[Role of nicotinamide in the onset and course of streptozotocin-induced diabetes].

The authors have studied the preventive and therapeutic effects of high doses of nicotinamide on diabetes course in rats with streptozotocin-induced condition. Plasma glucose, glucosuria, C-peptide were assessed at the beginning of experiment and on day 40. Histologic studies were carried out over the course of experiment. On day 40 all rats administered nicotinamide showed almost normal glucose tolerance, and histologic examination showed just slight insulitis. In four of the six rats administered nicotinamide starting from the day when marked glucosuria first manifested glucosuria completely disappeared and their glucose tolerance improved over the course of therapy, though urinary sugar levels normalized in only one of the six rats administered nicotinamide for two weeks after the onset of marked glucosuria. These data evidence a preventive and therapeutic effect of nicotinamide on streptozotocin-induced diabetes in rats and suggest a reversible nature of beta-cell damage as early as at the initial stages of the disease.