目的 探讨卡介菌多糖核酸(BCG-PSN)不同干预方式对哮喘小鼠气道炎症和气道反应性的影响.方法 选择Balb/c小鼠.以卵白蛋白致敏激发建立小鼠哮喘模型,设立正常组、哮喘组、BCG-PSN干预组. BCG-PSN剂量为20 μg/只,体积为60 μl,均为末次激发后进行干预,根据干预方式分为肌肉注射组(im)和麻醉滴鼻组(in).分别于末次激发后2、14 d采用美国Buxco公司小鼠整体体积扫描记法测定气道反应性,以乙酰甲胆碱各浓度激发时增强的呼吸间歇( Enhanced Pause, Penh)表示.以PC100[气道反应性升高为生理盐水( NS)值2倍时的Mch激发浓度]及Penh/NS%综合评价气道反应性.收集支气管肺泡灌洗液,涂片后苏木素-伊红(HE)染色计数嗜酸粒细胞比例,肺组织病理检测.结果 BCG-PSN im组早期PC100为(9.48±3.06)mg/ml、与哮喘组(4.79±1.51)mg/ml相比P<0.05,晚期PC100(4.96±1.88)mg/ml,哮喘组为(5.55±3.11)mg/ml,两组相比差异无统计学意义,BCG-PSN in组早期、晚期PC100分别为(12.39±4.89)mg/ml、(9.19±2.35)mg/ml,与哮喘组相比,均有统计学意义(P<0.05),且晚期激发 PC100 in 组明显高于 im 组.哮喘组 BALF 中 Eos%为(40.73±6.01)%、im 组为(35.65±4.27)%,与哮喘组相比无明显差异,in组(30.98±5.45)%显著低于哮喘组(P<0.05).结论 初步证实BCG-PSN对已造模成功的哮喘小鼠具有治疗作用.麻醉滴鼻相当于气道吸入BCG-PSN,对哮喘小鼠的作用效果与肌肉注射给药相当甚至更优.气道内给予BCG-PSN有望成为一种新的防治哮喘的方法.
Objective To investigate the effect of BCG-PSN by different methods of intervention on airway inflammation and airway reactivity in asthmatic mouse model. Methods Balb/c mice were sensitized by ovalbumin to establish the asthmatic mouse model and divided into normal group, asthma group and BCG-PSN intervention group.For BCG-PSN intervention group, the dose of BCG-PSN was 20 μg/60 μl, all of which were intervened after the final excitation, and according to the intervention methods, the intervention group was subdivided into the intramuscular injection group ( im) and intranasal administration after anesthesia group (in). Airway responsiveness was measured by Buxco company's mice overall volume scanning method in 2 d, 14 d respectively after final excitation, which was demonstrated by enhanced breathing intermittence (Enhanced Pause, Penh) under different concentrations of methacholine stimulation. Airway reactivity was evaluated by PC100 ( Mch excitation concentration when the increased airway reactivity is 2 times of physiological saline ( NS) ) and Penh/NS% comprehensively. The bronchoalveolar lavage fluid was collected and the ratio of eosinophils was counted in the smears stained with haematoxylin and eosin, and with pathological examination of lung tissue. Results BCG-PSN (im) group PC100 was (9.48±3.06) mg/ml in early stages, compared with asthma group (4.79±1.51)mg/ml, P<0.05, in the later stages PC100 was (4.96±1.88) mg/ml, (5.55± 3.11) mg/ml for asthma group, there was no statistically significant differences in these two groups, for BCG-PSN(in) group, PC100 is (12.39±4.89)mg/ml,(9.19±2.35)mg/ml in early and later stages respectively, compared with the asthma group, had statistical significance (P<0.05), and in later stages, BCG-PSN(in) group was significantly higher than BCG-PSN(im) group. For the Eos% in BALF, asthma group was (40.73± 6.01)%, and BCG-PSN(im) group was (35.65±4.27)%, there was no significant difference between these two groups, BCG-PSN(in) group was (30.98±5.45)%, which is significantly lower than the asthma group (P<0.05). Conclusion BCG-PSN has a therapeutic effect on the asthmatic mice. The effects of BCG-PSN by intranasal administration after anesthesia are equivalent to or even superior to the effects by intramuscular administration, BCG-PSN by intratracheal administration is expected to become a new way for prevention and therapy on asthma.