PHYSIOLOGY AND EXPERIMENTAL PATHOLOGY 113 



Gautrelet and Thomas (e) claim that the excitability of the sympathetic, 

 especially the abdominal, becomes very much lowered a few hours after 

 epinephrectomy. They used as criteria the pupillary response from stimu- 

 lation of the central end of the cut vago-sympathetic nerve trunk and 

 the blood pressure response from sciatic and splanchnic stimulation. 

 Stimulation of the depressor nerve in the decapsulated rabbit produced no 

 effect. (Blood pressure was 50 mm. Hg.) During the stage when the 

 heart becomes weak and the blood pressure becomes low, the vagus was 

 found to be less irritable than normal. They attributed the rapid heart 

 action in part to a loss in the vagus function because stimuli which for- 

 merly stopped the heart merely decreased the rate after decapsulation. 



After the removal of both suprarenals in the raBbit Roger (a) , on the 

 other hand, obtained greater inhibition of the heart by vagus stimula- 

 tion than is produced normally. Cardiac escape was later than usual 

 and the secondary rise of blood pressure was absent. Continuous injec- 

 tion of an amount of epinephrin which produced no apparent effect on 

 blood pressure caused decapsulated animals to respond as do normal ani- 

 mals. Roger believes that the suprarenal glands are responsible for the 

 diminishing effects of repeated vagal stimulations. 



Hoskins and Wheelon have tested the sympathetic irritability hy- 

 pothesis by studying the effects of afferent nerve stimulation and of in- 

 jections of epinephrin and nicotin, upon blood pressure. These were 

 tried four to nine hours after removal of both suprarenals in the dog. 

 Normal responses were obtained but this may have been due to an insuffi- 

 cient time for the development of symptoms. 



More to the point were the experiments of Hoskins (g) which indicated 

 that sympathetic failure was not a primary feature of the syndrome. Even 

 when a decapsulated animal had become so weak that it could scarcely 

 stand, its vasomotor system responds to stimulation perfectly well. There- 

 fore sympathetic failure is secondary, being preceded by muscular and 

 cardiac weakness. 



Yet it does appear from the numerous observations which indicate a 

 lessened irritability of portions of the autonomic nervous system, that this 

 is a frequent symptom in the advanced stage of suprarenal insufficiency. 

 More evidence is desirable. 



Post-mortem Findings in Suprarenal Insufficiency 



The most important post-mortem finding following suprarenal insuffi- 

 ciency is perhaps that sometimes occurring in the central nervous sys- 

 tem. Ettlinger and Nageotte have found vacuolization of the nerve 

 cells in animals which died a few hours after the operation (dog), while 

 similar changes failed to appear in control animals. The modification 



