Eckert K G, Eyer P
Biochem Pharmacol. 1986 Jan 15;35(2):325-9. doi: 10.1016/0006-2952(86)90533-2.
In vitro studies with freshly drawn human erythrocytes showed 4-dimethylaminophenol, a cyanide antidote, to be rapidly metabolized with the formation of a transient S,S-(2-dimethylamino-5-hydroxy-1,3-phenylene)bis-glutathione conjugate and a stable S,S,S-(2-dimethylamino-5-hydroxy-1,3,4-phenylene)tris-glutathione conjugate. The stable tri-glutathionyl derivative was actively transported across the red cell membrane with an apparent Vmax = 1 nmol/min/ml red cell suspension (15 g hemoglobin/100 ml) and Km = 0.5 mM. The transport system was strictly unidirectional, inhibited completely by sodium fluoride and reduced to one-fifth by lowering the temperature from 37 to 22 degrees. Similarly S-(2,4-dinitrophenyl)-glutathione, the glutathione-S-transferase mediated glutathione-S-conjugate with 1-chloro-2,4-dinitrobenzene, was unidirectionally transported, a process which was inhibited by sodium fluoride. Kinetic analysis revealed two different transport processes: Vmax = 0.9 nmol/min/ml, Km = 1.4 microM and Vmax = 4.5 nmol/min/ml, Km = 700 microM. Mutual inhibition of the low affinity transport system was found for both glutathione-S-conjugates. The apparent energies of activation for all these transport processes and for GSSG were identical (70 kJ/mol) suggesting at least one common carrier for the excretion of the three glutathione-S-conjugates.
对新鲜采集的人红细胞进行的体外研究表明，氰化物解毒剂4-二甲基氨基酚可迅速代谢，形成一种短暂的S,S-(2-二甲基氨基-5-羟基-1,3-亚苯基)双谷胱甘肽共轭物和一种稳定的S,S,S-(2-二甲基氨基-5-羟基-1,3,4-亚苯基)三谷胱甘肽共轭物。这种稳定的三谷胱甘肽衍生物以明显的Vmax = 1 nmol/分钟/毫升红细胞悬液（15克血红蛋白/100毫升）和Km = 0.5 mM的速率被主动转运穿过红细胞膜。该转运系统严格单向，完全被氟化钠抑制，并且通过将温度从37℃降至22℃，转运速率降低至五分之一。同样，谷胱甘肽-S-转移酶介导的谷胱甘肽与1-氯-2,4-二硝基苯的S-(2,4-二硝基苯基)-谷胱甘肽也被单向转运，该过程被氟化钠抑制。动力学分析揭示了两种不同的转运过程：Vmax = 0.9 nmol/分钟/毫升，Km = 1.4 microM和Vmax = 4.5 nmol/分钟/毫升，Km = 700 microM。发现这两种谷胱甘肽-S-共轭物对低亲和力转运系统存在相互抑制作用。所有这些转运过程以及谷胱甘肽二硫化物的表观活化能相同（70 kJ/mol），这表明至少有一种共同载体参与三种谷胱甘肽-S-共轭物的排泄。
