Abstract: AIM: To approach the effect of specific immunotherapy on transforming growth factor (TGF-β₁) Smads in asthmatic rats. METHODS: Forty Wistar rats were randomly divided into 4 groups:control group, asthma group, control of specific immunotherapy group and specific immunotherapy group, with 10 rats in each group.The model of asthma was established by the ovalbumin (OVA) challenge methods and the specific immunotherapy group received specific immunotherapy by repeated inhaling different doses of OVA. The concentrations of TGF-β₁ in BALF and serum were detected by ELISA.The expressions of TGF-β₁, phosphorylated Smad2/3(P-Smad2/3) and Smad7 proteins in lung tissue were detected by immunocytochemical method. RESULTS: In BALF or serum, the concentration of TGF-β₁ in control group was lower than that in asthma group or specific immunotherapy group respectively.The concentrations of TGF-β₁ in BALF or serum in specific immunotherapy group was lower than that in asthma group.The expressions of TGF-β₁ and PSmad2/3 in lung in asthma group were higher, but the expressions of Smad7 was lower than that in control group or in specific immunotherapy group respectively. CONCLUSION: Specific immunotherapy could decrease the expressions of TGF-β₁ and P-Smad2/3, while increase the expression of Smad7 in asthmatic rat, and relieve the airway inflammation in some extent and inhibit the occurrence and development of airway remodeling.

Key words: asthma, specific immunotherapy, TGF-β₁;, Smads