水环境中镉对鱼类的毒理效应研究进展

Research Progress on the Toxicity of Cadmium to Fish

镉在鱼类体内具有生物富集与毒理效应,本文从组织结构与功能完整性、生理代谢、生殖和免疫系统等方面总结了国内外研究进展,为更好地控制水环境中镉污染,保护水环境和水生生物提供科学依据。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;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。展望今后的研究方向,应加强低剂量和长周期镉胁迫的影响、水中镉与其他环境污染物的复合毒理效应、不同形态镉的毒理效应及机制等方面研究。

Cadmium is widely distributed in the aquatic environment and accumulates in aquatic organ⁃isms,effecting their metabolism and threatening human health through the food chain.In this paper,we se⁃lected fish as a representative aquatic organism and reviewed the toxicological effects of cadmium on fish,considering physiology,metabolism,reproduction and the immune system.The accumulation and distribu⁃tion of cadmium in fish are biologically specific and histologically different because of the diversity of feeding habits and metabolic pathways.Excess cadmium concentration results in various degrees of dam⁃age to the structure and functional integrity of gills and liver as well as effects on reproduction,the anti-ox⁃idant system,innate immune system and gene expression.Toxic effects vary with cadmium exposure lev⁃el,exposure time,fish species,developmental stage and sex.At the same time,the antioxidant system and immune system of fish play an important protective role in cadmium induced tissue damage.To better con⁃trol cadmium pollution in the aquatic environment,protect aquatic ecology and aquatic organisms,and to provide safe aquatic products for human beings,we recommend further research on the chronic toxic ef⁃fects of cadmium on fish at low exposure levels,the combined toxic effects of cadmium and other water pollutants and the toxic effects and mechanisms of cadmium in different forms.