Behavioral compensatory responses to continuous duodenal and upper ileal glucose infusion in rats

Abstract

A 30% glucose solution contributing 38% of the rats' normal voluntary daily energy intake was infused continuously for 24 hr into the intestines of two groups of rats, one catheterized in the duodenum and one in the upper ileum. Both groups responded by a compensatory reduction in voluntary food intake which was achieved by a statistically significant reduction in meal size but not in meal number. No significant change in food intake behavior occurred during similar infusion of equiosmotic NaCl solution, physiological saline or water. No significant differences in food intake behavior were observed between the group infused duodenally and the one infused intraileally. These findings suggest that, first, if an intestinal satiety mechanism exists, it is not exclusively located in the duodenum and, second, that any specific duodenal factors such as cholecystokinin are not indispensable in the control of meal-taking behavior.