茶碱壳聚糖缓释微球吸入对小鼠支气管哮喘模型气道炎症及气道痉挛的影响

Anti-inflammatory and bronchodilator effects of theophylline/chitosan microspheres on allergic bronchial asthma of mice

目的探讨茶碱缓释微球吸入对支气管哮喘(简称哮喘)小鼠肺泡灌洗液、细胞因子及肺组织病理改变的影响。方法 40只6～8周龄健康雄性BALB/C小鼠随机分为阴性对照组、模型组、布地奈德组、茶碱壳聚糖缓释微球吸入组,每组10只,同步饲养2周。小鼠于第1天、第8天及第15天OVA致敏,最后一次致敏后连续7d吸入1%的OVA激发,以建立哮喘模型。激发前各组给予所对应药物治疗,取肺泡灌洗液后,分别测定其中总蛋白、白细胞总数及分类,酶联免疫吸附试验测定BALF中IL-4、TNF-α。同时对肺组织切片进行HE染色,形态学检查和炎症状况的病理评分,采用计算机图像软件测定支气管壁面积(WAt)、管腔内径(T)并应用内周长(Pi)标准化。结果模型组中的白细胞总数、嗜酸粒细胞、总蛋白、IL-4、TNF-α均明显高于阴性对照组。吸入布地奈德、茶碱壳聚糖微球组的上述指标较哮喘模型组明显降低(P<0.05),两组之间差异无统计学意义;茶碱壳聚糖组中的巨噬细胞明显高于其余各组(P<0.01)。吸入布地奈德组和茶碱壳聚糖组小鼠肺组织切片病理形态显示,气道周围炎症较单纯哮喘模型组明显改善,两组患者炎症病理评分较单纯哮喘模型组亦明显改善,且两组之间差异无统计学意义。各实验组支气管壁面积无差别;茶碱壳聚糖微球组能够显著改善支气管直径,与单纯哮喘模型组比较差异具有统计学意义(P<0.05),而布地奈德组对支气管内直经无显著改善,与单纯模型组比较差异无统计学意义(P>0.05)。结论茶碱气道缓释微球吸入可以抑制气道炎症反应,扩张支气管平滑肌。因此,有望成为吸入激素加长效β2受体激动剂的补充或替代药物。

Objective To investigate the effects of theophylline/chitosan （TH/CTS） microspheres on the number of leucocytes and cytokines in the bronchoalveolar lavage fluid （BALF） and lung tissues in ovalbumin （OVA） sensitized and challenged mice. Methods 40 BALB/C mice were divided into four groups： including the control group, asthma model group, budesonide treatment group, TH/CTS microspheres treatment group. Mice were sensitized on days 0,7 and 14 by OVA and challenged from days 21 to 27 by OVA repeatedly to establish a asthma model. To assess the effects of BUD and TH/CTS microspheres, anminal were treated with BUD and TH/CTS microspheres. The total and differential number of leucocytes of the BALF were counted by a blood analyser. Tumor neucrosis factor （TNF-α）, interleukin-4 （IL-4） levels of the BALF were measured by ELISA. Lung tissues slices were stained by HE, the lumen diameter of bronchial （T）, the area of wall （WAt）, the perimeter of basement membrance of bronchioles （Pi） were measured by Image processing software. Results In repeatedly OVA-challenged mice, the total and differential leucocytes counts, IL4 and TNF-α levels increased greatly when comparedwith control group. Both budesonide and TH/CTS microsphers can decrease these index of inflammation （ P 〈0.05）. The mice treated by TH/CTS microspheres has a higher macrophage cell than other group （ P 〈 0.01）. No statistically significant difference for WAt/Pi was seen between the four groups. In model group T/Pi ratio decreased when compared with control group. TH/CTS microsphers treatment enlarges the lumen diameter of bronchial, and BUD has no such effect. Conclusions TH/CTS microspheres suggesting an anti-inflammatory and smooth muscle relaxant effects,and chitosan could also adjust the imbalance of Th1/Th2. The microspheres has the potential to be a supplemnt and substitute drugs of ICS＋ LABA.