IRSTEA, Unité de Recherche Hydrosystèmes et Bioprocédés, 1 rue P.-G. de Gennes, 92731 Antony, France.
Laboratoire des Sciences du Climat et de l׳Environnement LSCE (CEA-CNRS-UVSQ), UMR 8212, Bât. 12 Av. de la Terrasse, 911198 Gif-sur-Yvette cedex, France.
Ecotoxicol Environ Saf. 2014 Dec;110:182-9. doi: 10.1016/j.ecoenv.2014.09.001. Epub 2014 Sep 20.
Gammarids are aquatic amphipods widely used for water quality monitoring. To investigate the copper and cadmium diet-borne metal uptake in Gammarus pulex, we adapted the pulse-chase stable isotopes-based approach to determine the food ingestion rate (IR), the gut retention time (GRT) and the metal assimilation efficiencies (AE). G. pulex were fed with (65)Cu-, (106)Cd-, and (53)Cr-labeled alder leaves for 7.5h and then with unlabeled leaves for 5d. The metal stable isotope contents in the gammarids, leaves, filtered water and periodically collected feces were determined. Chromium was poorly assimilated by the gammarids; thus, Cr was used as an unassimilated tracer. The first tracer defecation occurred before the first feces harvest, indicating a gut passage time of less than 9h. A 24-h GRT and a 0.69gg(-1)d(-1) IR were estimated. The Cd AE value was estimated as 5-47%, depending on the assimilation determination method applied. The Cu AE value could not be evaluated regardless of the determination method used, most likely because of the rapid Cu regulation in gammarids in addition to analytical uncertainties when determining the Cu content in leaves. Application of the Cd AE value in the framework of the biodynamic bioaccumulation model shows that the diet-borne uptake of Cd significantly contributes (66-95%) to the metal bioaccumulation in G. pulex fed with alder leaves.
卤虫是一种水生端足目甲壳类动物，被广泛用于水质监测。为了研究铜和镉在食源途径下在食蚊鱼中的金属摄入情况，我们采用基于脉冲-追踪稳定同位素的方法来确定食物摄入率（IR）、肠道保留时间（GRT）和金属同化效率（AE）。我们用（65）Cu、（106）Cd 和（53）Cr 标记的桤木叶喂养食蚊鱼 7.5 小时，然后用未标记的叶子喂养 5 天。测定了食蚊鱼、叶子、过滤水和定期收集的粪便中的金属稳定同位素含量。铬在食蚊鱼中同化程度较差；因此，Cr 被用作未同化的示踪剂。第一次排粪发生在第一次粪便收获之前，这表明肠道通过时间少于 9 小时。估计出 24 小时 GRT 和 0.69gg(-1)d(-1)的 IR。Cd AE 值的估计值在 5-47%之间，具体取决于所应用的同化测定方法。无论使用哪种测定方法，都无法评估 Cu AE 值，这很可能是由于食蚊鱼体内 Cu 的快速调节以及在测定叶子中 Cu 含量时存在分析不确定性。将 Cd AE 值应用于生物动力学生物累积模型框架中表明，食源途径摄入的 Cd 对食蚊鱼（用桤木叶喂养）中的金属生物累积有显著贡献（66-95%）。
