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。 PURPOSE AND METHODS: Kunming mouse swimming model and 15NGlycine and 3HLeucine isotope tracer technique were used to explore the uptake of BCAA by myocardium and skeletal muscle and the effect of BCAA on protein synthesis. RESULTS: Myocardial and skeletal muscle during exercise significantly increased BCAA uptake from the circulation while serum BCAA levels were reduced. Conclusion: There are differences in myocardial metabolism and skeletal muscle protein metabolism, skeletal muscle protein synthesis rate higher than myocardial; exercise myocardial protein metabolism accelerated, BCAA supplementation reduces the impact of exercise on myocardial protein metabolism, is conducive to skeletal muscle protein synthesis or protein Decompose lower.