OBJECTIVETo investigate the phenotype change of airway smooth muscle cell (SMC) in bronchial asthma and the effect of Zhichuan Capsule (ZCC) on it.

METHODSSixty male SD rats were randomized into 5 groups equally, the normal control group, the model group, and three treated groups treated with ZCC, Western medicine (WM) and ZCC + WM respectively. Excepting rats in the control group, they were all made into bronchial asthma model rats and received respective treatment. Histomorphology of the airway SMC was observed by electron microsope at the 4th week, and the expressions of smalpha-actin and sm-MHC were examined at the 2nd and the 4th week after provocation.

RESULTSAs compared with the control group, moyfilaments in SMC were lesser, secretive organelles were more and levels of smalpha-actin and sm-MHC expressions at the 4th week were lower in the model group (P < 0.05). While histomorphology of SMC in the WM group was as narmal, but some hypoxia changes were seen, such as the fracture of mitochondria cristae and deplation of matrix; histomorphology of SMC in the ZCC treated group and the ZCC + WM treated group were similar to that in the normal control group, and their expressions of smalpha-actin and sm-MHC were enhanced as compared to those in the model group (P < 0.05).

CONCLUSIONAirway SMC changes from contractile phenotype to synthetic phenotype in asthma rats, but the progress of change may be inhibited by ZCC.