Combining uptake and subcellular partitioning/toxicokinetics and toxicodynamics in modelling Cu2+ toxicity to zebra mussels, taking into account water chemistry

结合吸收和亚细胞分配/毒代动力学和毒动力学来模拟 Cu2 对斑马贻贝的毒性，同时考虑水化学

• 批准号: 322918513
• 负责人: Dr. Thi Thu Yen Le, Ph.D.
• 金额: --
• 依托单位: Abteilung Aquatische Ökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/322918513?language=en
• 关键词: Combining; uptake; subcellular; partitioning; toxicokinetics

Metal toxicity to organisms is determined by various factors. Abiotic ligands in the environment might affect the amount of metals available for uptake. Dissolved organic carbon may complex metals, reducing the interactions of the metals with organisms. Major cations, e.g. Na+ and Ca2+, might compete with toxic ions for binding to sites on biological surfaces, influencing the uptake of toxic metals. Bioaccumulation is a prerequisite, but not always a reliable predictor of metal toxicity, attributed to the capacity of organisms to sequester and detoxify metals. Therefore, subcellular partitioning is another determinant of metal toxicity. These factors have separately been considered in different approaches. Effects of environmental chemistry on metal speciation as well as accumulation at biological surfaces have been included in the Biotic Ligand Model. Metal bioaccumulation has been predicted as a balance of influxes and effluxes in biodynamic models and related to toxic effects in the Critical Body Residue approach. Subcellular partitioning has been taken into account in modelling metal toxicity, but shortcomings are inherent in available approaches. For instance, the assessment of metal exposure based on the induction of metallothionein-like proteins does not account for other detoxification mechanisms. Dynamic subcellular partitioning of metals cannot effectively be described by a ratio between metal concentrations in the metal-sensitive and biologically detoxified fractions. Further delineation of subcellular partitioning does not consider metal accumulation in sensitive fractions when detoxification mechanisms are not overwhelmed whereas relationships between subcellular partitioning and biological responses are lacking.The zebra mussel Dreissena polymorpha has widely been used in biomonitoring programs, particularly because of its widespread distribution, high filtering efficiency, and high capacity to accumulate metals. The delineation of metal subcellular partitioning in the zebra mussel facilitates more accurate estimates of metals biomagnified in other aquatic organisms like fish and crustaceans. Although bioavailability and toxicity of Cu2+ to aquatic organisms have been extensively investigated, uncertainties are still remaining in available approaches, probably related to the exclusion of some of the factors mentioned above.The proposed research aims at developing a model for predicting Cu2+ toxicity to the zebra mussel, taking into account influence of environmental conditions, bioaccumulation, and the ability of the zebra mussel to detoxify and sequester Cu. The proposed model is a combination of uptake kinetics and subcellular partitioning dynamics while accounting for effects of environmental chemistry. The toxicity of Cu2+ will be related to the accumulation of Cu at the metabolically-active organs represented by the metal-sensitive fraction, which will be simulated based on uptake, elimination, and detoxification.

金属对生物的毒性取决于各种因素。环境中的非生物配体可能会影响可用于摄取的金属量。溶解的有机碳可能会使金属复杂，从而减少了金属与生物体的相互作用。主要阳离子，例如Na+和Ca2+可能与有毒离子竞争，以与生物表面上的位点结合，从而影响有毒金属的摄取。生物积累是一种先决条件，但并不总是是金属毒性的可靠预测指标，归因于生物体隔离和排毒金属的能力。因此，亚细胞分配是金属毒性的另一种决定因素。这些因素已在不同的方法中分别考虑。生物配体模型中包括环境化学对金属物种物种形成以及生物表面上的积累的影响。金属生物蓄积已被预测为生物动力模型中流入和外排的平衡，并且与关键身体残留方法中的毒性作用有关。在对金属毒性建模时已经考虑了亚细胞分配，但是可用方法中固有的缺点是固有的。例如，基于金属硫蛋白样蛋白的诱导评估金属暴​​露的评估不能解释其他排毒机制。金属的动态亚细胞分配无法通过金属敏感和生物学排毒馏分中的金属浓度之间的比率有效地描述。当排毒机制不是压倒性的同时，而缺乏亚细胞分配与生物学反应之间的关系时，亚细胞分配的进一步描述不会考虑金属在敏感分数中的积累。高过滤效率和累积金属的高容量。斑马贻贝中金属亚细胞分配的描述促进了对在鱼类和甲壳类动物（例如鱼类和甲壳类动物）中生物磁性的更准确估计。尽管已经对Cu2+对水生生物的生物利用度和毒性进行了广泛的研究，但不确定性仍在可用的方法中仍然存在，可能与排除上述某些因素有关。拟议的研究目的旨在开发一种模型来预测CU2+对Zebra的毒性的模型贻贝考虑了环境条件，生物积累的影响以及斑马贻贝排毒和隔离Cu的能力。提出的模型是摄取动力学和亚细胞分配动力学的组合，同时考虑了环境化学的影响。 Cu2+的毒性将与Cu在代谢活性器官中的积累有关，该器官代表金属敏感的馏分将基于摄取，消除和排毒。