Greenspon L W, Morrissey W L
Am Rev Respir Dis. 1986 May;133(5):735-9. doi: 10.1164/arrd.1986.133.5.735.
To evaluate the factors that contribute to inhibition of airways reactivity, we compared the effect of inhaled isoproterenol, 125 micrograms, on the response to methacholine-induced bronchoconstriction in 10 normal and 10 asthmatic subjects. We measured in each subject baseline lung function, response to inhaled bronchodilator, dose of bronchodilator causing 50% maximal response, and degree of airways reactivity to inhalation of methacholine before and after isoproterenol. In asthmatics, but not normal subjects, inhalation of isoproterenol led to significant inhibition of methacholine-induced bronchospasm. In asthmatics, the greater the airways reactivity to methacholine the greater the inhibition by isoproterenol (p less than 0.05). In both groups, there was significant correlation between baseline lung function and level of airways reactivity. In neither normal subjects nor asthmatics did the maximal bronchodilator response to isoproterenol inhalation correlate with inhibition of airways reactivity. Studies evaluating inhibition of airways reactivity should take into account the population tested, baseline lung function, and baseline level of airways reactivity.
为评估导致气道反应性受抑制的因素，我们比较了吸入125微克异丙肾上腺素对10名正常受试者和10名哮喘受试者乙酰甲胆碱诱发支气管收缩反应的影响。我们测量了每位受试者的基线肺功能、对吸入支气管扩张剂的反应、引起50%最大反应的支气管扩张剂剂量以及异丙肾上腺素前后吸入乙酰甲胆碱时的气道反应程度。在哮喘患者中，而非正常受试者中，吸入异丙肾上腺素导致乙酰甲胆碱诱发的支气管痉挛受到显著抑制。在哮喘患者中，对乙酰甲胆碱的气道反应性越高，异丙肾上腺素的抑制作用就越强（p<0.05）。在两组中，基线肺功能与气道反应性水平之间均存在显著相关性。无论是正常受试者还是哮喘患者，吸入异丙肾上腺素的最大支气管扩张反应均与气道反应性抑制无关。评估气道反应性抑制的研究应考虑受试人群、基线肺功能和气道反应性基线水平。
