运动小鼠心肌和骨骼肌对支链氨基酸的摄取及其对蛋白质合成的作用

目的和方法：本实验采用昆明种小鼠游泳运动模型，及１５ＮＧｌｙｃｉｎｅ和３ＨＬｅｕｃｉｎｅ同位素示踪技术探讨了运动状态下心肌和骨骼肌对ＢＣＡＡ的摄取量及ＢＣＡＡ对蛋白质合成的作用。结果：运动时心肌和骨骼肌从血循环中摄取ＢＣＡＡ显著增加，同时血清中ＢＣＡＡ的含量降低。结论：心肌和骨骼肌的蛋白质代谢存在差异，骨骼肌的蛋白质合成率高于心肌；运动使心肌蛋白代谢加速，补充ＢＣＡＡ降低了运动对心肌蛋白质代谢的影响，有利于骨骼肌蛋白质合成或使蛋白质分解降低。

UPTAKE OF BRANCHED CHAIN AMINO ACID BY MYOCARDIUM AND SKELETAL MUSCLE AND ITS EFFECT ON PROTEIN TURNOVER IN EXERCISING MICE

Aim and Methods: With the 15 N Glycine and 3 H Leucine tracer techniques,both the Uptake of Branched Chain Amino Acid(BCAA) by myocardium and skeletal muscle and the effect of BCAA supplementation on protein turnover of myocardium and skeletal muscle were explored in trained mice during swimming.Results: The uptake of BCAA by myocardium and skeletal muscle was significantly increased during swimming, and the BCAA content in serum was decreased. There were different patterns of protein turnover between myocardium and skeletal muscle, the rate of protein synthesis in skeletal muscle was higher than that in myocardium.Conclusion:Protein turnover in myocardium was increased by exercise, increased BCAA availability could lower the effect of exercise on protein turnover in myocardium and stimulate protein synthesis or inhibit the protein degradation in skeletal muscle.