Antioxidant enzyme status of ischemic and postischemic liver and ischemic kidney in rats.
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).
Barnard
M L
ML
Department of Biomedical Sciences, College of Allied Health Professions, University of South Alabama, Mobile 36688.
Snyder
S J
SJ
Engerson
T D
TD
Turrens
J F
JF
D000818:Animals; D000975:Antioxidants; D002374:Catalase / Q000378:metabolism; D005609:Free Radicals; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007511:Ischemia / Q000201:enzymology*; D007668:Kidney / Q000098:blood supply*; D008099:Liver / Q000098:blood supply*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D005609:Free Radicals; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase