Fish J E, Ankin M G, Kelly J F, Peterman V I
J Appl Physiol Respir Environ Exerc Physiol. 1981 May;50(5):1079-86. doi: 10.1152/jappl.1981.50.5.1079.
We examined the effects of lung inflation on induced airway obstruction in 14 atopic asthmatic and 14 atopic nonasthmatic subjects. Subjects were challenged with aerosols of methacholine (MCh) and pollen antigen (Ag), and the effects of inflation were assessed with partial ad full flow-volume curves and by comparing airway conductance measurements before and after deep inspiration to total lung capacity (TLC). Whereas bronchoconstriction was transiently abolished or reduced with inspiration in nonasthmatics, these effects were absent or diminished in asthmatic subjects. Dissimilarities could not be explained by differences in base-line lung function or degree of obstruction produced. Deep inspiration had a greater effect in reducing airway obstruction produced with MCh than with Ag in nonasthmatics. In addition, atropine pretreatment had no effect on inspiration responses in asthmatics given Ag, suggesting that vagal reflexes were not the cause of an impaired ability to reduce bronchomotor tone by lung inflation. Our findings reveal the existence of an intrinsic means of regulating bronchomotor toe by active changes in lung volume and that such a mechanism is impaired in asthma. We suggest that airway hyperactivity in asthma is perhaps less a reflection of enhanced end-organ responsiveness than a reflection of this impaired capacity.
我们研究了肺膨胀对14名特应性哮喘患者和14名特应性非哮喘患者诱发气道阻塞的影响。受试者接受了乙酰甲胆碱（MCh）和花粉抗原（Ag）气雾剂的激发试验，并通过部分和全流量-容积曲线以及比较深吸气至肺总量（TLC）前后的气道传导率测量来评估膨胀的影响。在非哮喘患者中，吸气可使支气管收缩短暂消失或减轻，而在哮喘患者中，这些效应不存在或减弱。差异不能用基线肺功能或所产生的阻塞程度的差异来解释。在非哮喘患者中，深吸气对减轻由MCh引起的气道阻塞的作用比对由Ag引起的气道阻塞的作用更大。此外，阿托品预处理对给予Ag的哮喘患者的吸气反应没有影响，这表明迷走神经反射不是肺膨胀降低支气管运动张力能力受损的原因。我们的研究结果揭示了通过肺容积的主动变化来调节支气管运动张力的一种内在机制的存在，并且这种机制在哮喘中受损。我们认为，哮喘中的气道高反应性可能与其说是终末器官反应性增强的反映，不如说是这种受损能力的反映。
