Effects of Simvastatin on Femoral Biomechanics in Ovariectomized Rats

Objective: To investigate the effect of Simvastatin on biomechanics of femur in ovariectomized rats.

Methods: Forty-eight female SD rats were randomly divided into three groups: Sham-operated group (S), ovariectomized group (OVX) and Simvastatin ovariectomized rats group (OVX+SIM) with 8 rats in each group. Operation was performed after 1 week of feeding. Eight weeks later, Simvastatin were administered orally with 5mg•kg(-1)•d(-1) to OVX+SIM group and equal normal saline to the other two groups. After operation, half of the rats were sacrificed at 4 weeks and 12 weeks respectively. The femora were taken out for the three-point bending test to measure the femoral biomechanical properties in terms of maximal loading, elastic loading, maximal deformation, elastic deformation, coefficient of bending stiffness and coefficient of bending ductility.

Results: (1) In 4 weeks after treatment, the maximal loading and maximal deformation of femur in SHAM group were significantly higher than those in the OVX group (P<0.05) . The coefficient of bending ductility of the femur in the OVX+SIM group was significantly higher than that in the OVX group (P<0.01) while the elastic loading of the femur in OVX+SIM group was significantly lower than that in the OVX group (P<0.05). (2) Twelve weeks after treatment, the maximal loading of the femur in the OVX+SIM group or that in the SHAM group was significantly higher than that in the OVX group (P<0.05, P<0.01), the elastic loading of the femur in the OVX+SIM group was significantly higher than that in the OVX group (P<0.05), while the coefficient of bending ductility of the femur in the OVX+SIM group or that in the SHAM group was significantly lower than that in the OVX group (P<0.05, P<0.01Conclusion: Simvastatin could promote the bone remodeling