| Abstract: | We have investigated the effects of Pro-Met-Asp-Phe-NH2 (PMAP) on insulin and glucagon release from human fetal pancreatic microfragments in vitro. Four batches of precultured microfragments were incubated for 24 hrs in medium containing 5.5 mM glucose, 17 mM glucose, 1 microM PMAP or 1 microM PMAP plus 17 mM glucose. PMAP significantly enhanced both basal and glucose-stimulated insulin release (2.2- and 4.1-fold, respectively). Glucagon secretion was markedly inhibited by glucose (17 mM). PMAP neither affected the basal glucagon release nor potentiated the inhibitory action of glucose on glucagon release. Hence, PMAR selectively regulates insulin production in human fetal islet tissue without affecting glucagon production. Our results suggest that the substances similar or related to PMAP may prove to be of clinical value in drug correction of diabetes mellitus. |
