人体吸入氧气分级变化过程中的呼出一氧化氮
Exhaled NO during graded changes in inhaled oxygen in man.
作者信息
Schmetterer L, Strenn K, Kastner J, Eichler H G, Wolzt M
机构信息
Department of Clinical Pharmacology, University of Vienna, Austria.
出版信息
Thorax. 1997 Aug;52(8):736-8. doi: 10.1136/thx.52.8.736.
BACKGROUND
Nitric oxide (NO) is present in the exhaled air of animals and humans. In isolated animal lungs the amount of exhaled NO is decreased during hypoxia. A study was undertaken to determine whether changes in arterial oxygen tension affect levels of exhaled NO in humans.
METHODS
Sixteen healthy subjects were randomised to inhale different gas mixtures of oxygen and nitrogen in a double blind crossover study. Eight gas mixtures of oxygen and nitrogen (fractional inspired oxygen concentration (FiO2) 0.1 to 1.0) were administered. Exhaled NO was measured with a chemiluminescence detector from end expiratory single breath exhalation.
RESULTS
A dose-dependent change in exhaled NO during graded oxygen breathing was observed (p = 0.0012). The mean (SE) exhaled NO concentration was 31 (3) ppb at baseline, 39 (4) ppb at an FiO2 of 1.0, and 26 (3) ppb at an FiO2 of 0.1.
CONCLUSIONS
The NO concentration in exhaled air in healthy humans is dependent on oxygen tension. Hyperoxia increases the level of exhaled NO, which indicates increased NO production. The mechanism behind this phenomenon remains to be elucidated.
背景
一氧化氮（NO）存在于动物和人类的呼出气体中。在离体动物肺中，低氧时呼出的NO量会减少。本研究旨在确定动脉血氧张力的变化是否会影响人类呼出NO的水平。
方法
在一项双盲交叉研究中，16名健康受试者被随机分配吸入不同的氧气和氮气混合气体。给予八种氧气和氮气混合气体（吸入氧分数（FiO2）为0.1至1.0）。使用化学发光检测器从呼气末单次呼气中测量呼出的NO。
结果
在分级吸氧过程中观察到呼出NO的剂量依赖性变化（p = 0.0012）。呼出NO浓度的平均值（标准误）在基线时为31（3）ppb，FiO2为1.0时为39（4）ppb，FiO2为0.1时为26（3）ppb。
结论
健康人类呼出气体中的NO浓度取决于氧张力。高氧增加呼出NO的水平，这表明NO生成增加。这一现象背后的机制仍有待阐明。
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