Effect of methylated prostaglandin E2 analogue on insulin secretion in man.

Previous studies of the effect of E series prostaglandins /PGs/ on insulin secretion gave conflicting results in animals and little information in man. This study was designed to determine the effect of methylated PGE2 analogue /15/S/- 15-methyl PGE2 methyl ester/, given orally, intraduodenally or intravenously, on insulin secretion, both under basal conditions and in response to intraduodenal or intravenous administration of glucose in 22 male volunteers. Methylated PGE2 kept basal serum insulin level unchanged, but significantly reduced insulin response by 15 +/- 6 microunits/ml to intravenous glucose pulse injection /0.1 g/kg/ or by 45 +/- 11 microunits/ml to intraduodenal glucose infusion /0.5 g/kg-hr/. Blood glucose level was unaffected in tests with intraduodenal methylated PGE2, but in tests with intravenous administration it was significantly reduced. These studies demonstrate that methylated PGE2 analogue given orally, intraduodenally or intravenously results in a potent suppression of insulin response to glucose challenge.