The Rats Empirical Study Of The Effects Of Different-intensity Exercise On Earlier Period Degeneration Of Articular Cartilage

ObjectiveThere was a large number of study of articular cartilage injury by sports, but it was lack of quantization. Our is to make a simple original treadmill, to establish different intensity training models. To observe the effects of different-intensity exercise on biomarkers in rats articular cartilage, serum and synovium which was discovered in earlier period osteoarthritis,to quantize the relationship between exercise and osteoarthritis by change of biomarkers in rats articular cartilage, serum and synovium. At the same time, this study can confirm the mechanism of cataplasis in articular cartilage.Method50 8-week-old male depuratory-grade S-D rats were randomly assigned into one of four groups:a non-exercise control group(n=8),moderate-intensity exercise group(n=21) and high-intensity exercise group(n=21).The exercise intensity was referenced with Bedford-Plan. Every day, the moderate-intensity exercise group were trained for 60 minutes at speeds of 18m/min,the high-intensity exercise group were trained to be exhausted or for 60 minutes at speeds of 30m/min. to change a run machine used by human into a simple animal original treadmill. After a week adaptive treadmill exercise, to begin formal exercise. Meanwhile, to observe the training state of all group rats. Five weeks training later, to collect venous blood, to measure density of C-telopeptide of typeâ…¡collagen (CTX-â…¡) by ELISA after centrifugalization; meanwhile to obtain cartilage and synovium of knee, fix, dewater, slice. Cartilage sections were stained with haematoxylin and eosin (H & E), toluidine blue, in immunohistochemistry with collagen-â…¡. Synovium sections were stained with haematoxylin and eosin and in immunohistochemistry with MMP-13.The average gray density of collagen-â…¡and MMP-13 were measured and statistic analysed. The HE sections were observed by morphology in light microscope.ResultsA simple original treadmill can ensure that rats complete the task of different intensity. The training of rats in different velocity can be the model of different intensity completely. And the exercise capacity of high-intensity exercise group is lower than other groups. Concentration of CTX-â…¡in blood in high-intensity exercise group was higher than other groups obviously (P<0.01). The average gray density of collagen-â…¡in high-intensity exercise group was lower than control group significantly (P<0.01). The average gray density of MMP-13 in high-intensity exercise group's synovium was higher than control group significantly (P<0.01). Cartilage sections of high-intensity exercise group stained with toluidine blue were decreased than control group. Cartilage sections of moderate-intensity exercise group stained with toluidine blue were strengthened than control group. In HE sections:cartilage chondrocyte in high-intensity exercise group were more than other groups but the extracellular matrix was less. The synovium phlegmasia cells in high-intensity exercise group were more than others.ConclusionsThe rats can be trained in different intensity on the original treadmill completely. The cost of this simple original treadmill is lower than the speciality treadmill. The training of rats can be the model of different intensity completely. Moderate-intensity exercise can induce the content of glycosaminoglycan increased which is good for cartilage remodeling. High-intensity exercise damaged the cartilage and resulted in cataplasis. This experiment illustrated that mechanism of the injury in cartilage by high-intensity exercise was that more MMP-13 degrated collagen-â…¡resulting in cartilage injury and degration.