氯化镉所致DNA损伤及锌的拮抗效应的研究

Study on DNA Damage Induced by CdCl_2 in vitro and Antagonistic Effects of Zn Ion

目的通过体外实验,了解氯化镉(CdCl2)对中国仓鼠肺成纤维细胞(V79细胞)的直接DNA损伤作用及锌的拮抗作用,初步探讨镉的遗传毒性机制及预防措施。方法采用甲基四唑法(MTT法)了解CdCl2对于V79细胞的毒性,通过碱性单细胞凝胶电泳常用的几个评价指标,研究CdCl2体外对于V79细胞DNA的断裂损伤,并采用生理浓度ZnCl2(10μmol/L)加以拮抗。结果MTT试验中,CdCl2对于V79细胞的毒性随染毒剂量增加而增高,呈线性关系,线性方程为:y=-0.009 4x+94.472;在碱性单细胞凝胶电泳中,CdCl2单独染毒,随着染毒剂量增加,DNA损伤加重,而锌具有明显的拮抗作用。结论本实验条件下,CdCl2能造成V79细胞DNA损伤,生理浓度的锌可以拮抗镉的DNA损伤效应。

Objective To investigate the effeets of Cd^2＋ and Zn^2＋ on DNA damage of Chinese hamster lung fibrohlast cells （V79） in culture. Methods Methyl tetrazolium test （MTT） assay was used to detect the cytotoxicity of CdCl2 on V79 cell line. By general indexes of SCGE assay, DNA strand breaks induced by CdCl2 in vitro on V79 cells and with zinc as antagonizer were observed. Results In MTT test, the cytotoxicity effeet of CdCl2 on V79 raised as the increase in dosage showing linear relationship with the linear equation y= -0. 009 4 x＋94. 472. In alkali SCGE assay, CdCl2 could damage the DNA of V79 proportionally with the dosages. ZnCl2 showed obvious antagonistic effeet. Conclusions CdCl2 could induee DNA damage on V79 cells under the experimental condition, while Zn in physiological concentration may antagonize the damage.