吸入糖皮质激素对哮喘豚鼠肺组织NK2受体mRNA表达的影响

摘要

目的 观察哮喘豚鼠气管及肺组织中NK2受体mRNA表达情况,并探讨糖皮质激素(布地奈德悬浊液)对其的影响.方法 用吸入卵蛋白致敏及激发诱喘方法制作哮喘豚鼠模型,随机分成激素治疗组(吸入布地奈德混悬液)和非激素治疗组,另设正常对照组;用RT-PCR方法检测肺组织NK2受体mRNA相对含量,用原位杂交法在显微镜下观察NK2受体mRNA在气管及肺组织中表达的部位及强度.结果 NK2受体主要分布在气管黏膜下、气管平滑肌周围和肺组织.哮喘豚鼠肺组织、器官黏膜下及平滑肌周围NK2受体mRNA相对含量均高于正常对照组(P均<0.05);激素治疗组均明显低于非激素治疗组(P均<0.05),与正常对照组比较无统计学差异.结论 哮喘豚鼠气管黏膜下、气管平滑肌周围及肺组织NK2受体mRNA相对含量表达上调.糖皮质激素具有显著下调哮喘豚鼠气管黏膜下、平滑肌周围及肺组织中NK2受体mRNA表达的作用.%Objective To investigate the effect of inhaled glucocorsteride on the expression of NK2 receptor mRNA in lungs of guine-pigs with asthma. Methods Exposured to aerosolized ovalbumin and challenged by the same antigen, asthma models were established. They were randomly divided into inhaled glucocorsteride group and non-steroid group. Normal control animal were treated with normal saline (NS) instead of aerosolized ovalbumin. The expressions of NK2 receptor mRNA in the lung tissues were examined by RT-PCR. The distribution of NK2 receptor mRNA in the lungs was detected by bybridization insitu of using oligonuclectide probe. Resulfts NK2 receptor mRNA exprssion could be observed in the trachea,bronchus and the lung tissue in asthmatic guinea pigs. NK2 receptor mRNA were mainly located in the submucosa, around the smooth muscle of the trachea and bronchus; the contents of NK2 receptor mRNA of asthmatic guinea pigs under bronchus mucosa, around smooth muscle and the lung of asthmatic guinea pigs were higher than those in normal control ( all P ＜0.05). NK2 receptor mRNA contents in the lungs, the submucosa, mound the smooth muscle of the trachea and bronchus of asthmatic guinea pigs in inhaled glucocorsteride group were significantly lower than three in non-steroid group (P ＜0.05) ;there were no significant differences in NK2 receptor mRNA contents between inhaled gtucocorsteride group and normal control (P＞0.05). Conclusions The expressions of NK2 receptor mRNA are up-regulated under bronchus mucosa and around the smooth muscle of the trachea of asthmstic guinea-pig; the contents of NK2 receptor mRNA increase in the lung tissues of guine-pigs with asthma. Inhaled glucocorsteride can down-regulate the expression of NK2 receptor mRNA in the lungs, the submucosa, around the smooth muscle of the trachea and bronchus of asthmatic guinea pigs.