Gárriz Ángela, Del Fresno Pamela S, Carriquiriborde Pedro, Miranda Leandro A
Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas Instituto Tecnológico de Chascomús "Dr. Raúl Alfonsín", IIB-INTECH (CONICET-UNSAM), Calle Intendente Marino Km. 8.200 (B7130IWA), Chascomús, Buenos Aires, Argentina.
Centro de Investigaciones del Medio Ambiente (CIMA), Facultad de Ciencias Exactas, UNLP - CONICET, Calle 47 y 115, 1900 La Plata, Buenos Aires, Argentina.
Gen Comp Endocrinol. 2019 Mar 1;273:152-162. doi: 10.1016/j.ygcen.2018.06.013. Epub 2018 Jun 22.
Some heavy metals related to human activities were measured in the water of Chascomús lake. The maximum concentrations were: 0.23 μg/L for Cd, 4.28 μg/L for Cr, 22.09 μg/L for Cu, 2.49 μg/L for Ni, 3.24 μg/L for Pb and 210.76 μg/L for Zn. The values of Cd, Cr, Cr, Pb and Zn were above the Argentine National Guidelines for the Protection of the Aquatic life. The analysis of gonadal condition of pejerrey fish (Odontesthes bonariensis) from this lake did not revealed any reproductive damages. However, exposures with environmental concentrations of Cd, Cr, Cu and Zn under laboratory conditions of pejerrey males (14 days), caused a significant increase of the expression of the three variants of gnrh in the brain (within Cd exposure) and a decrease in cyp19a1b mRNA (within Cu exposure). Furthermore, at pituitary level, a decrease in fshb transcript levels was observed in the fish exposed to Cd and Cr and a decrease in the expression of both gonadotropin receptors at gonadal level in Zn exposure. Moreover, the gonads of the fish exposed to all the tested metals suffered structural damages showing shortness of the spermatic lobules, fibrosis, testis ova and the presence of piknotic cells. All these findings alert that heavy metals pollution affects the expression of key reproductive genes and gonadal structure of fish species that represent the predominant group of organisms and are considered sentinel species in the aquatic ecosystems.
对查斯科穆斯湖水中与人类活动相关的一些重金属进行了测量。最大浓度分别为：镉0.23μg/L、铬4.28μg/L、铜22.09μg/L、镍2.49μg/L、铅3.24μg/L、锌210.76μg/L。镉、铬、铅和锌的值高于阿根廷水生生物保护国家指南。对该湖银汉鱼（Odontesthes bonariensis）性腺状况的分析未发现任何生殖损伤。然而，在实验室条件下，让银汉鱼雄性暴露于环境浓度的镉、铬、铜和锌中（14天），导致大脑中gnrh三种变体的表达显著增加（镉暴露时）以及cyp19a1b mRNA减少（铜暴露时）。此外，在垂体水平，暴露于镉和铬的鱼中fshb转录水平降低，在锌暴露时性腺水平的两种促性腺激素受体表达均降低。而且，暴露于所有测试金属的鱼的性腺遭受结构损伤，表现为精小叶变短、纤维化、睾丸卵子以及出现固缩细胞。所有这些发现警示，重金属污染会影响代表水生生态系统中主要生物群体且被视为指示物种的鱼类关键生殖基因的表达和性腺结构。
