EFFECT OF INSULIN ON TESTICULAR ALTERATIONS IN THE NONOBESE DIABETIC MOUSE

Severe spermatogenic alterations occur in association with diabetic ma nifestations in the nonobese diabetic (NOD) mouse. A study was underta ken to determine whether or not administration of insulin during initi al appearance of diabetic changes could inhibit the interference with spermatogenesis. Male NOD mice injected with cyclophosphamide to promo te onset of overt diabetes were divided into insulin-treated and nontr eated groups. Testicular specimens were then examined by light and ele ctron microscopy. Insulin-treated animals showed variable changes rang ing from normal spermatogenesis to moderate to severe alterations. Ani mals with diabetes that did not receive insulin exhibited extensive sp ermatogenic disruption. The findings indicate a blunting of testicular damage when insulin is administered early in the development of diabe tic manifestations. Although spermatogenic abnormalities could not be prevented entirely by insulin treatment, the results provide evidence for a direct metabolic effect on the pathogenesis of the testicular al terations.