Effects of L-Carnitine on the sperm parameters disorders, apoptosis of spermatogenic cells and testis histopathology in diabetic Rats

Background: Diabetes mellitus affects male reproductive system that is known to cause male infertility. Objective: The aim of the present study was to assess the effects of L-carnitine (LC) on sperm parameters, apoptosis of spermatogenic cells and testis histopathology in Streptozotocin-induced diabetic Rats. Materials and Methods: The study was carried out on 36 male Wistar adult rats (220 +/- 30 gr) randomly divided into six groups (n = 6/each). 1 (Control); 2 (LC 100 mg/kg); 3 (Diabetic); 4, 5, and 6 (Diabetic + LC 50 or 100 or 200 mg/kg, respectively). Daily injections were administered intraperitoneally for 48 days. Then, rats were sacrificed, left testis and epididymis were harvested for sperm analysis and histopathology, morphometric and spermatogenesis assessments, and Tunnel assay. Results: L-carnitine in group 6 significantly decreased blood glucose level (p < 0.01) in comparison with group 3. L-carnitine in groups 5 and 6 significantly (p < 0.001) and dose-dependently increased the count, motility, viability, maturity, and chromatin quality of sperm and decreased the abnormal morphology of sperm in comparison with group 3. In groups 4, 5, and particularly 6, in comparison with group 3, there has been a significant difference in the increase of seminiferous tubule diameter, germinal epithelium height (p < 0.001), maturity quality of the seminiferous tubules (p < 0.001), decrease apoptosis of spermatogenic cells (p < 0.001), and testis tissue histopathological complications. Conclusion: The data obtained from the present study suggest that in the diabetic rats, LC decreases serum glucose level, improves the diameter and thickness of the epithelium of spermatogenic cells, reduces germ cells' apoptosis, and improves epididymal sperm parameters. Therefore, it seems that LC plays an effective role in diabetes-induced infertility.