DETERMINANTS OF MUSCLE MAXIMAL 02 UPTAKE AND PERFORMANCE

描述：(改编自申请者摘要)：本报告的目的 研究旨在阐明限制02最大摄入量的因素 (V02max)和工作骨骼肌中的表现。1)假设 V02的最大值可以受到O2在 外周组织将使用隔离的原位犬科动物进行测试 腓肠肌模型和人体膝关节伸肌模型。 建立了一个包含扩散限制的数学模型。 结合了菲克扩散定律和菲克原理。一个。 这个模型将被用来预测各种实验的结果 通过动脉血氧饱和度降低、贫血和 缺血症。在特殊实验中，)2传递(肌肉血液流动 X动脉02含量)将在不同的条件下保持相同 低氧血症、贫血和肌肉血流将在这两种动物中使用 和人体研究，试图将血流灌注限制与 扩散限制。B.因为肌肉血液流动到V02的异质性 可以模拟02扩散限制，组织的异质性问题会 在犬腓肠肌模型中也使用阶跃变化进行了研究 在惰性气体和02水平的动脉血中，并跟随肌肉 静脉反应，使用开发的方法调查肺 异质性。2)决定肌肉功能的几个因素和 还将调查高强度工作期间的表现。A. 将测量渐进工作期间的NAD氧化还原状态，以确定 组织氧合作用及其对代谢的调控。B.政府部门的作用 高强度工作期间糖酵解的影响和增加 收缩功能和疲劳的激活-松弛循环将是 调查过了。这些实验还将提供关于 用于膜的糖酵解产生的三磷酸腺苷的量 功能。C.在所有实验中，02交付是 操控后，疲劳的发展将随着变化而研究 血液和肌肉的酸碱平衡。D)最后，联合国开发计划署的潜在作用 肌微循环术后粒细胞封闭在减少并发症中的应用 还将调查原位最大血流量。

DESCRIPTION: (Adapted from applicant's abstract): The objective of this study is to elucidate the factors that limit maximal 02 consumption (V02max) and performance in working skeletal muscle. 1) The hypothesis that V02 max can be limited by the capacity for 02 diffusion in the peripheral tissue will be tested using an isolated, in situ canine gastrocnemius model, and the isolated knee extensor muscle model in humans. A mathematical model incorporating diffusion limitation has been developed from a combination of Fick's law of diffusion and the Fick principle. A. This model will be used to predict the outcome of various experiments in which 02 delivery is altered through lowered arterial P02, anemia, and ischemia. Special experiments in which the )2 delivery (muscle blood flow X arterial 02 content) will be kept equal between varied conditions of hypoxemia, anemia, and muscle blood flow will be used in both the animal and human studies in an attempt to separate perfusion limitation from diffusion limitation. B. Because muscle blood flow to V02 heterogeneity can mimic 02 diffusion limitation, the problem of tissue heterogeneity will also be investigated in the canine gastrocnemius model using step changes in inert gas and 02 levels of arterial blood and following the muscle venous responses, using methodology developed investigating for pulmonary heterogeneity. 2) Several factors that determine muscle function and performance during high-intensity work will also be investigated. A. The NAD redox state during progressive work will be measured to determine tissue oxygenation and its control of metabolism. B. The role of glycolysis during intense work and the impact of increased activation-relaxation cycles on contractile function and fatigue will be investigated. These experiments will also provide information concerning the amount of ATP produced by glycolysis that is used for membrane functions. C. In all of the experiments in which 02 delivery is manipulated, the development of fatigue will be studied along with changes in blood and muscle acid-base balance. D) Finally, the potential role of granulocyte plugging of muscle microcirculatin after surgery in reducing in situ maximal blood flow will also be investigated.