呼吸道合胞病毒感染诱发哮喘大鼠模型的建立与评价

目的:探讨用呼吸道合胞病毒(RSV)诱导鸡卵白蛋白(OVA)致敏,建立病毒感染哮喘大鼠模型的方法,并评价其效果。方法:40只SD大鼠随机分为磷酸盐缓冲液(PBS)对照组、OVA组、RSV组、和OVA/RSV组4组。应用OVA腹腔注射致敏、OVA气道雾化吸入结合RSV滴鼻激发复制病毒性哮喘模型,PBS组不造模。观察大鼠哮喘发作症状;动物体描箱法测定乙酰甲胆碱(Mch)激发条件下气道反应性(以Penh值表示);H.E染色观察肺组织病理变化,以地高辛多标记点原位杂交检测肺组织中RSV RNA。结果:RSV组和OVA/RSV组肺组织中可见明显的RSV的阳性信号(棕黄色),PBS组、OVA组则未见RSV的阳性信号。与PBS组相比,除在浓度为0mg/ml(PBS)时OVA组无显著性差异(P>0.05),余各组在各浓度Penh值均增高(P<0.05,P<0.01);与OVA/RSV组相比,各组Penh值均降低(P<0.05,P<0.01)。结论:运用OVA致敏、激发,以RSV连续滴鼻的方法制备大鼠病毒性哮喘模型,病理生理特征更符合哮喘定义;且用有活力的RSV感染诱发的哮喘与临床病毒性哮喘的实际发病情况相近,该模型的建立可以为哮喘研究提供更好的选择工具。

Reproduction and Evaluation of Asthmatic Rat Model Infected by Respiratory Syncytial Virus

Objective: To reproduce a type of acute viral asthma model in ovalbumin( OVA)-sensitized SD rats by induction with respiratory syncytial virus( RSV). Methods: 40 SD rats were randomly divided into four groups: phosphate-buffered saline( PBS) control group,OVA group,RSV group and OVA/RSV group. The asthmatic model was reproduced by sensitization with intraperitoneal injection of OVA,followed by repeated inhalation of OVA combined with repeated intranasal instillation of RSV.Asthmatic symptoms were observed. The changes in airway responsiveness was represented by Penh stimulated by Methacholine( Mch). Lung histopathology was evaluated by hematoxylin and eosin( HE) stain and hybridization in situ to evaluate whether the RSV have been planted in the lung. Results: Hybridization in situ to evaluate effects of butylph thalide on RSV RNA expression in rat's lung: Positive signal of RSV RNA can be found in the RSV-infected rat's lung compared with that of the control and OVA group. In comparison with PBS group,Penh of all groups were significantly increased when stimulated by all concentrations of Mch( P < 0. 05,P < 0. 01),except OVA group when stimulated by 0 mg/m L Mch( PBS) with no significance( P > 0. 05). Compared with OVA / RSV group,Penh of all groups were decreased significantly when stimulated by all concentrations of Mch( P < 0. 05,P< 0. 01). Conclusion: Establishment of model: The model was established by ovalbumin( OVA) sensibilization and long-term inhalation provocation,followed by repeated intranasal instillation of RSV. Its characteristics of pathophysiology is the same as asthma and the disease characteristics of asthma induced by live RSV infection is similar with actual situation of asthma induced by viral infection. An animal model of asthma induced by virus is successfully reproduced by nasal inoculation with RSV in OVA-sensitized SD rats. It is a better choice for asthma research by using this model.