Influence of SERMª²raloxifene on bone mineral density and blood biochemical parameters in ovariectomized rats

    DUAN Yongª²Hong£¬LIU Jian£¬MENG Guoª²Lin

    PLA Institute of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To study the influence of raloxifene (RAL), a selective estrogen receptor modulator (SERM), on bone mineral density(BMD) loss in cancellated bone and compact bone of ovariectomized rats. METHODS: Twentyª²four female SD rats were divided into 3 groups (8 rats per group): sham operation group, ovariectomized(OVX) group and therapeutic(OVX+RAL) group. Bilateral ovariectomies were performed in OVX group and OVX+RAL group. The latter was treated with raloxifene 7 d after operation. Sixteen weeks after operation, all rats were sacrificed. BMD of L3ª²L5 vertebrae, proximal femoral segment and femoral shaft were measured by dual energy Xª²ray absorptiometry (DEXA). L2 vertebrae were histomorphometrically analyzed and serum biochemical markers were measured before and after drug administration. RESULTS: Serum total calcium [(3.02¡À0.38) mmol/L vs(2.24¡À0.30) mmol/L] and total alkaline phosphatase [(2.336¡À0.032) ¦Ìkat/L vs (1.832¡À0.028 )¦Ìkat/L] significantly increased in OVX group compared with those in sham group (P<0.01, P<0.05 respectively). The above parameters decreased in RAL group compared with those the ovariectomized group [(2.38¡À0.39) mmol/L vs(3.02¡À0.38)mmol/L,(1.952¡À0.023) ¦Ìkat/L vs (2.336¡À0.032) ¦Ìkat/L] (P<0.05). Sixteen weeks after ovariectomy, BMD of L3ª²L5 vertebrae, proximal femoral segment [(0.181¡À0.021) g/cm2 vs (0.287¡À0.025 )g/cm2] and femoral shaft [(0.157¡À0.034) g/cm2 vs (0.260¡À0.039) g/cm2] decreased significantly (P<0.01) and the trabecular became thin and irregular compared with those in sham group. After treatment of RAL, the above parameters restored (P<0.05) but not to the level of sham group (P>0.05). CONCLUSION: Ovariectomy induces a significant decrease of cancellated bone mass and compact bone mass. RAL is an effective medicine to inhibit bone loss, increase the BMD of lumbar spine, total hip bone and total body and decrease the bone turnover. ......