title: Antioxidant depletion in aortic crossclamping ischemia: increase of the plasma alpha-tocopheryl quinone/alpha-tocopherol ratio.
abstract: To assess whether oxidative stress contributes to the ischemia/reperfusion injury of aortic surgery, the contents of alpha-tocopherol, alpha-tocopheryl quinone, ascorbate, lipid-derived malondialdehyde, protein thiols, cholesterol, and lactate were analyzed in plasma samples from 24 patients subjected to aortic crossclamping. alpha-Tocopherol, ascorbate, and protein thiols decreased during ischemia, whereas alpha-tocopheryl quinone increased in all but two cases, doubling on average in proportion to alpha-tocopherol. Upon reperfusion alpha-tocopherol, ascorbate, and protein thiols remained low, whereas alpha-tocopheryl quinone returned to the preischemic level. Lipid-derived malondialdehyde (a measure of lipid hydroperoxides) increased significantly only during reperfusion. The results suggest that oxidative stress occurs simultaneously with ischemia/reperfusion during aortic surgery, and that measurement of the tocopheryl quinone/tocopherol ratio may shed new light on the underlying pathological events.
authors.affiliation: Institut für Physiologische Chemie I, Heinrich-Heine Universität Düsseldorf, Germany.
authors.forename: M E
authors.initials: ME
authors.lastname: Murphy
authors.forename: R
authors.initials: R
authors.lastname: Kolvenbach
authors.forename: M
authors.initials: M
authors.lastname: Aleksis
authors.forename: R
authors.initials: R
authors.lastname: Hansen
authors.forename: H
authors.initials: H
authors.lastname: Sies
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D001014:Aortic Aneurysm / Q000097:blood / Q000601:surgery*; D003250:Constriction; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D015427:Reperfusion Injury / Q000097:blood* / Q000209:etiology; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D014810:Vitamin E; D008315:Malondialdehyde; C002421:tocopherylquinone