Objective: To investigate the protective effects of nicotinamide (NA) on newborn rat islets of Langerhans.
Methods: Newborn rat islets were isolated by digestion of collagenase V. The effects of IL-1 beta and/or NA on insulin release and nitric oxide (NO) production and 3H-thymidine incorporation were studied.
Results: NA had no effects on both accumulated insulin release and insulin release at an acute glucose challenge, but increased 3H-thymidine incorporation. 25 mmol/L of NA reduced the inhibition of accumulated insulin release and 3H-thymidine incorporation induced by 40/ml of IL-1 beta. However. NA was not able to reverse the reduced ability of IL-1 beta-treated islets to respond to an acute glucose challenge. NA dose-dependently reduced NO production induced by IL-1 beta.
Conclusion: There is the protective effect of NA on IL-1 beta-induced damage to islets of Langerhans. The mechanism of this effect might be related to that NA stimulates islet cells replication and reduces NO production induced by IL-1 beta.