Rennie M J
Division of Molecular Physiology, University of Dundee, Scotland, UK.
Int J Sport Nutr Exerc Metab. 2001 Dec;11 Suppl:S170-6. doi: 10.1123/ijsnem.11.s1.s170.
The major anabolic influences on muscle are feeding and contractile activity. As a result of feeding, anabolism occurs chiefly by increases in protein synthesis with minor changes in protein breakdown. Insulin has a permissive role in increasing synthesis, but the availability of amino acids is crucial for net anabolism. We have investigated the role of amino acids in stimulating muscle protein synthesis, the synergy between exercise and amino acid availability, and some of the signaling elements involved. The results suggest that muscle is acutely sensitive to amino acids, that exercise probably increases the anabolic effects of amino acids by a separate pathway, and that for this reason it is unlikely that accustomed physical exercise increases protein requirements.
对肌肉的主要合成代谢影响因素是进食和收缩活动。进食后，合成代谢主要通过蛋白质合成增加而发生，蛋白质分解仅有微小变化。胰岛素在增加合成方面起允许作用，但氨基酸的可利用性对净合成代谢至关重要。我们研究了氨基酸在刺激肌肉蛋白质合成中的作用、运动与氨基酸可利用性之间的协同作用以及一些相关的信号传导元件。结果表明，肌肉对氨基酸高度敏感，运动可能通过一条独立途径增强氨基酸的合成代谢作用，因此，长期进行体育锻炼不太可能增加蛋白质需求量。
