198 CORTEX 



decerebration. Hence the adrenals are not the only organs 

 involved in the changes in carbohydrate metabolism which 

 follow the operations described above. The parasympathetic 

 nerves by influencing the secretion of insulin from the pancreas 

 also play a part. The liver is also affected directly for if the 

 hepatic nerves are cut, stimulation of the splanchnics produces 

 a lesser degree of hyperglycemia than normally. 



In considering the relation of the adrenal glands to carbo- 

 hydrate metabolism, it is necessary to dissociate the effects 

 due to epinephrine and those due to the cortical hormone. 

 As we have seen in Chapter VII, epinephrine exerts a striking 

 hyperglycemic activity. The hyperglycemia which follows 

 the injection of many drugs and accompanies various physio- 

 logical procedures is due to the liberation of epinephrine from 

 the medulla. Hyperglycemia can be elicited, however, in the 

 absence of the adrenals, as Stewart and Rogoff 588 and others 

 have shown, so that epinephrine is not the sole agency re- 

 sponsible for a rise in the blood sugar. For example, Sund- 

 berg 606 has shown that operative interference, pain, etc. give 

 rise to an hyperglycemia in adrenalectomized animals, but the 

 hyperglycemic response is less marked than it is in animals 

 with intact glands. 



In the adrenalectomized animal, not only is there an absence 

 of the medullary secretion, but, unless the cortical hormone is 

 administered, the results are complicated by the partial corti- 

 cal insufficiency which may be simultaneously produced. The 

 variation in the degree of this cortical insufficiency accounts 

 for. the divergence in the results obtained by different authors 

 on the reaction of the blood sugar to stimuli after excision of 

 the adrenals. 



EFFECTS OF CORTICAL INSUFFICIENCY 



Bierry and Malloizel 58 in 1908 first demonstrated the exist- 

 ence of hypoglycemia in dogs after adrenalectomy. This result 

 was confirmed by Porges 611 who also showed that the hypogly- 



