EFFECTS OF LEUCINE ENHANCED AMINO ACID DRINK ON MUSCLE PROTEIN METABOLISM IN THE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 随着年龄的增长，许多成年人的骨骼肌群逐渐减少。随之而来的收缩组织和功能能力的丧失(即骨骼减少)会增加跌倒、骨折的风险，并可能严重损害许多日常生活活动。 鉴于肌肉蛋白质净合成是肌肉力量和机能的主要代谢决定因素，这项研究的目标是确定与仅包含必需氨基酸的同等氨基酸饮料相比，亮氨酸强化氨基酸饮料是否会更大程度地刺激肌肉蛋白质净合成。这两种饮料的直接比较将为在饮料中加入更多亮氨酸(与其他必需氨基酸相比)的效果提供新的信息，这将作为后续研究的重要初步数据，以期优化老年人的氨基酸补充。为实现本研究的目标，共有8名既往无心血管或外周血管疾病的健康患者参加本研究。受试者将是年龄在60岁至85岁之间的正常健康男性和女性。这项研究将包括两个8小时的试验，分别在不同的日子进行。这项研究将检测在摄入含有氨基酸的饮料之前和之后的肌肉蛋白质动力学。肌肉蛋白质动力学将使用已建立的稳定同位素示踪方法、动静脉采样和肌肉活组织检查来确定。

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. Many adults experience a progressive loss of skeletal muscle mass with increasing age. This concomitant loss of contractile tissue and functional capacity (i.e., sarcopenia) contributes to increased risk of falls, bone fracture and may substantially impair many activities of daily living. Given the fact that net muscle protein synthesis is a major metabolic determinant of muscular strength and functional capacity, the goal of this study is to determine if a leucine enhanced amino acid drink will stimulate net muscle protein synthesis to a greater extent compared to an equivalent (same weight in terms of amino acid composition) amino acid drink containing only the essential amino acids. The direct comparison of those two drinks will provide new information on the effects of including a larger amount of leucine (compared to the other essential amino acids) in a drink, which will serve as important preliminary data for subsequent investigations looking at optimizing amino acid supplementation in elderly individuals. To achieve the goals of this research, a total of 8 healthy patients with no prior cardiovascular or peripheral vascular disease will participate in this research study. Subjects will be normal healthy males and females between the ages of 60 and 85. The study will consist of two 8-hour trials performed on separate days. The study will examine muscle protein kinetics prior to and following the ingestion of the amino acids containing drinks. Muscle protein kinetics will be determined using established stable isotope tracer methodology, arterial-venous sampling and muscle biopsies.