Effects of iloprost on bleomycin-induced pulmonary fibrosis in rats compared with methyl-prednisolone

Objective: prostacyclin (pgi2) has been shown to inhibit the expression of pro-inflammatory and pro-fibrotic mediators in pulmonary fibrosis. in this study,we aimed to test the preventive effects of intraperitoneally administered iloprost,a stable pgi2 analog,on bleomycin-induced pulmonary fibrosis in rats and to compare the effects of iloprost with the effects of methyl-prednisolone,a traditional therapy. methods: rats were randomly allocated into four groups: 1. saline alone (. n=. 6); 2. bleomycin. +. placebo (. n=. 7); 3. bleomycin. +. methyl-prednisolone (. n=. 7); 4. bleomycin. +. iloprost (. n=. 7). fibrotic changes in the lungs were demonstrated by analyzing the cellular composition of bronchoalveolar lavage fluid,histological evaluation and lung hydroxyproline content. results: fibrosis was made in the lungs of rats by bleomycin experimentally. fibrosis scores in the methyl-prednisolone and the iloprost groups were significantly lower than in the placebo group (. p<. 0.05). furthermore,the score of the iloprost group was significantly lower than the score of the methyl-prednisolone group. the hydroxyproline content was significantly less in the methyl-prednisolone and the iloprost groups (. p<. 0.05). in the placebo group,the neutrophil percentage in bronchoalveolar lavage was significantly higher than in the other groups,whereas the macrophage percentage in placebo group was significantly lower (. p<. 0.05). conclusion: iloprost has protective effect on the pulmonary fibrosis induced by bleomycin and it may be more effective in decreasing fibrotic changes than methyl-prednisolone. © 2011 sociedade portuguesa de pneumologia.