Bombesin inhibits insulin release from isolated pancreatic islets of rats in vitro.

The effect of bombesin on insulin release from isolated pancreatic islets of rats was examined in vitro. Bombesin, at the doses ranging from 10 ng/ml to 1 microgram/ml, significantly inhibited 16.7 mM glucose-induced insulin release, while bombesin had no inhibitory effect on insulin release at 8.3 mM and 3.3 mM glucose. Moreover, bombesin also suppressed insulin release elicited by 10 mM arginine at the doses of 100 ng/ml and 1 microgram/ml. These results indicate that bombesin has a direct inhibitory action on insulin release.