Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, C.P. 486, 30161-970, Minas Gerais, Brazil.
Departamento of Química, Universidade Federal de Minas Gerais, Belo Horizonte, C.P. 486, 30161-970, Minas Gerais, Brazil.
Sci Total Environ. 2017 Aug 15;592:693-703. doi: 10.1016/j.scitotenv.2017.02.181. Epub 2017 Mar 22.
The Velhas River is the most polluted river in the state of Minas Gerais, south-eastern Brazil. Due to its historical and environmental relevance, the aim of this study was to evaluate the effects of oestrogenic endocrine disruptors on the reproduction of the lambari Astyanax rivularis, a small-sized species found in headwaters of the São Francisco River basin. Quarterly field samplings were carried out during a reproductive cycle in three streams of the upper Velhas River: S1 (reference site) and S2 and S3 (sites contaminated by untreated sewage). The main oestrogenic compounds were evaluated in water using HPLC/MS. Molecular, histological and reproductive biomarkers were assessed in liver and gonad. The results showed higher average concentrations of oestradiol (>200ng/l) in S2 and S3, oestrone (>250ng/l) in S2 as well as oestriol (>200ng/l), bisphenol A (>190ng/l), and nonylphenol (>600ng/l) in S3 compared to S1 (<70ng/l for all compounds). In S2 and S3, there was an increase in the proportion of females, higher ELISA levels of vitellogenin (Vtg) and proteins of the zona radiata (Zrp) in liver males. Insulin-like growth factor (IGF-I) levels were lower in S2 males, which also had a smaller body size, a smaller seminiferous tubule diameter, a higher proportion of spermatogonia, and lower proportion of spermatozoa in relation to S1. Histopathological analyses detected an increase in yolk deficient oocytes and over-ripening in the contaminated sites, and these alterations were associated to a reduction of hepatic Vtg levels and a delay in spawning, respectively. Intersex specimens with perinucleolar follicles in a multifocal distribution in the testis were detected in S2 and S3. These results indicate that chronic exposure to oestrogenic compounds induced endocrine disruption that may affect wild populations of A. rivularis in the Velhas River.
巴西东南部米纳斯吉拉斯州的维拉河是污染最严重的河流。由于其历史和环境意义重大，本研究旨在评估雌激素内分泌干扰物对小口脂鲤（Astyanax rivularis）生殖的影响，小口脂鲤是一种生活在圣弗朗西斯科河流域上游的小型鱼类。在一个生殖周期内，每季度在维拉河上游的三条溪流中进行实地采样：S1（参照点）和 S2 和 S3（未经处理的污水污染点）。使用 HPLC/MS 评估水中的主要雌激素化合物。在肝脏和性腺中评估了分子、组织学和生殖生物标志物。结果表明，S2 和 S3 中的雌二醇（>200ng/l）、S2 中的雌酮（>250ng/l）以及 S3 中的雌三醇（>200ng/l）、双酚 A（>190ng/l）和壬基酚（>600ng/l）的平均浓度均高于 S1（所有化合物均<70ng/l）。在 S2 和 S3 中，雌性的比例增加，肝脏雄性的 ELISA 水平升高，卵黄蛋白原（Vtg）和辐射带蛋白（Zrp）升高。S2 雄性的胰岛素样生长因子（IGF-I）水平较低，其体型较小，生精小管直径较小，精原细胞比例较高，精子比例较低与 S1 相比。组织病理学分析在污染点检测到卵黄缺乏卵母细胞和过度成熟的增加，这些变化分别与肝 Vtg 水平降低和产卵延迟有关。在 S2 和 S3 中检测到睾丸中具有核周滤泡的间质细胞的雌雄同体标本，呈多灶性分布。这些结果表明，慢性暴露于雌激素化合物会导致内分泌干扰，可能会影响维拉河中小口脂鲤的野生种群。
