THE PITUITARY BODY 



tions have been made in fish, a reptile, other amphibia, the 

 cat, and the dog. 



The glycosuria of hypophysectomized-pancreatectomized 

 dogs may be moderate or slight, but usually disappears dur- 

 ing fasting. The D/N ratio is low (0.9-1.9). Similarly, the 

 concentration of sugar in the blood is much lower (e.g., 210- 

 280 mg. per cent) than in pancreatectomized dogs (e.g., 420 

 mg. per cent). If the doubly operated dog is starved, the 

 amount of sugar in the blood may fall precipitously so that 

 symptoms of a hypoglycemia appear. The animal can live in 

 a fair state of health for months without insulin. On the 

 other hand, the insulin-sensitivity, characteristic of hypo- 

 physectomy, persists after the removal of the pancreas. This 

 fact throws doubt on the attempt to explain insulin-sensitiv- 

 ity in the hypophysectomized animal as due to an increased 

 secretion of insulin, perhaps following the removal of an 

 inhibitory or antagonistic pituitary secretion. 



If glucose is administered to hypophysectomized-pan- 

 createctomized dogs, a variable amount — roughly 50 per cent 

 — is recovered in the urine. After the intravenous injection 

 of glucose the respiratory quotient rises (but later than in 

 hypophysectomized dogs). The glycemic curve is similar to 

 that of hypophysectomized dogs except that the return to 

 the pre-injection level is slower. After the double operation, 

 therefore, the metabolism of carbohydrates is unstable, ex- 

 treme changes occurring after the administration of insulin 

 or epinephrin, or in the presence of a deficiency or an excess 

 of available carbohydrate (Lucke and others). On the basis 

 of the amelioration of the symptoms of pancreatic diabetes, 

 Houssay and Biasotti postulated the secretion of a "diabeto- 

 genic" hormone by the pars glandularis. The effects of an- 

 terior-lobe extracts on the metabolism of carbohydrates 

 in hypophysectomized or hypophysectomized-pancreatecto- 

 mized animals will be considered later (pp. 292-93). 



4. Adrenalectomy and pancreatectomy. — Long and Lukens 



[290] 



