Hinshaw D B, Burger J M, Delius R E, Hyslop P A
Surgical Service, Ann Arbor Veterans Administration Medical Center, MI 48105.
Surgery. 1990 Aug;108(2):298-304; discussion 304-5.
Glutamine supplementation before oxidant exposure has recently been shown to significantly enhance adenosine triphosphate (ATP) levels and viability in endothelial cells. The aim of this study was to determine if glutamine can help cells after oxidant injury has been initiated and to demonstrate the mechanism of its action. The activity of glyceraldehyde 3-phosphate dehydrogenase was measured in bovine pulmonary artery endothelial cells exposed to H2O2 (0 to 10 mmol/L). Glyceraldehyde 3-phosphate dehydrogenase activity was completely inhibited by 10 mmol/L H2O2 after 1 minute, resulting in inhibition of glycolysis. The endothelial cells were then exposed to 10 mmol/L H2O2, with glutamine (2 mmol/L) being added at different times in relation to the injury. ATP levels were monitored during a 3-hour time course, and short-term viability was measured 6 hours after addition of the oxidant. Significant improvement of endothelial cell ATP levels and short-term viability was seen with addition of glutamine as late as 15 minutes after addition of H2O2. Mitochondrial inhibition with oligomycin (650 nmol/L) abolished the protective effect of glutamine on ATP levels and short-term viability. Cellular survival at 24 hours was not enhanced by glutamine, which suggests that ATP may not be the only factor determining long-term survival after oxidant injury.
最近有研究表明，在暴露于氧化剂之前补充谷氨酰胺可显著提高内皮细胞中的三磷酸腺苷（ATP）水平并增强其活力。本研究的目的是确定在氧化剂损伤已经发生后谷氨酰胺是否能对细胞起到帮助作用，并阐明其作用机制。在暴露于过氧化氢（0至10 mmol/L）的牛肺动脉内皮细胞中测量了3-磷酸甘油醛脱氢酶的活性。1分钟后，10 mmol/L的过氧化氢完全抑制了3-磷酸甘油醛脱氢酶的活性，导致糖酵解受到抑制。然后将内皮细胞暴露于10 mmol/L的过氧化氢中，并在与损伤相关的不同时间添加谷氨酰胺（2 mmol/L）。在3小时的时间进程中监测ATP水平，并在添加氧化剂6小时后测量短期活力。在添加过氧化氢后15分钟时添加谷氨酰胺，可见内皮细胞的ATP水平和短期活力有显著改善。用寡霉素（650 nmol/L）抑制线粒体消除了谷氨酰胺对ATP水平和短期活力的保护作用。谷氨酰胺并未提高24小时时的细胞存活率，这表明ATP可能不是决定氧化剂损伤后长期存活的唯一因素。
