布地奈德对哮喘大鼠中性粒细胞诱导型一氧化氮合酶表达的影响

Effect of budesonide on the expression of inducible nitric oxide synthase at blood heterophil granulocyte in asthma rats

目的:观察诱导型一氧化氮合酶(iNOS)蛋白在哮喘大鼠血中性粒细胞(PMN)中的表达,探讨PMN参与哮喘炎症的可能机制,并研究布地奈德的影响。方法:采用卵白蛋白(OVA)和Al(OH)3制备大鼠哮喘模型,分离纯化血PMN,免疫细胞化学法检测PMN中iNOS蛋白的表达水平,比色法测定支气管肺泡灌洗液(BALF)中NO浓度。结果:哮喘组大鼠PMN中iNOS蛋白的表达水平显著高于正常对照组(P<0.01),布地奈德治疗组PMN中iNOS蛋白的表达水平显著低于哮喘组(P<0.01);哮喘组支气管壁iNOS蛋白的表达水平显著高于正常对照组(P<0.01),布地奈德治疗组支气管壁iNOS蛋白的表达水平显著低于哮喘组且高于正常对照组(均P<0.01);哮喘组BALF中NO浓度显著高于正常对照组(P<0.01),布地奈德治疗组BALF中NO浓度显著低于哮喘组(P<0.01);PMN中iNOS蛋白的表达水平与BALF中NO浓度呈显著正相关(n=29,r=0.754,P<0.01);支气管壁iNOS蛋白的表达水平与BALF中NO浓度呈显著正相关(n=29,r=0.760,P<0.01)。结论:哮喘大鼠PMN合成iN-OS蛋白的功能增加,PMN可能部分通过iNOS参与哮喘的发病,这种功能可以部分被布地奈德所抑制。

AIM：To observe the effect of budesonide on the expression of inducible nitric oxide synthase（iNOS） at blood polymorphonuclear leukocyte（PMN） in asthma rats.And to approach the pathogenesis of PMN in asthma inflammation.METHODS： The model rats of asthma were induced by OVA and Al（OH）3.The blood PMN was isolated and purified.The expressions of iNOS protein at blood PMN were detected by immunohistochemical method.The concentration of nitric oxide（NO） at bronchoalveolar lavage fluids（BALF） were detected by colorimetric method.RESULTS： Expressions of iNOS protein at PMN in asthma group were significantly higher than those in control group（P〈0.01）.And the expressions of iNOS protein at PMN in budesonide treated group were significantly lower than those in asthma group（P〈0.01）.The expressions of iNOS protein at bronchial wall in asthma group were significantly higher than those in control group（P〈0.01）.And the expressions of iNOS protein in budesonide treated group were significantlylower than those in asthma group,but higher than those in control group（all P〈0.01）.Concentrations of NO at BALF in asthma group were significantly higher than those in control group（P〈0.01）.Concentrations of NO at BALF in budesonide treated group were significantly lower than those in asthma group.There was significant positive correlation between the expressions of iNOS protein at blood PMN and NO concentration at BALF（n=29,r=0.754,P〈0.01）.And there was significant positive correlation between the expressions of iNOS protein at bronchial wall and NO concentration at BALF（n=29,r=0.760,P〈0.01）.CONCLUSION： The levels of iNOS protein synthesized by PMN are increased in asthma rats.PMN may be implicated with asthma pathogenesis via iNOS,but this function of PMN can be partly inhibited by budesonide.