CELLULAR MECHANISMS FOR SARCOPENIA IN THE ELDERLY

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。随着年龄的增长，随着肌肉组织的选择性消耗，身体蛋白质的损失发生，被称为肌肉减少症。由于瘦体重的损失主要来自肌肉组织，因此它对维持肌肉力量和功能具有重要意义。除了对肌肉功能的严重后果外，肌肉减少症还减少了在压力下可用于动员的氨基酸的储备。在危重病期间，消瘦患者的氨基酸储备减少是预后的主要决定因素。 肌肉蛋白质不断地合成和降解。当蛋白质合成和降解的速率平衡时，肌肉蛋白质质量得以维持，但如果蛋白质降解超过合成，则肌肉蛋白质将损失。在组织水平上，老年人肌肉蛋白质的损失与肌肉蛋白质合成速率的降低有关，而年轻和老年受试者之间的肌肉降解没有差异。因此，在寻找老年人肌肉萎缩的机制时，考虑控制肌肉中蛋白质合成的因素是很重要的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Loss of body protein occurs with advancing age with selective depletion of muscle tissue, is known as sarcopenia. Since the loss of lean body mass is primarily from muscle tissue, it has important implications for the maintenance of muscle strength and function. In addition to the serious consequences for muscle function, sarcopenia also reduces the reserve of amino acids available for mobilization in times of stress. Diminished reserve of amino acids in wasted patients during critical illness is a major determinant of outcome. Muscle protein undergoes continual synthesis and degradation. When the rates of protein synthesis and degradation are balanced, muscle protein mass is maintained, but if protein degradation exceeds synthesis, there will be a loss of muscle protein. At the tissue level, loss of muscle protein in the elderly has been associated with a reduction in the rate at which muscle protein is synthesized with no difference in muscle degradation between younger and older subjects. It is therefore important to consider the factors that control protein synthesis in muscle when seeking the mechanism of muscle wasting in the elderly.