Wiggs B R, Bosken C, Paré P D, James A, Hogg J C
University of British Columbia, St. Paul's Hospital, Vancouver, Canada.
Am Rev Respir Dis. 1992 Jun;145(6):1251-8. doi: 10.1164/ajrccm/145.6.1251.
We have examined the effect of airway wall thickening, loss of lung recoil, and airway smooth muscle shortening on the increase in airway resistance using a model of the human tracheobronchial tree. The values for airway wall thickening were determined morphometrically on the postmortem or surgically resected lungs of normal subjects, patients with moderate chronic obstructive pulmonary disease, and patients with severe asthma. Loss of recoil was simulated by deflating airways along their pressure-area curves by 1 to 3 cm H2O. Values of smooth muscle shortening between 20 and 40% were used in the model to generate sigmoidal-shaped "dose-response" curves. The analysis shows that moderate amounts of airway wall thickening, which have little effect on baseline resistance, can profoundly affect the airway narrowing caused by smooth muscle shortening--especially if the wall thickening is localized in peripheral airways. The combination of a loss of recoil and airway wall thickening are more than additive in their effect on simulated airway responsiveness. We conclude that airway wall thickening and a loss of lung recoil can partially explain the airway hyperresponsiveness observed in patients with chronic obstructive lung disease and asthma.
我们使用人体气管支气管树模型，研究了气道壁增厚、肺弹性回缩力丧失和气道平滑肌缩短对气道阻力增加的影响。气道壁增厚的值通过形态计量学方法，在正常受试者、中度慢性阻塞性肺疾病患者和重度哮喘患者的尸检或手术切除肺上测定。通过沿气道压力-面积曲线将气道压力降低1至3 cm H₂O来模拟弹性回缩力丧失。模型中使用20%至40%之间的平滑肌缩短值来生成S形的“剂量-反应”曲线。分析表明，适量的气道壁增厚对基线阻力影响不大，但可显著影响平滑肌缩短引起的气道狭窄，尤其是当壁增厚局限于外周气道时。弹性回缩力丧失和气道壁增厚共同作用对模拟气道反应性的影响大于两者单独作用之和。我们得出结论，气道壁增厚和肺弹性回缩力丧失可部分解释慢性阻塞性肺疾病和哮喘患者中观察到的气道高反应性。
