The protective effect of exercise on osteopenia in ovariectomized rats / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the protective effect of exercise on osteopenia female rats caused by ovariectomy and its mechanism. Methods Twenty-four female rats aged 6 months were randomly divided into 3 groups control group(CON),ovariectomized model group(OVX) and exercise group(Ex).The ovariectomy operation was performed with rats in OVX and Ex groups. Rats in Ex group were trained on a treadmill at a velocity of 18m/min for 1h, once daily for 5 days a week. Each group of rats were sacrificed at 12 weeks postoperatively and Dual-energy X-ray absorptiometry was carried out to measure the bone mineral density(BMD) of the femur. IGF-1 proteins in trabecular bone of proximal femur were examined by using immunochemical stain and the intensity of IGF-1 was determined by use of imaging analysis techniques. The apoptotic osteocytes in the trabecular bone of proximal femur were detected by using terminal-deoxynucleotidyl mediated nick end labeling (TUNEL) technique. Results The BMD of CON, Ex and OVX group was (0.170?0.011)g/cm2,(0.154?0.013)g/cm2 and(0.167?0.013)g/cm2, respectively. The difference of the BMD level between Ex and CON groups was not significant, however, the BMD level in OVX group was significantly lower than that of the Ex and CON groups (P