Li Na, Hou Yu-hua, Ma Dan-dan, Jing Wei-xin, Dahms Hans-Uwe, Wang Lan
School of Life Science, Shanxi University, Taiyuan, Shanxi 030006, China; School of Arts and Sciences, Shanxi Agriculture University, Taigu, Shanxi 030081, China.
School of Life Science, Shanxi University, Taiyuan, Shanxi 030006, China.
Ecotoxicol Environ Saf. 2015 Jul;117:20-7. doi: 10.1016/j.ecoenv.2015.03.019. Epub 2015 Mar 27.
Lead (Pb) is one of the most toxic environmental pollutants and known to exert multiple toxic effects including gonadotoxic and spermiotoxic effects. In order to understand toxic mechanisms of lead (Pb) on the testes and the accessory glands of crabs, we investigated Pb accumulation in testes and accessory glands and the survival rate of sperms of freshwater crab, Sinopotamon henanense. The tissue damaging effects of Pb was also investigated by histopathological examination and analyses of antioxidant enzymes as well as lipid peroxidation. Crabs were exposed to different Pb concentrations (0, 3.675, 7.35, 14.7, 29.4 and 58.8 mg/L) for 3, 5 and 7 days. The results showed that Pb levels in testes and accessory glands increased significantly following Pb exposure for 5 and 7 days in almost all treated groups, and survival rate of sperm decreased with increasing Pb concentrations at 5 and 7 days. Morphological changes identified histologically were discovered in testes, including a disordered arrangement of germ cells, a decreased number of sperm in the lumina of the seminiferous tubules, extensive necrosis in the germinal layer of the seminiferous tubules, etc. At the same time, histological abnormalities were discovered in accessory glands, the wall cells were separated from the basement membrane, and wall cells were missing partly. The activities of SOD, GPx and CAT in testes showed no statistically significant changes compared to the control for 3 days, and initially increased and subsequently decreased with increasing Pb concentrations at 5 and 7 days. The antioxidant enzyme activities in accessory glands initially increased and subsequently decreased with increasing Pb concentrations and Pb exposure. This was accompanied with an increase in malondialdehyde (MDA) content in a concentration-dependent manner. These results showed that acute Pb exposure led to a reduction of survival rate of sperm and harmful effects at the cellular level of crab testes and accessory glands, which are most likely linked to Pb-induced oxidative stress.
铅（Pb）是毒性最强的环境污染物之一，已知会产生多种毒性作用，包括性腺毒性和精子毒性作用。为了解铅（Pb）对蟹类睾丸和附属腺的毒性机制，我们研究了河南华溪蟹睾丸和附属腺中铅的积累情况以及精子的存活率。还通过组织病理学检查、抗氧化酶分析以及脂质过氧化分析研究了铅的组织损伤作用。将蟹暴露于不同铅浓度（0、3.675、7.35、14.7、29.4和58.8mg/L）下3、5和7天。结果表明，几乎所有处理组在铅暴露5天和7天后，睾丸和附属腺中的铅含量显著增加，且在5天和7天时，精子存活率随铅浓度升高而降低。组织学鉴定发现睾丸存在形态学变化，包括生殖细胞排列紊乱、曲细精管管腔中精子数量减少、曲细精管生发层广泛坏死等。同时，附属腺也发现组织学异常，壁细胞与基底膜分离，部分壁细胞缺失。睾丸中SOD、GPx和CAT的活性在3天时与对照组相比无统计学显著变化，在5天和7天时随铅浓度增加先升高后降低。附属腺中的抗氧化酶活性随铅浓度增加和铅暴露时间先升高后降低。同时，丙二醛（MDA）含量呈浓度依赖性增加。这些结果表明，急性铅暴露导致蟹类睾丸和附属腺细胞水平上精子存活率降低和有害影响，这很可能与铅诱导的氧化应激有关。
