Effects of galanin on amylase secretion from dispersed rat pancreatic acini

Dispersed rat pancreatic acini were used to determine the effect of galanin on the exocrine pancreas and on basal and secretagogue-stimulated amylase secretion. Basal amylase secretion and amylase release stimulated by cholecystokinin octapeptide, bombesin, 12-o-tetradecanoyl-phorbol-13-acetate (TPA), secretin, and vasoactive intestinal peptide were not affected by galanin in doses ranging from 10(-12) to 10(-6) M. Galanin, however, significantly inhibited the amylase release stimulated by sub- and supramaximal doses of carbachol. A time course study showed that the inhibition by galanin occurred during the sustained phase of carbachol-stimulated amylase secretion. The inhibitory action of galanin disappeared in acini obtained from animals pretreated with pertussis toxin (PTX). These results suggest that galanin inhibits carbachol-stimulated amylase secretion through a mechanism related to a PTX-sensitive G protein.