Harris R C, Foster C V, Hultman E
J Appl Physiol (1985). 1987 Jul;63(1):440-2. doi: 10.1152/jappl.1987.63.1.440.
To study the changes in carnitine during intense muscular effort subjects underwent 4 min intermittent electrical stimulation of the quadriceps femoris muscle and on a separate occasion performed 4 min exercise on a bicycle ergometer. Biopsies of the vastus lateralis muscle were taken at rest and after 2 and 4 min of stimulation or exercise. Resting mean muscle total carnitine content was 20.0 mmol/kg dry muscle. Approximately 77% was free carnitine and 19% acetylcarnitine. Four minutes of stimulation or intense exercise did not effect total carnitine but did result in a marked fall in free carnitine and almost equivalent rise in acetylcarnitine. The results indicate that acetylcarnitine is a major metabolite formed during intense muscular effort and that carnitine may function in the regulation of the acetyl-CoA/CoA ratio by buffering excess production of acetyl units.
为研究剧烈肌肉运动期间肉碱的变化，受试者接受了股四头肌4分钟的间歇性电刺激，并在另一个时间段在自行车测力计上进行了4分钟的运动。在休息时以及刺激或运动2分钟和4分钟后，取外侧股肌活检样本。休息时肌肉总肉碱平均含量为20.0 mmol/kg干肌肉。约77%为游离肉碱，19%为乙酰肉碱。4分钟的刺激或剧烈运动对总肉碱无影响，但导致游离肉碱显著下降，乙酰肉碱几乎等量增加。结果表明，乙酰肉碱是剧烈肌肉运动期间形成的主要代谢产物，肉碱可能通过缓冲乙酰单位的过量产生来调节乙酰辅酶A/辅酶A的比例。
