Mannino F, Sposato B, Ricci A, Grasso D, De Clementi F, Mariotta S
Dipartimento di Scienze Cardiovascolari e Respiratorie, Sezione Malattie Respiratorie, Università "La Sapienza", Rome, Italy.
Lung. 2001;179(3):137-45. doi: 10.1007/s004080000056. Epub 2002 Feb 4.
Forty-eight patients suffering from intermittent bronchial asthma underwent methacholine challenge test. Response was stronger in 29 patients and less pronounced in 19. The two groups had the same characteristics except for the cumulative methacholine dose which was lower in severe hyperresponsiveness. The patients were studied both in the phase of induced bronchospasm and in the subsequent phase of spontaneous recovery. Dose-response curves to methacholine were analyzed as FEV1% decline/methacholine dose for the induction phase of bronchoconstriction and as FEV1% increase*methacholine dose/time after PD20FEV1 for the recovery phase. The phase of induced bronchospasm as well as spontaneous recovery had a linear pattern in severe hyperresponsiveness; in patients with moderate response, induced bronchoconstriction had a curvilinear pattern whereas spontaneous recovery had a linear pattern. This latter group had to break down an amount of methacholine that was fivefold greater than the former, therefore the mechanism of local homeostasis recovery may be more efficient in moderate hyperresponsiveness. However, in both groups recovery after the bronchospasm was not complete after 60 min (p < 0.01 versus baseline). Furthermore, recovery was faster in the first 15 min than in the remaining time. In conclusion the behavior of methacholine-induced bronchospasm and its spontaneous recovery in both severe and moderate hyperresponsiveness seem to be different although several and not well-established mechanisms may be responsible for this phenomenon.
48例间歇性支气管哮喘患者接受了乙酰甲胆碱激发试验。29例患者反应较强，19例患者反应较弱。除严重高反应性患者的累积乙酰甲胆碱剂量较低外，两组具有相同的特征。对患者在诱发支气管痉挛阶段和随后的自发恢复阶段进行了研究。乙酰甲胆碱的剂量反应曲线在支气管收缩诱发阶段分析为FEV1%下降/乙酰甲胆碱剂量，在恢复阶段分析为PD20FEV1后FEV1%增加×乙酰甲胆碱剂量/时间。在严重高反应性患者中，诱发支气管痉挛阶段以及自发恢复阶段呈线性模式；在中度反应患者中，诱发支气管收缩呈曲线模式，而自发恢复呈线性模式。后一组患者必须分解的乙酰甲胆碱量比前一组大五倍，因此局部内稳态恢复机制在中度高反应性患者中可能更有效。然而，两组患者在支气管痉挛后60分钟内恢复均不完全（与基线相比，p<0.01）。此外，最初15分钟内的恢复比其余时间更快。总之，乙酰甲胆碱诱发的支气管痉挛及其在严重和中度高反应性患者中的自发恢复行为似乎有所不同，尽管可能有几种尚未明确的机制导致了这一现象。
