title: Effect of dietary vitamin E supplementation on the integrity of skeletal muscle in exercised horses.
abstract: The effect of vitamin E intake on indicators of muscle integrity was studied in exercised horses. Nineteen horses were blocked by sex and then assigned to one of three diets: no supplemental vitamin E (BASAL), BASAL plus 80 IU of supplemental vitamin E/kg DM (80), or BASAL plus 300 IU of supplemental vitamin E/kg DM (300). The BASAL diet contained less than 44 IU of vitamin E/kg DM, but it was adequate in all other nutrients. During the 90-d treatment period, horses were exercised 5 d/wk; in addition, serum and middle gluteal muscle alpha-tocopherol concentrations were measured at 0, 30, and 90 d. All horses performed a repeated submaximal exercise test (RSET) at the end of the 90-d period. The following were measured before and after the RSET: alpha-tocopherol, thiobarbituric acid reactive substances (TBARS), conjugated diene (CD) concentrations of the middle gluteal muscle, and serum creatine kinase (CK) and aspartate aminotransferase (AST) activities. Serum alpha-tocopherol concentrations of horses receiving the BASAL and 80 diets decreased (P < .05 and P < .06, respectively) during the 90-d treatment period but did not change in horses receiving the 300 diet. Serum and muscle alpha-tocopherol concentrations were higher (P < .05) at 30 and 90 d in horses receiving the 300 diet than in horses receiving the BASAL and 80 diets. Serum CK and AST activities increased (P < .05) following RSET but were not affected by dietary vitamin E level. Muscle alpha-tocopherol level did not affect muscle CD or TBARS.
authors.affiliation: Department of Animal Sciences, Lexington, KY 40546-0215, USA.
authors.forename: P D
authors.initials: PD
authors.lastname: Siciliano
authors.forename: A L
authors.initials: AL
authors.lastname: Parker
authors.forename: L M
authors.initials: LM
authors.lastname: Lawrence
mesh_terms: D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D004032:Diet / Q000662:veterinary*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005527:Food, Fortified; D006736:Horses / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000032:analysis / Q000097:blood / Q000494:pharmacology*
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D001219:Aspartate Aminotransferases; D003402:Creatine Kinase