Studies on human pancreatic acini: action of secretagogues on amylase release and cellular cyclic AMP accumulation

Abstract

A technique for preparing a suspension of dispersed functional acini from human pancreas has been developed. The changes in pancreatic enzyme secretion and accumulation of cellular cyclic AMP caused by various secretagogues have been studied. Ca2+-mobilizing agents stimulated amylase release from human pancreatic acini. The relative potencies with which secretagogues increased amylase release were as follows: gastrin-releasing peptide's potency (Ec50, 0.1 +/- 0.01 nM) was greater than bombesin 14's (Ec50, 0.2 +/- 0.01 nM), which was greater than litorin's (Ec50, 0.6 +/- 0.18 nM), which was greater than bombesin 9's (Ec50, 6 +/- 0.1 nM). For CCK-peptides, the relative potencies were as follows: CCK-39's potency (Ec50, 0.28 +/- 0.15 microM) was equal to cerulein's (Ec50, 0.3 +/- 0.07 microM). Both of these potencies were greater than CCK-8's (Ec50, 1.6 +/- 0.1 microM), which was greater than that of CCK-4. Carbamyl choline was poorly potent (Ec50 greater than 1 mM). The 12-O-tetradecanoylphorbol-13-acetate (TPA) was active from 0.1 nM to 0.1 microM. Neither secretin nor VIP increased amylase release from human pancreatic acini but they did cause an accumulation of cellular cyclic AMP, secretin (Ec50, 0.5 +/- 0.2 nM) being more potent than VIP.