幼年哮喘大鼠气道重塑各阶段支气管组织感觉神经肽受体表达变化

摘要

目的：探讨感觉神经肽受体（NK-1R）在幼年哮喘大鼠气道重塑发生、发展中的意义。方法幼年SD大鼠64只，随机分为哮喘组及对照组各32只。哮喘组大鼠采用卵蛋白（ OVA）激发法制作哮喘模型，对照组以等剂量生理盐水处理。将各组32只均分为4个亚组，分别于处理2、4、6、8周后采集标本。采用HE染色进行肺组织病理学观察，图像分析系统测定支气管基底膜周径（Pbm）、总管壁面积（WAt）及平滑肌面积（WAm），并用Pbm将测量值标化；样本碱水解法测定肺组织羟脯氨酸水平；免疫组化法、Western blot 法检测支气管组织中的NK-1R，Real-time PCR检测NK-1R mRNA。结果 HE染色光镜下观察，哮喘组各亚组支气管病理变化明显，以哮喘8周组最为明显。哮喘组各亚组Wam／Pbm、肺组织羟脯氨酸水平均高于对照组，哮喘4、6、8周组Wat／Pbm高于对照组（ P均＜0．05），且Wat／Pbm、Wam／Pbm、羟脯氨酸水平哮喘8周组＞哮喘6周组＞哮喘4周组＞哮喘2周组（ P均＜0．05）。哮喘组各亚组大鼠支气管中NK-1R mRNA及其蛋白表达均高于对照组，且哮喘8周组＞哮喘6周组＞哮喘4周组＞哮喘2周组（P均＜0．05）。结论哮喘大鼠气道重塑各所段支气管组织中NK-1R mRNA及其蛋白表达增高。 NK-1 R可能与哮喘气道重塑的发生、发展有关。%Objective To investigate the expression of neurokinin-1 receptor and it′s effect in different stages of young asthmatic rats of airway remolding.Methods A total of 64 young SD rats were randomly divided into asthma group and normal control group with 32 rats in each group.Asthma group were challenged with OVA to establish asthma rat model .The control group underwent treatment with normal saline instead of OVA .Each group was randomly divided into 4 subgroups and they were anatomized at 2 weeks, 4 weeks, 6 weeks, 8 weeks.HE staining and image analysis were used to measure Wat/Pbm and Wam/Pbm.Alkaline hydrolysis method was used to determine the hydroxyproline content .The expression of neurokinin-1 receptor were respectively located and measured by immunohistochemistry and Western blotting method.The level of neurokinin-1 receptor mR-NA were detected by using Real-time PCR.Results HE staining of control group showed that bronchial epithelial integrity , in-flammatory cells infiltrated rarely and smooth muscle layer thinner.HE staining of asthma group showed that pathological changed obviously, especially in 8w group.Wam/Pbm and hydroxyproline of airway smooth muscle in asthma group were both higher than the control group(P<0.05).Wat/Pbm of 4 weeks, 6 weeks, 8 weeks in sthma group were higher than the control group (P<0.05).The comparion of Wat/Pbm,Wam/Pbm and hydroxyproline of asthma subgroups were 8 weeks>6 weeks>4 weeks>2 weeks (P<0.05).The expression of neurokinin-1 receptor mRNA and protein in asthma groups were higher than the control groups and 8 weeks>6 weeks>4 weeks>2 weeks (P<0.05).Conclusions Asthma rats appear airway remodeling in a early phase of incidence.The expression of neurokinin-1 receptor mRNA and protein increased in bronchial tissue with the time of air-way remodeling.Sensory neuropeptide receptors play an important role in the development of asthmatic airway remodeling .