Effect Of Calcitonin On Bone Microdamage And Biomechanics In Ovariectomized SD Rat

Objective:To explore effects of Calcitonin on bone microdamage and biomechanics in ovariectomized Spargue-Dawley rats.Methods:70female44-week-old Spargue-Dawley rats were randomly divided into four groups:10rats in baseline group(BS),20rats in sham-operated (SHAM),20rats in ovariectomized group(OVX) and20rats in ovariectomized+calcitonin group(OVX+C), The baseline group were killed at the beginning of the experiment. At the4rd,12th week after operation the rats were killed respectively. The4th vertebrae were used for fatigue damage test by PLD5010bone fatigue experiment device. The parameters of linear microcrack were measured and the right femur were used for three-point bending tests.Results:Microdamage could be viewed in every sample, including microcrack, few cross-hatching microdamage, diffuse damage and microfracture. microcrack was the most usual microdamage type. At4th week, Significant difference of microcrack parameters(Mean microcrack length, Microcrack surface density, Microcrack density)of vertebrae was observed between OVX group and SHAM group(P<0.05), OVX group and OVX+C group(P<0.05), also between OVX+C and SHAM group(P< 0.05).At12th week, Significant difference of microcrack parameters of vertebrae was observed between OVX group and SHAM group(P<0.05), also between OVX group and OVX+C group(P<0.05), but not between SHAM and OVX+C group(P>0.05).There is no significant difference of biomechanics parameters of the right femur in each group at4th and12th week(P>0.05).Conclusion:Calcitonin can improve bone microstructure of vertebrae and there is no significant effect on biomechanics of the femur in ovariectomized Spargue-Dawley rats. The microcrack parameters can be considered alternative parameters in the evaluation of bone microstructure quality.