A theoretical analysis of factors determining V(O2)MAX at sea level and altitude
A theoretical analysis of factors determining V(O2)MAX at sea level and altitude
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DOI：
10.1016/s0034-5687(96)00086-2
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发表时间：
1996-12-01
期刊：
影响因子：
--
通讯作者：
Wagner, PD
中科院分区：
文献类型：
--
作者：
Wagner, PD
当最大 V-O2 (V(O2)MAX) 受到 O-2 供应限制时，通常认为心输出量 (QT) 起主要作用，但其他 O-2 传输传导 [通气 (VA)； [血红蛋白]；肺（DL（O2））和肌肉（DM（O2））扩散能力]也可能影响V（O2）MAX。交互连接肺部、循环和肌肉的数值分析旨在比较每个电导分量对三个海拔高度 V(O2)MAX 的影响：PB = 760、464 和 253 Torr。对于任何给定的一组电导，该分析同时求解了肺泡、动脉和静脉 P-O2 和 P-CO2 的六个方程。这些方程代表两种气体的肺质量平衡、肺扩散和肌肉扩散。当 PB = 760 时，[Hb]、DL(O2) 和 DM(O2) 在限制 V(O2)MAX 方面与 QT 一样有影响力。随着海拔的升高，QT 和 [Hb] 的影响下降，而 VA、DL(O2) 和 DM(O2) 的影响逐渐增加，直到 PB = 253，V(O2)MAX 与 QT 和 [Hb] 无关。因此，慢性缺氧导致的最大 QT 间期下降和 [Hb] 上升似乎都不会影响 V(O2)MAX。然而，高通气量、DL(O2) 和 DM(O2) 似乎有利于高原运动。
When maximal V-O2 (V(O2)MAX) is limited by O-2 supply, it is generally thought that cardiac output (QT) is mostly responsible, but other O-2 transport conductances [ventilation (VA); [Hb]; pulmonary (DL(O2)) and muscle (DM(O2)) diffusion capacities] may also influence V(O2)MAX. A numerical analysis interactively linking the lungs, circulation and muscles was designed to compare the influences of each conductance component on V(O2)MAX at three altitudes: PB = 760, 464 and 253 Torr. For any given set of conductances the analysis simultaneously solved six equations for alveolar, arterial, and venous P-O2 and P-CO2. The equations represent pulmonary mass balance, pulmonary diffusion, and muscle diffusion for both gases. At PB = 760, [Hb], DL(O2) and DM(O2) were as influential as QT in limiting V(O2)MAX. With increasing altitude, the influence of QT and [Hb] fell while that of VA, DL(O2), and DM(O2) progressively increased until at PB = 253, V(O2)MAX was independent of QT and [Hb]. Neither the fall in maximal QT nor rise in [Hb] with chronic hypoxia therefore appear to affect V(O2)MAX. However, high values of ventilation, DL(O2) and DM(O2) appear to be advantageous for exercise at altitude.