The Effect Of Intra-articular Injection With Doxycycline On The Early Degeneration Of Opposite Knee Of The Immobilizied Rabbit Model Osteoarthritis

Purpose:study on The effect and action mechanism of Intra-articular Injection with doxycycline on the early degeneration of opposite knee of the braking rabbit model osteoarthritis.Methods:The 36 rabbits were divided into blank control group, model control group, and experimental animals according to the weight and the sex,6 cases for blank control group,18 cases for model control group and 12 cases for experimental group. Model control group animals were randomly divided into three groups acording to time,6 cases for each group. Experimental group animals were randomly divided into two groups acording to time,6 cases for each group. Both Model control group and experimental group were given left lower extremity fixed by gypsum.After 4 week, the treatment group were intraarticularly injected 1.33% doxycycline 0.3ml once a day in eight weeks in left. Histological change of cartilage and synovium of left knee joint each animals were detected.Results:1. compare with the blank control group, the colour of cartilage of model group became dark. Mankin score high (P<0.05), high activities of MMPs-3,IL-1β(P<0.05) in blood and in knee joint, high activities of iNOS and NO in knee joint2. compare with the model control group, the cartilage of experiment group is smooth, Mankin score Low (P<0.05), low activities of MMPs-3,IL-1β(P<0.05) in blood and in knee joint. (P<0.01).low activities of iNOS and NO in knee joint.Conclusion:1. The change on the early degeneration of opposite knee of the Immobilizied rabbit model osteoarthritis is same to the original human osteoarthritis.2. Mitigative Effect of Intraarticularly injection with doxy-cycline on the early degeneration of opposite knee of the Immobilizied rabbit model osteoarthritis.3. Mitigative Effect of Doxycycline on the early degeneration of opposite knee of the Immobilizied rabbit model osteoarthritis, The action mechanism was positively related with the expression of MMP-3,IL-1β,iNOS and NO.The MMP-3,IL-1β,iNOS and NO levels in serum and synovial fluid of the knees can reflect the degree of synovitis and accumulative cartilage injury as a biomarker, especially accumulative cartilage injury.