WANG Guangª²Hui1, JIN Faª²Guang1, CHU Dongª²Ling1, DUAN Li2

    1Department of Respiratory Diseases, Tangdu Hospital, Xi¬ðan 710038, China, 2Institute of Neurosciences, School of Basic Medicine, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To investigate the roles of matrix metalloproteinaseª²9 (MMPª²9) and tissue inhibitor of metalloproteinaseª²1 (TIMPª²1) in airway remodeling of asthmaric guinea pigs. METHODS: Guinea pigs were sensitized with ovalbumin conjuncted with Al(OH)3£¬ and subsequently challenged repeatedly with ovalbumin aerosol. The guinea pigs were randomly divided into the control group£¬asthmatic 4, 6, 8ª²week groups. The expressions of MMPª²9 and TIMPª²1 in bronchi and lung tissues were observed by immunohistochemistry combined with the microª²image analysis.The levels of MMPª²9 mRNA and TIMPª²1 mRNA were determined by semiª²quantitative PCR. RESULTS: ¢Ù After repeated allergen challenge, smooth muscle hyperplasia was obvious in guinea pig bronchi.Expression levels of MMPª²9 and TIMPª²1 in the epithelial cells of bronchi were significantly higher in asthmatic animals than those of control group. ¢Ú The expression of MMPª²9 in asthmatic guinea pigs¬ð lung tissues was 0.52¡À0.05 in 4ª²week group, 0.74¡À0.05 in 6ª²week group, 0.48¡À0.04 in 8ª²week group , 0.21¡À0.04 in control group (P<0.05). The expression of TIMPª²1 in asthmatic guinea pigs¬ð lung tissues was 0.36¡À0.04 in 4ª²week group,0.83¡À0.05 in 6ª²week group, 0.97¡À0.05 in 8ª²week group , 0.20¡À0.02 in control group (P<0.05). ¢Û The results of immunocytochemistry were consistent with those of RTª²PCR. ¢Ü The upª²regulation of MMPª²9 expression become slower than TIMPª²1 since the 4th week in asthmatic animals. So ratio of MMPª²9/ TIMPª²1 was decreased. CONCLUSION: The expression levels of MMPª²9 and TIMPª²1 were closely correlated with asthma airway remodeling, and the ratio of MMPª²9/ TIMPª²1 may reflecte the degree of asthma airway remodeling. ......