饮水型地方性砷中毒患者皮肤损伤与甲基化代谢关系

Relationship between methylation capacity and skin lesions among patients chronically exposed to arsenic through drinking water

目的探讨饮水型砷中毒患者皮肤损伤与甲基化代谢能力的关系。方法依据诊断标准对某饮水型砷中毒病区患者症状进行分级,测定血中无机砷(iAs)、甲基砷(MMA)、二甲基砷(DMA)含量并计算百分比(iAs%、MMA%、DMA%),以iAs、MMA及DMA的总和表示总砷(tAs)水平,以(MMA+DMA)/tAs及DMA/(MMA+DMA)分别计算一甲基化率(FMR)和二甲基化率(SMR)水平。结果患者血中形态砷和甲基化指标水平在性别间差异无统计学意义(P>0.05);轻、中、重度患者FMR水平差异无统计学意义(P>0.05);中度及重度患者SMR水平[(0.36±0.11)、(0.37±0.08)]均低于轻度患者(0.48±0.11),MMA%[(0.50±0.06)、(0.52±0.03)]均高于轻度患者(0.41±0.09);SMR水平与患者皮肤损伤症状等级之间呈负相关(r=-0.429,P<0.05)。结论SMR水平下降及MMA%水平增高与砷性皮肤损伤关系密切。

Objective To explore the relationship between methylation capacity and skin lesions among the patients chronically exposed to arsenic through drinking water.Methods Patients with arsenic related skin lesions were graded according to the Chinese Standard of Diagnosis for Endemic Arsenicosis.Levels of inorganic arsenic（iAs）,monomethylated arsenic（MMA）,dimethylated arsenic（DMA） in blood were detected by atomic absorption spectrophotometer with an arsenic speciation pretreatment system.iAs%,MMA%,and DMA% were calculated.Total arsenic（tAs）,the first methylation ratio（FMR） and the second methylation ratio（SMR） were calculated as iAs＋MMA＋DMA,（MMA＋DMA）/tAs and DMA/（MMA＋DMA）,respectively.Results There were no significant gender differences in the level of iAs,MMA,DMA,tAs,iAs%,MMA%,DMA%,FMR,and SMR.No significant difference in FMR was found among the mild,moderate and advanced group of skin lesions.SMR of moderate and advanced group（0.36±0.11,0.37±0.08） were markedly lower than that of mild（0.48±0.11）,while MMA% of moderate and advanced group（0.50±0.06,0.52±0.03） was significantly higher than that of mild（0.41±0.09）.Significant negative correlation was found between SMR and the grade of skin lesions（r=-0.429,P0.05）.Conclusion The results suggest that low secondary arsenic methylation capacity and high MMA proportion are associated with the severity of arsenic-related skin lesion.