PROTECTION BY VERAPAMIL OF MITOCHONDRIAL GLUTATHIONE EQUILIBRIUM AND PHOSPHOLIPID CHANGES DURING REPERFUSION OF ISCHEMIC CANINE MYOCARDIUM
PROTECTION BY VERAPAMIL OF MITOCHONDRIAL GLUTATHIONE EQUILIBRIUM AND PHOSPHOLIPID CHANGES DURING REPERFUSION OF ISCHEMIC CANINE MYOCARDIUM
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DOI：
10.1161/01.res.61.2.301
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发表时间：
1987-08-01
影响因子：
20.1
通讯作者：
MCMILLINWOOD, JB
中科院分区：
文献类型：
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作者：
KAJIYAMA, K;PAULY, DF;MCMILLINWOOD, JB
用维拉帕米预处理缺血心肌可防止缺血性心脏骤停和再灌注期间观察到的线粒体呼吸抑制。由于缺血性线粒体功能似乎不会被再灌注进一步改变，本研究的目的是确定一个生化事件，影响线粒体是特别相关的再灌注损伤。有人提出，增加细胞内钙离子流入和氧毒性可能会导致重新引入冠状动脉流量。增加的胞质Ca 2+被传递到线粒体，随后激活Ca 2+依赖性事件，包括磷脂酶A2。当再酰化机制被抑制时，溶血磷脂的净产生（以及线粒体中总二酰基磷脂的损失）将继续进行。由于酰基辅酶A：溶血磷脂酰基转移酶是一种巯基敏感酶，并且由于谷胱甘肽过氧化物酶活性增加使线粒体巯基缓冲液谷胱甘肽水平向氧化方向移动，因此在不存在或存在维拉帕米预处理的再灌注期间测量谷胱甘肽水平及其氧化态。缺血降低总谷胱甘肽和减少氧化还原比（还原型谷胱甘肽：氧化型谷胱甘肽）85%。再灌注通过使氧化型谷胱甘肽从基质中消失而使氧化还原比部分恢复到对照。维拉帕米将谷胱甘肽的浓度和氧化还原电位维持在对照水平。伴随着还原型谷胱甘肽的改变：氧化型谷胱甘肽是缺血性线粒体磷脂含量的减少。在再灌注过程中，磷脂酰乙醇胺及其主要成分脂肪酸（C18：0和C20：4）从线粒体膜上特异性丢失。再灌注期间花生四烯酸的显著损失伴随着11-OH、12-OH和15-OH花生酸盐含量的降低。这些脂质过氧化产物在缺血时不增加。有人提出，在缺血过程中的谷胱甘肽的基质谷胱甘肽谷胱甘肽二硫化物的氧化结果形成谷胱甘肽-蛋白质混合二硫化物和巯基敏感的蛋白质，包括酰基辅酶A溶血磷脂酰基转移酶的抑制。因此，缺血期内发生的代谢事件为再灌注期间的长期功能障碍奠定了基础。
Pretreatment of the ischemic myocardium with verapamil protects against mitochondrial respiratory depression observed during ischemic arrest as well as during reperfusion. Since ischemic mitochondrial function appears not to be altered further by reperfusion, the purpose of this study is to identify a biochemical event affecting mitochondria that is specifically associated with reperfusion injury. It has been proposed that increased cellular Ca2+ influx and oxygen toxicity may result from reintroduction of coronary flow. Increased cytosolic Ca2+ is transmitted to the mitochondria with subsequent activation of Ca2+-dependent events, including phospholipase A2. Net production of lysophospholipids (and loss of total diacylphospholipids from the mitochondria) will proceed when reacylation mechanisms are inhibited. Since acyl-CoA:lysophospholipid acyltransferase is a sulfhydryl-sensitive enzyme and since increased activity of glutathione peroxidase shifts the levels of the mitochondrial sulfhydryl buffer, glutathione, towards oxidation, levels of glutathione and its oxidation state were measured during reperfusion in the absence or presence of verapamil pretreatment. Ischemia lowers total glutathione and reduces the redox ratio (reduced glutathione:oxidized glutathione) by 85%. Reperfusion partially returns the redox ratio to control by causing oxidized glutathione to disappear from the matrix. Verapamil maintains both the concentration and the redox potential of glutathione at control levels. Concomitant with alterations in reduced glutathione:oxidized glutathione is a decrease in ischemic mitochondrial phospholipid content. During reperfusion, phosphatidylethanolamine and its major constituent fatty acids (C18:0 and C20:4) are specifically lost from the mitochondrial membrane. Accompanying the significant loss of arachidonic acid during reperfusion is the decreased content of 11-OH, 12-OH, and 15-OH arachidate. These lipid peroxidation products are not increased in ischemia. It is proposed that oxidation of matrix glutathione to glutathione disulfide during ischemia results in formation of glutathione-protein mixed disulfides and inhibition of sulfhydryl-sensitive proteins, including acyl-CoA lysophosphatide acyltransferase. Thus, metabolic events occurring within the ischemic period set the stage for prolonged dysfunction during reperfusion.