OBJECTIVETo study the role of urotension-II in serum and bronchoalveolar lavage fluid (BALF) in the process of airway remodelling in asthmatic rats.

METHODSThirty-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.

RESULTSThe bronchial wall thickness and the airway smooth muscle thickness in the three asthmatic groups significantly increased compared with those in the normal control group (P<0.01). The urotension-II contents in serum and BALF in the three asthmatic groups also increased significantly compared with those in the normal control group (P<0.01). 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 (P<0.01). 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.

CONCLUSIONSThe 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.