Effects and Mechanisms of Glucocorticoid Combined with IFN-γ on Pulmonary Fibrosis in Mice

BACKGROUND AND AIM:To explore therapeutic effects of IFN-γ combined with glucocorticoid on pulmonary fibrosis in mice.MATERIALS AND METHODS: Mice were divided into five random groups: negative control(NS)group;model(bleomycine,BLM)group;dexamethasone(DXM) treatment group;IFN-γ treatment group;DXM combined IFN-γ treatment group.To establish the pulmonary fibrosis model,the last four groups received BLM intratracheally at a dose of 3 mg/kg,NS group received NS by the same way.From 1st day after BLM treatment,DXM group and combined group were treated with 20 mg/kg DXM subcutaneously.And from 15th day after BLM treatment,IFN-γ and combined groups were treated with IFN-γ 0.01 μg/g subcutaneously.After the different treatments,animals were killed at 22nd day.The pathological changes were examined,hydroxyproline content(Hyp)was assayed by acid hydrolyzation,TNF-α expression was shown by IHC,and GSH/GSSG ratio,MDA content as well as T-SOD activity were determined by fluorimetry.RESULTS: Pathological score and Hyp content of combined group were both significantly lower than BLM and individual treatment groups(P0.05).TNF-α expression was highest in IFN-γ treatment group,while that of combined group was between the BLM and DXM treatment groups.Compared with BLM and individual treatment groups,GSH/GSSG ratio was higher but MDA content was lower in combined group(P0.05).T-SOD activities were not significantly different among groups(P0.05).CONCLUSION: The results indicated the effects of DXM combined withIFN-γ was better than their individual effect.