Histological and Immunohistochemical Study on the Possible Therapeutic Effect of Insulin Glargine on Testes of Alloxan- Induced Diabetic Rats

Background: Diabetes mellitus (DM), a condition of chronic hyperglycemia, represents one of the greatest concerns to modern global health. DM is a well-recognized cause of male sexual dysfunction and affects male reproductive system. It is accompanied by impaired antioxidant defenses including nitric oxide (NO). Aim of the work was to; (1) study the possible therapeutic effect of insulin glargine on testes of diabetic rats, (2) investigate the immunoexpression of endothelial nitric oxide synthase (e-NOS) in testes of diabetic rats and those treated with insulin glargine. Materials and methods: Forty albino rats were divided into; control group, non-treated diabetic group and diabetic group treated with insulin glargine. DM was induced by single intraperitoneal injection of 125mg/kg body weight of alloxan. The experiment continued for six weeks. Testicular tissue sections were prepared then stained with Hx. E., PAS and immunostained with anti e-NOS antibodies. Results: Testes of diabetic rats revealed irregular thickening and separation of the basement membrane of seminiferous tubules (STs). Some tubules were atrophied and vacuolated while others revealed multinucleated giant cells. Many tubules had spermatogenic arrest. The interstitial tissue revealed focal increased number of Leydig cells, thickening of blood vessels walls and exudate. Using polyclonal e-NOS antibodies, non-treated diabetic group revealed decreased immunoexpression. When insulin glargine was administered, the development of these diabetic changes was significantly prevented to a great extent with a significant increase in e-NOS immunoexpression. Conclusion: When insulin glargine was given early to insulin dependent diabetic rats, it significantly attenuated DM induced testicular complications. NO proved important for spermatogenesis and insulin played a role in e-NOS expression.