Department of Biology, University of Nebraska-Omaha, Omaha, Nebraska, USA.
Environ Toxicol Chem. 2013 Jul;32(7):1544-51. doi: 10.1002/etc.2220. Epub 2013 May 28.
The objectives of the present study were to determine 1) if temporal variability influenced the toxicity of Elkhorn River, Nebraska, USA, water, and 2) if the toxic effect was consistent between 2 sentinel organisms, the fathead minnow (Pimephales promelas) and the northern leopard frog (Rana pipiens). During spring 2012, atrazine indicator strips were used to document the occurrence of agrichemical pulses in the Elkhorn River. Polar organic chemical integrative samplers (POCIS) were deployed for 14 d during both a pulse and a postpulse period as indicated by the atrazine strips. Pesticide concentrations detected in the POCIS extracts ranged from 1.6-fold to 281-fold higher during the pulse period compared to the postpulse period. Fish and frog bioassays were conducted for 7 d, and hepatic mRNA expression of vitellogenin (VTG) and estrogen receptor alpha (ERα) was determined by quantitative real-time polymerase chain reaction. Compared with lab water controls, fish exposed to water collected during an agrichemical pulse experienced significant reductions in VTG and ERα, whereas exposed female frogs did not. Male leopard frogs, in contrast, experienced significant increases in the expression of ERα, whereas pulse-exposed male minnows did not. The significant effects observed following agrichemical pulse exposure demonstrate that episodic agrichemical runoff adversely impacts sentinel organisms, and that the adverse impacts observed depend on the sex and species of the sentinel organism.
1）时间变异性是否会影响美国内布拉斯加州埃尔克霍恩河的毒性，以及 2）两种指示生物，黑头呆鱼（Pimephales promelas）和北方豹蛙（Rana pipiens）之间的毒性效应是否一致。在 2012 年春季，使用莠去津指示带记录埃尔克霍恩河中农用化学品脉冲的发生情况。在莠去津条带指示的脉冲和脉冲后期间，部署了 14 天的极性有机化学综合采样器（POCIS）。在 POCIS 提取物中检测到的农药浓度在脉冲期比脉冲后期间高 1.6 至 281 倍。进行了为期 7 天的鱼类和蛙类生物测定，并通过定量实时聚合酶链反应确定卵黄蛋白原（VTG）和雌激素受体α（ERα）的肝 mRNA 表达。与实验室用水对照相比，暴露于采集自农用化学品脉冲期间的水中的鱼类经历了 VTG 和 ERα 的显著减少，而暴露的雌性青蛙则没有。相比之下，雄性豹蛙经历了 ERα 的表达显著增加，而暴露于脉冲的雄性呆鱼则没有。在农用化学品脉冲暴露后观察到的显著影响表明，突发性农用化学径流对指示生物有不利影响，并且观察到的不利影响取决于指示生物的性别和物种。
