ObjectiveTo explore the expressions of nerve growth factor (NGF) and leukemia inhibitory factor (LIF) in both asthmatic mice and respiratory syncytial virus(RSV)-infected mice,explore if there is a same neurogenic mechanism between ashtma and RSV infection,in order to find a new treatment target for asthma. MethodsOne hundred healthy Balb/c inbred mice were randomly divided into a control group,a RSV group,an asthma group,an asthma with RSV group,and a dexamethasone group. The lung tissue pathology was observed by hematoxylin-eosin staining(HE). The quantitative analysis of NGF mRNA and LIF mRNA of lung tissue was detected by RT-PCR. The expression of NGF protein and LIF protein was detected by immunohistochemical method. ResultsUnder light mocroscope,there were alveolar septum widening,alveolar epithelium swelling,and interstitial edema in the RSV group. There were widen alveolar septum,narrowed bronchial lumen,thicken bronchial wall and a large number of inflammatory cells infiltration around the small blood vessels,alveolar and bronchioles both in the asthma group and the asthma with RSV group,with the latter being more serious. Compared with the RSV group,the inflammation was relieved significantly in the dexamethason group. There were mRNA and protein expressions of NGF and LIF in all groups, which were highest in the asthma with RSV group,then the RSV group and the asthma group,and lowest in the dexamethasone group. ConclusionsThe expressions of LIF and NGF in the lung of mice after RSV infection and futher increase when combined with asthma. Dexamethason can inhibit the expression of NGF and LIF to some extent.