Hopkins S R, McKenzie D C, Schoene R B, Glenny R W, Robertson H T
Faculty of Medicine, Division of Sports Medicine, University of British Columbia, Vancouver, Canada.
J Appl Physiol (1985). 1994 Aug;77(2):912-7. doi: 10.1152/jappl.1994.77.2.912.
To investigate pulmonary gas exchange during exercise in athletes, 10 high aerobic capacity athletes (maximal aerobic capacity = 5.15 +/- 0.52 l/min) underwent testing on a cycle ergometer at rest, 150 W, 300 W, and maximal exercise (372 +/- 22 W) while trace amounts of six inert gases were infused intravenously. Arterial blood samples, mixed expired gas samples, and metabolic data were obtained. Indexes of ventilation-perfusion (VA/Q) mismatch were calculated by the multiple inert gas elimination technique. The alveolar-arterial difference for O2 (AaDO2) was predicted from the inert gas model on the basis of the calculated VA/Q mismatch. VA/Q heterogeneity increased significantly with exercise and was predicted to increase the AaDO2 by > 17 Torr during heavy and maximal exercise. The observed AaDO2 increased significantly more than that predicted by the inert gas technique during maximal exercise (10 +/- 10 Torr). These data suggest that this population develops diffusion limitation during maximal exercise, but VA/Q mismatch is the most important contributor (> 60%) to the wide AaDO2 observed.
为研究运动员运动期间的肺气体交换情况，10名有氧能力较高的运动员（最大有氧能力 = 5.15 +/- 0.52升/分钟）在静息状态、150瓦、300瓦以及最大运动强度（372 +/- 22瓦）下于自行车测力计上进行测试，同时静脉输注微量的六种惰性气体。采集动脉血样本、混合呼出气体样本以及代谢数据。采用多惰性气体消除技术计算通气-灌注（VA/Q）不匹配指数。基于计算所得的VA/Q不匹配情况，由惰性气体模型预测氧的肺泡-动脉差值（AaDO2）。VA/Q异质性随运动显著增加，预计在重度和最大运动强度时AaDO2会增加超过17托。在最大运动强度时，观察到的AaDO2增加幅度显著大于惰性气体技术预测的增加幅度（10 +/- 10托）。这些数据表明，该群体在最大运动强度时出现了弥散受限，但VA/Q不匹配是观察到的较大AaDO2的最重要因素（> 60%）。
