Therapeutic effect of pulmonary surfactant on airway remodeling in rats with allergic asthma

AIM: To study the therapeutic effect of pulmonary surfactant (PS) on airway remodeling in rats with allergic asthma and to investigate the possible mechanism. METHODS: Sixty rats were randomly divided into three groups: control (20), asthmatic (20) and therapeutic group (20). After incubating with different stimulus, lung tissue sections were stained with HE. The airway internal perimeter, wall area, external perimeter were measured by image analysis system and percentage of muscle shortening (PMS) was calculated. The expression and distribution of endothelium growth factor (EGF) in small airway of rats were detected using immunohistochemistry technique. RESULTS: ① The degree of airway remodeling in therapeutic group decreased significantly than that in asthmatic group, but compared with control group it was not statistically significant. ② Responsiveness of airway smooth muscle to adenosine (represented by PMS) in asthmatic group increased 24% compared with that in control group, but PMS decreased 15% in therapeutic group compared with that in asthmatic group. PMS to acetylcholine in asthmatic group increased 25% compared with that in control group, but PMS decreased 16% in therapeutic group compared with that in asthmatic group. ③ In the asthmatic group, the expression and distribution of EGF increased significantly than that in controls (P0.01), but decreased significantly in therapeutic group compared with that in asthmatic group (P0.01). CONCLUSION: Exogenous PS can effectively prevent airway remodeling in rats with allergic asthma, possibly by downregulating the synthesis and release of EGF.