中性粒细胞弹性蛋白酶、髓过氧化物酶在大鼠哮喘中的变化及意义

目的：观察中性粒细胞（PMN）、中性粒细胞弹性蛋白酶（NE）和髓过氧化物酶（MPO）在大鼠哮喘中的表达水平变化及意义。方法:18只大鼠被随机平均分成2组：哮喘组、正常对照组，以卵清白蛋白（OVA）致敏激发法复制大鼠哮喘模型，对血PMN进行分离纯化，免疫组化和比色法检测MPO的表达水平，ELISA法测定NE的蛋白浓度。 结果:（1）免疫组化法显示哮喘组血PMN和支气管壁中MPO的表达水平均显著高于对照组（P<0.01），比色法显示哮喘组支气管肺泡灌洗液（BALF）和肺组织中MPO的活性显著高于对照组（P<0.05，P<0.01）；（2）哮喘组PMN和BALF中NE蛋白浓度显著高于对照组（P<0.01）；（3）哮喘组BALF、支气管壁、肺组织中PMN的计数均显著高于对照组（P<0.01）。 结论:PMN 计数、NE和MPO的表达水平在此实验性哮喘中增加，PMN可能通过分泌NE、MPO参与哮喘炎症过程。

Role of neutrophil elastase and myeloperoxidase in asthma of rats

AIM: To observe the changes of polymorphonuclear leukocytes (PMN), neutrophil elastase (NE) and myeloperoxidase (MPO) expression in rat asthma. METHODS: Eighteen rats were randomly divided into two groups on average, including asthma group and control group. The rat model of asthma was established by the ovalbumin (OVA) challenge methods. Blood PMN were isolated and purified. The protein expression of MPO were detected by immunohistochemistry and chromatometry techniques. NE was detected by ELISA. RESULTS: (1) Immunohistochemistry showed that the levels of MPO expression around bronchus and in purified PMN in asthma group were significantly increased compared with those in control group (P<0.01). Activities of MPO were significantly increased in bronchoalveolar lavage fluid (BALF) and lung tissue in asthma group compared with those in control group (P<0.05, P<0.01). (2) Levels of NE were significantly increased in BALF and PMN in asthma group compared with control group (P<0.01). (3) Number of PMN were significantly higher in BALF, bronchus and lung tissue in asthma group than those in control group (P<0.01). CONCLUSION: Levels of PMN counting and expression of MPO and NE are significantly increased in experimental asthma rats. PMN may be involved in inflammation in asthma via increasing the levels of NE and MPO.