Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
EPF Lausanne, School of Architecture, Civil and Environmental Engineering, Lausanne, Switzerland.
ALTEX. 2020;37(1):37-46. doi: 10.14573/altex.1905032. Epub 2019 Jul 11.
Testing chemicals for fish acute toxicity is a legal requirement in many countries as part of environmental risk assessment. To reduce the numbers of fish used, substantial efforts have been focussed on alternative approaches. Prominently, the cell viability assay with the rainbow trout (Oncorhynchus mykiss) gill cell line, RTgill-W1, has been recognized, owing to its high predictive power and robustness. Like gills, the intestine is considered a major site of chemical uptake and biotransformation but, in contrast to gills, is expected to be exposed to rather hydrophobic chemicals, which enter the fish via food. In the present study, we therefore aimed to extend the cell bioassay to the rainbow trout epithelial cell line from intestine, RTgutGC. Using 16 hydrophobic and volatile chemicals from the fragrance palette, we showed that also the RTgutGC cell line can be used to predict fish acute toxicity of chemicals and yields intra-laboratory variability in line with other bioassays. By comparing the RTgutGC toxicity to a study employing the RTgill-W1 assay on the same group of chemicals, a fragrance specific relationship was established which reflects an almost perfect 1:1 relationship between in vitro and in vivo toxicity results. Thus, both cell lines can be used to predict fish acute toxicity, either by using the obtained in vivo-in vitro relationship or by taking the in vitro results at face value. We moreover demonstrate the derivation of non-toxic concentrations for downstream applications which rely on a healthy cell state, such as the assessment of biotransformation or chemical transfer.
测试化学品对鱼类的急性毒性是许多国家环境风险评估的法定要求。为了减少鱼类的使用数量，人们已经做出了大量努力来开发替代方法。其中，由于其高预测能力和稳健性，使用虹鳟（Oncorhynchus mykiss）鳃细胞系 RTgill-W1 的细胞活力测定法得到了认可。与鳃不同，肠道被认为是化学物质吸收和生物转化的主要部位，但与鳃不同的是，肠道预计会暴露于相当疏水的化学物质中，这些化学物质通过食物进入鱼类体内。因此，在本研究中，我们旨在将细胞生物测定法扩展到来自肠道的虹鳟上皮细胞系 RTgutGC。使用来自香精系列的 16 种疏水和挥发性化学物质，我们表明 RTgutGC 细胞系也可用于预测鱼类急性毒性和化学物质的体内变异性，与其他生物测定法一致。通过将 RTgutGC 毒性与使用相同化学物质的 RTgill-W1 测定法的研究进行比较，建立了一种特定于香精的关系，反映了体外和体内毒性结果之间几乎完美的 1:1 关系。因此，这两种细胞系都可用于预测鱼类急性毒性，既可以使用获得的体内-体外关系，也可以直接采用体外结果。此外，我们还证明了可以为依赖健康细胞状态的下游应用（如生物转化或化学转移的评估）推导出无毒浓度。
