The trivalent arsenic glutathione complexes arsenic triglutathione, methylarsonous diglutathione, and dimethylarsinous glutathione are key intermediates in the mammalian metabolism of arsenite and possibly represent the arsenic species that are transported from the liver to the kidney for urinary excretion. Despite this, the comparative stability of the arsenic-sulfur bonds in these complexes has not been investigated under physiological conditions resembling hepatocyte cytosol. Using size-exclusion chromatography and a glutathione-containing phosphate buffered saline mobile phase (5 or 10 mM glutathione, pH 7.4) in conjunction with an arsenic-specific detector, we chromatographed arsenite, monomethylarsonous acid, and dimethylarsinous acid. The on-column formation of the corresponding arsenic-glutathione complexes between 4 and 37 degrees C revealed that methylated arsenic-glutathione complexes are more stable than arsenic triglutathione. The relevance of these results with regard to the metabolic fate of arsenite in mammals is discussed.

中文翻译：

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甲基化的三价砷-谷胱甘肽复合物比它们的亚砷酸盐类似物更稳定。

三价砷谷胱甘肽复合物三价砷谷胱甘肽、甲基砷二谷胱甘肽和二甲基砷谷胱甘肽是哺乳动物亚砷酸盐代谢的关键中间体，可能代表从肝脏转运到肾脏进行尿排泄的砷种类。尽管如此，尚未在类似于肝细胞胞质溶胶的生理条件下研究这些复合物中砷硫键的相对稳定性。使用尺寸排阻色谱法和含谷胱甘肽的磷酸盐缓冲盐水流动相（5 或 10 mM 谷胱甘肽，pH 7.4）以及砷特异性检测器，我们对亚砷酸盐、单甲基亚砷酸和二甲基亚砷酸进行色谱分离。4 到 37 摄氏度之间相应的砷谷胱甘肽复合物的柱上形成表明甲基化砷谷胱甘肽复合物比砷三谷胱甘肽更稳定。讨论了这些结果与哺乳动物中亚砷酸盐代谢命运的相关性。