Investigation of Opioid Growth Factor Pathway Inhibition on the Histologic Structure of Testicular Tissue and Microscopic Indices of Spermatogenesis in Adult Diabetic Mice

Abstract

Abstract Background and aims: Endogenous opioids function as negative factors affecting the growth has been established. The most influential factor in the growth and differentiation of the proliferating cells is the opioid growth factor (OGF). Recently, some studies have been completed about the effects of opioid growth factor in the pathogenesis of diabetes and the beneficial effects of inhibition of this growth pathway have been demonstrated. The aim of this study was to investigate the effect of inhibition of opioids growth pathway, in proliferation and growth of testicular germ cells and spermatogenesis following experimental diabetes in adult mice. Material and methods: Diabetes was induced in adult mice by Streptozotocin. Diabetic animals were treated with Naltrexone 15, 30 and 60 mg/kg for 60 days. At the end of the study, testicular and body weight was recorded, tissue samples were collected and histomorphometrical studies were performed under light microscope. Results: The results showed that the use of naltrexone has a little effect on preventing diabetic weight loss. Histomorphometric indices such as tubular diameter and germinal epithelium height were improved dose dependently in naltrexone treated diabetic mice. The number of tubular germ cells was increased non-significantly in diabetic animals following administration of naltrexone. Improvement of microscopic indices of spermatogenesis was observed in naltrexone treated diabetic mice. Conclusions: According to the results of this study and the role of naltrexone as OGF-OGF receptor inhibitor and up-regulating activity of naltrexone which leads to increased DNA synthesis and cell division process, the administration of naltrexone could be effective in reduction of diabetic induced alterations of spermatogenesis.