Effects of fasting and insulin on carbohydrate metabolism of the domestic fowl

Abstract

Prolonged fasting caused a rise in blood glucose which reached a maximum above the prefast level on the 6th day. Concurrently the liver glycogen, rapidly depleted at the start of the fast, was partially replaced. Blood NPN increased continuously. Thus, gluconeogenesis appeared likely not only to be responsible for the blood glucose increase but also to play a role in the restoration of liver glycogen after initial glycogenolysis due to fasting. Fasting for 48 hours increased cardiac glycogen up to three times the prefasting level; a rapid decrease in this moiety occurred with further abstinence. Glucagon and growth hormone increased the cardiac glycogen of nonfasted birds; but had little, if any, influence on the effects of fasting. The daily injection of 60–70 u of either regular or HGF-free insulin per kilogram body weight resulted in an hyperglycemic rebound 24 hours after each injection. This rebound could be blocked completely by feeding Dibenzyline.