• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of the International Society of Sports Nutrition >Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?
【24h】

Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?

机译：人类中的支链氨基酸和肌肉蛋白质合成：神话还是现实？

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The branched chain amino acids (BCAAs) are leucine, valine and isoleucine. A multi-million dollar industry of nutritional supplements has grown around the concept that dietary supplements of BCAAs alone produce an anabolic response in humans driven by a stimulation of muscle protein synthesis. In this brief review the theoretical and empirical bases for that claim are discussed. Theoretically, the maximal stimulation of muscle protein synthesis in the post-absorptive state in response to BCAAs alone is the difference between muscle protein breakdown and muscle protein synthesis (about 30% greater than synthesis), because the other EAAs required for synthesis of new protein can only be derived from muscle protein breakdown. Realistically, a maximal increase in muscle protein synthesis of 30% is an over-estimate because the obligatory oxidation of EAAs can never be completely suppressed. An extensive search of the literature has revealed no studies in human subjects in which the response of muscle protein synthesis to orally-ingested BCAAs alone was quantified, and only two studies in which the effect of intravenously infused BCAAs alone was assessed. Both of these intravenous infusion studies found that BCAAs decreased muscle protein synthesis as well as protein breakdown, meaning a decrease in muscle protein turnover. The catabolic state in which the rate of muscle protein breakdown exceeded the rate of muscle protein synthesis persisted during BCAA infusion. We conclude that the claim that consumption of dietary BCAAs stimulates muscle protein synthesis or produces an anabolic response in human subjects is unwarranted.
机译：支链氨基酸（BCAA）是亮氨酸，缬氨酸和异亮氨酸。数百万美元的营养补品行业围绕这样一个概念发展，即仅BCAA的饮食补品会在刺激肌肉蛋白质合成的驱动下在人体中产生合成代谢反应。在这篇简短的评论中，讨论了该主张的理论和经验基础。从理论上讲，仅对BCAA的响应，在吸收后状态下对肌肉蛋白质合成的最大刺激就是肌肉蛋白质分解和肌肉蛋白质合成之间的差异（比合成高约30％），因为合成新蛋白质需要其他EAA只能源自肌肉蛋白质分解。实际上，肌肉蛋白质合成的最大增加30％是高估了，因为EAA的强制性氧化永远无法完全被抑制。大量的文献检索表明，没有对人类受试者中的肌肉蛋白质合成对口服摄取的BCAA的反应进行定量的研究，而仅对两项静脉内注射的BCAA的作用进行了评估的研究。这两项静脉输液研究均发现BCAAs减少了肌肉蛋白质的合成以及蛋白质的分解，这意味着肌肉蛋白质更新的减少。在BCAA注入过程中，肌肉蛋白分解速率超过肌肉蛋白合成速率的分解代谢状态持续存在。我们得出结论认为，饮食中的BCAAs的摄入会刺激肌肉蛋白质合成或在人类受试者中产生合成代谢反应的说法是没有根据的。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号