Protective effect of 3-aminobenzamide,an inhibitor of poly (ADP-ribose) synthetase,against streptozotocin-induced diabetes

Summary The addition of 3-aminobenzamide (a potent inhibitor of poly(ADP-ribose)synthetase) into the incubation medium, prevents streptozotocin-induced inhibition of glucose-stimulated insulin release from isolated islets [control 142±14U·islet^–1·h^–1; streptozotocin (0.5mg/ml) 31±8; 3-aminobenzamide (l.0 mg/ml) 96±11; streptozotocin plus 3-aminobenzamide 122±19]. In vivo, intraperitoneal 3-aminobenzamide 300 mg/kg body weight prevents the appearance of overt diabetes in streptozotocin-treated rats. These protective effects of 3-aminobenzamide are dose-dependent and are similar to those exerted by nicotinamide. Taking into account that poly ADP-ribosylation is involved in the repair of damaged DNA, the protection exerted by 3-aminobenzamide against the diabetogenic effect of streptozotocin strongly supports the view that this acute effect may be a major consequence of the activation of DNA repair mechanisms in islet cells.