Instituto de Química de San Luis, INQUISAL (UNSL-CONICET), Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis, Argentina; UNESP - Universidade Estadual Paulista, Departamento de Biologia, São José do Rio Preto, São Paulo, Brazil.
UNESP - Universidade Estadual Paulista, Departamento de Biologia, São José do Rio Preto, São Paulo, Brazil; Instituto de Biociências (InBio), Universidade Federal de Mato Grosso do Sul, UFMS, Brazil.
Environ Pollut. 2019 Jan;244:733-746. doi: 10.1016/j.envpol.2018.10.073. Epub 2018 Oct 17.
Brazil is an important consumer of herbicides. In sugarcane cultivation-the country's most extensive agricultural crop-atrazine-based formulations are the principal form of weed control. Several studies have investigated adverse effects of atrazine or their formulations on anurans, but not specifically on Brazilian species. Our aim was therefore to investigate the lethal and sublethal effects of an atrazine-based herbicide in Rhinella schneideri tadpoles and, in particular, effects on the pigmentation system as a new endpoint in ecotoxicological studies. Rhinella schneideri tadpoles at the Gosner-30 stage were exposed to the atrazine-based herbicide formulation, SIPTRAN 500 SC, in acute bioassays at concentrations of 1.5-25 mg/L. The lethal and sublethal effects induced were analysed at different ecotoxicological levels: organismal level (alterations in behaviour, growth, development, and body mass; morphologic abnormalities), histological level (liver histopathology), the pigmentation system (melanomacrophages and dermal-melanophores), and cellular level (erythrocyte micronucleus formation and other nuclear-abnormalities). This herbicide induced sublethal effects at the organismal level with alterations in swimming and growth and morphologic abnormalities. These results demonstrated that, in anuran tadpoles, the atrazine-based agrochemical increased the frequency of micronucleus formation and other nuclear-abnormalities in erythrocytes and caused liver damage. In addition, we demonstrated for the first time effects of an atrazine-based formulation on the pigmentation system of anuran tadpoles, specifically an increase in the number of melanomacrophages and dermal melanophores. This study is the first to use several widely differing endpoints at different ecotoxicological levels in a comprehensive manner for assessment of the effects of environmental stressors in order to determine the health status of Neotropical anuran species. In doing so, this study establishes a foundation for future ecological assessments.
巴西是除草剂的重要消费国。在甘蔗种植——该国最广泛的农业作物——中，以莠去津为基础的制剂是杂草控制的主要形式。有几项研究调查了莠去津或其制剂对有尾两栖动物的不良影响，但没有专门针对巴西物种。因此，我们的目的是调查莠去津基除草剂对 Rhinella schneideri 蝌蚪的致死和亚致死效应，特别是作为生态毒理学研究新终点的色素系统效应。处于 Gosner-30 阶段的 Rhinella schneideri 蝌蚪在浓度为 1.5-25mg/L 的急性生物测定中暴露于莠去津基除草剂配方 SIPTRAN 500 SC 中。在不同的生态毒理学水平上分析了诱导的致死和亚致死效应：个体水平（行为、生长、发育和体重变化；形态异常）、组织学水平（肝组织病理学）、色素系统（黑色素巨噬细胞和真皮黑色素细胞）和细胞水平（红细胞微核形成和其他核异常）。这种除草剂在个体水平上引起了亚致死效应，导致游泳和生长改变以及形态异常。这些结果表明，在有尾两栖动物中，基于莠去津的农用化学品增加了红细胞微核形成和其他核异常的频率，并导致了肝损伤。此外，我们首次证明了基于莠去津的制剂对有尾两栖动物色素系统的影响，特别是黑色素巨噬细胞和真皮黑色素细胞数量的增加。这项研究首次使用了不同生态毒理学水平的几种广泛不同的终点，全面评估环境胁迫对新热带有尾两栖动物物种健康状况的影响。通过这样做，本研究为未来的生态评估奠定了基础。
