Acute and chronic gastrin-releasing peptide decreases food intake in baboons

Gastrin-releasing peptide (GRP) is a peptide structurally related to bombesin that appears to be localized to the mammalian gastrointestinal tract. This study examined the ability of GRP, when administered on either an acute or chronic basis, to suppress food intake in baboons. When administered at 8 micrograms/kg iv before a morning meal, GRP significantly suppressed both food intake and the postprandial rise of plasma glucose and insulin. GRP at doses of 1, 2, 4, and 8 micrograms/kg stimulated basal insulin secretion. Chronic administration of GRP (q.o.d. for 11 days) at a low dose before the A.M. meal resulted in suppression of the A.M. meal and an initial suppression of total food intake, which recovered before the end of the treatment period. In conclusion, GRP appears to be effective in acute suppression of food intake and stimulation of basal insulin secretion in the nonhuman primate.