Zoology Department, Faculty of Science, New Valley University, Egypt.
Department of Aquaculture, Faculty of Natural Resources and Environment, Behbahan Khatam Alanbia University of Technology, Iran.
Comp Biochem Physiol C Toxicol Pharmacol. 2019 Nov;225:108583. doi: 10.1016/j.cbpc.2019.108583. Epub 2019 Aug 5.
The present study aimed to evaluate the protective role of Selenium (Se) (0.1 ppm) on the male reproductive system of the catfish Clarias gariepinus exposed to sublethal doses of Mercury (Hg) (0.04 and 0.12 ppm) for 30 days. Indicators of seminal and gonadal hormone disruption (testosterone, estradiol and 11 keto testosterone), antioxidants (total antioxidant capacity (TAO), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)), oxidative stress biomarkers (lipid peroxidation (LPO), percentage of DNA fragmentation, carbonylated proteins (CP) and nitric oxide (NO)) and histopathological alterations in testicles of Clarias gariepinus were determined. The exposure to Hg resulted in a high accumulation of residues of this metal in testicular tissues. The results showed a significant decrease in sperm count, activity and motility and in all gonadal hormones in Hg exposed groups. Hg exposure also induced a decline in TAO, SOD, CAT and GPx, whereas LPO, DNA fragmentation, CP and NO significantly increased in testicles of C. gariepinus respect to the control group. Although exposure to Se did not reduce the degree of mercury bioconcentration in the testicles, the sperm quality parameters were recovered. Moreover, TAO levels and GPx activity significantly increased after fish exposure to Se, whereas CP levels decreased. LPO, NO, CAT and SOD were also partially normalized when compared with the groups exposed to only Hg. In conclusion, the results showed that Hg, even in the small doses is capable to induce reproductive toxicity in the male catfish. Se exposure partially restored the values of biochemical parameters and sperm quality in Hg-treated fish suggesting protective effects against Hg reproductive toxicity.
本研究旨在评估硒（Se）（0.1ppm）对鲶鱼（Clarias gariepinus）生殖系统的保护作用，该鱼在亚致死剂量的汞（Hg）（0.04 和 0.12ppm）暴露 30 天后。精液和性腺激素破坏的指标（睾丸酮、雌二醇和 11 酮睾丸酮）、抗氧化剂（总抗氧化能力（TAO）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GPx））、氧化应激生物标志物（脂质过氧化（LPO）、DNA 片段化百分比、羰基化蛋白（CP）和一氧化氮（NO））以及鲶鱼睾丸的组织病理学变化。暴露于 Hg 会导致睾丸组织中该金属的残留量大量积累。结果表明，Hg 暴露组的精子计数、活力和运动能力以及所有性腺激素均显著下降。Hg 暴露还导致 TAO、SOD、CAT 和 GPx 下降，而 LPO、DNA 片段化、CP 和 NO 在 C. gariepinus 睾丸中明显高于对照组。尽管 Se 的暴露并没有降低睾丸中汞的生物浓缩程度，但精子质量参数得到了恢复。此外，暴露于 Se 后，TAO 水平和 GPx 活性显著增加，而 CP 水平下降。与仅暴露于 Hg 的组相比，LPO、NO、CAT 和 SOD 也部分恢复正常。总之，结果表明，即使是小剂量的 Hg 也能引起雄性鲶鱼的生殖毒性。Se 的暴露部分恢复了 Hg 处理鱼的生化参数和精子质量值，表明对 Hg 生殖毒性具有保护作用。
