支链氨基酸对运动大鼠和小鼠蛋白质代谢的影响

目的 :　探讨在运动状态下 ,支链氨基酸 ( BCAA)对大鼠和小鼠蛋白质代谢的影响。方法 :　利用15N-甘氨酸稳定同位素作为示踪剂 ,观察动物在游泳运动条件下的氮平衡、氨基氮流率、蛋白质合成率和分解率 ,以及心肌、肝脏、股四头肌的蛋白质代谢状况。结果 :　补充 BCAA使整体氨基氮流率、蛋白质合成率、更新率有不同程度增高 ;BCAA可调节运动对心肌、肝脏蛋白质代谢的影响 ,使骨骼肌的氨基氮流率增高明显。结论 :　补充 BCAA可调节运动状态下机体蛋白质代谢 ,使运动状态的骨骼肌氨基氮流率增高。

EFFECT OF BRANCHED CHAIN AMINO ACID ON PROTEIN METABOLISM IN EXERCISED RATS AND MICE

Objective: Effect of branched chain amino acid (BCAA) on protein metabolism was studied in exercised rats and mice. Methods: 15 N glycine was used as tracer to observe the nitrogen balance, amino nitrogen flux rate, protein synthesis rate, protein catabolic rate in the whole body of exercised animals, and the state of protein metabolism in their liver, myocardium, and skeletal muscle. Results: In the group of BCAA the whole body amino nitrogen and protein turnover were higher; protein synthesis rate of myocardium was decreased; liver and skeletal muscle protein synthesis were higher; the amino acid flux was significantly increased.Conclusion: After supplementation of BCAA the metabolism of protein under exercise condition is changed, and the protein turnover rate is increased in the skeletal muscle of exercised animals.