142 



G. N. STEWART 



by a vaso-cpnstriction if the suprarenals have not been interfered with, but 

 only show the initial passive dilatation due to the rise of blood-pressure, 

 if the suprarenals have been extirpated. He drew the conclusion that 

 stimulation of the sciatic reflexly increases the rate of liberation of epi- 

 nephrin. But granting that the characteristic vaso-constriction can only 

 be elicited with intact adrenals, and von Anrep's careful work has been 



recently confirmed by Pearlman and Vin- 

 cent, this does not prove that during stim- 

 ulation of the nerve more epinephrin is 

 being poured into the blood per unit of 

 time than without stimulation, for during 

 the stimulation the condition of the test 

 object is greatly altered. The rise of blood- 

 pressure must necessarily increase the rate 

 of blood flow through the denervated region. 

 If the suprarenals merely continue to dis- 

 charge epinephrin at the normal rate, the 

 amount of epinephrin passing per unit of 

 time through the vascular tract in question 

 is abruptly and markedly augmented. If 

 such denervated areas are as sensitive to 

 epinephrin as is claimed, they may be ex- 

 pected to respond to this increase in the 

 amount of epinephrin traversing them, even 

 if no change whatever has taken place in 

 the rate of liberation from the suprarenals. 

 That such a redistribution of the epi- 

 nephrin-contaimng blood, without any in- 

 crease in the output, can elicit the reaction 

 is shown by the observation of v. Anrep 

 himself, that "if one splanchnic nerve is 

 intact while the suprarenal on the other side 

 is extirpated, stimulation of the splanchnic 

 nerve on the side of the extirpated supra- 

 renal may still cause constriction of a 

 denervated limb. Only after the other 

 splanchnic nerve is cut does the constric- 

 tion disappear." The reaction studied by v. Anrep accordingly is not at 

 all out of harmony with the observations of Stewart and RogofT(/) (1916, 

 1920), who, working with cat's suprarenal blood obtained from a cava 

 pocket, and estimating quantitatively the rate of epinephrin output on 

 rabbit intestine segments (Fig. 11), failed to obtain any definite effect 

 upon the output when sensory nerves were stimulated. They pointed out 

 that observations, made without regard to changes in the rate of blood 



Fig. 13. Uterus tracings, with 

 blood specimens from the same 

 cat as in Fig. 12. Ringer's solu- 

 tion was replaced at 45 by the 

 2nd suprarenal blood specimen 



(without asphyxia) ; at 46 by 

 the 4th specimen (asphyxia) ; at 

 47 by the 3rd specimen (with- 

 out asphyxia). Specimens were 

 diluted with 16 volumes 

 Ringer's solution. Ringer's so- 

 lution was replaced at 50 by 

 "adrenalin" in jugular blood 



(1:1,600,000); and at 51 by 

 "adrenalin" in jugular blood 



(1:800,000). The "adrenalin" 

 was added to the undiluted blood 

 in the concentrations mentioned, 

 the mixtures being then diluted 

 with 16 volumes Ringer's solu- 

 tion before application to the 

 segment. (Reduced to one-half.) 



(After Stewart and Rogoff, J. 

 Pharm. & Exper. Therap.) 



