Histological effects of zinc and melatonin on rat testes

Background: The objective of this study is to examine the histological effects of zinc and melatonin, alone or in combination, on rat testes. Methods: For this purpose four study groups of ten Sprague-Dawley male rats were formed and treated for one month as follows: (1) Controls; (2) Rats injected with 3 mg/kg/day zinc, as zinc sulfate; (3) Rats injected with 3 mg/kg/day melatonin and (4) Rats injected with 3 mg/kg/day each zinc and melatonin. Results: After four weeks the rats treated with melatonin showed inhibited spermatogenesis, testicular tubular degeneration and necrosis, obstruction of tubular lumen and lymphocytic infiltration. The two zinc-treated groups showed no histological differences to controls but the melatonin-only group showed inhibited spermatogenetic activity, tubular degeneration and necrosis, as well as obstruction of tubule lumens and lymphocytic infiltration. Conclusion: The obtained results suggest that 4-week treatment with melatonin leads to histological and physiological impairments of testis and that zinc supplementation might offset these damaging effects (Tab. 2, Fig. 4, Ref. 12). Full Text in free PDF www.bmj.sk.