Alloxan-induced and insulin-resistant diabetes mellitus affect semen parameters and impair spermatogenesis in male rats.

The purpose of this study was to determine the effects of diabetes mellitus and insulin resistance on semen parameters, histology of reproductive organs and serum concentrations of testosterone and luteinizing hormone (LH). Male Sprague-Dawley rats weighing 180 - 200g were made diabetic by intravenous injection of alloxan (40 mg/kg): and insulin resistant by chronic fructose feeding (25% fructose) for 12 weeks. Rats were anaesthetized, followed by laparatomy. Blood was obtained by cardiac puncture for measurement of testosterone and LH concentrations by radioimmunoassay. Semen analysis was carried out; reproductive organs were isolated, fixed in Bouin's fluid and processed for histological studies. All semen parameters analyzed were significantly reduced (P < 0.05) in the diabetic and insulin resistant rats compared to control rats. Body weight and weight of reproductive organs were also significantly reduced (P < 0.05). Furthermore, tissue fixation studies revealed changes in the cytoarchitecture of reproductive organs in the diabetic and insulin resistant rats compared to control rats. However, serum concentrations of testosterone and LH were not significantly different in all the groups. We conclude that diabetes mellitus and insulin resistance affect semen parameters and impair distinct phases of spermatogenesis in male rats. Some mechanisms responsible for this impairment are suggested.