三步序贯法对激素干预后哮喘模型大鼠肺组织IL-5 mRNA表达的影响

目的观察三步序贯法对激素干预后哮喘模型大鼠肺组织白细胞介素-5（IL-5）mRNA表达的影响。方法将SD大鼠随机分为正常对照组、哮喘模型组、激素干预组、三步序贯组、第一步方组、第二步方组、第三步方组、普米克令舒组。制备激素干预后哮喘模型大鼠，于第3周起开始撤减激素用量，按照每周地塞米松0．1mg／kg递减，直至第7周完全撤除。采用原位杂交技术检测各组大鼠肺组织中IL-5mRNA的表达变化。结果三步序贯组IL-5mRNA表达与哮喘模型组和激素干预组比较，在各个时段均明显降低（P〈0．01）。与普米克令舒组比较，在第2周末，差异无显著性（P〉0．05）；在第7、9周末，差异均有显著性（P〈0．01）。与第一、二、三步方组比较，三步序贯组IL-5mRNA表达在第2周末与第一步方组比较差异无显著性（P〉0．05），与第二步方组比较差异有显著性（P〈0．05），在其余各个时段比较差异均有显著性（P〈0．01）。在撤减激素的动态变化过程中，三步序贯组第7、9周末IL-5mRNA表达明显降低，与第2周末比较，差异有显著性（P〈0．05，P〈0．01），但7、9周末两时间点比较差异无显著性（P〉0．05）。在第9周末，三步序贯组IL-5mRNA的表达降至最低点，与正常对照组比较，差异无显著性（P〉0．05）。结论三步序贯法对激素干预后哮喘模型大鼠肺组织IL-5mRNA表达具有明显抑制作用。

Effect of Three-stage Sequential Method on Interleukin-5 mRNA Expression in the Lung Tissue of Asthmatic Model Rat Treated with Steroid

ObjectiveTo observe the effect of three-stage sequential method (TSSM) on interleukin-5 (IL-5) mRNA expression in the lung tissue of asthmatic rat model treated with steroid. MethodsSD rats were randomly divided into 8 groups, the normal control group (GA), the model group (GB), the model with steroid intervention group (GC) and the 5 treated groups (GD-GH). Excepting those in the GA, all rats were established into the asthma model and rats in GC-GH were intervened by dexamethasone, with the dosage reduced by 0.1 mg/kg per week starting from the 3rd week and withdrawn completely till the 7th week. At the same time, rats in GD-GH were treated with TSSM, and the 1st, 2nd and 3rd recipe of TSSM, as well as pulmicort respules (as positive control) respectively. IL-5 mRNA expression in the lung tissue of rats was detected at different time points by in situ hybridization. ResultsComparisons of GD with other groups in IL-5 mRNA expression showed: it was remarkably lowered than that in GB and GC at all time points (P<0.01); compared to GH, the difference was insignificant at the end of the 2nd week, but significant at the end of the 7th and 9th week (P<0.01); as for the difference between GD with GE, GF and GG, it showed very significant difference (P<0.01) at all the time points besides that at the end of the 2nd week, it showed insignificance to GE (P>0.05) and significance to GF (P<0.05). The dynamic changes of IL-5 mRNA expression in GD during the steroid withdrawal period showed the lowering was more significantly at the end of the 7th and 9th week than that at the end of the 2nd week (P<0.05, P<0.01), but its levels were equal at the former two time points; its lowest level appeared at the end of the 9th week, which approaching the level in GA (P>0.05). ConclusionThree-stage sequential method could remarkably inhibit IL-5 mRNA expression in the lung tissue of asthmatic rats undergoing steroid treatment.