Effect of L-carnitine supplementation and aerobic training on FABPc content and beta-HAD activity in human skeletal muscle.
Both regular physical exercise and carnitine supplementation exert a role in energy metabolism and may improve endurance capacity. We investigated whether a combination of long-term carnitine ingestion and exercise training reveals any interactive effects on cytosolic fatty acid-binding protein (FABPc) expression and beta-hydroxyacyl CoA dehydrogenase (beta-HAD) activity in human skeletal muscle. Twenty-eight untrained healthy males randomly divided into four experimental groups: a placebo (CON; n = 7), exercise training (ET; n = 7, 40 min session(-1), five times per week at 60% VO2max), carnitine supplementation (CS; n = 7, 4 g day(-1)), and exercise training and carnitine supplementation (CT; n = 7). Before and after 6-week treatment, muscle biopsy samples were taken from the vastus lateralis. Nonesterified carnitine and acid-soluble acylcarnitine concentrations were increased in CT (P < 0.05), and serum triacylglycerol concentration was elevated almost twofold in ET and CT (P < 0.05). No interactive effects in FABPc expression were shown from any of treatment groups. Although FABPc increased by 54% in ET compared to CON, it failed to reach statistical significance. In addition, there was no change in FABPc expression from any of experimental groups. Similar trends with FABPc contents were demonstrated in beta-HAD activity. It is concluded that the combination of exercise training and L-carnitine supplementation does not augment in FABPc expression and beta-HAD activity in human skeletal muscle indicating that combined treatment does not exert additive effect in fat metabolism. Thus L-carnitine supplementation would be unlikely to be associated with the enhanced exercise performance.
Lee
Jang Kyu
JK
Department of Human Physiology, Korea National Sport University, 88-15 Oryun-dong, Songpa-gu, Seoul, South Korea.
Lee
Jong Sam
JS
Park
Hyon
H
Cha
Youn-Soo
YS
Yoon
Chung Su
CS
Kim
Chang Keun
CK
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism*; D002331:Carnitine / Q000378:metabolism / Q000494:pharmacology*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology; D050556:Fatty Acid-Binding Proteins / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000187:drug effects; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D010641:Phenotype; D010807:Physical Endurance / Q000502:physiology*; D013997:Time Factors
D050556:Fatty Acid-Binding Proteins; D015094:3-Hydroxyacyl CoA Dehydrogenases; D002331:Carnitine