Evidence for the participation of the stimulated sympathetic nervous system in the regulation of carnitine blood levels of soccer players during a game.

Catecholamines and carnitine blood levels are closely implicated with training. The aim of the study was to investigate the effect of sympathetic nervous system stimulation on carnitine and its fraction levels during training. Blood was obtained from 14 soccer players pregame, at intermission, and postgame. Catecholamines were measured with high-performance liquid chromatography methods; muscle enzymes creatine kinase and lactate dehydrogenase as well as lactate, pyruvate, and total antioxidant status with commercial kits; and carnitine and fraction levels with tandem mass spectrometry. Total antioxidant status (2.97 +/- 0.13 vs 0.96 +/- 0.10 mmol/L, P < .01) as well as free carnitine levels (20.47 +/- 4.0 vs 12.30 +/- 2.8 micromol/L, P < .001) were remarkably decreased especially postgame. Total acylcarnitines (5.20 +/- 1.8 vs 9.42 +/- 3.0 micromol/L, P < .001) and especially total very long-chain acylcarnitines (0.80 +/- 0.01 vs 1.85 +/- 0.03 micromol/L, P < .001) as well as catecholamine levels (adrenaline: 230 +/- 31 vs 890 +/- 110 pmol/L, P < .01; noradrenaline: 1.53 +/- 0.41 vs 3.7 +/- 0.6 nmol/L, P < .01) were significantly increased in players postgame. A statistically significant inverse correlation was found between adrenaline and free carnitine (r = -0.51, P < .01); and a positive correlation was found between adrenaline, total acylcarnitines (r = 0.58, P < .01), and total long-chain acylcarnitine (r = 0.49, P < .01). The significant positive correlation of adrenaline levels with total acylcarnitine and total long-chain acylcarnitine blood levels in athletes as well as the inverse correlation with free carnitine levels may indicate participation of the stimulated sympathetic nervous system in the regulation of some carnitine fraction levels during exercise.