MR DIAGNOSIS OF MUSCLE METABOLISM AND FUNCTION

肌肉代谢和功能的 MR 诊断

• 批准号: 2081120
• 负责人: Martin J Kushmerick
• 金额: $ 28.26万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-02-01 至 1998-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2081120
• 关键词: adenosinetriphosphatase; bioenergetics; exercise; human subject; ischemia; magnetic resonance imaging; muscle contraction; muscle disorder diagnosis; muscle function; muscle metabolism; stoichiometry; striated muscles

The long-term goal is to develop diagnostic procedures for human muscle function using well established strategies previously used for evaluating the metabolic and contractile properties of animal muscle. In this project we use imaging and spectroscopy to define the basis energetic paradigm in normal limb muscle. First, we develop and validate a new exercise stress test to measure oxidative and contractile capacity of human limb muscle. Second, we use these capacities to assess muscle function based on the energy balance attained during normal exercise. Quantitative Energetic Stress Test: This test uses neural stimulation in ischemic muscle to determine ATPase (contractile) capacity as the rate of creatine phosphate breakdown (dPCr/dt). The PCr recovery rate after ischemia defines the ATP synthesis (oxidative) capacity (Specific Aims 1 and 2). Together these capacities yield quantitative information beyond muscle fiber-type classification for assessment of muscle functional capacity. Energy Balance: To validate the predictive power of the strategy, we determine the energy balance attained under steady-state neural stimulation and natural exercise. We test whether a higher oxidative capacity results in 1) less depletion of PCr at the same exercise level and 2) greater sustained force production and exercise levels. This work builds on an extensive body of spectroscopic information gained from normal and diseased human muscle, and on principles of bioenergetics and metabolic integration derived from animal studies. What is new is the energy balance concept is applied for the first time to human muscle in a way in which both the supply and demand side of the metabolic economy can be quantitatively assessed and related to muscle functional capacity.

长期目标是开发人类肌肉的诊断程序 使用先前用于评估的既定策略的功能 动物肌肉的新陈代谢和收缩特性。在这 项目我们使用成像和光谱学来定义基础能量 正常四肢肌肉的范例。首先，我们开发并验证了一个新的 运动负荷试验测定大鼠的氧化和收缩能力 人体四肢肌肉。其次，我们使用这些能力来评估肌肉 基于在正常运动中达到的能量平衡而产生的机能。 定量能量应激测试：该测试使用神经刺激 在缺血肌肉中测定ATPase(收缩)能力为 磷酸肌酸分解(dPCR/dt)。聚合酶链式反应后的回收率 缺血定义了ATP合成(氧化)能力(特定目标 1和2)。这些能力加在一起产生了量化信息 Beyond肌肉纤维类型分类用于肌肉评估 功能能力。 能量平衡：为了验证战略的预测力，我们 确定稳态神经网络所达到的能量平衡 刺激和自然锻炼。我们测试一种更高的氧化性 能力导致1)在相同的运动水平下减少聚合酶链式反应的消耗 (2)更大的持续力量生产和锻炼水平。这部作品 建立在从以下项目获得的大量光谱信息基础上 正常和患病的人类肌肉，并根据生物能量学和 来自动物研究的新陈代谢整合。最新的是 能量平衡概念首次应用于人体肌肉 一种新陈代谢经济的供需双方 可以进行定量评估，并与肌肉功能能力相关。