THE EFFECT OF DOSE AND COMPOSITION OF DIETARY BEEF ON MUSCLE PROTEIN ANABOLISM

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。背景：随着年龄的增长，许多人失去了肌肉和力量。造成这一损失的因素之一可能是饮食的变化。具体地说，老年人可能没有摄入足够的饮食蛋白质，或者他们吃的蛋白质可能没有有效地被肌肉组织同化。具体目标和程序：这项研究的目标是测量年轻人和老年人在摄入不同份量和脂肪含量的牛肉后血浆氨基酸浓度和肌肉蛋白质合成的变化。实验设计：研究对象为健康男性和女性志愿者各90名，年龄分别为20~50岁(青年)和60~85岁(老年)。我们将使用成熟的技术，包括稳定同位素示踪方法、血液采样和肌肉活检来测量血浆激素和氨基酸浓度以及骨骼肌合成的变化。意义(摘要)：我们建议调查一种实用的营养干预措施的代谢反应，该干预措施将解决导致肌肉蛋白质合成和衰老过程中肌肉损失的一些机制。

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. Background: Many individuals lose muscle mass and strength as they get older. One of the factors that may contribute to this loss is changes in the diet. Specifically, elderly individuals may not eat sufficient dietary protein or the protein they do eat may not be as efficiently assimilated into muscle tissue. Specific Aims and Procedure: The goal of this study is to measure changes in plasma concentrations of amino acids and muscle protein synthesis in young and elderly individuals following ingestion of beef differing in portion size and fat content. Experimental Design: We will study a total of 90 healthy male and female volunteers between the ages of 20 and 50 (young) and 60 and 85 (elderly). We will use established techniques including stable isotope tracer methodology, blood sampling and muscle biopsies to measure changes in plasma hormone and amino acid concentrations and skeletal muscle synthesis. Significance (summary): We propose to investigate the metabolic response to a practical nutritional intervention that will address a number of the mechanisms contributing to muscle protein synthesis and muscle loss during aging.