Dissociation of vascular resistance with endocrine pancreas secretion: the effects of epoxymethano analogs of PGH2.

The epoxymethano analogs of PGH2 caused rapid and persistent increase in perfusion pressure in isolated rat pancreata without significant effect on glucagon and insulin secretory responses to PGH2 and PGE2. The changes in perfusion pressure are interpreted as alterations in vascular resistance since the flow rate was kept constant at 2.5 mL per min. PGH2 alone caused significant elevation in pressure. However, PGH2 administration superimposed upon an infused epoxymethano analog of PGH2, decreased perfusion pressure significantly, whereas PGH2 induced hormone release was not decreased. The analogs neither stimulated nor inhibited the endocrine pancreas secretion. These studies provide evidence for complete dissociation of vascular constriction from pancreatic hormone release and further suggest that the effects of PGH2 on islet hormone secretion may result from the conversion of PGH2 to other prostanoids.