Abstract: Objective To witness whether systemic administration of bone marrow mesenchymal stem cells (BMMSCs) can preventing osteoporosis of ovariectomized rat via ameliorating osteogenesis of endogenous BMMSCs. Methods Twelve female Sprague-Dawley rats were randomly divided into group Sham, OVX, High-dose and Low-dose. Established OVX and Sham model. 24 hours after operation, rats in group high-dose and low-dose were systemically injected BMMSCs via tail vein at the dose of 1.5×107 and 0.375×107 cells/kg, representatively. Proximal femurs were analysed by MicroCT. Osteogenesis of BMMSCs was examined by ALP, alizarin red staining and real-time PCR. Results Bone mineral density (BMD) and trabecular bone number (Tb.N) of group OVX were lower than those from group Sham. BMD and Tb.N of group High-dose were higer than group OVX. Compared to group OVX, osteogenesis of endogenous BMMSCs derived from group High-dose and Low-dose were much better, and that from group High-dose turned out to be better than group Low-dose. Conclusion It is effective to relieve symptoms of osteoporosis in ovariectomized rats through treating them with exogenous BMMSCs by the way of rescuing osteogenesis of endogenous BMMSCs.

Key words: Key words: systemic injection, bone marrow mesenchymal stem cells, osteogenesis, osteoporosis