Department of Marine Science, University of Texas at Austin, Port Aransas, Texas 78373, USA.
International Institute for Sustainable Development─Experimental Lakes Area, Winnipeg, Manitoba R3B 0T4, Canada.
Environ Sci Technol. 2022 Jul 19;56(14):10193-10203. doi: 10.1021/acs.est.2c01079. Epub 2022 Jun 24.
Metformin is routinely detected in aquatic ecosystems because of its widespread use as a treatment for Type 2 diabetes. Laboratory studies have shown that exposure to environmentally relevant concentrations of metformin can alter metabolic pathways and impact the growth of early life stage (ELS) fish; however, it is unknown whether these effects occur in wild populations. Herein, we evaluate whether findings from laboratory studies are representative and describe the relative sensitivities of both populations. Duplicate exposures (0, 5, or 50 μg/L metformin) were conducted using wild- and lab-spawned fathead minnow () embryos. Apart from the water source, exposure conditions remained constant. Wild embryos were exposed to previously dosed lake water to account for changes in bioavailability, while reconstituted freshwater was used for the laboratory study. Developmental metformin exposure differentially impacted the growth and morphology of both cohorts, with energy dyshomeostasis and visual effects indicated. The fitness of wild-spawned larvae was impacted to a greater extent relative to lab-spawned fish. Moreover, baseline data reveal important morphological differences between wild- and lab-spawned ELS fatheads that may diminish representativeness of lab studies. Findings also confirm the bioavailability of metformin in naturally occurring systems and suggest current exposure scenarios may be sufficient to negatively impact developing fish.
二甲双胍由于被广泛用于治疗 2 型糖尿病，因此在水生生态系统中经常被检测到。实验室研究表明，暴露于环境相关浓度的二甲双胍会改变代谢途径并影响早期生命阶段（ELS）鱼类的生长；然而，尚不清楚这些影响是否发生在野生种群中。在此，我们评估实验室研究的结果是否具有代表性，并描述两个种群的相对敏感性。使用野外和实验室繁殖的黑头呆鱼（）胚胎进行了重复暴露（0、5 或 50μg/L 二甲双胍）。除了水源外，暴露条件保持不变。野外胚胎暴露于先前剂量的湖水以考虑生物利用度的变化，而实验室研究则使用重新配制的淡水。发育中的二甲双胍暴露对两个群体的生长和形态都有不同的影响，表现为能量动态失衡和视觉影响。与实验室养殖的鱼类相比，野生产卵的幼虫的适应性受到更大的影响。此外，基线数据揭示了野外和实验室繁殖的 ELS 黑头呆鱼之间存在重要的形态差异，这可能会降低实验室研究的代表性。研究结果还证实了二甲双胍在自然发生系统中的生物利用度，并表明当前的暴露情况可能足以对发育中的鱼类产生负面影响。
