title: Equine endurance exercise alters serum branched-chain amino acid and alanine concentrations.
abstract: Six 2-year-old Arabian horses were used to determine whether 60 km prolonged endurance exercise (approximately 4 h) alters amino acid concentrations in serum and muscle, and the time required for serum amino acid concentrations to return to basal resting values. Blood and muscle samples were collected throughout exercise and during a 3 day recovery period. Isoleucine concentration in muscle tended to increase and leucine and valine did not change due to exercise. Serum alanine concentrations did not increase immediately after exercise, but increased at 24, 48 and 72 h postexercise. Serum isoleucine, leucine, and valine concentrations decreased after exercise and time required to reach pre-exercising concentrations was 48 h. In conclusion, endurance exercise in the horse decreases serum isoleucine, leucine, and valine concentrations, and increases serum alanine concentration. The decrease in serum branched-chain amino acid concentrations did not correspond to a measurable increase in total muscle branched-chain amino acid concentrations.
authors.affiliation: Department of Animal Science, Michigan State University, East Lansing 48824-1225, USA.
authors.forename: N L
authors.initials: NL
authors.lastname: Trottier
authors.forename: B D
authors.initials: BD
authors.lastname: Nielsen
authors.forename: K J
authors.initials: KJ
authors.lastname: Lang
authors.forename: P K
authors.initials: PK
authors.lastname: Ku
authors.forename: H C
authors.initials: HC
authors.lastname: Schott
mesh_terms: D000409:Alanine / Q000097:blood*; D000597:Amino Acids, Branched-Chain / Q000097:blood*; D000818:Animals; D005260:Female; D006736:Horses / Q000097:blood / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012420:Running; D013997:Time Factors
chemical_list: D000597:Amino Acids, Branched-Chain; D000409:Alanine