FUNCTIONAL-SIGNIFICANCE OF INCREASED AIRWAY SMOOTH-MUSCLE IN ASTHMA AND COPD
FUNCTIONAL-SIGNIFICANCE OF INCREASED AIRWAY SMOOTH-MUSCLE IN ASTHMA AND COPD
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DOI：
10.1152/jappl.1993.74.6.2771
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发表时间：
1993-06-01
影响因子：
3.3
通讯作者：
PARE, PD
中科院分区：
文献类型：
--
作者：
LAMBERT, RK;WIGGS, BR;PARE, PD
使用计算模型，我们研究了哮喘和慢性阻塞性肺疾病(COPD)患者中观察到的形态决定的气道平滑肌质量、外膜质量和粘膜下质量增加对支气管收缩刺激引起的气道阻力增加的影响。Wiggs等人的计算模型。(J.Appl.)物理。69：849-860,1990)进行了修改，使得肌肉的缩短受到最大应力的限制，从而肌肉可以在收缩的长度上发育。外膜厚度的增加通过减少实质的相互依赖而增加收缩。对于任何程度的平滑肌缩短，粘膜下厚度的增加都会导致更大的管腔闭塞。肌肉厚度的增加允许更大的平滑肌缩短，以对抗实质相互依赖和气道壁僵硬所提供的弹性负荷。我们发现，对于恒定的呼吸道力学，如气道的被动面积-压力曲线所反映的，肌肉质量的增加可能是导致哮喘和COPD患者因支气管收缩刺激而观察到的阻力增加的最重要的异常。对于给定的最大肌肉应力，肌肉厚度越大，就会产生更大的张力，从而使管腔更加收缩。
Using a computational model, we investigated the effect of the morphologically determined increased airway smooth muscle mass, adventitial mass, and submucosal mass observed in patients with asthma and chronic obstructive pulmonary disease (COPD) on the increase in airway resistance in response to a bronchoconstricting stimulus. The computational model of Wiggs et al. (J. Appl. Physiol. 69:849-860,1990) was modified in such a way that smooth muscle shortening was limited by the maximal stress that the muscle could develop at the constricted length. Increased adventitial thickness was found to increase constriction by reducing parenchymal interdependence. Increased submucosal thickness led to greater luminal occlusion for any degree of smooth muscle shortening. Increased muscle thickness allowed greater smooth muscle shortening against the elastic loads provided by parenchymal interdependence and airway wall stiffness. We found that for constant airway mechanics, as reflected by the passive area-pressure curves of the airways, the increased muscle mass is likely to be the most important abnormality responsible for the increased resistance observed in response to bronchoconstricting stimuli in asthma and COPD. For a given maximal muscle stress, greater muscle thickness allows the development of greater tension and thus more constriction of the lumen.