罗红霉素通过诱导型一氧化氮合酶/一氧化氮途径抑制哮喘大鼠气道炎症

Roxithromycin inhibited airway inflammation through pathway of inducible nitric oxide synthase and nitric oxide in rat asthmatic model

目的探讨罗红霉素对哮喘大鼠支气管诱导型一氧化氮合酶(iNOS)及一氧化氮(NO)的影响。方法24只成年哮喘大鼠随机分成对照组、哮喘组以及罗红霉素组。对支气管肺泡灌洗液(BALF)细胞总数及嗜酸性粒细胞计数,免疫组织化学检测大鼠支气管上皮细胞iNOS蛋白表达,RT-PCR检测肺组织iNOS mRNA表达,分光光度计检测肺组织iNOS活性及NO含量。双抗体夹心法检测肺组织白细胞介素-4(IL-4)及干扰素-γ(IFN-γ)。结果哮喘组大鼠BALF细胞总数及嗜酸性粒细胞分类分别为(7.28±1.65)×108.L-1、(7.73±1.54)%,均高于对照组(3.76±0.97)×108.L-1、(1.27±0.60)%;罗红霉素组BALF细胞总数及嗜酸性粒细胞分类分别为(5.68±0.95)×108.L-1、(5.54±1.53)%,明显低于哮喘组,差异有统计学意义。哮喘组肺组织IL-4浓度、iNOS活性及NO含量高于对照组,罗红霉素组肺组织IL-4浓度、iNOS活性及NO含量低于哮喘组。哮喘组肺组织IFN-γ浓度低于对照组,罗红霉素组肺组织IFN-γ浓度高于哮喘组。哮喘大鼠支气管上皮细胞iNOS蛋白及肺组织iN-OSmRNA表达分布吸光度值分别为(0.25±0.06)、(0.52±0.14),较对照组[(0.14±0.05),(0.33±0.05)]明显增强;但罗红霉素组iNOS蛋白及mRNA表达为(0.15±0.03)、(0.35±0.07),均明显较哮喘组减弱。结论罗红霉素通过干预哮喘大鼠气道IL-4、IFN-γ以及iNOS/NO体系,抑制哮喘气道炎症反应。

Aim To investigate the effect of roxithromycin on expression of inducible nitric oxide synthase （iNOS） and content of nitric oxide （NO） and cytokines （IL-4, IFN-γ ） in bronchiole epithelial cell of asthmatic rats. Methods Twenty four mate Sprague- Dawley rats were randomly divided into three groups, namely control group, asthmatic group and roxithromycin group. The numbers of total cell and eosinophils cell in bronchoalveolar lavage fluid （BALF） were counted. The expression of inducible nitric oxide synthase was detected by immunohistochemistry method, and iNOS mRNA was detected by reverse transcriptionlolymerse chain reaction （RT-PCR）. The activity of iNOS and content of NO in lung homogenates were measured by spectrophotometry. The concentrations of IL-4 and IFN-γ were detected by sandwich enzymelinked immunosorbent assay （ELISA）. Results The numbers of eosinophils cell and the ratios of eosinophils to total cell in BALF of asthmatic group [ （7.28 ±1.65）×10^8·L^-1,（7.73 ±1.54）%]were significantly higher than those of control group [ （3.76 ±0.97） ×10^8·L^-1,（1.27 ±0.60）%],but those of roxithromyein group[（5.68 ±0.95）×10^8·L^-1, （ 5.54±1.53 ） % ] were lower compared with asthmatic group. The concentration of IL-4, activity of iNOS and content of NO in lung homogenates of asthmatic group were significantly higher than those of control group, while those of roxithromyein group were lower compared with asthmatic group. The concentration of IFN-γ in lung homogenats of asthmatic group was significantly lower than that of control group, while that of roxithromycin group were higher compared with asthmatic group. The absorbance of iNOS protein expression in bronchiole epithelial cell and mRNA expression in lung homogenats of asthmatic group[ （0.25±0. 06）, （0. 52 ±0. 14） ] were markedly increased compared with control group[（0.14 ±0.05）,（0.33 ±0.05）],while those of roxithromyein group[ （0. 15 ±0. 03）, （0. 35 ±0.07 ）]were decreased compared with asthmatic group. Conclusions Roxithromycin can affect the concentrations of IL-4, IFN-γ and the pathway of iNOS/NO in airway of asthma rat, through which inhibit asthmatic airway inflammation reaction.