支气管哮喘小鼠气道反应性无创检测方法的建立

Establishment of non-invasive method for measuring airway responsiveness of asthmatic mouse model

目的目前国内对支气管哮喘（简称哮喘）小鼠的评价多数仅立足于气道炎性指标，不能完全反映哮喘的病理生理特征。本所率先从国外引进了小动物无创检测和有创检测肺功能仪。无创法检测时小鼠不必麻醉，而且每次可以同时检测多只小鼠，具有较大的优越性，但能否取代有创法尚需更多的数据。本研究旨在建立无创检测小鼠气道高反应性的检测方法，并与有创检测方法进行比较。方法根据动物模型和气道反应性检测方法不同，动物分为：①无创哮喘组；②无创对照组；③有创哮喘组；④有创对照组。采用卵白蛋白致敏和激发，建立BALB／c小鼠哮喘模型，生理盐水作为对照，分别用无创和有创的方法测定气道反应性。哮喘动物雾化吸入0．2～50g／L倍增浓度的乙酰甲胆碱（Mch），测定相应浓度下的增强呼气间歇（Penh）值或气道阻力（RL）值等指标。将小鼠吸入Mch后Rt或Penh增加2倍的激发浓度以PC100来表示。所有动物都行支气管肺泡灌洗，收集灌洗液，涂片染色后分类计数。结果无创哮喘组PCm均≤6．25g／L，对照组PC100均≥12．5g／L。其Log2（10PC100）值（5．36±0．84）显著低于对照组（7．97±0．82）（P〈0．01）。无创哮喘组从Mch浓度3．12g／L开始，其Penh值明显高于对照组。有创哮喘组RL值从Mch浓度0．39g／L开始就明显高于相应对照组（P〈0．05）。无创组与有创组的气道反应性相关系数R=0．96（P〈0．01）。无创哮喘组和有创哮喘组的嗜酸粒细胞分别为（54．00±5．96）％，（55．93±5．92）％，显著高于各自对照组的（0．38±0．52）％，（0．63±0．74）％（P〈0．01）。结论本研究表明以Penh为主要测定指标的无创方法，可以成功检测哮喘小鼠气道高反应性。

Objective Most of the evaluation on asthmatic mouse model only based on the airway inflammation, not fully reflecting its pathophysiology. Noninvasive method of measuring bronchial hyperresponsiveness can detect several conscious mice in one time, but whether it can replace the invasive technique needs more data to be identified. This study aims to establish a non-invasive detection of mouse airway hyperresponsiveness,comparing with the invasive method. Methods According to different ways of detection, mice were divided into four groups ： non-invasive asthma group, non-invasive control group, invasive asthma group and invasive control group. Mouse was sensitized and challenged with ovatbumin（OVA） for asthmatic model. The mice were challenged with increasing concentrations of methacholine aerosol from 0.2- 50 g/L,and the airway resistance was measured. Enhance pause（Penh） or airway resistance（RL） was taken for each group. The dose of methacholine causing 100% increase of respiratory resistance was defined as PC100. The PC100, values were converted into Log2 （ 10PC100 ） for statistical analysis. Bronchoalveolar lavage cytology was performed to evaluate the airway inflammation. Results The PC100 of non-invasive asthma group was 46.25 g/L, and the noninvasive control group＇s ≥ 12.5 g/I.. Its Log2 （10PC100） value was significantly less than that of control group,（5.36±0.84） vs （7.97±0.82）（ P〈0.01）. The Penh value of non-invasive asthma group began significantly increasing when the concentration of Mch was 3.12 g/L. The R/ value of invasive asthma group was increasing at the beginning of 0.39 g/L（ P〈0.05）.The coefficient rate of two groups was 0.96（ P 〈0.01 ）. The EOS（ % ） of non-invasive asthma group or invasive asthma group was 54.00± 5.96,53.93 ±5.92 respectively, significantly larger than that of control group （0.38 0.52,0. 63±0. 74, P 〈.0.01 ）. Conclusions This study shows that single-chambered barometric whole-body plethysmography as a non invasive lung function test can successfully detect airway responsiveness in asthmatic mouse model.