The Effect Of Moderate Intensity Exercise On Bone Metabolism And The Protein Expression Of Gelatinases In Bone Of Ovariectomized Female Rats

The postmenopausal women has apt to got osteoporosis than other people. After the women entering menopause, the function of ovary decrease, so the level of oestrogen decrease quickly and hasten the bone reduction and bone tissue micro-structural damagement. Recently, study about exercise therapy with cheap and safety preventing osteoporosis has become popular. In this study, we observed morphological markers, biochemical markers of serum, bone mineral density, and other guidelines to estimate comprehensively the effect of exercise on bone and the protein expression changes of the gelatinases in bone in ovariectomized rats and find the function of exercise therapy on preventing osteoporosis.Seventy female Sprague Dawly(SD) rats with 3 months old were divided into following groups by body weight randomly: sham-operated(SHAM), sham-operated with exercise(SHAM+EX), ovariectomized(OVX), ovariectomized with exercise(OVX+EX), ovariectomized with estrogen(OVX+ES), ovariectomized with exercise and estrogen(OVX+EX+ES) and ovariectomized with sham- estrogen(OVX+SHAM-ES).Exercise groups were carried on the exercise stimulation from 4w and estrogen groups were given estrogen from 3w. Body weight alteration was recorded by every week. At the end of 17w, all of rats were killed. Collecting blood for applying tests for serum biochemical markers such as calcium, phosphorus, ALP, TRACP and bone carboxyglutamic-acid proteins (BGP); extracting uteri and observing its changement; extracting femur and measuring the Bone miner density (BMD) and observe the structure of femur by hematoxylin-eosin stain; extracting tibia and observe the changes of the gelatinase expression on the protein in bone which were examined by immunohistochemistry. The results such as:(1) The uteri of OVX group was atrophic obviously but OVX+EX group was on the contrary; the weight of belly cavity fat of the OVX group was larger than the SHAM and OVX+SHAM-ES. The body weight was significant different in each group after 8w,12w and 16w and the change are the same trend after 12w and 16w. (2) There were significant difference in serum calcium, ALP and TRACP and serum osteocalein(BGP), but serum phosphorus of each group has no statistical significance. (3) In the structure of femur by hematoxylin-eosin stain, we find that the trabeculae connectivity of SHAM group is relatively complete, but OVX group lose the integrality; the trabeculae connectivity of OVX+EX group is more integral than OVX, but less than OVX+ES group, and the trabeculae connectivity of OVX+ES group is less integral than SHAM group. (4) The protein expression of gelatinases of each group has no significanct difference.The conclusion are that moderate intensity exercise and estrogen can increase the BMD of ovariectomized female rats and reduce the incidence of osteoporsis; The effect of moderate intensity exercise on the protein expression of Gelatinases in bone of ovariectomized female rats wasn't observed.