Resting and exercise ventilatory chemosensitivity across the menstrual cycle
Resting and exercise ventilatory chemosensitivity across the menstrual cycle
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DOI：
10.1152/japplphysiol.00727.2011
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发表时间：
2012-03-01
影响因子：
3.3
通讯作者：
Sheel, A. William
中科院分区：
文献类型：
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作者：
MacNutt, Meaghan J.;De Souza, Mary Jane;Sheel, A. William
MacNutt MJ, De Souza MJ, Tomczak SE, Homer JL, Sheel AW。月经周期内休息和运动通气化学敏感性。中国生物医学工程学报（英文版），2012；首次发表于2011年12月15日；doi: 10.1152 / japplphysiol.00727.2011。我们假设当女性在月经周期的黄体期雌激素和黄体酮水平最高时，静息和运动通气的化学敏感性会增强。健康的年轻女性（n = 10；年龄= 23±5岁）在一个完整的周期内进行评估：在卵泡早期（EF）、卵泡晚期（LF）、黄体早期和黄体中期（ML）期。我们每天测量尿液中雌激素和黄体酮的结合物。为了比较不同性别间的通气化学敏感性和日常变化，在1个月的时间内，对10名男性（年龄= 26 +/- 7岁）进行了5天的非连续评估。静息通气测量和低氧化学敏感性评估使用等apic低氧通气反应（iHVR）测试。采用Read再呼吸方案和改良的再呼吸试验评估高碳酸血症通气反应。参与者在常氧和低氧条件下完成了次最大周期运动。我们观察到月经周期对静息分钟通气的显著影响，在ML期相对于EF和LF期升高。与雄性相比，雌性潮末CO2在潮末期和潮末期减少，而在潮末期没有减少。我们发现iHVR不受月经周期的影响，在男性和女性之间没有差异。对化学刺激的敏感性不受月经周期的影响，这意味着任何激素介导的影响都不足以超过这些化学敏感性测量的固有变化。在女性中，CO2的通气量招募阈值通常较低，这表明与激素相关的通气量招募阈值降低。我们没有发现月经周期阶段对亚极限运动通气的影响，并发现男性和女性对常氧和低氧运动的通气反应在数量上相似。这表明运动过程中的前馈和反馈影响超过了性激素自然变化的影响。
MacNutt MJ, De Souza MJ, Tomczak SE, Homer JL, Sheel AW. Resting and exercise ventilatory chemosensitivity across the menstrual cycle. J Appl Physiol 112: 737-747, 2012. First published December 15, 2011; doi:10.1152/japplphysiol.00727.2011.-We hypothesized that resting and exercise ventilatory chemosensitivity would be augmented in women when estrogen and progesterone levels are highest during the luteal phase of the menstrual cycle. Healthy, young females (n = 10; age = 23 +/- 5 yrs) were assessed across one complete cycle: during early follicular (EF), late follicular (LF), early luteal, and mid-luteal (ML) phases. We measured urinary conjugates of estrogen and progesterone daily. To compare values of ventilatory chemosensitivity and day-to-day variability of measures between sexes, males (n = 10; age = 26 +/- 7 yrs) were assessed on 5 nonconsecutive days during a 1-mo period. Resting ventilation was measured and hypoxic chemosensitivity assessed using an isocapnic hypoxic ventilatory response (iHVR) test. The hypercapnic ventilatory response was assessed using the Read rebreathing protocol and modified rebreathing tests. Participants completed submaximal cycle exercise in normoxia and hypoxia. We observed a significant effect of menstrual-cycle phase on resting minute ventilation, which was elevated in the ML phase relative to the EF and LF phases. Compared with males, resting end-tidal CO2 was reduced in females during the EF and ML phases but not in the LF phase. We found that iHVR was unaffected by menstrual-cycle phase and was not different between males and females. The sensitivity to chemical stimuli was unaffected by menstrual-cycle phase, meaning that any hormone-mediated effect is of insufficient magnitude to exceed the inherent variation in these chemosensitivity measures. The ventilatory recruitment threshold for CO2 was generally lower in women, which is suggestive of a hormonally related lowering of the ventilatory recruitment threshold. We detected no effect of menstrual-cycle phase on submaximal exercise ventilation and found that the ventilatory response to normoxic and hypoxic exercise was quantitatively similar between males and females. This suggests that feed-forward and feed-back influences during exercise over-ride the effects of naturally occurring changes in sex hormones.