RESUMO
Objective To explore the effect of the simvastatin administration on the expression of connective tissue growth factor （CTGF） in fihrotic lungs of rats. Methods The cats were treated with single intratracheal instillation of bleomycin （BLM） or instillation of the same volume of normal saline （NS） as a control. The administration of simvastatin（20 mg/kg）began once a day immediately or 7 days later after intratracheal BLM instillation respectively with the same volume of NS was given as a vehicle control. The rats were killed on day 7,14 and 28 respectively. Pathological alteration of lung tissue was observed hy HE staining and Masson staining. Hydroxyproline（HYP）content in lung tissue was used to determine the severity of pulmonary fibrosis. The expression of CTGF in lung tissue was exanfined by immunohistochem- istry staining and photodeusitometry. Results Histopathological changes of pulmonary fibrosis emerged gradually after the instillation of BLM. The expression level of CTGF was increased in lungs of rats after intratracheal instillation of BLM, compared with the control. The administration of simvastatin immediately or 7 days after intratracheal instillation of BLM, attenuated the histopathological changes of bleomycin- induced puhnonary fibrosis and prevented the increased expression of CTGF in lung tissue on day 28. Conclusion The adntinistration of simvastatin, immediately or 7 days after intratracheal BLM instillation, prevented the up-regulation of CTGF in fibrotic lungs of rats, which ntight be one of the mechanisms of the anti-fihrosis of simvastatin in lungs.