WHOLE BODY AND MUSCLE PROTEIN METABOLISM ARE NOT AFFECTED BY ACUTE DEVIATIONS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 背景资料：急性偏差蛋白质摄入量之前，定量蛋白质动力学在老年人可能会解释争议的影响，老年肌肉蛋白质合成和蛋白质水解率。目的：我们假设，从习惯性摄入的蛋白质摄入量的急性减少与较低的肌肉蛋白质合成和较高的蛋白质水解率相关，而从习惯性摄入的蛋白质摄入量的急性增加与较高的肌肉蛋白质合成和较低的蛋白质水解率相关。设计图：在112名居住在社区的65-90岁健康男性中，我们量化了参与者食用3天对照研究餐（0.9-1.1 g蛋白质/kg/d）后的静息全身1，2 - 13 C2-亮氨酸动力学、肌肉混合蛋白质分数合成率（FSR）和肌肉蛋白酶体蛋白水解酶活性，这些研究餐含有比他们习惯性食用的更多或更少的蛋白质。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Background: Acute deviations in protein intake prior to quantifying protein kinetics in older humans may explain the controversy over the effects of older age on muscle protein synthesis and proteolysis rates. Objective: We hypothesized that an acute decrease in protein intake from habitual intake is associated with lower muscle protein synthesis and higher proteolysis rates, while an acute increase in protein intake from habitual is associated with higher muscle protein synthesis and lower proteolysis rates. Design: In 112 community-dwelling healthy 65-90 year old men, we quantified resting whole body 1,2-13C2-leucine kinetics, muscle mixed protein fractional synthesis rates (FSR), and muscle proteasome proteolytic enzyme activities after participants consumed 3 d controlled research meals (0.9-1.1 g protein/kg/d) that contained more or less protein than they habitually consumed.