Effect of cyclosporine and aminophylline on streptozotocin-induced diabetes in rats.

Diabetes induced in rats by multiple low doses of streptozotocin is thought to mimic type 1 disease in man. We tested the effect of concomitant treatment with immunomodulator drugs in this diabetic experimental model. Administration of cyclosporine resulted in a rapid appearance of hyperglycemia, perhaps by a potentiation of the direct cytotoxic action of streptozotocin on beta cells. By contrast, aminophylline administration protected the animals from the diabetogenic action of streptozotocin. Concomitant treatment with aminophylline and cyclosporine failed to protect the rats from the hyperglycemia induced by streptozotocin.