title: Antioxidant status and muscle cell leakage during endurance exercise.
abstract: Antioxidant status of 35 endurance horses was studied during an 80 (OD80) or 160 km (OD160) race. Packed cell volume (PCV), total plasma protein (TPP), plasma ascorbic acid (VIT C), plasma alpha-tocopherol (VIT E) and erythrocyte glutathione (GSH) concentrations, erythrocyte glutathione peroxidase (GPX), plasma aspartate aminotransferase (AST) and plasma creatine kinase (CK) activities were measured at 0, 40, 80 km and 60 min of recovery (REC) at OD80, and 0, 64, 106, 142, 160 km and REC at OD160. In both races, no changes were found in plasma VIT E concentration, but VIT C and GSH concentrations decreased (P<0.05), and mean GPX, AST and CK activities increased from 0 km (P<0.05). Indices of muscle cell leakage (plasma AST and CK) were correlated (r = 0.36 to 0.67; P<0.03) with indices of antioxidant status (VIT C, GSH and GPX). Associations between increased muscle leakage and decreased antioxidant status may, in part, reflect oxidative stress and suggest the testing of antioxidant supplements in endurance horses to improve performance and welfare.
authors.affiliation: Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg 24061-0306, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Hargreaves
authors.forename: D S
authors.initials: DS
authors.lastname: Kronfeld
authors.forename: J N
authors.initials: JN
authors.lastname: Waldron
authors.forename: M A
authors.initials: MA
authors.lastname: Lopes
authors.forename: L S
authors.initials: LS
authors.lastname: Gay
authors.forename: K E
authors.initials: KE
authors.lastname: Saker
authors.forename: W L
authors.initials: WL
authors.lastname: Cooper
authors.forename: D J
authors.initials: DJ
authors.lastname: Sklan
authors.forename: P A
authors.initials: PA
authors.lastname: Harris
mesh_terms: D000827:Animal Welfare; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D001798:Blood Proteins / Q000032:analysis; D003402:Creatine Kinase / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology / Q000502:physiology; D005260:Female; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006400:Hematocrit / Q000662:veterinary; D006736:Horses / Q000097:blood / Q000502:physiology*; D008297:Male; D032342:Muscle Cells / Q000201:enzymology / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology; D013997:Time Factors; D024502:alpha-Tocopherol / Q000097:blood
chemical_list: D000975:Antioxidants; D001798:Blood Proteins; D005979:Glutathione Peroxidase; D001219:Aspartate Aminotransferases; D003402:Creatine Kinase; D005978:Glutathione; D024502:alpha-Tocopherol; D001205:Ascorbic Acid