Opposite effects of bombesin on insulin and gastrin response to food in humans

SUMMARY The effect of bombesin on insulin and gastrin response to a standard labelled meal was studied in eight healthy male volunteers. The gastric emptying of solids was simultaneously evaluated. During intravenous infusion of the peptide (5 ng/kg/min) the insulin release after eating was greatly reduced whereas food stimulated gastrin release was significantly enhanced. Both effects of bombesin are likely to be connected with the marked inhibition of gastric emptying induced by the peptide. Bombesin is a frog skin tetradecapeptide which has been found to have similar immunologically charac-tensed counterparts in mammalian gut. 1-3 An heptacosapeptide has been isolated from porcine non-antral gastric tissue: the so called gastrin releas-ing peptide (GRP).4 The homology of its C-terminal decapeptide with C-terminal decapeptide of bombesin is impressive. As a consequence, both these peptides have the same spectrum of biologica