Possible Role of Prostaglandins in the Regulation of Insulin Release from Rat Pancreatic Islets

To clarify whether prostaglandin synthesis is involved in the regulation of insulin release from isolated rat islets, we performed three different experiments. The direct effects of prostaglandin E_1 and prostacyclin on insulin release were investigated. Neither prostaglandin had any effect in the presence of low and high concentrations of glucose. Indomethacin, aspirin^<[○!R]> (acetylsalicylic acid) and flurbiprofen, inhibitors of cyclooxygenase, did not have a significant effect on insulin release evoked by glucose. Exogenous phospholipase A_2 purified from bee venom and melittin stimulated insulin release. A potent and selective inhibitor of phospholipase A_2,mepacrine, inhibited glucose-induced insulin release. The present work indicates that 1) cyclooxygenase does not participate early release of insulin from islet 2) activation of phospholipase A_2 might be involved in insulin stimulus-secretion coupling.