不同代谢活化条件对N-亚硝胺类化合物细菌回复突变结果的影响

Effect of different metabolic activation conditions on the results of bacterial reverse mutation test of N-nitrosamine compounds

目的检测N-亚硝基二甲胺(NDMA)和N-亚硝基二乙胺(NDEA)的致突变风险,探讨不同肝微粒体S_(9)混合液对N-亚硝胺类化合物致突变结果的影响。方法将鼠疫伤寒杆菌TA97、TA98、TA100、TA102、TA1535、TA1537和待测化合物分别与SD大鼠、CD-1小鼠和人的肝脏S_(9)混合液混合后于37℃预培养1 h,之后接种于6孔细胞培养板,并继续在37℃孵箱中培养约48 h,观察回复突变菌落的数目。结果在非S_(9)条件下NDEA、NDMA均无致突变性。小鼠S_(9)及人S_(9)条件下NDEA、NDMA均无致突变性且在小鼠S_(9)及人S_(9)预培养条件下NDEA、NDMA也无致突变性。SD大鼠S_(9)预培养条件下NDMA、NDEA使TA97、TA100、TA102和TA1535菌株发生回复突变。当大鼠S_(9)含量为30%时,NDEA、NDMA产生明显致突变性的浓度范围为10~1000μg/孔,与阴性对照(DMSO,20μl/孔)比较存在显著性差异(回复突变率超过阴性对照组的2~3倍),且存在一定剂量相关性。结论证实使用经诱导的SD大鼠S_(9)混合液检测N-亚硝胺类化合物致突变性的合理性和准确性,为后续研究N-亚硝胺类化合物遗传毒性奠定基础。

Objective The effects of different S_(9)mixes on the mutagenic results of N-nitrosamine compounds were explored by detecting the mutagenic risks of N-nitrosodimethylamine(NDMA)and N-nitrosodiethylamine(NDEA).Methods The S.typhimurium TA97,TA98,TA100,TA102,TA1535,TA1537,the test compound and its mixture with S_(9)mixes of SD rats,CD-1 mice and human livers were pre-cultured at 37℃for 1 h,then inoculated into a six-well cell culture plate for incubation at 37℃for about 48 h to observe the number of revertant.Results Under non-S_(9)conditions,NDEA and NDMA have no mutagenicity.NDEA and NDMA are not mutagenic under mouse S_(9)and human S_(9)conditions,and NDEA and NDMA are also not mutagenic under mouse S_(9)and human S_(9)pre-culture conditions.Under SD rat S_(9)pre-culture conditions,NDMA and NDEA resulted in increased revertants of TA97,TA100,TA102 and TA1535 strains.When 30%rat S_(9)was applied,the mutagenic concentration of NDEA and NDMA was 10-1000μg/well,which was significantly different from that of the negative control(DMSO,20μl/well)(the number of revertants was 2-3 times higher than that of the negative control)with a dose correlation.Conclusion This study confirms the rationality and accuracy of using induced SD rat S_(9)mix to detect the mutagnenicity of N-nitrosamine compounds,and provides a foundation for subsequent studies on the genotoxicity of N-nitrosamine compounds.