卡介菌-多糖核酸不同干预方式对哮喘小鼠气道反应性和气道炎症的影响

Effects of bacillus calmette-guerin polysaccharide nucleotide by different ways of intervention on airway inflammation and airway hyperresponsiveness in asthmatic mouse model

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、BCGPSN干预组。BCG-PSN剂量为20μg/只,体积为60μl,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 BCGPSN（ 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（ P0.05）. 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.