应用胞质分裂阻滞微核法检测三卤甲烷和卤乙腈的遗传毒性

Genotoxicity detection of trihalomethanes and haloacetonitriles using cytokinesis-block micronucleus test

目的:探讨两大类饮用水消毒副产物三卤甲烷(氯仿、一溴二氯甲烷、二溴一氯甲烷、溴仿)和卤乙腈(三氯乙腈、二溴乙腈)的遗传毒性。方法:上述6种消毒副产物分别设4个染毒剂量,以苯并芘为阳性对照,二甲基亚砜为溶剂对照。应用胞质分裂阻滞微核法(cytokinesis-block micronucleus test,CBMNT)检测上述消毒副产物对人来源的肝肿瘤细胞HepG2微核率和核分裂指数(nuclear division index,NDI)的影响。结果:与溶剂对照组相比,4种三卤甲烷除溴仿外,均可使HepG2细胞的微核率显著增加(P<0.01或P<0.05),但诱导微核率显著增加的最低可观察水平高达10 000μmol/L(氯仿和一溴二氯甲烷)和3 000μmol/L(二溴一氯甲烷);两种卤乙腈分别在2 000μmol/L(三氯乙腈)和30μmol/L(二溴乙腈)时可诱导HepG2细胞微核率显著增加(P均<0.01)和NDI的显著下降(P均<0.05)。结论:运用CBMNT方法可检出三卤甲烷和卤乙腈的遗传毒性,三卤甲烷和卤乙腈对HepG2细胞染色体具有断裂作用。

OBJECTIVE：To investigate the genotoxicity induced by two types of disinfection by-products （DBPs） trihalomethanes（chloroform,bromodichloromethane,chlorodibromomethane and bromoform） and haloacetonitriles （trichloroacetonitrile and dibromoacetonitrile）.METHODS：Human hepatocellular carcinoma cell line HepG2 cells were treated with the DBPs mentioned above at four concentrations to evaluate their effects on the formation of micronuclei and nuclear division index（NDI） by means of cytokinesis-block micronucleus test（CBMNT）.Dimethyl sulfoxide and benzo（a）pyrene were used as solvent control and positive control,respectively.RESULTS：Chloroform,bromodichloromethane and chlorodibromomethane were found to induce statistically significant increases in the frequency of micronuclei at the concentrations of 10 000 and 3 000μmol/L（P 0.05）,while bromoform did not show similar effect on HepG2 cells in comparison with the solvent control.Trichloroacetonitrile and dibromoacetonitrile also induced statistically significant increases in the frequency of micronuclei and decreases in NDI at the lowest observed adverse effect levels of 2 000 and 30μmol/L（P 0.05）,respectively.CONCLUSION：CBMNT could be used to detect the genotoxicity of trihalomethanes and haloacetonitriles,which were found to cause chromosome breakage in HepG2 cells.