氯化镉遗传毒性及氯化锌拮抗作用的机制研究

Study on Mechanism of Genotoxicity of CdCl_2 and Antagonism of ZnCl_2 in vitro

目的观察镉、锌体外染毒对中国仓鼠肺成纤维细胞(V79)胞内镉离子含量及自由基含量的影响,初步探讨镉遗传毒性的机制。方法采用等离子体光谱仪及激光共聚焦显微镜法研究不同浓度氯化镉(CdCl2,终浓度分别为1,2,4,8μmol/L及1,5,10μmol/L)单独或与生理浓度氯化锌(ZnCl2,10μmol/L)同时染毒对细胞内Cd2+、Zn2+含量及过氧化氢(H2O2)含量的影响。结果随着CdCl2染毒浓度的增加,细胞内Cd2+及H2O2含量均增加,且均呈现出浓度-效应关系。同时给予ZnCl2可使细胞内Cd2+及H2O2含量降低,与对应的镉单独染毒组相比,差异有显著性(P<0.05)。结论在本实验条件下,CdCl2可通过镉直接毒性作用及通过自由基的间接毒性作用而发挥其毒性效应,锌可以从这两方面的机制拮抗镉的毒作用。

Objective To investigate the effect of CdCl2 and ZnCl2 on intracellular concentration of Cd^2＋ and Zn^2＋ in Chinese hamster lung fibroblast cells （V79） in culture and to explore the mechanism on genotoxicity of Cd2＋. Methods The mass spectrograph and the fluorescent probe of H2O2 （DCFH-DA） combined with Confocal Scanning Laser Microscope （CSLM） were carried out to investigate the intracellular content of Cd^2＋ and Zn^2＋ ions and H2O2 respectively after the treatment with CdCl2 alone or with ZnCl2 simultaneously. Results The intracellular concentrations of Cd^2＋ and H2O2 both increased linearly with the content of CdCl2 in the culture medium, while ZnCl2, when added to the culture with CdCl2 simultaneously, could inhibit Cd^2＋ ion from entering the cells, it could also decrease the production of H2O2 in V79 cells. The difference between CdCl2 group and the corresponding CdCl2 ＋ZnCl2 group showed statistically significant （P d0. 05）. Conclusions The mechanism on the genotoxicity of CdCl2 might be of direct and indirect ways, while Zn^2＋ could inhibit the effects of Cd^2＋ through these two ways.