Ontogeny and insulin-dependence of the satiation which follows carbohydrate absorption in the rat

In adult rats, the first meal on restoring access to food following the complete absorption of an intragastric carbohydrate load is smaller than the meal following a nonnutritive load. The weanling rat does not show this postabsorptively induced satiation. The effect does not appear until above a body weight of about 200 g. Subcutaneous injection of a moderate dose of insulin (0.2 units/kg) at the time of glucose intubation results in postabsorptive satiety appearing in the immature rat. The inhibitor of insulin secretion, D-mannoheptulose, injected shortly before glucose intubation, considerably reduces the satiety effect in the 300 g rat. It is suggested that an abundant secretion of insulin during absorption is necessary to establish the parenteral satiety signal operative under these conditions.