College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R.China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070, P.R.China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, P.R.China.
College of Fisheries, Huazhong Agricultural University, Wuhan 430070, P.R.China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070, P.R.China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, P.R.China.
Aquat Toxicol. 2014 Oct;155:110-8. doi: 10.1016/j.aquatox.2014.06.010. Epub 2014 Jun 25.
Up to now, in vivo studies on toxic effects of microcystins (MCs) on the reproductive system are limited and the underlying molecular mechanisms of MCs-induced reproductive toxicity remain to be elucidated. In an acute toxic experiment, female zebrafish (Danio rerio) were injected intraperitoneally (i.p.) at doses of 50 and 200 μg MC-LR/kg body weight (BW) respectively, and histopathological lesions and antioxidant enzymatic activities and gene expression in the ovary were studied at 1, 3, 12, 24, 48 and 168 h post injection (hpi). Pathological lesions of zebrafish ovary progressed in severity and extent with the increasing exposure time and dose within 12 hpi. Concurrently, the increases in malondialdehyde (MDA) contents as well as the enzymatic activities and transcriptional levels of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) showed the occurrence of oxidative stress, indicating that MC-LR induced adverse effects on the structure and functional activity of zebrafish ovary. Oxidative stress plays a significant role in the reproductive toxicity of MC-LR. The significant decrease of glutathione (GSH) content in zebrafish ovary suggested the importance of MC-LR detoxification by glutathione S-transferases (GST) via GSH. The final recovery of histostructure and antioxidative indices indicated that ovarian efficient antioxidant defense system might be an important mechanism of zebrafish to counteract MC-LR. Although the negative effects of MC-LR can be overcome by ovarian antioxidant system in this study, the potential reproductive risks of MC-LR should not be neglected because of its wide occurrence.
到目前为止，有关微囊藻毒素（MCs）对生殖系统的毒性作用的体内研究还很有限，MCs 诱导生殖毒性的潜在分子机制仍有待阐明。在急性毒性实验中，分别以 50 和 200μg MC-LR/kg 体重（BW）的剂量经腹腔注射雌性斑马鱼（Danio rerio），研究了注射后 1、3、12、24、48 和 168 小时（hpi）卵巢的组织病理学损伤和抗氧化酶活性及基因表达。在 12 hpi 内，随着暴露时间和剂量的增加，斑马鱼卵巢的组织病理学损伤严重程度和范围均有所增加。同时，丙二醛（MDA）含量的增加以及抗氧化酶 CAT、SOD 和 GPx 的酶活性和转录水平的增加表明发生了氧化应激，表明 MC-LR 对斑马鱼卵巢的结构和功能活性产生了不良影响。氧化应激在 MC-LR 的生殖毒性中起着重要作用。斑马鱼卵巢中谷胱甘肽（GSH）含量的显著下降表明 GSH 通过谷胱甘肽 S-转移酶（GST）对 MC-LR 的解毒作用很重要。卵巢组织学结构和抗氧化指标的最终恢复表明，卵巢有效的抗氧化防御系统可能是斑马鱼对抗 MC-LR 的重要机制。尽管在本研究中，卵巢抗氧化系统可以克服 MC-LR 的负面影响，但由于其广泛存在，MC-LR 的潜在生殖风险不应被忽视。
