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 secre-tion. Basal amylase secretion and amylase release stimu-lated 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^-12to 10^-6M. Galanin, however, significantly inhibited the amylase release stimulated by sub-and supramaximal doses of carbachol. Atime 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 pre-treated with pertussis toxin (PTX). These results suggest that galanin inhibits carbachol-stimulated amylase secre-tion through a mechanism related to a PTX-sensitive G protein.