Effects of prostacyclin and its stable analog, iloprost, upon insulin secretion in isolated pancreatic islets.

We investigated the effects of prostacyclin in three concentrations of 2.7 nM, 53.8 nM and 267 nM on insulin release by isolated rat islets. The lowest concentration produced no significant effects. The middle concentration led to stimulation followed by inhibition of the reaction studied, while the highest concentration strongly depressed insulin release. These effects of prostacyclin appeared to be specific, because they were mimicked by its stable analog, iloprost, but not by its metabolite, 6-keto-PGF1 alpha. The results suggest that prostacyclin generated in islets might exert locally an influence upon insulin release.