哮喘大鼠模型肺组织中嗜酸粒细胞趋化因子及肺组织和骨髓组织中嗜酸粒细胞趋化因子受体的表达

目的:探讨嗜酸粒细胞趋化因子(Eotaxin)及其受体(CCR3)在支气管哮喘发病机制中的作用.方法:健康雄性SD大鼠24只,随机分为哮喘组和对照组,每组12只.哮喘组采用卵蛋白(OVA)激发哮喘,对照组用生理盐水代替OVA.于末次激发后4～6 h断尾取血,涂片.麻醉动物,制备肺组织标本与骨髓细胞涂片.计数外周血、骨髓细胞涂片及肺组织嗜酸粒细胞(Eos)百分率;免疫组化技术观察肺组织中Eotaxin蛋白表达及肺组织和骨髓组织中CCR3蛋白表达;原位杂交方法观察肺组织中Eotaxin mRNA的表达.结果:与对照组相比,哮喘组大鼠外周血、骨髓、肺组织Eos百分率明显升高(P＜0.01);肺组织中Eotaxin蛋白和mRNA表达明显升高(P＜0.01),且和肺组织中Eos百分率呈正相关(P＜0.05);肺组织及骨髓中CCR3蛋白表达均明显增加(P＜0.01).结论:Eotaxin及其受体CCR3参与了哮喘的发病机制;在Eos从骨髓迁徙到外周血再募集到肺组织这一过程中,Eotaxin与CCR3起重要作用.

Expression of Eotaxin in lung tissue and CCR3 in lung tissue and bone marrow of asthmatic rats

Aim: To evaluate the role of Eotaxin and CCR3 in mechanisms for the pathogenesis of asthma.Methods: A total of 24 rats were randomly divided into asthma group and normal control group.Ovalbumin was used to induce the model of asthma.Eos in peripheral blood, bone marrow, and lung tissue was counted. The expression of Eotaxin protein in rat lung tissue and the expression of CCR3 protein in both lung tissue and bone marrow were detected using immunohistochemistry, and the expression of Eotaxin mRNA in rat lung tissue was detected using in situ hybridization.Results: The amount of Eos in peripheral blood, bone marrow, and lung tissue from asthma group increased significantly compared with that from control group(P<0.01). The expression of Eotaxin protein and mRNA as well as the expression of CCR3 protein in lung tissue and bone marrow from asthma group were up-regulated significantly compared with those from control group. Conclusion: Eotaxin and CCR3 play an important role in mechanisms for the pathogenesis of asthma when Eos moves from bone marrow to peripheral blood and then to lung tissue.