Habib M P, Paré P D, Engel L A
J Appl Physiol Respir Environ Exerc Physiol. 1979 Jul;47(1):51-8. doi: 10.1152/jappl.1979.47.1.51.
Dose-response curves to inhaled histamine were studied in 12 normal subjects. Pulmonary resistance (RL) and dynamic compliance (Cdyn) were measured during tidal breathing, and maximum expiratory flow rates, at an absolute lung volume corresponding to 40% of control vital capacity, were obtained during forced expiration from tidal end inspiration (Vmax40p) and from total lung capacity (Vmax40c). Threshold was defined as the histamine dose at which a departure from the range of normal measurements was observed. RL and Vmax40p indicated lowest threshold values, which varied by a factor of 32 and 38, respectively. There was no correlation between reactivity, which reflects the slope of the dose-response curve beyond the threshold dose, and threshold doses, nor between the initial RL (normalized for lung volume) and either threshold or reactivity. In eight subjects, restudied on two occasions after 10 mg propranolol or after saline, injected in a double-blind manner, there was no change in the dose-response curves. These results indicate that different indices of bronchoconstriction may yield different dose-response curves and hence different sensitivities. In addition, a wide variation of airway responses to inhaled histamine exists in the normal population and beta-blockade does not influence this variability.
对12名正常受试者进行了吸入组胺的剂量反应曲线研究。在潮气呼吸时测量肺阻力（RL）和动态顺应性（Cdyn），并在从潮气末吸气（Vmax40p）和肺总量（Vmax40c）进行用力呼气期间，在相当于对照肺活量40%的绝对肺容积下获得最大呼气流量率。阈值定义为观察到偏离正常测量范围的组胺剂量。RL和Vmax40p显示出最低阈值，其变化系数分别为32和38。反映阈值剂量以上剂量反应曲线斜率的反应性与阈值剂量之间，以及初始RL（根据肺容积标准化）与阈值或反应性之间均无相关性。在8名受试者中，以双盲方式注射10mg普萘洛尔或生理盐水后进行了两次重新研究，剂量反应曲线没有变化。这些结果表明，支气管收缩的不同指标可能产生不同的剂量反应曲线，因此敏感性也不同。此外，正常人群中对吸入组胺的气道反应存在很大差异，β受体阻滞剂不影响这种变异性。
