Abstract: | The aim of this study was to investigate the protective effects of Nano‐Se against Ni‐induced testosterone synthesis disorder in rats and determine the underlying protective mechanism. Sprague‐Dawley rats were co‐treated with Ni (5.0 mg/kg, i.p.) and Nano‐Se (0.5, 1.0, and 2.0 mg/kg, oral gavage) for 14 days after which various endpoints were evaluated. The Ni‐induced abnormal pathological changes and elevated 8‐OHdG levels in the testes were attenuated by Nano‐Se administration. Importantly, decreased serum testosterone levels in the Ni‐treated rats were significantly restored by Nano‐Se treatment, particularly at 1.0 and 2.0 mg/kg. Furthermore, the mRNA and protein levels of testosterone synthetase were increased by Nano‐Se compared to the Ni group, whereas phosphorylated protein expression levels of mitogen‐activated protein kinase (MAPK) pathways were suppressed by Nano‐Se administration in the Ni‐treated rats. Overall, the results suggest that Nano‐Se may ameliorate the Ni‐induced testosterone synthesis disturbance via the inhibition of ERK1/2, p38, and JNK MAPK pathways. |