Zamel N, Webster P M
Bull Eur Physiopathol Respir. 1984 Jan-Feb;20(1):19-23.
Lung recoil, Pst(1), dependence and gas density dependence of maximum expiratory flow (Vmax) using air and an 80% helium + 20% oxygen (HeO2) gas mixture before and 60 +/- 4 (means +/- SD) days after cessation of smoking were determined in five male and five female subjects (33.4 +/- 6.4 years). Pst(1) dependence of Vmax, a relationship dependent on airway elastance at the "choke", was estimated by measuring the slope and the zero flow intercept using the maximum flow-static recoil (MFSR) curve. MFSR slope was unchanged by abstinence. The intercept showed no difference between air and HeO2 before or after cessation of smoking. Density independence of the zero flow intercept is deducible from wave speed theory if there is no change at the "choke" and the slope truly reflects the elastic behaviour of the "choke". This correspondence of theory and measurement suggests that the "choke" was not changed by abstinence. The reduction of Pst(1) with smoking cessation, without any fall in Vmax at the same lung volume, suggests a complementary reduction in lung recoil and frictional energy loss upstream of the "choke". This would suggest that a decrease in small airway muscle tone was the single cause of a reduction of Pst(1) and peripheral airway resistance.
在5名男性和5名女性受试者（33.4±6.4岁）中，测定了戒烟前及戒烟后60±4（均值±标准差）天使用空气和80%氦气+20%氧气（HeO2）混合气体时肺回缩、Pst(1)、最大呼气流量（Vmax）的依赖性以及气体密度依赖性。通过使用最大流量-静态回缩（MFSR）曲线测量斜率和零流量截距来估计Vmax对Pst(1)的依赖性，这是一种依赖于“狭窄处”气道弹性的关系。禁欲后MFSR斜率未改变。戒烟前后，空气和HeO2之间的截距无差异。如果“狭窄处”没有变化且斜率真实反映“狭窄处”的弹性行为，则可从波速理论推导出零流量截距的密度独立性。理论与测量结果的这种对应表明禁欲并未改变“狭窄处”。戒烟后Pst(1)降低，而在相同肺容积下Vmax没有任何下降，这表明“狭窄处”上游的肺回缩和摩擦能量损失有互补性降低。这表明小气道肌张力降低是Pst(1)和外周气道阻力降低的唯一原因。
