Accumulation of allantoin uric acid in plasma of exercising trotters

• Published in: American journal of veterinary research Vol. 54; no. 11; p. 1923
• Main Authors: Rasanen, L.A, Myllymaki, T, Hyyppa, S, Poso, A.R
• Format: Journal Article
• Language: English
• Published: United States 01.11.1993
• Subjects: ACIDE URIQUE; ACIDO URICO; ACTIVIDAD FISICA; ACTIVITE PHYSIQUE; ADENOSINE TRIPHOSPHATE; Adenosine Triphosphate - metabolism; ADENOSINTRIFOSFATO; ALANTOINA; Allantoin - blood; ALLANTOINE; Animals; CABALLO DE CARRERA; CHEVAL DE COURSE; DIFERENCIAS BIOLOGICAS; DIFFERENCE BIOLOGIQUE; Exercise Test - veterinary; Female; FIBRAS MUSCULARES; FIBRE MUSCULAIRE; Horses - blood; Horses - physiology; Hypoxanthine; Hypoxanthines - blood; Lactates - blood; Lactic Acid; Male; Muscles - metabolism; Physical Exertion - physiology; PLASMA SANGUIN; PLASMA SANGUINEO; PURINAS; PURINE; RACE; RAZAS; Running; Uric Acid - blood
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.1993.54.11.1923

Plasma concentrations of hypoxanthine, uric acid, and allantoin, which are breakdown products of adenine nucleotides, were measured in Standardbred and Finnhorse trotters during and after an exercise test on a high-speed treadmill, after an incremental exercise test performed on a racetrack, and after a racing competition. Fiber-type composition of the middle gluteal muscle and the muscle concentrations of adenine nucleotides and inosine monophosphate were measured after the racetrack test. Changes in the concentration of hypoxanthine were not observed in any of the tests. Peak concentration of uric acid was measured between 5 and 30 minutes after exercise, and it was three- to tenfold higher than the value at rest. The variability can be explained by intensity of the exercise test and variation among horses. The concentration of allantoin after exercise was 2 to 3 times as high as that at rest, depending on the intensity of the exercise, although the absolute increase was about 10 times as high as the increase in the concentration of uric acid. Peak values of allantoin for the treadmill and the racetrack tests were obtained 4 to 6 minutes after exercise and 30 minutes after the races. Peak concentration of allantoin correlated positively with the percentage of type-II (IIA + IIB) fibers in the middle gluteal muscle. Significant correlations were not observed between plasma concentration of uric acid or allantoin and muscle concentrations of adenosine triphosphate (ATP) or inosine monophosphate. It can be concluded that in horses, breakdown of ATP during and after exercise continues until allantoin is produced. The peak concentration of allantoin increases with the intensity of exercise, is reached rapidly after exercise, and the variation in the time to the peak value is small among horses. It is suggested that the main source of allantoin is the fast-twitch, type-II fibers and that the mixed muscle concentrations of adenine n