Amelioration of diabetes mellitus in partially depancreatized rats by poly(ADP-ribose) synthetase inhibitors. Evidence of islet B-cell regeneration.

Ninety percent depancreatized rats received daily intraperitoneal injection of 0.5 g/kg nicotinamide and 0.05 g/kg 3-aminobenzamide, potent inhibitors of islet poly(ADP-ribose) synthetase. One to three months after the partial pancreatectomy, urinary and plasma glucose levels in nicotinamide- and 3-aminobenzamide-treated rats were markedly lower than those in saline-treated control rats. Morphologic examination of the remaining pancreata revealed that islets in the poly(ADP-ribose) synthetase inhibitor-treated rats were markedly enlarged and consisted largely of B-cells. These results suggest that poly(ADP-ribose) synthetase inhibitors induce islet B-cell regeneration, thereby preventing or improving diabetes mellitus in partially depancreatized rats.