水环境中镉对鱼类的毒理效应研究进展

水环境中镉是公认毒性最大、蓄积性最强的重金属之一，易富集于水生生物体内，对其生理代谢产生毒性效应，并通过食物链传递，威胁人类健康。本文以鱼类为代表性水生生物，综述了镉对鱼类的毒理效应研究进展。鱼类食性和摄食途径的差异造成镉在其体内的积累和分布具有生物特异性与组织差异性。水体镉浓度超标可导致鱼类的鳃和肝脏等组织结构与功能完整性受到不同程度损害，并对鱼类的抗氧化防御系统、生殖调控、非特异性免疫系统与基因表达等产生毒性效应，其毒性效应随镉暴露浓度、暴露时间、鱼类种类、发育阶段和性别不同而异。同时，鱼类的抗氧化防御系统和免疫系统在镉诱导的氧化损伤中发挥了重要的保护作用。通过总结国内外研究进展，展望今后的研究方向，为更加深入研究镉的毒理效应及机制，进而更好地控制水环境中镉污染，保护水生态环境和水生生物，以及为人类提供安全的水产品提供科学依据。

Research Progress on the Toxicity of Cadmium to Fish

Cadmium is widely recognized as one of the most toxic and accumulative heavy metals in the aquatic environment, which is easily enriched in aquatic organisms, thus toxics to its physiological metabolism and threatens human health through the food chain. This paper takes fish as the representative aquatic organism, the toxicological effects of cadmium on fish are reviewed. The accumulation and distribution of cadmium in fish by different feeding habits and pathways are biologically specific and histologically different. Excessive cadmium concentration can lead to different degrees of damage to the structure and functional integrity of fishes'' gills and liver, which have toxic effects to the anti-oxidative defense system, reproductive regulation and non-specific immune system and their gene expression. Toxicity effects varied with cadmium exposure concentration, exposure time, fish species, developmental stage, and sex. At the same time, the antioxidant defense system and immune system of fish play an important protective role in cadmium induced tissue damage. In order to further study of the toxicological effect of cadmium and its mechanism, so as to better control cadmium pollution in aquatic environment, protect aquatic ecological environment and aquatic organisms, and provide safe aquatic products for human beings for providing scientific basis, we summarize the research progress at home and abroad and prospect the research direction.