Biotechnic and Histochemistry, cilt.101, sa.1, ss.11-20, 2026 (SCI-Expanded, Scopus)
Clinical and experimental studies have shown that sitagliptin regulates blood glucose levels. This study was designed because it is thought that sitagliptin may reduce diabetes-induced apoptosis in testes by affecting blood glucose levels and may have a beneficial effect on spermatogenesis by regulating hormonal activity. Thirty-four male Sprague-Dawley rats were divided into three groups: Control group (n = 10), given citrate buffer only; Diabetes group (n = 12), after 2 weeks of the high-fat diet, given a single dose of 35 mg/kg streptozotocin (STZ, dissolved in citrate buffer, intraperitoneally); Diabetes + Sitagliptin group (n = 12), after 2 weeks of the high-fat diet, diabetes was induced with STZ and 10 mg/kg sitagliptin (intragastric) was administered daily for 6 weeks. At the end of the experiment, blood glucose levels measured in the sitagliptin-treated group were found to be significantly lower than in the diabetes group. Serum testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, seminiferous tubule diameter, Johnsen score, and proliferation indices were significantly lower in the diabetic groups compared to the control group, while no significant difference was found between the diabetes and sitagliptin groups. Basement membrane thickness, apoptotic cell and apoptotic tubul indexes, Fas, FasL, and caspase8 immunoreactivities were higher in diabetic groups compared to the control group, while no difference was found between the diabetic and sitagliptin groups. In conclusion, although 10 mg/kg sitagliptin reduced blood glucose levels in diabetes-induced hyperglycemia, it did not alter serum testosterone, FSH and LH levels, and did not appear to have a beneficial effect on diabetes-induced apoptosis and proliferation in the testes.