The effect of glucocorticoid on TGF-β,MCP-1 in bleomycin-induced pulmonary fibrosis rats

Objective:To approach the possible mechanism of glucocorticoid in prevention of experimental pulmonary fibrosis. Method:The models of pulmonary fibrosis were made by intratracheal injection of beomycin into the lungs. All animals were randomly divided into 3 groups which were control group (group C), model group (group M) and dexamethasone intervention group (group D) respectively, each of them including 10 rats. The dexamethasone (0.3 mg/100 g) were injected into abdominal cavity of rats in group D each day. The detection of TGF-β and MCP-1 in blood serum and BALF of all animals were made with ABC-ELISA method in week 1 and week 4 respectively. At meantime, the pathological changes of lungs in all groups rats were observed.Result:1.In week 1, the lung coefficient,BALF total cells and PMN counts in group M were higher than those in group C(P0.05), the main pathological change was alveolitis. The same was true in were 4 except for the pathologic change with a remarkable pulmonary fibrosis, but the alevolitis and pulmonary fibrosis of group D was lessened. 2.The levels of TGF-β and MCP-1 were not significantly different among these groups in week 1. By week 4, TGF-β of serum (834.04±148.47) and TGF-β、MCP-1 of BALF[(68.24±13.89); (63.41±6.04)] in group M were significantly higher than those in group C and group D (P0.01,P0.05), but there were no significant differences between group D and group C. Conclusion:Dexamethasone can lessen the extention of alveolitis and pulmonary fibrosis in experimental rats, the mechanism may involve the suppression of TGF-β, MCP-1.