Weber 1987 Am J Physiol: Difference between revisions
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|title=Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW (1987) Lactate kinetics in exercising Thoroughbred horses: regulation of turnover rate in plasma. Am J Physiol 253: R896-R903. | |title=Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW (1987) Lactate kinetics in exercising Thoroughbred horses: regulation of turnover rate in plasma. Am J Physiol 253: R896-R903. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/3425768 PMID: 3425768] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/3425768 PMID: 3425768 Open Access] | ||
|authors=Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW | |authors=Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW | ||
|year=1987 | |year=1987 |
Latest revision as of 15:22, 28 October 2013
Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW (1987) Lactate kinetics in exercising Thoroughbred horses: regulation of turnover rate in plasma. Am J Physiol 253: R896-R903. |
Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW (1987) Am J Physiol
Abstract: Plasma lactate turnover rate of Thoroughbred racehorses was measured by bolus injection of [U-14C]lactate at rest and two levels of submaximal treadmill exercise (3-4 m/s trot, 6% incline, and 6.5 m/s horizontal canter). Our goals were 1) to determine the relative effects of changes in cardiac output and in plasma lactate concentration on turnover rate [using cardiac output data from Weber et al. (28)] and 2) to assess the importance of lactate as a metabolic fuel in a trained animal athlete. Lactate turnover rates were 9.3 mumol.min-1.kg-1 (rest), 75.9 mumol.min-1.kg-1 at the beginning of the trot protocol [45% maximum O2 uptake (VO2max)], 50.3 mumol.min-1.kg-1 later in the same protocol (50% VO2max), and 66.1 mumol.min-1.kg-1 during the canter protocol (55% VO2max). Both changes in cardiac output and in plasma lactate concentration had a significant effect on turnover rate. Variation in plasma lactate fluxes of Thoroughbreds during exercise follows the standard mammalian pattern, but this substrate only plays a minor role as an oxidizable fuel in horses. The oxidation of plasma lactate accounts for less than 5% of metabolic rate (VO2) during submaximal work. Adjustments in cardiac output and in metabolite concentration represent, respectively, the coarse and fine controls for the regulation of plasma metabolite turnover rate.
Labels: MiParea: Exercise physiology;nutrition;life style
Organism: Horse