title: Age-related changes in the peroxyl radical scavenging capacity of human plasma.
abstract: Aging and the diseases that typically follow with increasing age, notably atherosclerosis and cancer, are often proposed to be involved in increased oxidative stress. Animal studies, on the other hand, show no clear-cut pattern of age-related changes in enzymatic antioxidant defences. In this study we have demonstrated that total peroxyl radical scavenging antioxidant capacity (TRAP) in human plasma changes with age. We also found that among the antioxidants in human plasma there exists a major fraction of so far unidentified antioxidant(s). A chemiluminescent TRAP assay was used to determine the presence of peroxyl radical scavenging antioxidants in human plasma. The material consisted of 87 healthy volunteers, aged 20-96 years, who used no regular medication, vitamins, or trace elements. In females, total antioxidant capacity increased significantly during the life span. The increase in TRAP was mainly due to unidentified antioxidants. In males, TRAP increased until age 51-74, and then significantly decreased. The decrease observed among males was also due to the sharp decline in the concentration of unidentified antioxidants.
authors.affiliation: Laboratory of Neurobiology, Medical School, University of Tampere, Finland.
authors.forename: R T
authors.initials: RT
authors.lastname: Aejmelaeus
authors.forename: P
authors.initials: P
authors.lastname: Holm
authors.forename: U
authors.initials: U
authors.lastname: Kaukinen
authors.forename: T J
authors.initials: TJ
authors.lastname: Metsä-Ketelä
authors.forename: P
authors.initials: P
authors.lastname: Laippala
authors.forename: A L
authors.initials: AL
authors.lastname: Hervonen
authors.forename: H E
authors.initials: HE
authors.lastname: Alho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D000818:Animals; D000975:Antioxidants / Q000032:analysis; D001205:Ascorbic Acid / Q000097:blood; D002839:Chromans / Q000097:blood; D005260:Female; D016166:Free Radical Scavengers / Q000097:blood*; D005609:Free Radicals / Q000378:metabolism; D005978:Glutathione / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D010545:Peroxides / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000097:blood; D014527:Uric Acid / Q000097:blood; D014810:Vitamin E / Q000097:blood
chemical_list: D000975:Antioxidants; D002839:Chromans; D016166:Free Radical Scavengers; D005609:Free Radicals; D010545:Peroxides; D013438:Sulfhydryl Compounds; D014810:Vitamin E; D014527:Uric Acid; C049375:perhydroxyl radical; D005978:Glutathione; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid