Stimulation of Insulin Secretion in Rats by Pargyline and Mebanazine

Intravenous injections of pargyline and mebanazine, both of which possess monoamine oxidase-inhibitor activity, resulted in an acute rise in plasma insulin in rats. A significant decline in plasma glucose was observed after the injection of pargyline. The hyperglycemic effect of epinephrine was not inhibited by pargyline nor was the insulinreleasing effect of pargyline blocked by epinephrine. Diazoxide completely abolished the effects of pargyline on insulin release. Simultaneous injection of glucose and pargyline resulted in an additive effect upon insulin release. Treatment of rats for five days with pargyline and mebanazine resulted in decreased plasma glucose and insulin levels associated with a reduction in food intake. The present studies suggest that the hypoglycemia associated with monoamine oxidase-inhibitor therapy is unrelated to the insulinreleasing effects.