Effect of intense sports activity on carnitine metabolism in youth and children

背景：肉碱在脂肪酸氧化中起重要作用，脂肪酸氧化是有氧运动中肌肉的主要能量来源之一。最近，一些药物(一些抗生素、抗惊厥药物、抗肿瘤药物)被报道导致肉碱缺乏。目的：研究大强度运动对青少年儿童肉碱代谢的影响。方法：采用串联质谱仪对肉碱及其前体进行分析。结果：建立了二次离子质谱法测定游离肉碱、乙酰肉碱、丁基甜菜碱、三甲基赖氨酸的分析方法。运动导致血清中丁基甜菜碱、乙酰肉碱、C4-和C8-酰肉碱水平升高，血清游离肉碱水平下降。服药后血清游离肉碱水平下降，血清CK和肌红蛋白水平升高。结论：服药所致肉碱缺乏症可导致肌肉组织脂肪酸氧化损伤和代谢损伤。

Background : Carnitine plays an important role in fatty acid oxidation, that is one of main energy sourses of muscles during aerobic exercise. Recently, several drugs (some of antibiotics, anticonvulsants, antineoplastics) have been reported to cause carnitine deficiency. Children and youth, who participate in intense regular exercise, may have an opportunity to take these drugs.Objective : To study the effects of intense physical activity on carnitine metabolism in youth and children.Methods : Carnitine and its precursors were analyzes by tandem mass spectrometry.Results : Analytical methods for free carnitne, acylcarnitines, butyrobetaine, trimethyllysine were established by tandem mass spectrometry in secondary ion mass spectrometric mode, that enabled us to conduct the study of physical exercise because of a small amount of sample volume required. Sports activity caused increased serum levels of butyrobetaine, acetylcarnitine, C4-and C8-acylcarnitines and decreased serum levels of free carnitine. Administration of pivalate-containing antibiotic caused decreased serum levels of free carnitne and increased serum CK and myoglobin.Conclusion : Carnitine deficiency induced by drug administration may cause impaired fatty acid oxidation and metabolic damage of muscular tissue.