Effects of Dexamethason on the Expressions of STAT1 and PDGF in Lung Tissue of Pulmonary Fibrosis Rats Induced by Bleomycin / 医学研究杂志

ABSTRACT

Objective To study the effect of dexamethasone on pulmonary fibrosis model induced by bleomycin in rats and the expression of STAT1 and PDGF in lung tissue,and to discuss the possible mechanism.Methods Forty-five Wistar rats were randomly divided into three groups(15 in each group).They were dexamethasone group(DXM group),bleomycin group(BLM group) and control group(NS group)① The DEX group were intratracheally instilled with belomycin(BLM)(5mg/kg,in 1ml 0.9% NaCl solution),and then were treated with dexamethasone 3mg/kg via celiac injection daily;② BLM group were intratracheally instilled with BLM(5mg/kg),and then were treated with saline 3mg/kg via celiac injection daily;③ NS group were intratracheally instilled with saline(5mg/kg),and then were treated with saline 3mg/kg via celiac injection daily.Five rats in each group were sacrificed at 7,14,and 28 days after intratrachel instillation.Histological changes of the lungs were evaluated by HE stain.The bronchoalveolar lavage fluid(BALF) of right lung was gotten and the cells counting as well as differentiation were figured out.The expression of STAT1 and PDGF protein was assessed by immunohistochemistry.Results(1) The total number of inflammatory cells in BALF in BLM group was the highest at day 7 and diminished at day 14 and 28,which was significant different compared with that of the NS group(P