Generation of superoxide in cardiomyocytes during ischemia before reperfusion
Generation of superoxide in cardiomyocytes during ischemia before reperfusion
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DOI：
10.1152/ajpheart.1999.277.6.h2240
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发表时间：
1999-12-01
影响因子：
4.8
通讯作者：
Schumacker, PT
中科院分区：
文献类型：
--
作者：
Becker, LB;Vanden Hoek, TL;Schumacker, PT
虽然在再灌注过程中已经很好地描述了氧化剂的爆发，但对氧化还原状态的高度还原和低O-2缺血所产生的氧化剂知之甚少。本研究旨在进一步确定这些氧化剂的种类和来源。心肌细胞暴露于1小时的模拟缺血，同时通过细胞内二氢乙胺（DHE）氧化来评估氧化剂的产生。缺血1小时后显著增加DHE氧化（0.7 +/- 0.1至2.3 +/- 0.3）。Myxothiazol（线粒体III位点抑制剂）将氧化减弱至1.3 +/- 0.1，I位点抑制剂鱼藤酮（1.0 +/- 0.1），amytal（1.1 +/- 0.1）和黄蛋白氧化酶抑制剂二苯乙酮（0.9 +/- 0.1）也是如此。相比之下，IV位点抑制剂氰化物以及黄嘌呤氧化酶（别嘌呤醇）、一氧化氮合酶（硝基- l -精氨酸甲酯）和NADPH氧化酶（罗布麻碱）的抑制剂没有作用。最后，DHE氧化在二乙基二硫代氨基甲酸酯（2.7 +/- 0.1）抑制含铜和含锌超氧化物歧化酶（SOD）时升高，在外源SOD（1.1 +/- 0.1）抑制下降低。我们得出结论，在缺血再灌注前，线粒体电子传递链的亚二甲基醌位点产生了大量的超氧化物。
Although a burst of oxidants has been well described with reperfusion, less is known about the oxidants generated by the highly reduced redox state and low O-2 Of ischemia. This study aimed to further identify the species and source of these oxidants. Cardiomyocytes were exposed to 1 h of simulated ischemia while oxidant generation was assessed by intracellular dihydroethidine (DHE) oxidation. Ischemia increased DHE oxidation significantly (0.7 +/- 0.1 to 2.3 +/- 0.3) after 1 h. Myxothiazol (mitochondrial site III inhibitor) attenuated oxidation to 1.3 +/- 0.1, as did the site I inhibitors rotenone (1.0 +/- 0.1), amytal (1.1 +/- 0.1), and the flavoprotein oxidase inhibitor diphenyleneiodonium (0.9 +/- 0.1). By contrast, the site IV inhibitor cyanide, as well as inhibitors of xanthine oxidase (allopurinol), nitric oxide synthase (nitro-L-arginine methyl ester), and NADPH oxidase (apocynin), had no effect. Finally, DHE oxidation increased with Cu- and Zn-containing superoxide dismutase (SOD) inhibition using diethyldithiocarbamate (2.7 +/- 0.1) and decreased with exogenous SOD (1.1 +/- 0.1). We conclude that significant superoxide generation occurs during ischemia before reperfusion from the ubisemiquinone site of the mitochondrial electron transport chain.