饮水型砷暴露对人群甲基化代谢能力的影响

目的探讨饮水型砷暴露对人群甲基化代谢能力的影响。方法以带有砷化物预处理装置的原子吸收分光光度计测定砷暴露人群及无砷暴露对照人群血、尿中无机砷(iAs)、甲基胂(MMA)、二甲基胂(DMA)含量。以iAs、MMA及DMA的总和表示总胂(tAs)水平;以(MMA+DMA)/tAs及DMA/(MMA+DMA)分别计算一甲基化率(PMI)和二甲基化率(SMI)水平。结果砷暴露人群血中iAs、MMA、DMA、tAs及PMI水平均显著高于相应对照人群的水平,而SMI水平显著低于对照人群。尿中MMA水平分别与血中PMI及SMI水平呈显著正相关(r=0.419,P<0.01)及负相关(r=-0.326,P<0.05)。暴露组和对照组血中各种砷化物水平及甲基化率水平在男女间差异无显著性。结论砷暴露人群与无砷暴露人群相比甲基化率有差异,PMI显著增高,SMI显著降低。人群甲基化率无显著性别差异。

Effects of arsenic exposure through drinking water on methylation in persons

Objective To observe the effects of arsenic exposure through drinking water on methylation in persons.Methods The levels of inorganic arsenic(iAs),monomethylated arsenic(MMA),dimethylated arsenic(DMA) in blood and urine were detected by atomic absorption spectrophotometer with an arsenic speciation pretreatment system.Total arsenic(tAs),the first methylation index(PMI) and the second methylation index(SMI) were calculated as iAs MMA DMA,(MMA DMA)/tAs and DMA/(MMA DMA),respectively.Results iAs,MMA,DMA,tAs and PMI in blood of exposed persons were more higher than those of control,while SMI was more lower than that of control.Significant positive correlations were found between urinary MMA and blood PMI(r=0.419,P<0.01),while significant negative correlations were found between urinary MMA and blood SMI(r =-0.326,P<0.05).No significant differences were found in methylation capacity between men and women.Conclusion The arsenic methylation capacity of the persons exposed to arsenic was different from that of person non-exposed to arsenic,indicating an increase of PMI and decrease of SMI.There were no differences between sex in mythylation capacity.