血管内皮生长因子水平与大鼠支气管哮喘模型发病机制关系的研究

目的 探讨大鼠支气管哮喘(简称哮喘)模型支气管肺泡灌洗液(BALF)中血管内皮生长因子(VEGF)水平与哮喘嗜酸粒细胞(EOS)炎症及气道血管通透性之间的关系,以及吸入性激素的作用.方法 SD大鼠18只,随机分为对照组,哮喘模型组和地塞米松干预组各6只.以腹腔注射1%卵蛋白致敏和2%卵蛋白雾化吸入激发复制哮喘模型,干预组在每次激发前给予地塞米松干预.检测大鼠气道反应性,BALF中EOS百分数,VEGF(酶联免疫吸附法)及气道血管渗透指数.结果 BALF中EOS百分数,VEGF水平,气道反应性及气道血管渗透指数哮喘组明显高于对照组(P<0.05或P<0.01);经过6周吸入性激素治疗后,地塞米松组BALF中VEGF水平,EOS百分数,气道反应性及气道血管渗透指数较哮喘组明显降低(P<0.05或P<0.01),与对照组比较差异无统计学意义.相关分析显示,BALF中VEGF水平与EOS百分数呈正相关(r=0.76,P<0.01);VEGF水平与气道血管渗透指数呈正相关(r=0.84,P<0.01);VEGF水平与PC50呈负相关(r=-0.68,P<0.01).结论 大鼠哮喘模型BALF中VEGF水平增高,并与气道EOS百分数,气道反应性和气道血管渗透指数密切相关.该结果提示VEGF可能在哮喘的发病机制中起着重要作用.

Increased levels of vascular endothelial growth factor in BALF in asthmatic rats

Objective To investigate the relationship between vascular endothelial growth factor (VEGF) levels and eosinophilic inflammatory profiles,and the degree of airway vascular permeability in the asthmatic rats. We evaluated the effect of inhaled dexamethasone on VEGF levels in BALF. Methods Eighteen SD rats were randomly divided into three groups: the control group, the asthma model group and the dexamethasone group. Asthmatic model was established by sensitization and challenge with ovalbumin and rats were inhaled dexamethasone before challenge in dethamethasone group. The VEGF levels, the percentage of eosinophils,the airway vascular permeability index in BALF and the PC50 were examined.Results The VEGF levels,the percentage of eosinophils,the PC50 and the airway vascular permeability index in asthma model group were higher than that in control group( P <0.05 orP <0.01). After 6-week inhaled dexamethasone therapy,the VEGF levels, the percentage of eosinophils, the PC50 and the airway vascular permeability index in dexamethasone group were decreased compared to asthma model group( P<0.05 or P<0.01). The VEGF levels were negatively correlated with PC50, the percentage of eosinophils, the airway vascular permeability index( r = - 0. 68,0. 76,0. 84, P <0. 01). Conclusions The VEGF levels in BALF were increased in asthmatic rats and its levels were associated with airway percentage of EOS,airway responsiveness and airway vascular permeability. These findings provide strong evidence that VEGF may play an important role in pathogenesis of asthma.