Relationship between resting ventilatory chemosensitivity and maximal oxygen uptake in moderate hypobaric hypoxia
Relationship between resting ventilatory chemosensitivity and maximal oxygen uptake in moderate hypobaric hypoxia
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DOI：
10.1152/japplphysiol.00153.2007
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发表时间：
2007-10-01
影响因子：
3.3
通讯作者：
Nishiyasu, Takeshi
中科院分区：
文献类型：
--
作者：
Ogawa, Takeshi;Hayashi, Keiji;Nishiyasu, Takeshi
本研究验证了以下假设：在中度低压缺氧（H;模拟2，500 in）条件下进行最大运动期间观察到的Vo（2 max）和呼吸反应的降低程度受缺氧缓解和高碳酸血症缓解反应（分别为HVR和HCVR）的影响。20名男性（5名未训练者，7名长跑运动员，8名中长跑运动员）在H和常压常氧（N）条件下进行递增力竭跑试验。在跑步试验中，测定Vo（2）、肺通气量（VF）和动脉血氧饱和度（Sa（o2）），在N期间进行的两次呼吸反应试验中，使用再呼吸法评价HVR和HCVR。平均HVR和HCVR分别为0.36 +/- 0.04和2.11 +/- 10.2 l.min（-/-）mmHg（-1）。HVR与H条件下观察到的Vo（2 max）（%dVo（2 max））、Sa（o2）[%dSa（o2）=（N-H）.N-1.100]和V-E/V-o2的下降百分比显著相关。相比之下，HCVR与测试的任何变量都不相关。H和N之间最大V-E的增量与%dVo（2）显著相关。我们的研究结果表明，O-2化学敏感性在决定中度缺氧时运动过度通气水平方面起着重要作用;因此，在这些条件下，较高的O-2化学敏感性与Vo（2 max）和Sa（o2）的较小下降相关。
This study tested the hypothesis that the extent of the decrement in Vo(2max) and the respiratory response seen during maximal exercise in moderate hypobaric hypoxia (H; simulated 2,500 in) is affected by the hypoxia ventilatory and hypercapnia ventilatory responses (HVR and HCVR, respectively). Twenty men (5 untrained subjects, 7 long distance runners, 8 middle distance runners) performed incremental exhaustive running tests in H and normobaric normoxia (N) condition. During the running test, Vo(2), pulmonary ventilation (VF) and arterial oxyhemoglobin saturation (Sa(o2)) were measured, and in two ventilatory response tests performed during N, a rebreathing method was used to evaluate HVR and HCVR. Mean HVR and HCVR were 0.36 +/- 0.04 and 2.11 +/- 10.2 l.min(-/-)mmHg(-1), respectively. HVR correlated significantly with the percent decrements in Vo(2max) (%dVo(2max)), Sa(o2) [%dSa(o2) = (N-H).N-1.100], and V-E/V-o2 seen during H condition. By contrast, HCVR did not correlate with any of the variables tested. The increment in maximal V-E between H and N significantly correlated with %dVo(2),Our findings suggest that O-2 chemosensitivity plays a significant role in determining the level of exercise hyperventilation during moderate hypoxia; thus, a higher O-2 chemosensitivity was associated with a smaller drop in Vo(2max) and Sa(o2) under those conditions.