Early effects of ovariectomy on bone microstructure, bone turnover markers and mechanical properties in rats

Background: Fragility fracture is one of the most serious consequences of female aging, which can increase the risk of death. Therefore, paying attention to the pathogenesis of PMOP is very important for elderly women. Methods: and materials: Forty 12-week-old female rats were divided into two groups including the ovariectomy group and the control group. Four rats in each group were selected at 1, 4, 8, 12 and 16 weeks after operation. Vertebral bodies and femurs were dissected completely for micro-CT scanning, biological modulus detection and histomorphological observation. Results: : In OVX group, BV/TV, Conn.D and Tb.N decreased significantly with time ( P＜ 0.05). The elastic modulus of femur in OVX group was lower than that in control group, but there was no significant difference between them ( P＞ 0.05). Over time, the TRAP, BGP, PINP and CTX-I in OVX group increased significantly ( P＜ 0.05). The micrographs of the OVX group showed sparse loss of the trabecular interconnectivity and widening intertrabecular spaces over time. Conclusion: The bone turnover rate of OVX rats in the early stage of estrogen deficiency increased. The bone loss patterns of vertebral body and femur were different, and the changes of biomechanical properties weren’t obvious.