Effect of sports activity on carnitine metabolism. Measurement of free carnitine, gamma-butyrobetaine and acylcarnitines by tandem mass spectrometry.
The effects of sports activity on carnitine metabolism were studied using mass spectrometry. Serum levels of free carnitine, acylcarnitines (acetylcarnitine, propionylcarnitine, C4-, C5- and C8-acylcarnitine) and gamma-butyrobetaine, a carnitine precursor, were determined by tandem mass spectrometry in liquid secondary ion mass ionization mode. The coefficients of variation at three different concentrations were 2.8-7.9% for gamma-butyrobetaine, and 1.2 to approximately 6.7% for free carnitine. The recoveries added to serum were 109.1% for gamma-butyrobetaine, 89.3% for free carnitine. Sports activity caused increased serum levels of gamma-butyrobetaine, acetylcarnitine, C4- and C8-acylcarnitines and decreased serum levels of free carnitine. This method requires a small amount of sample volume (20 microl of serum) and short total instrumental time for the analysis (1 h for preparation, 2 min per sample for mass spectrometric analysis). Therefore, this method can be applied to study carnitine metabolism under various conditions that affect fatty acid oxidation.
Inoue
F
F
Department of Physical Education, Kyoto University of Education, Japan. finoue@wsml.kyokyo-u.ac.jp
Terada
N
N
Nakajima
H
H
Okochi
M
M
Kodo
N
N
Kizaki
Z
Z
Kinugasa
A
A
Sawada
T
T
D001622:Betaine / Q000031:analogs & derivatives* / Q000097:blood; D002331:Carnitine / Q000031:analogs & derivatives* / Q000097:blood*; D015444:Exercise; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*
C116917:acylcarnitine; D001622:Betaine; C002889:gamma-butyrobetaine; D002331:Carnitine