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The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocaproic acid.

Publication ,  Journal Article
Fielding, RA; Evans, WJ; Hughes, VA; Moldawer, LL; Bistrian, BR
Published in: Eur J Appl Physiol Occup Physiol
1986

Alpha-ketoisocaproic acid (KIC) is the product of the transamination of the indispensable amino acid leucine, which is the first step in the complete degradation of leucine. To determine the effects of intense exercise on muscle and blood levels of KIC, 7 male volunteers performed cycle exercise to exhaustion. After pedaling at an intensity of 90 W for 3 min, the load was increased by 60 W every 3 min until volitional fatigue. Muscle biopsies were obtained prior to and immediately after exercise and rapidly frozen for later determination of KIC. During exercise, blood lactate levels increased as expected, while plasma KIC levels did not change. Following exercise, plasma KIC levels rose significantly with peak values occurring 15 min after exercise and did not return to pre-exercise values until 60 min after exercise. In contrast, muscle KIC levels increased during exercise from a pre-exercise mean of 49.4 +/- 4.1 mumol X kg-1 wet wt to 78.1 +/- 6.5 mumol X kg-1 after exercise, an average increase of 48% (P less than 0.05). These data indicate that during intense exercise, leucine transamination in muscle may continue at a faster rate than the decarboxylation of KIC. In addition, plasma levels of KIC did not reflect the intracellular accumulation of KIC during exercise, suggesting a delay in the diffusion of KIC from muscle.

Duke Scholars

Published In

Eur J Appl Physiol Occup Physiol

DOI

ISSN

0301-5548

Publication Date

1986

Volume

55

Issue

5

Start / End Page

482 / 485

Location

Germany

Related Subject Headings

  • Sport Sciences
  • Physical Exertion
  • Muscles
  • Male
  • Lactic Acid
  • Lactates
  • Keto Acids
  • Humans
 

Citation

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ICMJE
MLA
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Fielding, R. A., Evans, W. J., Hughes, V. A., Moldawer, L. L., & Bistrian, B. R. (1986). The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocaproic acid. Eur J Appl Physiol Occup Physiol, 55(5), 482–485. https://doi.org/10.1007/BF00421641
Fielding, R. A., W. J. Evans, V. A. Hughes, L. L. Moldawer, and B. R. Bistrian. “The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocaproic acid.Eur J Appl Physiol Occup Physiol 55, no. 5 (1986): 482–85. https://doi.org/10.1007/BF00421641.
Fielding RA, Evans WJ, Hughes VA, Moldawer LL, Bistrian BR. The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocaproic acid. Eur J Appl Physiol Occup Physiol. 1986;55(5):482–5.
Fielding, R. A., et al. “The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocaproic acid.Eur J Appl Physiol Occup Physiol, vol. 55, no. 5, 1986, pp. 482–85. Pubmed, doi:10.1007/BF00421641.
Fielding RA, Evans WJ, Hughes VA, Moldawer LL, Bistrian BR. The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocaproic acid. Eur J Appl Physiol Occup Physiol. 1986;55(5):482–485.

Published In

Eur J Appl Physiol Occup Physiol

DOI

ISSN

0301-5548

Publication Date

1986

Volume

55

Issue

5

Start / End Page

482 / 485

Location

Germany

Related Subject Headings

  • Sport Sciences
  • Physical Exertion
  • Muscles
  • Male
  • Lactic Acid
  • Lactates
  • Keto Acids
  • Humans