THE PITUITARY BODY 



After hypophysectomy, rats continue to oxidize glucose 

 readily. In fact, when such animals depend upon their own 

 reserves of foodstuffs, as in fasting, they depend to an un- 

 usual extent on carbohydrate-oxidation for their energy re- 

 quirements (Fisher and Pencharz, 1936). Fisher and Pen- 

 charz also found that if hypophysectomized rats are fed glu- 

 cose, they oxidize more carbohydrate to supply energy than 

 do normal rats, despite the fact that the rate of oxygen- 

 consumption and of absorption of glucose is lower after 

 hypophysectomy.'^ A high-fat diet prior to glucose feeding 

 appeared to lessen the oxidation of glucose only slightly. 

 Greeley (1935) attempted to determine the rate of utilization 

 of glucose by hypophysectomized rabbits at the time of maxi- 

 mum need during fasting. He considered that such a need 

 occurred 5-8 hours after a drop in blood sugar appeared 

 (11-32 hours of fast) in fasting hypophysectomized rabbits. 

 He concluded that at least 0.50-0.67 gm. of glucose per kg. 

 body-weight per hour is required by an intravenous route, 

 if the blood sugar is to be maintained near (usually below) 

 the normallevel. Russell (1937) investigated the action of thy- 

 roxine on the metabolism of glucose by hypophysectomized 

 rats. From comparisons with operated animals receiving glu- 

 cose alone, she concluded that thyroxine causes an increase 

 in the rate of absorption of glucose and in the rate of oxida- 

 tion of glucose, roughly proportional to the increase in oxygen 

 consumption caused by the hormone. 



According to Weichselbaum, Heinbecker, and Somogyi 

 (1937), tolerance toward glucose is improved in hypophysec- 

 tomized dogs by a high-carbohydrate diet compared with a 

 high-fat diet. The diets did not uniformly cause this sort of 

 a difference in normal dogs. These authors also found 

 (Somogyi, Weichselbaum, and Heinbecker, 1937) that hyper- 

 glycemia following hypoglycemia due to the administration 



'- During the first 4 hours after the feeding of glucose, normal rats might oxidize 

 I44 mg. of the sugar per 100 gm. body-weight in comparison with 190 mg. per 

 100 gm. bodv-weight in hypophysectomized rats. 



[208I 



