地塞米松对大鼠肺纤维化及其肺组织ET-1的影响

目的探讨地塞米松对实验性大鼠肺纤维化肺组织内皮素-1（Endothelin-1,ET-1）的影响。方法实验分为博莱霉素组、地塞米松组和正常对照组。博莱霉素组和地塞米松组给以博莱霉素（5mg/kg）气管内注射复制大鼠肺纤维化模型,正常对照组以生理盐水替代。气管内注药,次日地塞米松组给以腹腔注射地塞米松（1mg/kg）隔日1次,博莱霉素组和正常对照组以生理盐水替代。造模后第28d处死大鼠,测定肺组织ET-1和羟脯氨酸（HYP）含量,并进行组织病理学观察。结果博莱霉素组肺组织内羟脯氨酸（790.530±131.930μg/g）高于正常对照组（570.964±62.411μg/g）和地塞米松组（584.447±51.921μg/g）（P〈0.01）,病理为肺纤维化改变。博莱霉素组肺组织中的ET-1水平（61.001±2.722pg/mL）高于正常对照组（57.618±2.731pg/mL）和地塞米松组（56.083±3.379pg/mL）（P〈0.01）。结论ET-1可能参与肺纤维化的形成,地塞米松可能通过降低ET-1水平抑制肺纤维化形成。

Effect of dexamethasone on pulmonary fibrosis and endothelin-1 in lung tissue of rats

Objective To discuss the effect of dexamethasone on changes of endothelin-1 （ET-1） in rats with pulmonary fibrosis induced by bleomycin （BLM）. Methods Rats were divided into model group, treatment group and control group. Pulmonary fibrosis was induced by endotracheal injection of bleomycin （5mg/kg）. Rats in treatment group were given intraperitoneal injection of dexamethasone （lmg/kg） every other day. Rats in control and model groups received saline instead of dexamethasone. On day 28, the rats were executed. ET-1 and hydroxyproline （HYP） levels in lung tissue were measured. Histopathological changes and endothelin-1 （ET-1） in rats with pulmonary fibrosis were observed. Results The HYP and ET-1 levels were significantly higher in model group than in control and treatment groups （P〈0.01）. Conclusion ET-1 plays a role in development of pulmonary fibrosis. Dexamethasone has some inhibitory effects on pulmonary fibrosis, possibly by decreasing the ET-1 level.