Institute of Environmental Medicine, Karolinska Institute, P.O. Box 210, 17177 Stockholm, Sweden.
Reprod Toxicol. 2011 Feb;31(2):210-8. doi: 10.1016/j.reprotox.2010.11.002. Epub 2010 Nov 13.
Exposure to inorganic arsenic during pregnancy may negatively influence the offspring, though efficient metabolism of arsenic to dimethylarsinic acid (DMA) likely reduces the health risks. This study aimed to evaluate methylation of arsenic over the entire pregnancy and the influence of nutritional status. We studied longitudinally the arsenic metabolite pattern in the urine of 324 pregnant women exposed to arsenic via drinking water and food in rural Bangladesh. Metabolism of arsenic to DMA increased markedly over the course of pregnancy, with the greatest improvement occurring in the first trimester, along with a marked decrease in the most risk-associated monomethylated metabolite. This improvement in methylation was not associated with nutritional status, including vitamin B(12) and folate. Efficient methylation to DMA was associated with improved urinary excretion of arsenic, relative to blood arsenic concentrations, indicating that micronutrient-independent up-regulation of arsenic metabolism already in early pregnancy may provide protection for the fetus.
孕期接触无机砷可能会对后代产生负面影响，而砷向二甲基砷酸（DMA）的有效代谢可能会降低健康风险。本研究旨在评估整个孕期砷的甲基化情况，以及营养状况的影响。我们对孟加拉国农村地区 324 名通过饮水和食物接触砷的孕妇的尿液中的砷代谢产物模式进行了纵向研究。随着孕期的进展，砷向 DMA 的代谢明显增加，其中第一孕期的改善最大，与最具风险的单甲基化代谢产物显著减少同时发生。这种甲基化的改善与营养状况无关，包括维生素 B(12)和叶酸。DMA 的有效甲基化与砷的尿液排泄增加有关，相对于血砷浓度而言，这表明妊娠早期砷代谢的非依赖于微量营养素的上调可能为胎儿提供保护。
