EFFECTS OF GALANIN ON AMYLASE SECRETION FROM DISPERSED RAT PANCREATICACINI

Dispersed rat pancreatic acini were used to determine the effect of ga lanin on the exocrine pancreas and on basal and secretagogue-stimulate d amylase secretion. Basal amylase secretion and amylase release stimu lated by cholecystokinin octapeptide, bombesin, 12-o-tetradecanoyl-pho rbol-13-acetate (TPA), secretin, and vasoactive intestinal peptide wer e not affected by galanin in doses ranging from 10(-12) to 10(-6) M. G alanin, however, significantly inhibited the amylase release stimulate d by sub- and supramaximal doses of carbachol. A time course study sho wed that the inhibition by galanin occurred during the sustained phase of carbachol-stimulated amylase secretion. The inhibitory action of g alanin disappeared in acini obtained from animals pretreated with pert ussis toxin (PTX). These results suggest that galanin inhibits carbach ol-stimulated amylase secretion through a mechanism related to a PTX-s ensitive G protein.