Hagen T M, Jones D P
Am J Physiol. 1987 May;252(5 Pt 1):G607-13. doi: 10.1152/ajpgi.1987.252.5.G607.
We used an in situ closed-loop vascular perfusion of rat small intestine to see whether intact glutathione (GSH) was transported from the lumen into the mesenteric circulation. Results using [3H] GSH showed radiolabel appearance in the perfusate, and high-performance liquid chromatography analysis confirmed that the transported radiolabeled species was intact GSH. Transepithelial transport was Na+ dependent, where Na+-free solutions on the luminal side inhibited transport but in the vasculature stimulated transport. Transport was inhibited by the GSH analogues ophthalmic acid and gamma-glutamylglutamate when added to the lumen. Probenecid caused inhibition only when added on the vascular side, suggesting that the transport systems on the two poles of the cells may be different. In vivo studies with GSH administration via stomach gavage caused marked increases in plasma GSH concentrations. These results establish that transepithelial transport of intact GSH occurs in rat small intestine. This process may allow dietary or biliary derived GSH to be utilized by various cell types that can take up intact GSH from the plasma. Moreover, the results show that oral administration of GSH may be therapeutically useful.
我们采用大鼠小肠原位闭环血管灌注法，以观察完整的谷胱甘肽（GSH）是否能从肠腔转运至肠系膜循环。使用[³H]GSH的结果显示灌注液中出现放射性标记，高效液相色谱分析证实转运的放射性标记物质为完整的GSH。跨上皮转运依赖于Na⁺，管腔侧无Na⁺溶液会抑制转运，但在血管侧则刺激转运。当向肠腔中添加GSH类似物眼用酸和γ-谷氨酰谷氨酸时，转运受到抑制。丙磺舒仅在添加于血管侧时才会引起抑制，这表明细胞两极的转运系统可能不同。通过胃管给予GSH的体内研究导致血浆GSH浓度显著升高。这些结果证实大鼠小肠存在完整GSH的跨上皮转运。这一过程可能使饮食或胆汁来源的GSH被各种能够从血浆中摄取完整GSH的细胞类型所利用。此外，结果表明口服GSH可能具有治疗作用。
