Jensen Dennis, Wolfe Larry A, O'Donnell Denis E, Davies Gregory A L
School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada K7L 3N6.
J Appl Physiol (1985). 2005 Mar;98(3):822-8. doi: 10.1152/japplphysiol.01208.2003. Epub 2004 Nov 19.
This study used a modified CO(2) rebreathing procedure to examine the effect of gender on the chemoreflex control of breathing during wakefulness in healthy men (n = 14) and women (n = 14). Women were tested in the follicular phase of the menstrual cycle. During rebreathing trials, subjects hyperventilated to reduce the partial pressure of end-tidal CO(2) (Pet(CO(2))) below 25 Torr and were then switched to a rebreathing bag containing a normocapnic hypoxic or hyperoxic gas mixture. During the trial, Pet(CO(2)) increased, while O(2) was maintained at a constant level. The point at which ventilation began to rise as Pet(CO(2)) increased was identified as the ventilatory recruitment threshold (VRT). Ventilation below the VRT was measured, and the slope of the ventilatory response above the VRT was determined. Gender had no effect on the hyperoxic or hypoxic VRT for CO(2). Central chemoreflex sensitivity was significantly greater in men than women but not after correction for forced vital capacity. Measures of peripheral chemoreflex sensitivity were similar between genders. However, the slope of the tidal volume (Vt) response to hyperoxic and hypoxic CO(2) rebreathing (corrected and uncorrected) was greater in men than women, respectively. We conclude that central chemoreflex sensitivity is greater in men compared with women as reflected by differences in ventilatory (uncorrected) and Vt (corrected and uncorrected) responses to CO(2). However, gender has no significant effect on the central chemoreflex VRT for CO(2). The peripheral chemoreflex control of breathing during wakefulness is similar between men and women.
本研究采用改良的二氧化碳再呼吸程序，以检验性别对健康男性（n = 14）和女性（n = 14）清醒状态下呼吸化学反射控制的影响。女性在月经周期的卵泡期接受测试。在再呼吸试验期间，受试者进行过度通气，将呼气末二氧化碳分压（Pet(CO₂)）降至25 Torr以下，然后切换至装有正常碳酸血症性低氧或高氧气体混合物的再呼吸袋。在试验过程中，Pet(CO₂)升高，而氧气保持在恒定水平。将随着Pet(CO₂)升高通气开始增加的点确定为通气募集阈值（VRT）。测量低于VRT的通气量，并确定高于VRT的通气反应斜率。性别对二氧化碳的高氧或低氧VRT没有影响。男性的中枢化学反射敏感性显著高于女性，但在校正用力肺活量后则无差异。性别之间的外周化学反射敏感性测量结果相似。然而，男性对高氧和低氧二氧化碳再呼吸（校正和未校正）的潮气量（Vt）反应斜率分别大于女性。我们得出结论，从对二氧化碳的通气（未校正）和Vt（校正和未校正）反应差异可以看出，男性的中枢化学反射敏感性高于女性。然而，性别对二氧化碳的中枢化学反射VRT没有显著影响。清醒状态下男性和女性的外周呼吸化学反射控制相似。
