Iioka H, Moriyama I, Kyuma M, Akasaki M, Katoh Y, Itoh K, Saitoh M, Hino K, Okamura Y, Itani Y
Nihon Sanka Fujinka Gakkai Zasshi. 1987 May;39(5):725-30.
The placental transport mechanism of glutathione (GSH) was investigated using microvillous membrane vesicles prepared from human term placenta. Using (3H-glycine)-labeled-GSH, it was clarified that GSH in the extravesicular compartment of placental microvillous membranes was rapidly degraded by gamma-GTP (gamma-glutamyltranspeptidase) and resulting amino acid, and 3H-labeled-glycine was actively transported via a sodium cotransport system. AT-125 treated microvillous membrane vesicles almost entirely lost its gamma-GTP activity, and showed intact GSH transport. Using AT-125 treated microvillous membrane vesicles, it was revealed that GSH was transported across the microvillous membrane as an anion via a membrane potential-dependent mechanism. These results indicated that gamma-GTP which existed in microvillous membrane played a role in GSH metabolism and that intracellular GSH was translocated out of the syncythiotrophoblast cell into the maternal blood space via a specific carrier in microvillous membrane because the GSH concentration was higher in intracellular than extracellular and extracellular membrane potential was positively charged.
利用从足月人胎盘制备的微绒毛膜囊泡研究了谷胱甘肽（GSH）的胎盘转运机制。使用（3H-甘氨酸）标记的GSH，明确了胎盘微绒毛膜囊泡外室中的GSH被γ-GTP（γ-谷氨酰转肽酶）迅速降解，产生的氨基酸，并且3H标记的甘氨酸通过钠共转运系统被主动转运。用AT-125处理的微绒毛膜囊泡几乎完全丧失了其γ-GTP活性，并表现出完整的GSH转运。使用经AT-125处理的微绒毛膜囊泡，发现GSH作为阴离子通过膜电位依赖性机制跨微绒毛膜转运。这些结果表明，存在于微绒毛膜中的γ-GTP在GSH代谢中起作用，并且细胞内GSH通过微绒毛膜中的特定载体从合体滋养层细胞转运到母体血腔中，因为细胞内GSH浓度高于细胞外，且细胞外膜电位带正电。
