| Objective To establish a rat model of osteosarcopenia (OS) with ovariectomy (OVX) combined with intraperitoneal injection of dexamethasone (DXM), and to determine the evaluation index of the disease. Methods Forty 6-month-old SPF female SD rats were randomly divided into Control group, Sham group, Sham + DXM group, OVX group, and OVX + DXM group, with 8 rats in each group. Rats in Sham group and Sham + DXM group underwent sham operation, while rats in OVX group and OVX + DXM group underwent bilateral ovariectomy. One week after the operation, rats in Sham + DXM group and OVX + DXM group were injected with DXM intraperitoneally for two weeks. Three months after the establishment of the model, the rats in each group were measured for grip, bone mineral density (BMD) of the whole body and the femur, skeletal muscle mass index (SMI) and relative skeletal muscle mass index (RSMI), bone microstructure of the distal femur. The evaluation indexes of the disease were discussed. Results (1) Compared with the Sham group, the rats in the Sham + DXM group had significantly lower forelimb grip, SMI, and RSMI. (2) Compared with those in the Sham group, forelimb grip, SMI and RSMI, the whole body BMD, the whole femur BMD, the distal femur bone volume fraction, the bone surface density, and the number of bone trabeculae in both the OVX group and the OVX + DXM group decreased significantly, and the separation of bone trabeculae increased significantly. (3) Compared with those in the OVX group, the forelimb grip strength of rats showed a downward trend, SMI and RSMI of the OVX + DXM group reduced significantly. Conclusion OVX combined with intraperitoneal injection of DXM can be used to establish the OS rat model, which has the advantages of short modeling cycle, stable model, strong availability, and low cost. The grip of the forelimb, SMI and RSMI, BMD of the whole body, BMD of the femur, and the bone microstructure of the distal femur can be used as the evaluation indexes of the disease. |