever the splanchnics on both sides when the question 

 is to decide whether the suprarenals are essential for the production of a 



