Nutritionally essential amino acids and metabolic signaling in aging.
Nutritionally essential amino acids and metabolic signaling in aging.
复制标题
DOI：
10.1007/s00726-012-1438-0
复制
发表时间：
2013-09
期刊：
影响因子：
3.5
通讯作者：
Dillon, E. Lichar
中科院分区：
文献类型：
--
作者：
Dillon, E. Lichar
衰老与骨骼肌质量和强度的逐渐下降有关，导致功能障碍的风险增加。虽然蛋白质合成和降解的基础速率在很大程度上不受年龄的影响，但老年肌肉细胞对必需氨基酸的合成代谢作用的敏感性似乎会下降。必需氨基酸通过其诱导合成代谢反应的主要途径涉及雷帕霉素（mTOR）复合物1的哺乳动物靶标，这是一种对支链氨基酸亮氨酸的调节特别敏感的信号传导途径。最近的证据表明，老年人的肌肉需要增加亮氨酸的浓度，以通过mTOR途径维持强大的合成代谢反应。虽然通过mTOR途径的营养信号传导的年龄相关改变的确切机制仍然难以捉摸，但越来越多的证据表明，对胰岛素作用的敏感性降低、内皮功能降低和氧化应激增加可能是合成代谢敏感性降低的潜在因素。确保充足的营养，包括优质蛋白质的来源，并促进定期的身体活动将仍然是预防老年人肌肉减少症发作的前线防御措施。
Aging is associated with a gradual decline in skeletal muscle mass and strength leading to increased risk for functional impairments. Although basal rates of protein synthesis and degradation are largely unaffected with age, the sensitivity of older muscle cells to the anabolic actions of essential amino acids appears to decline. The major pathway through which essential amino acids induce anabolic responses involves the mammalian target of rapamycin (mTOR) Complex 1, a signaling pathway that is especially sensitive to regulation by the branched chain amino acid leucine. Recent evidence suggests that muscle of older individuals require increasing concentrations of leucine to maintain robust anabolic responses through the mTOR pathway. While the exact mechanisms for the age related alterations in nutritional signaling through the mTOR pathway remain elusive, there is increasing evidence that decreased sensitivity to insulin action, reductions in endothelial function, and increased oxidative stress may be underlying factors in this decrease in anabolic sensitivity. Ensuring adequate nutrition, including sources of high quality protein, and promoting regular physical activity will remain among the frontline defenses against the onset of sarcopenia in older individuals.
登录
查看更多内容
DOI：
10.1093/gerona/glr036
发表时间：
2011-06-01
影响因子：
5.1
作者：
Chevalier, Stephanie;Goulet, Eric D. B.;Morais, Jose A.
通讯作者：
Morais, Jose A.
DOI：
10.1016/j.clnu.2010.03.010
发表时间：
2010-12
期刊：
Clinical nutrition (Edinburgh, Scotland)
影响因子：
--
作者：
Dillon EL;Durham WJ;Urban RJ;Sheffield-Moore M
通讯作者：
Sheffield-Moore M
DOI：
10.1152/ajpendo.00582.2007
发表时间：
2008-02-01
影响因子：
5.1
作者：
Dreyer, Hans C.;Drummond, Micah J.;Rasmussen, Blake B.
通讯作者：
Rasmussen, Blake B.
影响因子：
6.3
作者：
Borsheim, Elisabet;Bui, Quynh-Uyen T.;Wolfe, Robert R.
通讯作者：
Wolfe, Robert R.
影响因子：
3.5
作者：
Atherton, Philip J.;Smith, Ken;Rennie, Michael J.
通讯作者：
Rennie, Michael J.