The occurrence of iodinated contrast agents (ICAs) in the aquatic environment is relatively well documented, showing that these compounds can be found at several µg/L in natural waters, and up to hundreds of µg/L in waste water treatment plants inlets. Nevertheless, only few studies address their potential impacts and fate in aquatic organisms mainly because these compounds are considered non-toxic due to their intrinsic properties. However, as aquatic organisms are continuously exposed to these compounds, they could nonetheless induce some adverse effects on aquatic populations like filter feeder organisms. To verify this, we exposed model organisms, Dreissena polymorpha mollusks, to 100 µg/L of an ICA, diatrizoic acid (DTZ), to determine the potential biological effects caused by this compound using a non-targeted metabolomic approach based on liquid chromatography coupled to high resolution mass spectrometry. Metabolic profiles showed a slight effect of DTZ, with some metabolome variations linked to exposure. Indeed, to avoid any misinterpretation of DTZ effects, we also studied the natural evolution of the metabolome over time in unexposed mussels, showing that control mussels exhibited metabolomic changes over the exposure period. During DTZ exposure, we showed that the carnitine shuttle pathway of fatty acids and pyrimidine metabolisms were impacted, leading to dysregulation of mussels’ energy metabolism. Thus, this study demonstrates for the first time that compounds considered non-toxic like ICAs can have an impact on aquatic organisms such as bivalves by slightly modulating their metabolome.

中文翻译：

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碘造影剂泛影酸对软体动物 Dreissena polymorpha 的代谢组有影响


碘造影剂 （ICA） 在水生环境中的存在相对有据可查，表明这些化合物在天然水中含量为几 μg/L，在废水处理厂入口中含量高达数百 μg/L。然而，只有少数研究涉及它们在水生生物中的潜在影响和命运，主要是因为这些化合物由于其内在特性而被认为是无毒的。然而，由于水生生物不断暴露于这些化合物，它们仍然可能对滤食性生物等水生种群产生一些不利影响。为了验证这一点，我们将模式生物 Dreissena polymorpha 软体动物暴露于 100 μg/L 的 ICA、泛影酸 （DTZ） 中，以使用基于液相色谱与高分辨率质谱联用的非靶向代谢组学方法确定该化合物引起的潜在生物效应。代谢特征显示 DTZ 的轻微影响，一些代谢组变化与暴露有关。事实上，为了避免对 DTZ 效应的任何误解，我们还研究了未暴露的贻贝代谢组随时间的自然演变，表明对照贻贝在暴露期间表现出代谢组学变化。在 DTZ 暴露期间，我们发现脂肪酸的肉碱穿梭途径和嘧啶代谢受到影响，导致贻贝能量代谢失调。因此，这项研究首次证明，像 ICA 这样被认为是无毒的化合物可以通过轻微调节双壳类生物的代谢组来对双壳类等水生生物产生影响。