title: Effects of xanthine oxidase inhibition on oxidative stress and swimming performance in rats.
abstract: The aim of this study was to examine the effect of allopurinol, a xanthine oxidase inhibitor, on oxidative stress and physical performance after swimming until exhaustion in rats. Blood and gastrocnemius muscle samples were collected before, immediately after, and 5 h after exercise and the respective timepoints after allopurinol administration. Xanthine oxidase and total antioxidant capacity (TAC) were determined in plasma and muscle, whereas catalase activity and reduced (GSH) and oxidized (GSSG) glutathione were measured in erythrocytes and muscle. Thiobarbituric acid-reactive substances (TBARS) and protein carbonyls (PC) were determined in plasma, erythrocytes, and muscle. As expected, allopurinol inhibited xanthine oxidase activity. Compared with their nonallopurinol-treated counterparts, rats treated with allopurinol showed a 35% decrease in physical performance, as indicated by the shorter swimming time to exhaustion. Exercise alone increased PC and TBARS concentration in plasma, erythrocytes, and gastrocnemius muscle. Similarly, allopurinol alone increased PC and TBARS concentration in erythrocytes and gastrocnemius muscle, decreased TAC in plasma and gastrocnemius muscle, and decreased the GSH:GSSG ratio in erythrocytes. Our data illustrate that, in general, exercise and allopurinol alone increased the levels of most of the oxidative stress markers measured in plasma, erythrocytes, and gastrocnemius muscle. Xanthine oxidase inhibition provoked a marked reduction in physical performance.
authors.affiliation: Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece.
authors.forename: Aristidis S
authors.initials: AS
authors.lastname: Veskoukis
authors.forename: Michalis G
authors.initials: MG
authors.lastname: Nikolaidis
authors.forename: Antonios
authors.initials: A
authors.lastname: Kyparos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kokkinos
authors.forename: Charitini
authors.initials: C
authors.lastname: Nepka
authors.forename: Sotiris
authors.initials: S
authors.lastname: Barbanis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kouretas
mesh_terms: D000493:Allopurinol / Q000008:administration & dosage*; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D004912:Erythrocytes / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010807:Physical Endurance / Q000502:physiology*; D050050:Protein Carbonylation / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013550:Swimming / Q000502:physiology*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D000493:Allopurinol; D014969:Xanthine Oxidase