【摘要】 目的　检测醋酸镍诱导pSP189质粒在Vero细胞中的非定标性突变及其DNA损伤 ,分析其间的关系 ,为探讨镍的致癌机制提供线索。方法　醋酸镍染毒Vero细胞 2 5h ,再常规培养 2 4h后 ,转染野生型质粒pSP189,获取经该哺乳动物细胞复制过的质粒 ,转化其进入大肠杆菌MBM70 70 ,通过特殊培养基筛选突变子 ;用改良的单细胞凝胶电泳法检测开始转染时Vero细胞的DNA损伤。结果　醋酸镍浓度为 2 5 0 μmol/L和 10 0 0 μmol/L剂量组诱导出了非定标性突变 ,其突变率分别为 9 46×10 4 和 15 0 1× 10 4 ,是对照组的 4 41和 6 98倍 ,各剂量组的DNA链断裂、DNA 蛋白交联和DNA DNA交联均显著高于对照组 ,但无剂量 效应关系 ;突变率和DNA DNA交联均出现了剂量跳跃现象。结论　醋酸镍在穿梭质粒系统中可诱导出非定标性突变 ,并与宿主细胞的DNA DNA交联效应可能相关更多还原

【Abstract】 Objective To detect the nontargeted mutagenesis and DNA damage in Vero cells induced by nickel acetate and to analyze their association, to provide clues to carcinogenic mechanism of nickel. Method Vero cells were treated with nickel acetate for 2 5 hours and cultivated in routine condition for 24 hours, and transfected with wild plasmid pSP189 Plasmid replicated in mammalian cells was collected and was transferred into E coli MBM7070 The mutant was selected with special culture media DNA damage in Vero cells was detected with modified single cell gel electrophoresis. Results Nontargeted mutagenesis occurred in the cells pretreated with 250 μmol and 1 000 μmol nickel acetate, with mutagenesis frequencies of 9 46×10 4 and 15 01×10 4 , 4 41 and 6 98 folds more as compared with the control group, respectively Frequencies of DNA damage, DNA chain breaks, DNA protein cross links and DNA DNA cross links in all pretreated cells were significantly higher than those in the control group, but without dose effect relationship There was dose leap for mutagenesis frequencies and DNA DNAcross links.Conclusion Nickel acetate could induce nontargeted mutagenesis in the system of shuttle plasmid vectors, which could be related to DNA DNA cross links更多还原