嗜酸性粒细胞趋化蛋白在哮喘大鼠支气管肺泡灌洗液中的变化及红霉素对其调节作用探讨

Changes of Eotaxin in BALF in asthmatic rat and modulation effect of erythromycin

目的通过观察哮喘大鼠支气管肺泡灌洗液(BALF)中嗜酸性粒细胞趋化蛋白(Eotaxin)浓度的变化,探讨红霉素对哮喘气道炎症的调控作用。方法将大鼠随机分为3组,第1组正常对照组,第2组哮喘模型组,第3组红霉素干预组。治疗干预组动物OVA激发的同时口服红霉素(EM)[180mg/(kg·d)]。最后一次激发后24h处死大鼠,留取标本进行检测。用BALF和肺组织病理分析的方法检测肺组织炎症;用酶联免疫吸附测定法(ELISA)检测BALF中Eotaxin水平。结果肺组织病理形态学积分哮喘组(11.5±2.8),比对照组(3.0±0)显著升高(P<0.01);红霉素干预组(5.5±1.6),低于哮喘组但仍高于对照组(均P<0.05);BALF中白细胞总数计数哮喘组为(5.65±0.72)×109/L,显著高于对照组(2.59±0.16)×109/L(P<0.01),红霉素干预组为(3.60±0.36)×109/L,低于哮喘组但仍高于对照组,差异均有显著性(均P<0.01);BALF中Eotaxin浓度哮喘组为(23.54±6.12)pg/mL,显著高于对照组(9.14±4.82)pg/mL(P<0.01);红霉素干预组浓度为(15.93±5.48)pg/mL,低于哮喘组但高于对照组(均P<0.05)。哮喘组和红霉素组BALF中Eotaxin浓度和嗜酸性粒细胞(EOS)计数呈显著正相关(r=0.553,P<0.05)。结论哮喘大鼠BALF中Eotaxin浓度升高,Eotaxin是诱导EOS气道募集的重要趋化因子,红霉素能下调Eotaxin的水平,从而发挥抗嗜酸性粒细胞性气道炎症的作用。

[Objective] To discuss the possible mechanism of Erythromyein＇s therapeutic effect on asthma by investigating the level of eotaxin in bronchoalveolar lavage fluid （BALF） in rats. [Methods] The animal models were divided into three groups： control group, asthma group and Erythromycin treated group. In treated group, Erythromyein was administered （180 mg/kg.d） to SD rats by intragastric garage （ig） during the course of allergen exposure. WBC counts in BALF and lung specimen analysis were used to describe lung tissue inflammation. The level of eosinophil chemotaxin （eotaxin） in BALF was measured by enzyme-linked immunoadsorbent assay （ELISA）. Correlation between the level of eotaxin and eosinophils was assessed by Pearson Correlation analysis. [Results] In asthma group, pathological scores of lungs （11.5 ±2.8） were significantly increased （P 〈0.01） compared to those in the control group （3.0 ±0）; the scores of Erythromycin treated group （5.5±1.6） were decreased （P 〈0.05） compared to those of asthma group. The number of total WBC in BALF （5.65 ± 0.72） （×10^9/L） in the asthma group was significantly higher （P 〈0.01） than that in the control group （2.59 ± 0.16） （×10^9/L）, the Erythromycin treated group （3.60 ±0.36） （×10^9/L） was significantly lower （P 〈0.01） than that in the asthma group. In the asthmatic group, the level of eetaxin （23.54 ± 6.12） （pg/mL） was significantly elevated （P 〈0.01） compared to that in the control group （9.14 ± 4.82） （pg/mL）, the Erythromyein treated group （15.93 ± 5.48） （pg/mL） was decreased （P 〈0.05） compared to the asthma group. There was a significantly positive correlation between the level of eotaxin and eosinophils （r=0.553, P=0.026）. [Conclusions] Eotaxin actively partieipates in the process of eosinophilie inflammation. Erythromyein had an obvious proteetive role in allergic airway inflammation. It deeresed the number of eosinophils by inhibiting ehemotaxis of eotaxin. Key words：