Section IV. 1917 li23] Trans. R.S.C. 



On the Relations of the Adrenal Medulla to the Normal Blood-pressure in 



Animals. 



By K. J. AusTMANN, C. W. Halliday and Swale Vincent. 



(From the Physiological Laboratory, University of Manitoba, 



Winnipeg.) 



(Read May Meeting, 1917.) 



In the present communication a summary is given of some experi- 

 ments bearing upon the orthodox theory that the normal tone of the 

 svmpathe tic nervous system (particularly as exemplified in its effect 

 upon the normal blood-pressure), is maintained by the internal secre- 

 tion of the medulla of the adrenal bodies. Previous experiments in 

 this laboratory by Young and Lehmann,i 2^ ^nd by Young alone,^ 

 pointed strongly to the view that the normal blood-pressure is in- 

 dependent of the adrenal bodies. It was found that when these organs 

 were ligatured off, the blood-pressure did not fall even after con- 

 siderable lapse of time. The time allowed in these experiments was, 

 however, not sufficiently long to be completely convincing. In the 

 present series dogs have been employed, and have been maintained 

 after extirpation of the adrenals, or after ligature of their vessels as 

 long as possible under simple ether anesthesia, a continuous record of 

 blood-pressure being taken. The curve thus obtained has been care- 

 fully compared with that obtained from control animals similarly 

 kept under ether, but with the adrenals intact. With a few individual 

 exceptions the curves were very similar in the two cases. The adrenal 

 animals lived as long as the intact ones, and the blood-pressure showed 

 no greater tendency towards a fall. In both instances the animals 

 were kept alive for from twelve to thirty or forty hours. 



These experiments do not lend any support to the theory that the 

 normal blood-pressure is dependent upon the adrenal secretion. 



lYoung and Lehmann: Report of Ductless Glands Committee, Brit. Ass. 

 Dublin, 1908. 



^Young and Lehmann: Journ. of Physiol., July 18, 1908, XXXVI. 

 ^Young and Vincent "Internal Secretion," 1912, p. 221. 



