Effect of ambroxol on Pulmonary Fibrosis Caused by Hyperoxia in Neonatal Rats

Objective To study the protective effect of ambroxol on pulmonary fibrosis caused by hyperoxia in neonatal rats.Methods Thirty Sprague-Dawley(SD) clean neonatal rats,which were less than 12 hours old,were enrolled in this study.The neonatal rats were randomly divided into3 groups: air-exposed control group(group A);hyperoxia-exposed control group(group B);hyperoxia-exposed plus ambroxol-treated group(group C).The neonatal rats of group C were intraperitoneally injected with ambroxol [20 mg/(kg· d)] in solution of normal saline(NS),group A and group B were intraperitoneally given the same dose of NS.On14th day,10 rats of each group were killed,the pulmonary pathological changes were observed by HE staining under light microscope.The area percentages of collagen fibers were measured by Masson staining and imaging analysis,and the protein content of collagenⅢand Ⅳwere detected by ELISA,respectively.Results On the 14th day of the exposure,the histopathologic examination demonstrated broadened lung interstitium and reduced alveolar quantity and lung fibrosis were developed in group B;ambroxol treatment obviously alleviated the changes of lung histomorphology.At the 14th day of the exposure to hyperoxia,the neonatal rats of group B had a significant increase in the area percentage of collagen fibers and protein content of collagen Ⅲ and Ⅳ compared with those in group A(P0.05);the area percentage of collagen fibers and the protein content of collagen Ⅲ and Ⅳ in group C had a significant reduction compared with those in group B(P0.05).Conclusion Early use of ambroxol can decrease the severity of the pulmonary fibrosis of neonatal rats exposed to hyperoxia