MEASUREMENT OF ENDOTHELIAL-CELL FREE-RADICAL GENERATION - EVIDENCE FOR A CENTRAL MECHANISM OF FREE-RADICAL INJURY IN POSTISCHEMIC TISSUES
MEASUREMENT OF ENDOTHELIAL-CELL FREE-RADICAL GENERATION - EVIDENCE FOR A CENTRAL MECHANISM OF FREE-RADICAL INJURY IN POSTISCHEMIC TISSUES
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DOI：
10.1073/pnas.85.11.4046
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发表时间：
1988-06-01
影响因子：
11.1
通讯作者：
LUTTY, GA
中科院分区：
文献类型：
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作者：
ZWEIER, JL;KUPPUSAMY, P;LUTTY, GA
氧自由基已被证明是缺血后再灌注损伤的重要介质，在各种组织中，然而，自由基产生的细胞来源仍然未知。在这项研究中，电子顺磁共振测量与自旋陷阱5，5“-二甲基-1-吡咯啉-N-氧化物（DMPO）表明，牛内皮细胞缺氧和复氧成为超氧自由基和羟基自由基的有效发电机。在缺氧孵育45分钟后的复氧中观察到显著的DMPO-OH信号aN = aH = 14.9 G。进行这种自由基生成和自由基生成的时间过程的定量测量。超氧化物歧化酶和过氧化氢酶完全消除了这种自由基信号，表明O2是从O2-顺序减少。到H2 O2到OH。乙醇的加入导致乙氧基自由基的捕获，进一步证实了OH的产生。内皮自由基的产生导致细胞死亡，如台盼蓝摄取所证明的。自由基的产生部分抑制和部分清除黄嘌呤氧化酶抑制剂别嘌呤醇。观察到有效的黄嘌呤氧化酶抑制剂oxypurinol显著抑制自由基生成。这些研究表明，在缺血和再灌注组织中观察到的缺氧和复氧条件下，内皮细胞产生超氧化物衍生的羟基自由基的爆发，进而导致细胞损伤和细胞死亡。大部分自由基的产生似乎来自黄嘌呤氧化酶。因此，内皮细胞自由基的产生可能是缺血后组织中细胞损伤的中心机制。
Oxygen free radicals have been demonstrated to be important mediators of postischemic reperfusion injury in a broad variety of tissues; however, the cellular source of free radical generation is still unknown. In this study, electron paramagnetic resonance measurements with the spin trap 5,5''-dimethyl-1-pyrroline-N-oxide (DMPO) demonstrate that bovine endothelial cells subjected to anoxia and reoxygenation become potent generators of superoxide and hydroxyl free radicals. A prominent DMPO-OH signal aN = aH = 14.9 G is observed on reoxygenation after 45 min of anoxic incubation. Quantitative measurements of this free radical generation and the time course of radical generation are performed. Both superoxide dismutase and catalase totally abolish this radical signal, suggesting that O2 is sequentially reduced from O2-. to H2O2 to OH.cntdot.. Addition of ethanol resulted in trapping of the ethoxy radical, further confirming the generation of OH.cntdot.. Endothelial radical generation was shown to cause cell death, as evidenced by trypan blue uptake. Radical generation was partially inhibited and partially scavenged by the xanthine oxidase inhibitor allopurinol. Marked inhibition of radical generation was observed with the potent xanthine oxidase inhibitor oxypurinol. These studies demonstrate that endothelial cells subjected to anoxia and reoxygenation, conditions observed in ischemic and reperfused tissues, generate a burst of superoxide-derived hydroxyl free radicals that in turn cause cell injury and cell death. Most of this free radical generation appears to be from the enzyme xanthine oxidase. Thus, endothelial cell free radical generation may be a central mechanism of cellular injury in postischemic tissues.