Study Of Intra-articular Injection With 5Fu In The Treatment Of Rabbit Knee Osteoarthritis

Osteoarthritis is the most common form of arthritis in elderly and the morbidity was around 2%-6%. It is the major disease, which led to disability, economic loss and affects the development of society. The inflammation of synovial membrane is the accompaniment of OA caused by degraded parts of cartilage matrix. The secretion of IL-1 increased and led to the amount and activity of matrix metallopratease increased causing destruction of cartilage. Normal membrane cell only secret micro amount IL-1, but much more in OA. Type B cell became more active and secret large amount IL-1 after be stimulated by sloughed cartilage matrix parts and that worsen OA. Under this background that we think the over reacting inflammation caused imbalance of inner environment lead to a series of pathologic changes. If the inflame proliferation of membrane could be controlled, the amount of harmful cytokines would drop significantly and that would broke the infernal circle and may stop the degeneration of cartilage. We choose anti-metabolism cytotoxic drug, Flurouracil for intra-articular injection act on membrane cells to control its proliferation through inhibiting the synthesis of DNA to end the mitosis. That makes the amount of membrane cell not over increased and the amount of IL-1 decreased. Decreased level of IL-1 depressed the secret of MMP and improve the destruction of cartilage. In order to explore the therapeutic effect of 5Fu on cartilage degeneration, we carried out the following five parts of experimental studies.(1) The establishment of rabbit osteoarthritis model with immobilization of knee in extension positionObjective: After rabbit knee immobilized in extension position, the pathologic changes of femoral condylar cartilage and synovial membrane were investigated to determine whether this animal model could be used in research work of OA prophylaxis and treatment. Methods: 10 rabbits with left knee immobilized in extension position, and right knee with no interferer as own control sacrificed after six week. Knees were harvested to observe the macroscopic changes of femoral condylar cartilage and pathological changes of cartilage and synovial membrane. Compare the Markin's scale of cartilage and the level of IL—1. Results: Left femoral condylar cartilage showed fissures and erosions, shadowy colour, thinner thickness, less cell amount and decreased proteoglycan staining. Synovial membrane showed congestion, edema, and hyperplasy. Higher IL—1 level (P<0. 05) with p<0. 01 in macroscopic grading scale and Mankin's grading scale. Conclusion: Pathologic changes of femoral condylar cartilages and synovial membrane in rabbit knee immobilization in extension position animal model are in accordance with the pathology of osteoarthritis. This model deserves further research and application in OA prophylaxis and treatment.(2) The therapeutic dose select of 5Fu intra-articular injection in the treatment of rabbit knee osteoarthritisObjective: To choose the best dosage according to effects of different dosage 5Fu intra-articular injection in the treatment of rabbit knee 0A. Methods: 32 rabbits randomly divided into 1mg/kg group, 2mg/kg group, 4mg/kg group and control group after 0A model established. They were received intra-articular 5Fu of 1mg/kg, 2mg/kg, 4mg/kg and physiologic saline injection respectively one times a week for 4 weeks and sacrificed one week after last injection. Knees were harvested to observe the macroscopic changes of femoral condylar cartilage and pathological changes of cartilage and synovial membrane. Compare the Markin's scale of cartilage and the level of IL—1. Results: The grade of degeneration of cartilage of control group is much higher than the other three groups (P<0.01). The grade of 1mg/kg group is much higher than 2mg/kg group and 4mg/kg group (P<0.05). The grade of degeneration of cartilage is similar between 2mg/kg group and 4mg/kg group (P>0.05). Changes of membrane and the level of IL—1 are similar with cartilage. Conclusion: The effects of 2mg/kg group and 4mg/kg group are similar and better than 1mg/kg group, so the 2mg/kg is the best choice.(3) Toxicity and side effects of 5Fu for intra-articular injection in the treatment of rabbit knee osteoarthritisObjective: To evalue the local and system toxicity and side effects of 5Fu intra-articular injection in the treatment of rabbit knee osteoarthritis. Methods: 24 rabbits with 16 divided into 5Fu group and control group after 0A model established randomly and another 8 as normal toxicity group. 