Injecting Tumor Necrosis Factor Alpha Into The Temporomandibular Joint Induces Osteoarthritis In Rabbit And Injury Mechanism Research

[Objective] To explore whether the tumor necrosis factor alpha can induce temporomandibular joints osteoarthritis by injecting tumor necrosis factor alpha into articular upper-cavity,and to study the influence of TNF a in PTG、osteoclast、Col Ⅱ、 VEGF、MMP-13.Through this study,it can provide experimental basis for futher understanding the pathogenesis of TMJOA.[Methods] Selecting and using ten New Zealand largeear white rabbits unlimited male and female which born to 16 to 18 weeks,dividing it into 2 groups,one group is blank control group named A including 2 rabbits and doing nothing to TMJ;the other group is experimental group named B including 8 rabbits,then group B were divided into 4 groups according to the sacrificed time,each group include 2 rabbits and each group were sacrificed at different time intervals after first injecting TNF a respectively are eleventh day,fourteenth day,twenty first day and twenty eighth day,we injected TNF a (60μg/ml) into TMJ articular upper-cavity of left side(experimental side) 3 times at first day、fourth day、eighth day and 60μl each time,the right side(control side) were injected equivalent PBS.Using HE staining to observe the change of bone matrix and cartilage matrix of temporomandibular joints osteoarthritis.Using toluidine blue and Safranin-O to observe the change of PTG,using TRAP staining to detect the change of osteoclast,Using immunohistochemical technique to detect the changes of condylar cartilage ColⅡ、VEGF、MMP-13 expression.[Result]1. It induces degenerative TMJ disease.The major chacteristic is articular cartilage injury accompanied by the change of synovial membrane and subchondral bone in HE after injecting TNF a into TMJ articular upper-cavity.2.Toluidine blue and safranin-O staining show that the PTG changed with time after injecting TNF a into TMJ articular upper-cavity,TRAP stainging show the osteoclast increasing after injecting TNF a.3.After injecting TNF a into TMJ articular upper-cavity,the Col Ⅱ has no differ ence in experimental side and control side and blank control group (p>0.05), while the VEGF and MMP-13 have difference in experimental side and blank control group(p<0.05),but there is no difference in experimental side and contro 1 side(p>0.05).[Conclusion]1.It is successful to establish the model of TMJOA by injecting TNF a into TMJ articular upper-cavity.2.PTG change with time and osteoclasts increase after injecting TNF a.3.TNF a may play a leading role in the pathogenesis of TMJOA,but it dose not influence the Col Ⅱ。4.TNF a increases the proinflammatory factor both VEGF and MMP13 and futher aggravated the symptoms of TMJOA.