Effects Of Whole-body Vibration On The Expression Of ER In Three Tissues Of Ovariectomized Osteoporosis Rats

Objective:The study of whole-body vibration on serum sex hormone level and the influence of the bone mineral density and estrogen receptor (ER) expression level in three tissues of ovariectomized osteoporosis rats tries to discuss the whole-body vibration in the treatment of postmenopausal osteoporosis mechanism of action.Methods:Thirty-six three months old female SD rats were randomly divided into following three groups by body weight:sham-operation (Sham), ovariectomized (OVX), and ovariectomized vibration (Vibration). After ten weeks of OVX, the Vibration group was treated with whole-body vertical vibration for15min at a frequency of90HC two times a day. After7weeks of whole-body vertical vibration treatment, with double can χline bone mineral density instrument testing the whole-body bone mineral density, bone mineral content and body composition, in the final vibration24-36hours animals to be put to death. Put to death before, take blood on abdominal aorta, separation serum, lumbar spine, femoral and tibial, with double can χline bone mineral density instrument testing in vitro lumbar spine, femoral and tibial bone mineral density; measurement of serum estrogen (E2) and progesterone (P) levels. The ER (estrogen receptor) expression levels in liver, muscle and fat tissue of tested rats were determined by RT-PCR also.Result:(1) Compared with the Sham group, weight in OVX group significantly was higher than Sham group, vibration group before and after, while the weight gain of vibration was significantly lower than OVX group.(2) Compared with the Sham group, OVX group distal femoral bone mineral density in vitro decreased significantly in near end, and there was no significant change in the middle. And the bone mineral density in distal femoral in near end significantly increased in ovarian static group compared to ovarian vibration group in vivo.(3) Compared with the OVX group, ER expression level significantly increased in the OVX vibration group.Conclusion:The whole body vertical vibration can reduce the fat and body weight gain for ovariectomized rats while it prevents the bone mass reduction for lumbar spine, the distal femur, proximal femur and proximal tibiaand enhances bone strength. However, it does not affect the hormone levels for E2, P and T4in rat serum. Vibration exercise up-regulated ER expression levels in three different tissues, liver, fat and muscle, which could improve osteogenesis that was impeded by lower sex hormones in ovariectomized rat.