Respiratory chain enzymes in muscle of endurance athletes: effect of L-carnitine.
The effects of L-carnitine on respiratory chain enzymes in muscle of long distance runners were studied in 14 athletes. These subjects received placebo or L-carnitine (2 g orally b.i.d.) during a 4-week period of training. Athletes receiving L-carnitine showed a significant increase (p < 0.01) in the activities of rotenone-sensitive NADH cytochrome c reductase, succinate cytochrome c reductase and cytochrome oxidase. In contrast, succinate dehydrogenase and citrate synthase were unchanged. No significant changes were observed after placebo administration. The levels of both total and free carnitine from athletes receiving placebo were significantly decreased (p < 0.01) after treatment. By contrast, total and free carnitine levels were markedly increased (p < 0.01) after supplementation with L-carnitine. Our results suggest that L-carnitine induces an increase of the respiratory chain enzyme activities in muscle, probably by mechanisms involving mitochondrial DNA.
Huertas
R
R
Centro de Investigación, Hospital 12 de Octubre, Madrid, Spain.
Campos
Y
Y
Díaz
E
E
Esteban
J
J
Vechietti
L
L
Montanari
G
G
D'Iddio
S
S
Corsi
M
M
Arenas
J
J
D000704:Analysis of Variance; D002331:Carnitine / Q000378:metabolism / Q000494:pharmacology*; D002950:Citrate (si)-Synthase / Q000378:metabolism; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D002149:Energy Intake; D006801:Humans; D008931:Mitochondria, Muscle / Q000187:drug effects / Q000201:enzymology; D009097:Multienzyme Complexes / Q000378:metabolism; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010807:Physical Endurance; D013177:Sports; D013385:Succinate Dehydrogenase / Q000378:metabolism
D009097:Multienzyme Complexes; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D016660:NAD(P)H Dehydrogenase (Quinone); D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D014450:Electron Transport Complex III; D002331:Carnitine