ABSTRACT
Objective:To discuss the influence of dexamethasone(DXM) to T-bet/GATA-3 of athma rats.Methods: 30 SD rats were randomly divided into normal group,model group and DXM group,10 rats in each group.Ovalbumin was intraperitoneal injected on the 1th and 8th day and aerosol inhaled from the 15th day,once a day,14 days altogether.Dexamethasone was intraperitoneal injected in 0.5 mg/kg from the 15th day,once per day,a total of 14 times.Flow cytometry tested the content of Th1 and Th2 in spleen and peripheral blood,immunohistochemistry and Western blot measured T-bet and GATA-3 protein expression and RT-PCR tested T-bet and GATA-3 mRNA expression.Results: Compared model group with normal group,the contents of Th1,Th2 in spleen and peripheral blood had a very significant increase(P<0.01);expression of T-bet,GATA-3 protein and mRNA in the lung tissue also had very significant risen(P<0.01).While compared DXM group with model group,T-bet/GATA-3 rose significantly(P<0.05)or very significantly(P<0.01).Conclusion: T-bet/GATA-3 is the key transcription factors that influence the balance of Th1/Th2,while DXM can raise the ratio of T-bet/GATA-3,which reduce the severity of asthma.