5Fu group and normal toxicity group were received 5Fu 2mg/kg intra-artilular injection and control group received same amount of physiologic saline one times a week for 4 weeks and sacrificed one week after last injection. Blood test was examined before and after treatment. Pathologic examinations of heart, lung, liver, spleen, kidney and artiluar tissue were taken after sacrificed. Results: Blood tests showed no changes before and after the treatment. There were no pathologic changes of major organs and articular tissue found. The pathologic change of cartilage and synovial membrane in 5Fu group is better than control group. Conclusion: When the dosage of 5Fu intra-articular injection in treatment of rabbit knee OA is 2mg/kg, no significant toxicity and side effects found. It is safe.(4) Study of Intra-articular Injection with 5Fu in the Treatment of Rabbit Knee OsteoarthritisObjective: To evaluate the effects of intra-articular 5Fu injection in the treatment of rabbit knee osteoarthritis. Methods: 24 rabbits were randomly divided into 5Fu group, OA group and Control group after the model of OA established. OA group were sacrificed at once. 5Fu group and Control group were received intra-articular 5Fu and physiologic saline injection respectively one times a week for 4 weeks and sacrificed one week after last injection. Optic and electron microscopic examinations were conducted to observe the pathological changes of articular cartilage and synovial membrane and Mankin's scale were performed. The Immunohistoche analyses of MMP-1distribution in cartilage were performed and the level of IL-1 of the serum and synovial fluid were determined with ELISE. Results: The destruction of cartilage was alleviated and synovialitis was depressed in 5Fu group. The Mankin's scale of 5Fu group was significantly decreased (P<0. 01). The level of IL-1 of the serum and synovial fluid decreased (P<0.05). The expression of MMP-1 in cartilage of 5Fu group decreased also. Conclusion: 5Fu could control the membrane inflammation and alleviate the destruction of cartilage. It could prevent the worsening of OA.(5)Comparative Study On Effects Of Intraarticular Injections Of 5-Fluorouracil, Sodium Hyaluronate, Triamcinolone Acetonide On Rabbit Knee OsteoarthritisObjective: To Evaluate the therapeutic effects of 5Fu intraa-rticular injection on rabbit knee osteoarthritis by comparing with sodium hyaluronate and triamcinolone acetonide. Methods: 32 rabbits were randomly divided into 5Fu group, SH group, TA group and control group after established the model of OA. 5Fu group , SH group, TA group and Control group were received intra-articular 5Fu, SH , TA and physiologic saline injections one time a week respectively. After four weeks, the histological examinations and immunohistochemistry analyses of distribution of MMP-1 of cartilage and synovium, Mankin's scale, macroscopic observation were performed. The level of IL-1 of the synovial fluid was determined with ELISE. Results: Macroscopic and microscopic observation , Mankin's scale showed the destruction of cartilage was alleviated in 5Fu group, SH group and TA group, 5Fu group was better than SH and TA group but there was no difference between the SH and TA group. Microscopic observation of synovial tissue showed the inflammation was mild in 5Fu group, worse in SH and TA group and worst in Control group. The level of IL-1 in synovial fluid and the distribution of MMP-1 in cartilage and synovial membrane were relative to the destruction of cartilage, 5Fu group has the lowest level of IL-1 and the least distribution of MMP-1, more in SH group and TA group, much more in control group. Conclusion: 5Fu, SH, TA all could alleviate the destruction of cartilage of OA , but the effects of 5Fu was the best which provide a new choice of drug in the treatment of OA.The results of above five parts showed that 5Fu intra-articular injection could depressed synovial membrane inflammation significantly and decreased the amount of membrane cell which come back to normal from active functional status. The destruction of articular cartilage recovered significantly with less harmful cytokines in synovial liquid and decreased distribution of MMP-1 in cartilage. It is found that the therapeutic effect of 5Fu is better than Sodium Hyaluronate and Triamcinolone Acetonide. Results from our research provide foundations and evidences for further study and clinic use, however we have to point out that this study is only a preliminary animal study on the therapeutic effects of intra-articular injection of 5Fu on OA. The biological effective utilization and long-term therapeutic effects need further study, also slow release preparation and target release system technology worth deep investigation.