哮喘大鼠气道重塑中尾加压素-Ⅱ的表达变化

Changes in urotensin-Ⅱ expression in airway remodelling in asthmatic rats

目的研究哮喘大鼠气道重塑血清和支气管肺泡灌洗液(BALF)中尾加压素-Ⅱ(U-II)含量的变化及其作用。方法32只雄性Sprague-Dawley大鼠随机分为正常对照组、哮喘2周组、哮喘4周组和哮喘8周组,每组8只。以卵清白蛋白(OVA)致敏与激发建立哮喘大鼠气道重塑模型,图像分析技术测量大鼠支气管壁总面积和平滑肌面积,计算单位基底膜周径(Pbm)的支气管壁厚度(Wat)和平滑肌厚度(Wam),ELISA法测定血清和BALF中U-II的含量。结果哮喘各组Wat及Wam均明显高于正常对照组(P<0.01);哮喘组血清和BALF中U-II含量均显著高于正常对照组(P<0.01),其中哮喘8周组血清和BALF中U-II含量显著高于哮喘4周组和哮喘2周组(P<0.01),哮喘4周组也显著高于哮喘2周组(P<0.01)。各组大鼠BALF中的U-II含量与Wat及Wam呈正相关,BALF与血清中U-II含量亦呈正相关。结论哮喘大鼠气道重塑血清和BALF中U-II含量增加;且U-II含量的变化与气道重塑相关。

Objective To study the role of urotension-II in serum and bronchoalveolar lavage fluid （BALF） in the process of airway remodelling in asthmatic rats.Methods Thirty-two male Sprague-Dawley （SD） rats were randomly divided into normal control and 2-week,4-week and 8-week asthmatic groups （OVA inhalation of 2,4 and 8 weeks respectively）.Rats were sensitized and challenged by OVA to establish a model of asthma.The bronchial wall thickness and the airway smooth muscle thickness were measured by image analysis system.The urotension-II contents in serum and BALF were determined using ELISA.Results The bronchial wall thickness and the airway smooth muscle thickness in the three asthmatic groups significantly increased compared with those in the normal control group （P0.01）.The urotension-II contents in serum and BALF in the three asthmatic groups also increased significantly compared with those in the normal control group （P0.01）.The urotension-II contents in serum and BALF in the 8-week asthmatic group were the highest,followed by the 4-week and the 2-week asthmatic groups （P0.01）.BALF urotension-II contents were positively correlated with the bronchial wall thickness and the airway smooth muscle thickness as well as serum U-II contents in the four groups.Conclusions The urotension-II contents in serum and BALF in the process of airway remodeling increase in asthmatic rats.The changes in serum and BALF urotension-II contents may be associated with airway remodeling in asthmatic rats.