Cyclooxygenase-2 transcription is stimulated and amylase secretion is inhibited in pancreatic acinar cells after induction of acute pancreatitis

Cyclooxygenases as the key enzymes of prostaglandin synthesis have an important role in regulation of inflammation. We describe that Cox-1 and Cox-2 are synthesized in rat pancreatic acinar cells. Upon induction of pancreatitis, Cox-2 mRNA increases while Cox-1 expression remains constant. However, the cyclooxygenase inhibitor indomethacin has no influence by a feed-back mechanism on the expression of the two isoforms. We have previously shown that prostaglandins of the E-type inhibit cholecytoskinin-stimulated amylase secretion. Consistent with this observation, we find here that pancreatitis inhibits CCK-stimulated amylase secretion from isolated acini. In agreement with this result, the effect is neutralized by indomethacin inhibition of prostaglandin synthesis. In summary, we have found that both cyclooxygenases are synthesized in pancreatic acinar cells and that their expression is differentially regulated which in turn influences amylase secretion.