Abstract: 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(P<0.05). 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(P<0.05). T-SOD activities were not significantly different among groups(P>0.05). CONCLUSION: The results indicated the effects of DXM combined with IFN-γ was better than their individual effect.

Key words: pulmonary fibrosis, IFN-γ, glucocorticoid