Ward S A, Whipp B J, Koyal S, Wasserman K
J Appl Physiol Respir Environ Exerc Physiol. 1983 Sep;55(3):742-9. doi: 10.1152/jappl.1983.55.3.742.
Pulmonary CO2 flow (the product of cardiac output and mixed venous CO2 content) is purported to be an important determinant of ventilatory dynamics in moderate exercise. Depletion of body CO2 stores prior to exercise should thus slow these dynamics. We investigated, therefore, the effects of reducing the CO2 stores by controlled volitional hyperventilation on cardiorespiratory and gas exchange response dynamics to 100 W cycling in six healthy adults. The control responses of ventilation (VE), CO2 output (VCO2), O2 uptake (VO2), and heart rate were comprised of an abrupt increase at exercise onset, followed by a slower rise to the new steady state (t1/2 = 48, 43, 31, and 33 s, respectively). Following volitional hyperventilation (9 min, PETCO2 = 25 Torr), the steady-state exercise responses were unchanged. However, VE and VCO2 dynamics were slowed considerably (t1/2 = 76, 71 s) as PETCO2 rose to achieve the control exercise value. VO2 dynamics were slowed only slightly (t1/2 = 39 s), and heart rate dynamics were unaffected. We conclude that pulmonary CO2 flow provides a significant stimulus to the dynamics of the exercise hyperpnea in man.
肺二氧化碳流量（心输出量与混合静脉血二氧化碳含量的乘积）被认为是中等强度运动中通气动力学的一个重要决定因素。因此，运动前体内二氧化碳储备的减少应会减缓这些动力学过程。为此，我们研究了通过控制性自主过度通气减少二氧化碳储备对6名健康成年人在100瓦骑行运动中心肺和气体交换反应动力学的影响。通气（VE）、二氧化碳排出量（VCO2）、氧气摄取量（VO2）和心率的对照反应包括运动开始时的突然增加，随后缓慢上升至新的稳定状态（t1/2分别为48、43、31和33秒）。自主过度通气（9分钟，呼气末二氧化碳分压 = 25托）后，运动的稳态反应未改变。然而，随着呼气末二氧化碳分压上升以达到对照运动值，VE和VCO2动力学显著减慢（t1/2 = 76、71秒）。VO2动力学仅略有减慢（t1/2 = 39秒），心率动力学未受影响。我们得出结论，肺二氧化碳流量对人体运动性通气增强的动力学提供了显著刺激。
