氨氯吡咪对大鼠慢性阻塞性肺疾病模型病理改变的影响

Effect of amiloride on the pathology of a rat model of chronic obstructive pulmonary disease

目的观察尿激酶型纤溶酶原激活物(u-PA)抑制剂氨氯吡咪对大鼠慢性阻塞性肺疾病(COPD)模型病理及病理生理改变的影响,探讨 u-PA 系统成分在 COPD 发病中的作用。方法健康 Wistar 大鼠24只随机分为3组:正常对照组、模型组和氨氯吡咪组。7周后检测各组大鼠的肺功能,支气管肺泡灌洗液(BALF)细胞计数及分类,天狼猩红染色观察支气管肺组织的胶原沉积,免疫组化染色观察 u-PA、u-PA 受体、纤溶酶原激活物抑制物1(PAI-1)的蛋白定位和表达。结果模型组大鼠的呼气阻力显著高于对照组和氨氯吡咪组,0.3 s 用力呼气容积/用力肺活量、呼气峰流速均显著低于对照组和氨氯吡咪组;模型组大鼠的 BALF 中白细胞总数、中性粒细胞、单核细胞和巨噬细胞构成比显著高于对照组和氨氯吡咪组;模型组大鼠以Ⅰ型胶原为主的细胞外基质在气道壁过度沉积,胶原面积显著高于对照组和氨氯吡咪组;模型组大鼠支气管肺组织 u-PA、u-PA 受体和 PAI-1蛋白表达的平均吸光度值[(0.166±0.010)、(0.158±0.024)和(0.171±0.012)]显著高于对照组[(0.137±0.015)、(0.122±0.009)和(0.144±0.005)]及氨氯吡咪组[(0.126±0.004)、(0.120±0.010)和(0.122±0.004)],且 u-PA 受体蛋白表达与中性粒细胞构成比呈显著正相关。结论应用 u-PA 抑制剂氨氯吡咪可显著减轻 COPD 大鼠的气道炎症和病理结构改变,u-PA 系统成分是 COPD 气道炎症和组织重塑环节中具有关联作用的重要物质。

Objective To study the effects of amiloride＇ an inhibitor of urokinase, on pathological and pathophysiological changes of chronic obstructive pulmonary disease （COPD） model, and to investigate the role of urokinase plasminogen activator system components in the pathogenesis of COPD. Methods Healthy Wistar rats （n = 24） were randomly divided into a control group, a model group and an amiloride group. After 7 weeks, lung function measurements were performed. The total and different white blood cell counts of bronchoalveolar lavage fluid （BALF） were determined, and collagen deposition of lung sections was observed by picrosirius staining. The expressions of u-PA, u-PAR and PAI-1 in bronchial lung tissues were examined by immunohistochemical analysis. Results In the model group the expiratory resistance （Re） was significantly higher than that of the control group and the amiloride group, while forced expiratory volume in the 0. 3 s/forced expiratory capacity （FEV0.3/FVC% ） and peak expiratory flow （PEF） were significantly lower than those of the other two groups. Significant increase in total white blood cells and percentage of neutrophils and macrophages in BALF was found in the model group as compared to the control group and the amiloride group. The collagen deposition, mainly type I collagen, in airway walls was significantly increased in the model group. The levels of u-PA, u-PAR and PAI-1 in the model group [ （0. 166 ±0. 010）, （0. 158 ±0. 024） , （0. 171 ±0. 012） ,respectively] were significantly higher than those in the control group [ （ 0. 137 ± 0. 015 ）, （ 0. 122 ± 0. 009 ） , （ 0. 144 ± 0. 005 ）, respectively ] and the amilofide group [ （0. 126 ± 0. 004）, （0. 120 ±0. 010 ）, （0. 122 ± 0. 004）, respectively ]. F values were 32. 463,4. 094,79. 562 respectively, and all P 〈 0. 001. Moreover, u-PAR protein level was positively correlated with neutrophils in BALF in the model group （r = 0. 754, P = 0. 031 ）. Conclusion Administration of u-PA inhibitor-amiloride significantly alleviated airway inflammation and the pathological changes in COPD rats, suggesting that the u-PA system components are key mediators regulating the inflammatory reaction and tissue remodeling in the pathological process of COPD.