The Mechanism Of Prevention Effect About Aerobic Exercise On Rabbit Knee Osteoarthritis

Objective:To investigate the preventive effects of aerobic exercise on osteoarthritis, studying the impact of different aerobic exercise on Rabbits osteoarthritis model about the level of Ⅱ collagen and glycosaminoglycan.Methods:The20healthy New Zealand white rabbits were first accustomed to exercise for one week.Then they were randomly divided into four groups:normal control group (A), model group (B), treadmill training0.5km/h group (C), treadmill training1.5km/h group (D), n=5.Normal group take cage free activities for9weeks. Model group take cage free activities for4weeks, then using the intra-articular injection of papain constructing osteoarthritis model, and continue the cage freely activity for4weeks. Treadmill Training0.5km/h group were regularly trained at speed of0.5km/h for20minutes/day at the frequency of three days/week, one side of the intra-articular injection of papain, then cage free activities for4weeks. Treadmill Training1.5km/h group were regularly trained at speed of1.5km/h for20minutes/day at the frequency of five days/week, one side of the intra-articular injection of papain cage, then free activities for4weeks. All animals were killed since the the running date for9weeks after the general observation and testing weight. Cut knee capsule, observed intra-articular soft tissue, synovium, synovial fluid, cartilage, etc. take the experiment specimens side of the femoral condyle cartilage fixed, off calcium, embedded, sectioned. HE staining were performed and analyzed with microscopic examination. We detect the content of chondrocytes with type Ⅱ collagen by the methods of immunohistochemical stain, Chondrocyte glycosaminoglycan content of Toluidine blue staining. Study the all data processing between the groups by statistics analysis ways.Result:1、HE staining:Compared with model group(group B), cartilage degradation in Treadmill Training1.5km/h group (group D) is significantly less severe (P<0.05), but more severe than that in normal control group (group A)(P<0.05).The Mankin grade in group B is higher than that in group A、C、D; there are no significant differences of those are found between group B and group C(P>0.05).2、immunohistochemical staining and toluidine blue staining:gived type Ⅱ collagen and glycosaminoglycan, model group (group B) is significantly lower than the normal group (group A)(P<0.01); treadmill training group (group C, D) is lower than the normal group (group A)(P<0.05); treadmill training1.5km/h group (group D) is higher than the model group (group B)(P<0.05).There was no significant difference between treadmill training0.5km/h group(C) and model group (B)(P> 0.05).Conclusion:1Moderate aerobic exercise can effectively prevent damage to the articular cartilage.2The expression of Type Ⅱ collagen and glycosaminoglycan in cartilage damage is reduced. Preventive effect of aerobic exercise on osteoarthritis may be through inhibiting the expression of type Ⅱ collagen and glycosaminoglycan reduction in articular cartilage injury achieved.