Possible role of endogenous prostaglandins in glucagon secretion by isolated guinea-pig islets.

摘要: Previous studies have demonstrated that prostaglandins stimulate glucagon secretionin vitro andin vivo. The present work was aimed at investigating the influence of two inhibitors prostaglandin synthesis, isopropyl-2 nicotinoyl-3 indole (L8027) and indomethacin, on basal arginine- or noradrenaline-stimulated release from isolated guinea-pig islets incubated in absence glucose. L8027 (10−4 10−5 mol/l) did not alter release, blocked almost completely response to arginine (10−2 mol/l), had no effect induced by noradrenaline (10−4H but reduced stimulatory a lower concentration (5.10−7 mol/l). kinetic study this inhibitory (1) it necessitates preincubation with for 30 minutes before addition arginine, (2) after short period (30 minutes) presence L8027, removal inhibitor time stimulation resulted enhanced response, (3) contrary, prolonged incubation (75 min) remained transiently detectable L8027. Indomethacin similarly noradrenaline-induced secretion. These results suggest an intra-insular synthesis is involved A cell noradrenaline.