Micro-CT Analysis of the Mandibles and Femurs in Warfarin-Administered Rats

Objective: This study was designed to investigate whether an administration of warfarin causes morphological changes of the mandibles and femurs in rats. Methods: Sixteen male Sprague-Dawly rats, at 12-week-old were divided into 2 groups, and received daily injection of either sodium warfarin (0.18mg/Kg, WF group) or physiologic saline (PS group) for 4 weeks. The other 8 rats were sacrificed at day 0 as a baseline control. Mandibles and bilateral femurs of all rats were removed and subjected to morphological analysis. Micro-CT (Scan Xmate-E80, