title: Xanthine oxidase: evidence against a causative role in renal reperfusion injury.
abstract: The conversion rates of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) were compared with the time course of in vivo lipid peroxidation (LPO) in an ischemia-reperfusion model of acute renal failure in the rat. LPO, measured as the renal release of malondialdehyde (MDA), was found to be markedly elevated only during the first 5 min of blood reflow following a 45-min interval of ischemia (arteriovenous MDA difference -277.3 +/- 53.5 vs. 3.7 +/- 5.7 nmol/l in controls, n = 14). After 30 min of reperfusion, arteriovenous MDA differences nearly reached control values (9.7 +/- 31.8 nmol/l, n = 7). In contrast to enhanced LPO, no significant conversion of XDH to XO was found (XO activity in controls: 23 +/- 1% of XO plus XDH activity vs. 26 +/- 3% after 45 min of ischemia, n = 7). Therefore XO-derived superoxide anion radicals cannot be considered causative for LPO in the reperfusion interval of experimental ischemic acute renal failure.
authors.affiliation: Institute of Physiology, University of Innsbruck, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Joannidis
authors.forename: G
authors.initials: G
authors.lastname: Gstraunthaler
authors.forename: W
authors.initials: W
authors.lastname: Pfaller
mesh_terms: D000818:Animals; D007511:Ischemia / Q000378:metabolism / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply* / Q000503:physiopathology; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D015427:Reperfusion Injury / Q000209:etiology*; D014968:Xanthine Dehydrogenase / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism / Q000502:physiology*
chemical_list: D008054:Lipid Peroxides; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase