We tested the hypothesis that airway wall dimensions are important
determinants for the mechanical properties of airways. Lung tissue was
obtained from 31 smokers with different degrees of chronic obstructive
pulmonary disease (COPD) who were operated on for a solitary lung lesion.
Segments of small airways (n = 35) were mounted on cannulas in an organ
bath and inflated and deflated cyclically between +15 and -15 cm H(2)O.
For each airway this was done at baseline, after methacholine, and after
isoprenaline. Specific compliance (sCdyn), specific hysteresis (seta), and
pressure at which the airways collapsed (Pcol) were calculated from each
recording. Airway wall dimensions were measured morphometrically. Lung
function parameters of airflow obstruction were correlated to sCdyn, seta,
and Pcol. At baseline, after methacholine, and after isoprenaline sCdyn
was 0.059, 0.052, and 0. 085 cm H(2)O(-)(1), seta was 13.5, 12.9, and
7.1%, and Pcol was -3.4, -3.5, and -1.9 cm H(2)O, respectively.
Differences between sCdyn, seta, and Pcol after methacholine and after
isoprenaline were highly significant (p < 0.001). Of all dimensions
studied, smooth muscle area, but not total wall ar
