Immunohistochemical Expression of MMP-13 and TIMP-1 in Rabbit Osteoar-thritis Mode

Objective To investigate the feasibility of rabbit model of osteoarthritis(OA)by excision of medial meniscus,medial collateral ligament and anterior cruciate ligament transaction(ACLT). To explore the roles of MMP-13 and TIMP-1 in the development of joint cartilage degeneration. Methods The right knee joints of thirty white rabbits received excision of medial meniscus,medial collateral ligament and ante- rior cruciate ligament transaction(ACLT),while their left knee joints received unilateral knee arthrotomy as pseudo-operation controls. Ten ex- perimental rabbits were killed at 4,8 and 12 weeks post surgery respectively. Knees were harvested to observe the macropathologic changes of the femoral condyle. MMP-13 and TIMP-1 were detected by immunohistochemisty. Results Cartilage degeneration was obvious at 4 weeks and became more severe at 8 and 12 weeks after operation,while cartilage remained normal until the end of this study. The scores of cartilage degeneration increased by the time. Expression intensity of MMP-13 and TIMP-1 in left knee joint cartilage were much more inferior than those in right. In right knee joint cartilage,MMP-13 had significantly strong expression,but became weak at 8week,12week. The expression of TIMP-1 was strongest at 8week. The ratios of MMP-13/TIMP-1 constantly decreased after operation. Conclusion This is a good method to establish an osteoarthritis model. MMP-13,TIMP-1 play an important role in the cartilage degeneration,especialy at early stage.The relation- ship of scores of cartilage degeneration and MMP-13/TIMP-1 was inverse,and the ratios of MMP-13/TIMP-1 could be a good marker in carti- lage degeneration.