糖皮质激素对哮喘大鼠肺组织IL-8表达的抑制作用

Inhibitory effect of glucocorticoids on expression of L-8 in lung tissue of asthmatic rat model

目的研究地塞米松(DXM)对哮喘大鼠肺组织IL-8mRNA及蛋白表达的影响。方法以1%卵蛋白(OVA)致敏并激发,建立大鼠哮喘模型。30只♂SD大鼠随机分为正常组,哮喘组,DXM干预组。在末次激发后24 h,将肺组织经脱水透明、石蜡包埋等处理后制作成肺标本切片。观察各组大鼠肺组织病理学改变。RT-PCR方法对肺组织IL-8 mR-NA表达检测,免疫组织化学方法技术测定大鼠肺组织标本IL-8表达。结果哮喘组肺组织IL-8 mRNA及蛋白的表达水平明显高于正常组(P<0.01),DXM组IL-8 mRNA及蛋白的表达与哮喘组相比明显减少(P<0.01)。结论哮喘大鼠肺组织IL-8水平增高,并且DXM可通过抑制IL-8的表达,减弱其对炎性细胞的趋化与激活,是激素减轻气道炎症重要机制之一。

Aim To investigate the effect of dexamethasone on mRNA and protein expression of IL-8 in the lung tissue of asthmatic rat.Methods The models of asthmatic rat were established by sensitization and challenge with 1% ovalbumin（OVA）.Thirty Sprague-Dawley（SD） male rats were randomly divided into three groups（10 in each）： control group,asthma model group and dexamethasone treated group.24 hours after the last challenge,lung tissue was made into lung biopsy specimens through dehydration,paraffin embedding.The pathological changes of lung tissue of each group were observed.The mRNA and protein expressions of IL-8 in lung tissue were measured by RT-PCR and immunohistochemical techniques.Results The mRNA and protein expressions of IL-8 in lung tissue of asthma group were higher than control group（P0.01）.The expressions of IL-8 mRNA and protein in lung tissue of DXM group were lower than asthma group（P0.01）.Conclusions IL-8 increases in lung tissue of asthmatic models.DXM may inhibit the expression of IL-8 through relieving aggregation and activation of eosinophil and neutrophil,which is one of the important mechanisms of reducing airway inflammation.