Barnard M L, Snyder S J, Engerson T D, Turrens J F
Department of Biomedical Sciences, College of Allied Health Professions, University of South Alabama, Mobile 36688.
Free Radic Biol Med. 1993 Aug;15(2):227-32. doi: 10.1016/0891-5849(93)90064-2.
The specific activity of seven enzymes involved in protecting tissue from oxidative stress was determined in rat kidneys subjected to 0, 2, 4, or 8 h of normothermic ischemia and in isolated rat livers during control perfusion, after 2 h ischemia, and after 2 h ischemia plus 1 h of reperfusion. In general, none of the antioxidant enzymes measured showed any consistent variation throughout the ischemic period even though mitochondrial function was significantly decreased, indicating substantial cell injury. Glutathione peroxidase (Se-GSH-Px) activity remained constant during 8 h of ischemia, although a small (29%) increase above control activity was noted at 4 h of ischemia. Se-independent GSH-Px activity (non-Se-GSH-Px) and glutathione reductase (GSSG-Red) remained constant up to 8 h of ischemia, when we measured an increase of 158% above controls in non-Se-GSH-Px and a decrease of 35% relative to controls in GSSG-Red. In perfused livers, the only change in enzyme activity after 2 h of ischemia was an increased GSSG-Red activity of 21% above control. This increase persisted into the reperfusion phase (35% above control activity) and was accompanied by decreases in both forms of GSH-Px (28% Se-GSH-Px and 44% non-Se-GSH-Px).
在经历0、2、4或8小时常温缺血的大鼠肾脏以及在对照灌注期间、缺血2小时后和缺血2小时加再灌注1小时后的离体大鼠肝脏中，测定了参与保护组织免受氧化应激的七种酶的比活性。总体而言，尽管线粒体功能显著下降，表明存在实质性细胞损伤，但所测的抗氧化酶在整个缺血期间均未显示出任何一致的变化。谷胱甘肽过氧化物酶（硒依赖性谷胱甘肽过氧化物酶，Se-GSH-Px）活性在缺血8小时期间保持恒定，不过在缺血4小时时，相对于对照活性有小幅（29%）增加。非硒依赖性谷胱甘肽过氧化物酶（non-Se-GSH-Px）活性和谷胱甘肽还原酶（GSSG-Red）在缺血长达8小时时保持恒定，此时我们测得non-Se-GSH-Px相对于对照增加了158%，而GSSG-Red相对于对照下降了35%。在灌注肝脏中，缺血2小时后酶活性的唯一变化是GSSG-Red活性比对照增加了21%。这种增加持续到再灌注阶段（比对照活性高35%），并伴随着两种形式的谷胱甘肽过氧化物酶活性下降（硒依赖性谷胱甘肽过氧化物酶下降28%，非硒依赖性谷胱甘肽过氧化物酶下降44%）。
