Ovrebø K K, Sørbye H, Svardal A, Grong K, Svanes K
Department of Surgery, University of Bergen, Haukeland Hospital, Norway.
Dig Dis Sci. 1997 Aug;42(8):1765-74. doi: 10.1023/a:1018882019802.
Glutathione has been studied as a possible mediator in gastric mucosal protection and healing, but its extracellular function is not fully understood. This study evaluates blood flow changes in normal gastric mucosa secondary to glutathione modulation under stable central hemodynamic conditions. Thiol substances were quantified by reverse-phase ion-pair liquid chromatography and fluorescence detection. Central hemodynamics remained stable when glutathione and N-acetylcysteine were administered in a dose of 0.5 mmol/kg. Higher doses than 0.5 mmol/kg of glutathione and N-acetylcysteine caused unstable hemodynamics. Glutathione (0.5 mmol/kg intravenously) and N-acetylcysteine (0.5 mmol/kg intravenously) reduced corpus mucosal blood flow by 28% and 26% (P < 0.0005), respectively, and glutathione reduced antral mucosa blood flow by 22% (P < 0.01). L-Buthionine-[S,R]-sulfoximine (2 mmol/kg intravenously) did not effect gastric mucosal blood flow. Cysteine content in mucosa and plasma increased while mucosal glutathione levels were largely unchanged after administration of reduced glutathione and N-acetylcysteine. Plasma glutathione only increased after injection of glutathione. L-Buthionine-[S,R]-sulfoximine reduced the glutathione level in both plasma and mucosa. We conclude that glutathione and N-acetylcysteine reduce gastric mucosal blood flow and that the effect may be related to increased cysteine levels in plasma or mucosa.
谷胱甘肽已被作为胃黏膜保护和愈合的一种可能介质进行研究，但其细胞外功能尚未完全明确。本研究评估在稳定的中心血流动力学条件下，谷胱甘肽调节对正常胃黏膜血流变化的影响。通过反相离子对液相色谱法和荧光检测对硫醇类物质进行定量分析。当以0.5 mmol/kg的剂量给予谷胱甘肽和N-乙酰半胱氨酸时，中心血流动力学保持稳定。高于0.5 mmol/kg的谷胱甘肽和N-乙酰半胱氨酸剂量会导致血流动力学不稳定。谷胱甘肽（静脉注射0.5 mmol/kg）和N-乙酰半胱氨酸（静脉注射0.5 mmol/kg）分别使胃体黏膜血流减少28%和26%（P < 0.0005），谷胱甘肽使胃窦黏膜血流减少22%（P < 0.01）。L-丁硫氨酸-[S,R]-亚砜亚胺（静脉注射2 mmol/kg）对胃黏膜血流无影响。给予还原型谷胱甘肽和N-乙酰半胱氨酸后，黏膜和血浆中的半胱氨酸含量增加，而黏膜谷胱甘肽水平基本未变。仅在注射谷胱甘肽后血浆谷胱甘肽增加。L-丁硫氨酸-[S,R]-亚砜亚胺降低了血浆和黏膜中的谷胱甘肽水平。我们得出结论，谷胱甘肽和N-乙酰半胱氨酸会减少胃黏膜血流，且这种作用可能与血浆或黏膜中半胱氨酸水平升高有关。
