School of Freshwater Sciences, University of Wisconsin - Milwaukee, 600 East Greenfield Ave, Milwaukee, WI 53204, USA.
School of Freshwater Sciences, University of Wisconsin - Milwaukee, 600 East Greenfield Ave, Milwaukee, WI 53204, USA.
Chemosphere. 2015 Sep;135:38-45. doi: 10.1016/j.chemosphere.2015.03.060. Epub 2015 Apr 18.
The occurrence of intersex fish, where male reproductive tissues show evidence of feminization, have been found in freshwater systems around the world, indicating the potential for significant endocrine disruption across species in the ecosystem. Estrogens from birth control medications in wastewater treatment plant effluent have been cited as the likely cause, but research has shown that endocrine disruption is not solely predictable based on hormone receptor interactions. Many other non-hormone pharmaceuticals are found in effluent at concentrations orders of magnitude higher than estrogens, yet there is little data indicating the impacts of these other medications. The widely prescribed anti-diabetic metformin is among the most abundant of pharmaceuticals found in effluent and is structurally dissimilar from hormones. However, we show here that exposing fathead minnows (Pimephales promelas) to a concentration of metformin found in wastewater effluent causes the development of intersex gonads in males, reduced size of treated male fish, and reduction in fecundity for treated pairs. Our results demonstrate that metformin acts as an endocrine disruptor at environmentally relevant concentrations.
具有雌雄同体特征的鱼类（雄性生殖组织出现雌性化迹象）在世界各地的淡水系统中被发现，这表明生态系统中不同物种可能受到重大内分泌干扰。污水处理厂废水中的避孕药雌激素被认为是可能的原因，但研究表明，内分泌干扰并不仅仅可以根据激素受体相互作用来预测。废水中还存在许多其他非激素药物，其浓度比雌激素高出几个数量级，但几乎没有数据表明这些其他药物的影响。广泛开处方的抗糖尿病药物二甲双胍是废水中含量最丰富的药物之一，其结构与激素不同。然而，我们在这里表明，将食蚊鱼（Pimephales promelas）暴露于废水中发现的二甲双胍浓度下会导致雄性鱼类出现雌雄同体的性腺、处理过的雄性鱼类体型减小以及处理过的配对鱼的繁殖力下降。我们的结果表明，二甲双胍在环境相关浓度下表现出内分泌干扰作用。
