Institute of Biosciences , São Paulo State University, Pça. Infante D. Henrique , 11330-900 São Vicente , Brazil.
Department of Environmental Sciences , University of California, Riverside , 900 University Avenue , Riverside , California 92521 , United States.
Environ Sci Technol. 2018 Mar 6;52(5):3146-3155. doi: 10.1021/acs.est.7b04970. Epub 2018 Feb 13.
Diuron is a herbicide used in agricultural and urban settings and also as an antifouling agent. Recent studies have indicated sublethal responses of diuron in the endocrine system of fish and amphibians. Given the potential of climate change to also alter fish endocrinology, the combination of environmental stressors with diuron may contribute to its sublethal toxicity. In this study, the effects of temperature and salinity on thyroid targets of diuron were assessed in juveniles of the estuarine fish Menidia beryllina under different conditions of salinity (10 and 20‰) and temperature (10 and 20 °C). Environmentally relevant concentrations of diuron affected the growth, and the higher temperature reduced the condition factor of animals. Increased levels of T3 were observed in fish from all treatments, and at 10 °C, T4 levels were augmented at 10‰ but reduced at 20‰. Increased gene expression of deiodinases at 20‰ in both temperatures suggests the influence of salinity on the regulation of hormone imbalance via deiodination pathway activation. Decreased transcripts of thyroid and growth hormone receptors were also observed following diuron treatment. These results indicate that changes in environmental stressors may have significant impacts on the ecological risk of diuron in estuarine fish.
敌草隆是一种用于农业和城市环境的除草剂，也可用作防污剂。最近的研究表明，敌草隆对鱼类和两栖类动物的内分泌系统有亚致死反应。考虑到气候变化也可能改变鱼类的内分泌，环境胁迫因子与敌草隆的结合可能导致其亚致死毒性。在这项研究中，评估了温度和盐度对河口鱼类 M. beryllina 幼鱼甲状腺靶标的影响，实验在不同盐度（10 和 20‰）和温度（10 和 20°C）条件下进行。环境相关浓度的敌草隆影响了鱼类的生长，高温降低了动物的体况系数。所有处理组的 T3 水平均升高，在 10°C 时，10‰盐度下 T4 水平增加，但 20‰盐度下 T4 水平降低。在两种温度下，20‰盐度下脱碘酶的基因表达增加，这表明盐度通过脱碘途径的激活对激素失衡的调节有影响。甲状腺和生长激素受体的转录本也随着敌草隆处理而减少。这些结果表明，环境胁迫因子的变化可能对河口鱼类中敌草隆的生态风险产生重大影响。
