Metabolism of inorganic arsenic in children with chronic high arsenic exposure in northern Argentina
Metabolism of inorganic arsenic in children with chronic high arsenic exposure in northern Argentina
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DOI：
10.2307/3434042
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发表时间：
1998-06-01
影响因子：
10.4
通讯作者：
Vahter, M
中科院分区：
文献类型：
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作者：
Concha, G;Nermell, B;Vahter, M
本研究涉及阿根廷北部三个村庄儿童中无机砷 (As) 的代谢：San Antonio de los Cobres 和 Taco Pozo，饮用水中砷含量约为 200 微克/升，罗萨里奥德莱尔马，饮用水中砷含量为 0.65 微克/升。研究结果显示，两个砷富集村儿童血液和尿液中砷浓度平均分别为9和380微克/升，为有记录以来儿童最高浓度。血液和尿液中的浓度分别比罗萨里奥德莱尔马的浓度高约 10 倍和 30 倍。尿液中总砷仅略高于无机砷代谢物（U-As-met）的总和，即无机砷、甲基胂酸（MMA）和二甲基胂酸（DMA）；这表明无机砷是摄入砷的主要形式。与之前对不同人群尿液中无机砷代谢物的研究相比，本研究中的儿童和妇女排泄的 MMA 非常少。因此，参与 As 甲基化的酶（甲基转移酶）似乎存在多态性。有趣的是，儿童尿液中无机砷的比例显着高于女性，分别为 50% 和 32%。此外，儿童中无机砷的百分比显着高于先前对其他人群中儿童（两项研究中约为 13%）和成人（约 15-25%）的研究。这可能表明儿童比成人对砷引起的毒性更敏感，因为甲基化代谢物与组织成分的结合比无机砷更少。在儿童中，随着 U-As-met 的增加，尿液中无机砷的百分比下降，DMA 的百分比增加，表明随着暴露的增加，砷甲基化会被诱导。
This study concerns the metabolism of inorganic arsenic (As) in children in three villages in northern Argentina: San Antonio de los Cobres and Taco Pozo, each with about 200 mu g As/l in the drinking water, and Rosario de Lerma, with 0.65 mu g As/l. Findings show that the concentrations of As in the blood and urine of the children in the two As-rich villages were on average 9 and 380 mu g/l, respectively, the highest ever recorded for children. The concentrations were about 10 and 30 times higher for blood and urine, respectively, than in Rosario de Lerma. Total As in urine was only slightly higher than the sum of metabolites of inorganic As (U-As-met) i.e., inorganic As, methylarsonic acid (MMA), and dimethylarsinic acid (DMA); this shows that inorganic As was the main form of As ingested. In contrast to previous studies on urinary metabolites of inorganic As in various population groups, the children and women in the present study excreted very little MMA. Thus, there seems to be a polymorphism for the enzymes (methyltransferases) involved in the methylation of As. Interestingly, the children had a significantly higher percentage of inorganic As in urine than the women, about 50% versus 32%. Also, the percentage of inorganic As in the children is considerably higher than in previous studies on children (about 13% in the two studies available) and adults (about 15-25%) in other population groups. This may indicate that children are more sensitive to As-induced toxicity than adults, as the methylated metabolites bind less to tissue constituents than inorganic As. In the children, the percentage inorganic arsenic in urine decreased, and the percentage of DMA increased with increasing U-As-met, indicating an induction of As methylation with increasing exposure.