摘要目的探讨在SD大鼠过敏性气道炎症情况下气道阻力及气道对乙酰胆碱的反应性变化情况.方法作者用卵清蛋白免疫和激发SD大鼠.以气道阻力较基线值升高200%时所需乙酰胆碱的负对数浓度(-LogPC200)为标准检测气道反应性.结果哮喘组基础气道阻力值较对照组明显升高(从2.282±0.128到3.193±0.239; P<0.01).反复过敏原激发后气道对乙酰胆碱的反应性明显降低(-LogPC200从4.006±0.554到2.059±0.262; P<0.01).支气管肺泡灌洗液和肺组织病理切片均证实过敏性气道炎症存在.结论本研究证实反复过敏原激发后支气管收缩反应和气道高反应性不存在相关性,同时提示反复过敏原激发后虽然出现过敏性气道炎症,但气道反应性降低伴持续支气管收缩反应.

abstractsObjective To investigate bronchial responsiveness to acetylcholine in allergic airway inflammation of SD rats.Methods SD rats were immunized and challenged by chicken ovalbumin (OVA). Airway responsiveness, acetylcholine (Ach) provocation concentration needed to increase baseline airway resistance by 200% (PC200) were measured. Results The value of baseline airway resistance in asthma group was significantly higher than that in control group (2.282±0.128 vs 3.193±0.239; P<0.01). After multiple ovalbumin exposures, airway responsiveness to intravenous injection of acetylcholine decreased significantly (-LogPC200: 4.006±0.554 vs 2.059±0.262; P<0.01). Bronchial alveolar lavage fluid (BALF) and lung tissue specimen analysis indicated that airway allergic inflammation was present. Conclusions The study demonstrates a dissociation between the bronchoconstrictor response and bronchial hyper-responsiveness and indicates that multiple ovalbumin exposures induces persistent bronchoconstriction with airway hypo-responsiveness despite airway allergic inflammation.