The elucidative research of the factors which regulate the symptoms of chronic arsenic poisoning

本文研究了内蒙古包头县生活在天然砷污染地区和饮用不同剂量的井水接触砷的居民的砷暴露与皮肤病变的关系。男性居民的皮肤病变患病率，尤其是色素沉着患病率的优势比明显更高。甲基化砷的能力；通过测量个体受试者血液或尿液中的砷浓度及其化学类型来估计的第1或第2甲基化与他们的皮肤病变有关。雄性的第2甲基化能力低于雌性。第一甲基化能力较高、第二甲基化能力较低的患者，其色素沉着程度较重。尿液中第二甲基化能力较低的患者掌、足底角化过度和色素沉着较重。与血液中砷的化学形式有关的任何皮肤病变的患病率的优势比，随着性别和年龄的调整，单甲基砷最高，二甲基砷次之。换句话说，第二甲基化能力低于第一甲基化能力并导致单甲基砷在体内积累的个体有严重的皮肤病变，特别是色素沉着。在将饮用水改为低砷饮用水后的第一年，观察到皮肤病变的显著改善，但在随后的几年中，改善的步伐缓慢。甲基化能力与皮肤病变的改善之间没有相关性。相对低剂量（1、4和8微M）的三价无机砷（亚砷酸钠）通过自身产生GM-CSF和tgf - α促进正常人表皮角质形成细胞（NHEK）的增殖。在砷存在的NHEK培养中，子代染色体交换率也有所增加。低剂量砷诱导小鼠真皮成纤维细胞（3T3）增殖。砷对表皮角化细胞和真皮成纤维细胞增殖的促进作用，可能与长期饮水接触砷的居民所观察到的角化过度有关。少

We examined the relation between arsenic exposure and skin lesions in the residents who had been lived at naturally arsenic contaminated field and had been exposed to arsenic at various dose via drinking well water in Baotou county of Inner Mongolia, China. Odds ratio in prevalence of skin lesions especially of dyspigmentation was significantly higher in male residents. Ability to methylate arsenic ; 1st or 2nd methylation, estimated by measuring arsenic concentration with their chemical types in blood or urine from individual subjects was studied as being related to their skin lesions. Male showed lower ability of 2nd methylation compare with female. The cases with higher ability of 1st methylation and lower ability of 2nd methylation estimated with blood sample from both genders had heavier dyspigmentation. The cases with lower ability of 2nd methylation estimated with urine sample had heavier hyperkeratosis in palm and sole, and dyspigmentation. Odds ratios of prevalence of any skin … More lesions relating to chemical form of arsenic in blood adjusted with gender and age were the highest in monomethyl arsenic and the 2nd in dimethyl arsenic. In other words, the individual with less ability of 2nd than 1st methylation and resulted to accumulate monomethyl arsenic in their body had sever skin lesions, especially dyspigmentation. Significant improvement of skin lesions were observed in the first year after the changing drinking water to low arsenic, but the pace of improvement was slow in the ensuing years. There was no correlation between the ability of methylation and the improvement of skin lesions.Relatively low dose (1,4 and 8 micro M) of trivalent inorganic arsenic (sodium arsenite) enhanced the proliferation of normal human epidermal keratinocytes (NHEK) via production of GM-CSF and TGF-alpha by themselves. Increase of daughter chromosome exchange ratio was also observed in the NHEK culture with existence of arsenic. The proliferation of mouse dermal fibroblast (3T3) cells was induced by low dose of arsenic. The both enhancements of proliferation in epidermal keratinocyte and dermal fibroblast induced by arsenic were suggested to be association with hyperkeratosis observed in residents who had been exposed to arsenic via drinking water for long periods. Less