| Objective To investigate the effect of different doses of cyclophosphamide ( CP) on bone mineral density ( BMD) and bone microstructure in female SD rats.Methods Forty SD 3-month-old female rats were randomly divided into low dose of CP group, middle dose of CP group, high dose of CP group, and control group ( n=10 in each group) .Rats in the CP groups were intrapentonally injected with different doses of CP (5, 8, or 10 mg/kg, respectively).Rats in control group were intrapenitoneally injected with the same volume of normal saline.The injection was once a day, and lasted for 15 days.BMD and bone microstructure in rats were observed.Results BMD of the total body in different CP dose groups declined by 9.8%, 13.3%, and 15.6%, respectively, compared to that in control group.Trabecular number in the femur declined by 49.8%, 65.5%, and 72.8%, respectively.Trabecular separation of the femur increased by 225.2%, 416.9%, and 577.4%, respectively.Conclusion CP may decrease BMD and trabecular number in rats, and demage bone microstructure.The higher dose of cyclophosphamide, the more serious the damage of bone microstructure. |