Effect of azithromycin on airway remodeling of asthmatic rats

Objective To explore the effect of azithromycin on airway remodeling of asthmatic rats and its possible mechanism.Methods Thirty-two Sprauge-Dawley(SD) rats were divided randomly into normal control group(group C),asthma model group(group M),azithromycin treatment group(group A),and dexamethasone treatment group(group D),eight rats in each group.Twenty-four hours after the final atomization challenge,the rats in each group were executed and the right lung tissues of the rats were collected and then made into pathological sections.The lung tissue sections were examined by histopathology for pathologic changes.Parameters of airway remodeling were determined by medical image analysis system.The expressions of transforming growth factor-β1(TGF-β1),matrix metalloproteinase-9(MMP-9),vascular endothelium growth factor(VEGF) in rats lung tissue were observed by immunohistochemistry.Results Compared with the group C,rats in group M demonstrated that inflammatory cells infiltrated around the bronchus and the vascular with airway wall thickness,collagen deposition and the mucus production increased.In group A and group D,the histopathological changes were much lighter than those of group M.The thickness of airway wall and smooth muscle in group A and D increased compared with the group C and decreased compared with the group M(P0.01).The protein expressions of the TGF-β1,MMP-9,VEGF in group A and D were higher than those of group C(P0.01) and lower than those of group M(P0.01).There was a significantly positive correlation between the thickness of smooth muscle and the protein expressions of the TGF-β1,MMP-9,VEGF in lung tissue(P0.01).And among these three indices,the expression level was pairwise correlation(P0.01).Conclusion Azithromycin can improve the degree of airway remodeling.Its mechanism maybe relate to down-regulate the expression of the TGF-β1,MMP-9,and VEGF in lung tissue.