Glucagon-like peptide-1 does not mediate amylase release from AR42J cells

In this study, AR42J pancreatic acinar cells were used to investigate if gl ucagon-like peptide-1 (GLP-1) or glucagon might influence amylase release a nd acinar cell function. We first confirmed the presence of GLP-1 receptors on AR42J cells by reverse trasncriptase-polymerase chain reaction (RT-PCR) , Western blotting, and partial sequencing analysis. While cholecystokinin (CCK) increased amylase release from AR42J cells, GLP-1, alone or in the pr esence of CCK, had no effect on amylase release but both CCK and GLP-1 incr eased intracellular calcium. Similar to GLP-1, glucagon increased both cycl ic adenosine monophosphate (cAMP) and intracellular calcium in AR42J cells but it actually decreased CCK-mediated amylase release (n = 20, P < 0.01). CCK stimulation resulted in an increase in tyrosine phosphorylation of seve ral cellular proteins, unlike GLP-1 treatment, where no such increased phos phorylation was seen. Instead, GLP-1 decreased such protein phosphorylation s. Genestein blocked CCK-induced phosphorylation events and amylase secreti on while vanadate increased amylase secretion. These results provide eviden ce that tyrosine phosphorylation is necessary for amylase release and that signaling through GLP-1 receptors does not mediate amylase release in AR42J cells. Published 1999 Wiley-Liss, Inc.