The Mechanism Of Sangpi Zhike Recipe On Neurogenic Inflammation Of Airways In Mice With Cough After Infection

Objective:Through the experimental study,the cough times,pathological changes of lung tissue,the expression of SP,NGF and Trk A protein and gene in lung tissue of mice with cough after RSV infection were detected,and the effect of Sangpi Zhike Recipe on airway neurogenic inflammation of cough after infection was discussed To provide theoretical basis for clinical application.Materials and methods:1.Respiratory syncytial virus was used to establish the infected mice model.BALB / c mice were randomly divided into normal control group,RSV infection model group,western medicine group,Sangpi Zhike formula low,medium and high dose group.2.Study on the therapeutic effect and mechanism of Sangpi Zhike Recipe on cough mice infected with respiratory syncytial virus: each group used capsaicin atomization to induce cough,and observed the incubation period and times of cough in mice.The general state of mice in each group,pathological changes of lung tissue,protein expression positions and amounts of SP,NGF and Tr KA were detected by immunohistochemistry,and gene expression amounts of NGF m RNA and Tr KA m RNA in lung tissue were detected by real-time fluorescence quantitative PCR.Result:1.General state: after 2 weeks of modeling.In addition to the normal group,the mice in other groups were depressed in vigour,decreased in activity,accelerated in respiratory frequency,faded in hair color,and decreased in diet and drinking water;after administration,the general state of mice in each treatment group was significantly better than that in the model group.2.After 2 weeks of administration,compared with the model group,the cough latency and the number of coughs in the middle and high dose group and the western medicine group were significantly prolonged(P < 0.05).There was no significant difference between the high dose group and the western medicine group(P > 0.05).3.Lung histopathology: in the model group,a large number of inflammatory cells infiltrated into the lung tissue,with obvious congestion,edema and thickening of the bronchial wall;in each treatment group,the degree of inflammatory cell infiltration in the lung tissue was less than that in the model group,with congestion,edema and thickening improved.4.Immunohistochemistry: the expression of SP,NGF and Trk A protein in the lung tissue of the model group was significantly higher than that of the normal group(P Significant difference(P > 0.05).5.RT-PCR showed that the expression of NGF m RNA and Trk A m RNA in lung tissue of model group was significantly higher than that of normal group(P < 0.05),and the expression of NGF m RNA and Trk A m RNA in lung tissue of each treatment group was significantly lower than that of model group(P < 0.05).Conclusion:Sangpi Zhike Recipe can reduce cough reflex sensitivity and inflammatory pathological changes in lung tissue of infected cough mice.Its mechanism may be to reduce SP secretion by down-regulating NGF/Tr KA protein and gene expression in lung tissue of infected cough mice,thus reducing inflammatory infiltration in lung tissue,reducing airway neurogenic inflammation,and further regulating the interaction between nerve and immune system,thus achieving the effect of treating cough after infection.