title: Circulating xanthine oxidase in human ischemia reperfusion.
abstract: Reactive oxygen species (ROS) generated from xanthine oxidase (XO) play an important role in ischemia-induced injury. We hypothesize that XO and xanthine dehydrogenase (XDH) are released into the circulation with ischemia reperfusion to the human liver and intestine. Blood was drawn from a patient, before and at intervals after an aortic cross-clamp procedure. Plasma was incubated in the presence of xanthine, with NAD+ (for XD +XO) and without NAD+ (for XO). The amount of urate formed was quantified using a high-performance liquid chromatograph (HPLC). The calculated XDH+XO and XO activity increased from 1.88 and 1.66 microU/mg protein, respectively, before the cross clamp to 3.77 and 3.11 microU/mg, respectively, 7 minutes after reperfusion to the superior mesenteric, celiac, and right renal artery beds. The release of a significant biological source of ROS may explain the damage to lung or heart observed after ischemia to the human liver and intestine.
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham 35233, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tan
authors.forename: S
authors.initials: S
authors.lastname: Gelman
authors.forename: J K
authors.initials: JK
authors.lastname: Wheat
authors.forename: D A
authors.initials: DA
authors.lastname: Parks
mesh_terms: D000368:Aged; D000714:Anastomosis, Surgical; D001011:Aorta / Q000601:surgery; D001014:Aortic Aneurysm / Q000201:enzymology / Q000601:surgery; D002851:Chromatography, High Pressure Liquid; D003250:Constriction; D006801:Humans; D007422:Intestines / Q000098:blood supply* / Q000201:enzymology; D007511:Ischemia / Q000201:enzymology*; D008099:Liver / Q000098:blood supply* / Q000201:enzymology; D008297:Male; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000201:enzymology*; D014968:Xanthine Dehydrogenase / Q000097:blood*; D014969:Xanthine Oxidase / Q000097:blood*
chemical_list: D017382:Reactive Oxygen Species; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase