锌通过调节Th1/Th2平衡及抗氧化降低哮喘大鼠气道炎症

Zinc suppresses airway inflammation in asthmatic rats through regulation of Th1/Th2 balance and activity

目的探讨锌对哮喘大鼠气道炎症的影响及机制。方法建立哮喘大鼠模型,SD大鼠32只,按体质量随机分为4组,A组为缺锌饲料+卵清蛋白(OVA)激发组;B组为补锌饲料+OVA激发组;C组为正常锌饲料+OVA激发组;D组为正常锌饲料+生理盐水激发组。诱喘后24 h取右肺HE染色,观察气道壁细胞成分;取左肺制备肺组织匀浆检测γ干扰素(IFN-γ)、白细胞介素4(IL-4)、超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GPX)水平。结果与C组相比,A组大鼠支气管壁中嗜酸粒细胞、中性粒细胞、巨噬细胞数及肺组织匀浆中MDA均明显增加(P<0.05),而IFN-γ、IFN-γ/IL-4、SOD及GPX均明显减少(P<0.05);B组大鼠上述炎性细胞及MDA均明显减少(P<0.05),而IFN-γ、IFN-γ/IL-4、SOD及GPX均明显增加(P<0.05);IL-4含量两组无明显变化。结论锌可能通过调节Th1/Th2平衡及抗氧化降低哮喘大鼠气道炎症。

Objective To investigate the effects and mechanism of zinc on airway inflammation in asthmatic rats. Methods Animal model of asthma was established by OVA challenging, zinc-deficient and zinc-supplementary diet were given accordingly. Thirty-two SD rats were divided into four groups according to weight： zinc-deficient diet with OVA challenge group （group A）, zinc-supplementary diet with OVA challenge group （group B）, zinc-normal diet with OVA challenge group （group C） and zinc-normal diet with saline challenge group （group D）. Twentyfour hours later asthma was induced, fight side lungs were harvested for HE staining to observe histomorphological changes and the respective numbers of eosinophirs, neutrophils and macrophage in the bronchial mucus were counted. The contents of interferon-γ （IFN-γ）, interleukin-4 （IL-4）, superoxide dismutase （SOD）, malondialdehyde （MDA） and glutathione peroxidase （GPX） in lung homogenate were detected. Results Compared with group C, the number of eosinophils, neutrophils and macrophage, and the contents of SOD increased in group A, but significantly decreased in group B （P 〈 0. 05）. At the same time, the contents of IFN-γ, SOD, GPX and the percentage of IFN-γ/IL-4 decreased in group A but increased in group B significantly （P 〈 0. 05 ）, no significant difference was observed for IL-4. Conclusion Zinc may suppress airway inflammation in asthmatic rats through the regulation of Th1/Th2 balance and antioxidant.