PARS GLANDULARIS AND METABOLISM 



terior pituitary extract into cats or rats is not observed after 

 complete adrenalectomy. Insulin-sensitivity is increased by 

 hypophysectomy, because an important physiological antag- 

 onist of insulin — diabetogenic hormone — is no longer avail- 

 able, and carbohydrate reserves both disappear at an ab- 

 normally rapid rate and probably are restored from other en- 

 dogenous sources only with great difficulty. After pan- 

 createctomy, secretion(s) of the anterior pituitary is not an- 

 tagonized (however indirectly) by insulin and may be re- 

 garded as an important contributor to changes which threat- 

 en life — e.g., the accumulation of acetone bodies. Anterior 

 pituitary secretion can also be pictured as interfering with 

 the oxidation of glucose which otherwise is facilitated by 

 insulin. If, however, both glands are removed, the important 

 means of regulating carbohydrate metabolism are lost. A 

 unique derangement of metabolism appears and, depending 

 upon conditions such as nutritional state before operation, 

 fasting, diet, etc., the animal resembles sometimes the dia- 

 betic animal — e.g., with hyperglycemia and glycosuria — and 

 sometimes the animal with hypophysial deficiency — e.g., 

 with hypoglycemia. 



Although the effects of subcutaneously injected epineph- 

 rine are less pronounced after hypophysectomy, it is prob- 

 able that delay in absorption accounts for most of this 

 change, provided that reserves of carbohydrate are adequate. 

 Any diminished effect of epinephrine is observed in respect of 

 all the expected changes — elevation of the level of sugar and 

 lactic acid in the blood, depression of the level of inorganic P, 

 lowering of the concentration of glycogen in muscle, etc. 



New observations support the belief that anterior pituitary 

 extract can cause hypertrophy of the islet tissue of the pan- 

 creas. The physiological significance of this effect has not 

 been adequately explored. 



Any attempt briefly to summarize our knowledge of the 

 relation of the anterior pituitary to carbohydrate metabolism 

 is necessarily confusing, because we know only some phases 



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