Aaseth J, Alexander J, Norseth T
Acta Pharmacol Toxicol (Copenh). 1982 Apr;50(4):310-5. doi: 10.1111/j.1600-0773.1982.tb00979.x.
Hexavalent chromium (Cr-VI), as Na2CrO4 in an aqueous solution, was reduced rapidly ot the trivalent form (Cr-III) in the presence of glutathione, GSH (0.3-3.0 mM). Such GSH-dependent reduction Cr-VI can take place in the cytosolic space of Cr-VI-exposed cells, since GSH is found in reactive concentrations in this compartment. The reduction makes chromium essentially impermeable through the cell membrane, explaining the observation that Cr-VI, when added to red cell suspensions, is bound quantitatively intracellularly after a few hours. Diethylmaleate conjugation of the SH-group of the intracellular GSH preventing the oxidation to GSSG, lowered the chromium-uptake significantly, showing that reduced GSH plays a role for the chromium binding. In healthy red cells chromium is partially bound to haemoglobin and partially to small molecular weight substances, probably in the trivalent form. This intracellular chromium cannot be removed to the extracellular space by addition of chelating agents as long as the cell membrane is intact.
在谷胱甘肽（GSH，0.3 - 3.0 mM）存在的情况下，水溶液中的六价铬（Cr-VI，以Na2CrO4形式存在）会迅速还原为三价形式（Cr-III）。这种依赖GSH的Cr-VI还原反应能够在暴露于Cr-VI的细胞的胞质空间中发生，因为在这个区室中发现GSH以具有反应活性的浓度存在。这种还原反应使得铬基本无法透过细胞膜，这就解释了以下现象：当将Cr-VI添加到红细胞悬液中时，数小时后它会定量地结合在细胞内。马来酸二乙酯与细胞内GSH的巯基结合，阻止其氧化为GSSG，这显著降低了铬的摄取量，表明还原型GSH在铬的结合过程中发挥作用。在健康的红细胞中，铬部分与血红蛋白结合，部分与小分子物质结合，可能是以三价形式存在。只要细胞膜保持完整，通过添加螯合剂无法将这种细胞内的铬转运到细胞外空间。
