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

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来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。背景：随着年龄的增长，许多人失去了肌肉质量和力量。可能导致这种损失的因素之一是饮食的变化。具体来说，老年人可能没有摄入足够的膳食蛋白质，或者他们摄入的蛋白质可能无法有效地被肌肉组织吸收。具体目标和程序：本研究的目的是测量摄入不同份量和脂肪含量的牛肉后，年轻人和老年人血浆氨基酸浓度和肌肉蛋白质合成的变化。 实验设计：我们将研究总共90名健康男性和女性志愿者，年龄在20至50岁（年轻人）和60至85岁（老年人）之间。我们将使用已建立的技术，包括稳定同位素示踪方法，血液采样和肌肉活检，以测量血浆激素和氨基酸浓度和骨骼肌合成的变化。 意义（总结）：我们建议调查代谢反应的一个实际的营养干预，将解决一些机制，有助于肌肉蛋白质合成和肌肉损失在衰老过程中。

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.