Abstract: Objective The aim of the present study is to investigate the influence of loading exercise on morphology and metabolism of articular cartilage in ovariectomized rats .Methods Forty female Sprague-Dawley rats were randomly assigned to 4 groups: ovariectomized (OVX), ovariectomized plus low loading exercise (low loading OVX-RUN), ovariectomized plus medium loading exercise (medium OVX-RUN), ovariectomized plus high loading exercise (high loading OVX-RUN); After 12 weeks, the following variables were compared among the 4groups. Knee joint and blood samples were collected，Test of rat serum related material were carried on the articular cartilage morphology (HE dyeing, sarranine O dyeing , toluidine) examination and immunohistochemical staining to detect the content of type Ⅱ collagen in articular cartilage. Result Accroding to the morphology and serum test results ,medium OVX-RUN group was helpful to maintain the steady state of articular cartilage (p<0.05). compared with OVX、low loading OVX-RUN group、medium OVX-RUN group, high loading OVX-RUN group was not conducive to the growth of the articular cartilage,induce thedegenerative-like changes in articular cartilage(p<0.05).Conclusion The different loading exercise has different effect on the cartilage of rats, moderate loading exercise on the prevention and treatment of osteoporosis has useful clinical significance.

Key words: osteoporosis, MMP-3, typeⅡcollagen