Sestier M, Pineau L, Cartier A, Martin R R, Malo J L
J Appl Physiol Respir Environ Exerc Physiol. 1984 Jan;56(1):122-8. doi: 10.1152/jappl.1984.56.1.122.
Eight asthmatic and six normal subjects had methacholine chloride inhalation tests on two visits. On first assessment the provocative concentration causing a 20% fall in forced expiratory volume in 1 s (PC20FEV1) was measured. On the second visit the provocative concentration causing a 35% fall in specific lung conductance (PC35sGL) was obtained in addition to the PC20FEV1. Lung resistance was continuously monitored to evaluate the bronchomotor effect of FEV1 maneuver. Results of PC20FEV1 were within one single twofold concentration on the two visits. In all subjects but one PC35sGL was lower than PC20FEV1, and in 10 instances this difference was superior to a single twofold concentration. The bronchodilator effect of FEV1 maneuver was significantly although loosely related to base-line airway caliber and excitability. However, we were unable to show a significant relationship between the differences between PC20FEV1 and PC35sGL and this bronchodilator effect. This suggests that other factors may explain the greater sensitivity of PC35sGL compared with PC20FEV1.
8名哮喘患者和6名正常受试者分两次进行了氯化乙酰甲胆碱吸入试验。首次评估时，测量引起第1秒用力呼气量（FEV1）下降20%的激发浓度（PC20FEV1）。第二次就诊时，除了PC20FEV1外，还获得了引起比气道传导率（sGL）下降35%的激发浓度（PC35sGL）。持续监测肺阻力以评估FEV1操作的支气管运动效应。两次就诊时PC20FEV1的结果在单一两倍浓度范围内。除1名受试者外，所有受试者的PC35sGL均低于PC20FEV1，且在10例中，这种差异超过单一两倍浓度。FEV1操作的支气管扩张效应虽然与基线气道口径和兴奋性有明显的松散关系，但仍很显著。然而，我们未能显示PC20FEV1和PC35sGL之间的差异与这种支气管扩张效应之间存在显著关系。这表明，其他因素可能解释了PC35sGL比PC20FEV1具有更高敏感性的原因。
