Accurate assessment of the toxic potential of waterborne chemicals is vital to pollution control and management in aquatic ecosystems. However, there is a global advocacy for the reduction, replacement, and refinement of the use of whole organisms in chemical screening studies. This has encouraged the development of alternative in vitro and computer-based techniques. In this study we investigated the possibility of optimising cultured rainbow trout gill epithelia to tolerate seawater and its use to assess toxicity of waterborne chemicals. Gill cells were obtained from rainbow trout acclimated to freshwater or to artificial seawater and were cultured in L-15 culture medium supplemented with or without cortisol. Intact gill epithelia were subjected to 20‰, 25‰ or 30‰ artificial seawater for 24 h and cell viability was assessed. The viability of gill cells obtained from freshwater or artificial seawater acclimated fish and grown without cortisol reduced to less than 80% compared to controls. The addition of cortisol to culture medium improved cell viability in seawater with 94%-95% viability compared to controls. The optimised gill cell epithelium was exposed to trace elements at concentrations previously reported as causing 50% response or mortality (EC/LC₅₀) using other cell-based and in vivo studies. Viability of the gill cells were compared to the 50% response or survival reported. The gill cells were found to be more sensitive than other isolated primary seawater-fish cells, having 5%, 16% and 37% survival on exposure to arsenic, cadmium, and lead, respectively. Results from this study has shown that cultured rainbow trout gill epithelia can be optimised to tolerate seawater and can be used in toxicological evaluations of pollutants resuspended in seawater, mimicking marine ecosystem conditions. The optimised gill cell system can serve as a viable in vitro method for marine ecosystem toxicological studies which would facilitate effective pollution control and management.

准确评估水性化学品的潜在毒性对于水生生态系统的污染控制和管理至关重要。然而，全球提倡减少、替代和改进在化学筛选研究中使用整个生物体。这鼓励了替代体外的发展和基于计算机的技术。在这项研究中，我们调查了优化养殖虹鳟鱼鳃上皮以耐受海水的可能性及其用于评估水性化学品毒性的可能性。从适应淡水或人工海水的虹鳟鱼获得鳃细胞，并在添加或不添加皮质醇的 L-15 培养基中培养。完整的鳃上皮细胞在 20‰、25‰ 或 30‰ 人工海水中浸泡 24 小时，并评估细胞活力。与对照相比，从淡水或人工海水驯化的鱼中获得的鳃细胞的生存力在没有皮质醇的情况下生长降低到低于 80%。向培养基中添加皮质醇可提高海水中的细胞活力，与对照相比，其活力提高了 94%-95%。₅₀ ) 使用其他基于细胞的和体内研究。将鳃细胞的存活率与所报告的 50% 反应或存活率进行比较。发现鳃细胞比其他分离的原代海水鱼细胞更敏感，暴露于砷、镉和铅的存活率分别为 5%、16% 和 37%。这项研究的结果表明，培养的虹鳟鱼鳃上皮细胞可以优化以耐受海水，并可用于模拟海洋生态系统条件重新悬浮在海水中的污染物的毒理学评估。优化后的鳃细胞系统可作为一种可行的体外海洋生态系统毒理学研究方法，有助于有效控制和管理污染。