Characterization of secretory and morphologic properties of primary cultured endocrine cells from porcine pancreata

We characterized morphologic and secretory properties of porcine pancreatic endocrine cells in primary culture obtained by autolytic preparation witho ut any exogenous proteolytic enzymes. The endocrine cells exhibited a neuro n-like shape, and insulin granules were accumulated at the terminal of the processes. Thus derived endocrine cells survived in culture medium containi ng nicotinamide and remained sensitive to glucose for at least 6 weeks afte r preparations. The cells responded well to physiologic concentrations of g lucose, and high K+ depolarization and the antidiabetic sulfonylureas, tolb utamide, and glibenclamide also elicited the release. With high glucose, in sulin release was markedly potentiated by forskolin, glucagon, glucagon-lik e peptide-1, and arginine and inhibited by somatostatin, the Ca2+ channel b locker nitrendipine, and the ATP-sensitive K+ channel opener diazoxide. Epi nephrine had dual effects on the release by glucose; enhanced within a low nanomolar range and inhibited at 1 mu mol/L. However, the cells were unresp onsive to leucine. Such secretory sensitivities to nutrients, hormones, and pharmacologic agents, and long survival rate las long as 5-6 weeks) of the se cells suggest to us therefore that derived endocrine cells may be useful for xenotransplantation of pancreatic beta cells for treatment of insulin- dependent diabetes mellitus.