A metabolic link between arsenite and selenite:: The seleno-bis(S-glutathionyl) arsinium ion
A metabolic link between arsenite and selenite:: The seleno-bis(S-glutathionyl) arsinium ion
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DOI：
10.1021/ja993064m
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发表时间：
2000-05-17
影响因子：
15
通讯作者：
Aposhian, HV
中科院分区：
文献类型：
--
作者：
Gailer, J;George, GN;Aposhian, HV
哺乳动物毒理学中最令人吃惊的观察结果之一是，致命剂量的硒可以被致命剂量的砷所克服。我们报告这种拮抗作用的分子基础。用X射线吸收光谱法，我们已经确定了一个新的砷硒化合物在兔的胆汁中注入水溶液亚硒酸盐和亚砷酸盐。该化合物含有等摩尔的砷和硒，其X射线吸收光谱与我们通过光谱鉴定为硒-双（S-谷胱甘肽）砷离子的溶液中的合成物质的X射线吸收光谱基本相同。这种化合物的体内检测与亚砷酸盐、亚硒酸盐和硫的哺乳动物代谢有关。它为这些类金属化合物之间的拮抗作用提供了分子基础，并为人类长期摄入无机砷与癌症的关联提供了潜在的解释。
Among the most startling observations in mammalian toxicology is that a lethal dose of selenium can be overcome by an otherwise lethal dose of arsenic. We report the molecular basis of this antagonism. Using X-ray absorption spectroscopy we have identified a new arsenic-selenium compound in the bile of rabbits injected with aqueous selenite and arsenite solutions. This compound contains equimolar arsenic and selenium and exhibits X-ray absorption spectra which are essentially identical with those of a synthetic species in solution which we have identified spectroscopically as the seleno-bis(S-glutathionyl) arsinium ion. The in vivo detection of this compound links the mammalian metabolism of arsenite, selenite, and sulfur. It provides a molecular basis for the antagonistic interaction between these metalloid compounds, and a potential explanation of the association of cancer with prolonged intake of inorganic arsenic in humans.