ACIDOSIS PROTECTS AGAINST LETHAL OXIDATIVE INJURY OF LIVER SINUSOIDAL ENDOTHELIAL-CELLS
ACIDOSIS PROTECTS AGAINST LETHAL OXIDATIVE INJURY OF LIVER SINUSOIDAL ENDOTHELIAL-CELLS
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DOI：
10.1002/hep.1840140125
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发表时间：
1991-07-01
期刊：
影响因子：
13.5
通讯作者：
GORES, GJ
中科院分区：
文献类型：
--
作者：
BRONK, SF;GORES, GJ
本研究的目的是确定在氧化应激过程中致死性内皮细胞损伤的pH依赖性和提议导致内皮细胞杀伤的那些细胞机制的pH依赖性。用H2 O2（5 mmol/L）诱导大鼠肝窦内皮细胞产生氧化应激。细胞存活率依赖于细胞外的pH值。事实上，在用H2 O2孵育180分钟后，在pH 7.4下细胞存活率仅为27%，在pH 6.8下为45%（p <0.05），在pH 6.4下为62%（p < 0.05）。尽管与pH 7.4相比，pH 6.4下的细胞存活率提高，但ATP水解和谷胱甘肽消耗的幅度相似。在相反的细胞存活，脂质过氧化测定丙二醛生成增加两倍，在pH 6.4相比，pH 7.4。在pH 7.4的氧化应激期间发生线粒体膜电位的快速和深刻的损失，其在pH 6.4时延迟（在30分钟时为初始值的0.3%对20%，p < 0.0001）。与H2 O2孵育60分钟后，pH 7.4下的NAD（P）H氧化比pH 6.4下更大（100%与64%，p < 0.05）。结果表明，酸中毒对氧化应激过程中细胞死亡的保护作用与抑制NAD（P）H氧化和延迟线粒体膜电位的损失有关。酸中毒似乎通过影响NAD（P）H的氧化还原状态来维持氧化应激期间细胞器和细胞的完整性。
The purposes of this study were to determine the pH dependence of lethal endothelial cell injury during oxidative stress and the pH dependence of those cellular mechanisms proposed to result in endothelial cell killing. Oxidative stress was produced in rat liver sinusoidal endothelial cells with H2O2 (5 mmol/L). Cell survival was dependent on the extracellular pH. Indeed, after 180 min of incubation with H2O2, cell survival was only 27% at pH 7.4,45% at pH 6.8 (p < 0.05) and 62% at pH 6.4 (p < 0.05). Despite improved cell survival at pH 6.4 compared with pH 7.4, the magnitude of ATP hydrolysis and glutathione depletion was similar. In contrast to cell survival, lipid peroxidation as measured by malondialdehyde generation was increased twofold at pH 6.4 compared with pH 7.4. A rapid and profound loss of the the mitochondrial membrane potential occurred during oxidative stress at pH 7.4 that was delayed at pH 6.4 (0.3% vs. 20% of the initial value at 30 min, p < 0.0001). After 60 min of incubation with H2O2, NAD(P)H oxidation was greater at pH 7.4 than at pH 6.4 (100% vs. 64%, p < 0.05). The results indicate that the protective effect of acidosis against cell death during oxidative stress is associated with the inhibition of NAD(P)H oxidation and delayed loss of the mitochondrial membrane potential. Acidosis appears to maintain organelle and cell integrity during oxidative stress by influencing the redox status of NAD(P)H.