Changes of p38 mitogen-activated protein kinase in lung tissue and effects of dexamethasone in asthmatic rats

AIM: To identify the changes of p38 mitogen-activated protein kinase (p38 MAPK) in lung tissue of asthmatic rats and the effects of dexamethasone on it. METHODS: Ovalbumin (OVA) was injected intraperitoneally and inhaled to produce the asthmatic model. Twenty rats were randomly divided into three groups: control group, asthma group and DEX group. The concentration of IL-5 in BALF and the expression of phospho-p38 MAPK in lung tissue were measured by ELISA and Western blot, respectively. RESULTS: The expression of phospho-p38 MAPK was up-regulated in the lung of asthmatic rats. The injection of DEX intraperitoneally decreased the expression of phospho-p38 MAPK and abolished the increases of airway resistance, the concentration of IL-5 and the number of eosinophil in BALF. Histopathologic damage of lung tissue was alleviated. There were positive correlations between the expression of phospho-p38 MAPK and airway resistance, the concentration of IL-5 and the number of eosinophil in BALF. CONCLUSION: p38 MAPK may play a role in pathological process of asthma. DEX can effectively treat asthma by inhibiting the expression of p38 MAPK.