Woolcock A J, Salome C M, Yan K
Am Rev Respir Dis. 1984 Jul;130(1):71-5. doi: 10.1164/arrd.1984.130.1.71.
In order to determine the shape of the dose-response curves of the human airways to bronchial challenge, changes in forced expiratory volume in one second (FEV1) after inhaled histamine were measured in 8 current asthmatic, 2 mildly asthmatic, and 10 normal subjects. The challenges were continued until a plateau was reached (in all the normal and in the 2 mildly asthmatic subjects), or the FEV1 had fallen by 60%. A sigmoidal equation was fitted to the data points to obtain values for alpha (the position constant) and beta (the slope constant). All the normal and the 2 mildly asthmatic subjects reached a plateau value for fall in FEV1. Current asthmatics were differentiated from normal and mildly asthmatic subjects by the failure to reach a plateau at a 60% fall in FEV1 by higher values for alpha (greater sensitivity to histamine) and by higher values for beta. Ipratropium bromide (an atropinelike drug), in doses that completely inhibited the effects of methacholine, caused no change in the shape or position of the curves in normal or asthmatic subjects. It is concluded that the nature of the airway response to histamine is different in asthmatic from that in normal subjects. It is possible that asthmatics lack a normal mechanism that inhibits severe airway narrowing during histamine challenge.
为了确定人类气道对支气管激发的剂量反应曲线的形状，对8名现患哮喘患者、2名轻度哮喘患者和10名正常受试者吸入组胺后一秒用力呼气量（FEV1）的变化进行了测量。激发持续进行，直到达到平台期（所有正常受试者和2名轻度哮喘患者），或FEV1下降60%。将一个S形方程拟合到数据点，以获得α（位置常数）和β（斜率常数）的值。所有正常受试者和2名轻度哮喘患者的FEV1下降均达到平台值。现患哮喘患者与正常受试者和轻度哮喘患者的区别在于，FEV1下降60%时未达到平台期、α值较高（对组胺更敏感）以及β值较高。异丙托溴铵（一种类似阿托品的药物），其剂量能完全抑制乙酰甲胆碱的作用，但在正常或哮喘受试者中，曲线的形状或位置未发生变化。结论是，哮喘患者气道对组胺的反应性质与正常受试者不同。哮喘患者可能缺乏一种在组胺激发期间抑制严重气道狭窄的正常机制。
