Effects Of Resveratrol On Osteoprotegerin And Osteoprotegerin Ligand Expression Of Femurs In Ovariectomized Rats

Objective To study effects of resveratrol on osteoprotegerin(OPG) and osteoprotegerin ligand(OPGL) expression in femur of ovariectmized rats.Methods There were 48 female SD rats(3 months old) randomly assigned to 6 groups: sham-operated group(SHAM); ovariectomized group(OVX); 17 3 -estradiol replacement therapy group(ERT,0.1mg.kg^-1.d^-1,sc); high-dose resveratrol-treated group (RH, 40mg.kg^-1.d^-1,ip); middle-dose resveratrol-treated group (RM, 20mg. kg^-1 .d^-1,ip); low- dose resveratrol -treated group (RL,10mg.kg^-1.d^-1,ip). Except SHAM group, rats in other groups were operated by bilateral ovariectomy. Administration started on 8th day after operation and lasted 8 weeks. At the end of 9^th week after operation, all rats were sacrificed. The calcium (Ca ), phosphonium (P ), alkaline phosphatase( ALP) in serum and hydroxyproline (HOP), carnine (Cr) in urine,and bone mineral density(BMD) and vitodynamics properties(including ELASTIC, M-STRESS, M-LORD and STIFFNESS) of femurs and lumbar vertebrae in ovariectmized rats were measured. The expression of OPG and OPGL in femurs of rats were observed by immunohistochemical staining methods.Results 1. The BMD, ELASTIC, M-STRESS, M-LORD of femurs and lumbar vertebrae in OVX group were lower than those of SHAM group .In RH ,RM and ERT group, BMD , ELASTIC , M-STRESS, M-LORD of lumbar vertebrae and BMD , ELASTIC , M-STRESS of femurs were higher than those of OVX group. In RL group, M-LORD of lumbar vertebrae was higher than that of OVX group. 2. Compared with OVX group, the Ca , P level in serum of RH, RM, RL group rats was lower, and the ratio of uric HOP and Cr was lower, too. Serum alkaline phosphatase was no significantly change. 3. Compared with OVX group, resveratrol treatment (40mg.kg^-1.d^-1 and 20mg.kg^-1.d^-1)increased expression of OPG in femurs while decreased that of OPGL in ovariectmized rats.Conclusion 1. Resveratrol could improve bone mineral density and vitodynamics properties of femurs and lumbar vertebrae in ovariectmized rats. 2 Resveratrol increased expression of OPG in femur while decreased that of OPGL in ovariectmized rats, which was probably one of mechanism that resveratrol prevented from osteoporosis.