5i8 



Pituitary and Carbohydrate Metabolism 



or blood-sugar levels, or the relative disposition of fed carbohydrate. It did 

 restore the glucose absorption rate to normal, the only method by which this 

 has been accomplished so far, and since the metabolic rate was increased, the 

 amount of carbohydrate which was oxidized in the hypophysectomized rats 

 given thyroid hormone was still much greater tjjan in the normal.^ The ad- 

 ministration of APE and thyroxin at the same time to hypophysectomized 

 rats permitted very nearly normal metabolic rates, absorption rates, and 

 peripheral deposition of carbohydrate (table 7). Only the liver-glycogen dep- 

 osition was still quite low. 



TABLE 7 



Carbohydrate Levels in Hypophysectomized Rats Fed Glucose 



(Four hours after feeding) 



In summary, it can be said that the thyroid hormone affects the general 

 metabolic rate, and thereby may limit the over-all rates of such processes as 

 gluconeogenesis or carbohydrate oxidation. It also controls the rate of in- 

 testinal absorption of sugars, but it does not appear to affect specifically any 

 other processes of intermediary metabolism. Certainly, it does not critically 

 affect the relationship of the anterior pituitary to carbohydrate metabolism 

 in any demonstrable way. 



The Adrenocorticotrophic RelatioJiship: Another important trophic re- 

 lationship of the anterior pituitary which may be concerned in the role of this 

 gland in metabolism is its effect upon the adrenal cortex. The present position 

 of the adrenal cortex in metabolism has been reviewed by Long and collabo- 

 rators,'" G. Evans,™ and Russell.^^ In summary, it appears that the adrenal 

 cortex has as its role in carbohydrate metabolism chiefly the making available 

 of protein as a source of carbohydrate. The exact point at which cortical hor- 

 mone is effective in this process is unknown. It affects the deamination of 

 amino acids to some extent,^- and the formation of carbohydrate from certain 

 keto acids derived from amino acids,'^ and it may also affect protein mobiliza- 

 tion directly, since under some circumstances gluconeogenesis from body pro- 



