Popa V T, Werner P
Chest. 1976 Aug;70(2):205-11. doi: 10.1378/chest.70.2.205.
Studies concerning the ability of an inhaled beta2-agonist to produce dose-related bronchodilatation are conflicting. In five asthmatic, five bronchitic, and five normal subjects, specific airway conductance (Gaw/VL), flow-volume curves, and single-breath nitrogen washout were recorded after noncummulative inhalation of 0.65 mg, 1.30 mg, 1.95 mg, and, in some subjects, 2.60 mg of metaproterenol sulfate. Bronchodilatation appeared to be dose-related and was best assessed by using Gaw/VL; in all but one subject with chronic bronchitis, there was a significant linear relationship between log dose and precent change in Gaw/VL. Measurements of flow rate could demonstrate significant log dose-responses in eight subjects, maximum midexpiratory flow being the most sensitive measurement of flow rate, followed in order by forced expiratory volume in one second, flow at 50 percent of forced vital capacity, peak expiratory flow rate, and flow at 75 percent of forced vital capacity. No log dose-respone curve could be observed by using the single-breath nitrogen-washout technique. This demonstration of significant log dose-responses to inhaled metaproterenol is consistent with the response to drugs acting upon receptors and suggests that patients may benefit from increasing doses of bronchodilators.
关于吸入性β2激动剂产生剂量相关支气管扩张能力的研究结果相互矛盾。在5名哮喘患者、5名慢性支气管炎患者和5名正常受试者中，在非累积吸入0.65毫克、1.30毫克、1.95毫克以及部分受试者吸入2.60毫克硫酸间羟异丙肾上腺素后，记录了比气道传导率（Gaw/VL）、流量-容积曲线和单次呼吸氮洗脱情况。支气管扩张似乎与剂量相关，使用Gaw/VL评估最为合适；除一名慢性支气管炎患者外，所有受试者的对数剂量与Gaw/VL的百分比变化之间均存在显著的线性关系。流量测量可在8名受试者中显示出显著的对数剂量反应，最大呼气中期流量是最敏感的流量测量指标，其次依次为一秒用力呼气量、用力肺活量50%时的流量、呼气峰值流速和用力肺活量75%时的流量。使用单次呼吸氮洗脱技术未观察到对数剂量反应曲线。吸入间羟异丙肾上腺素的显著对数剂量反应证明与作用于受体的药物反应一致，提示患者可能从增加支气管扩张剂剂量中获益。
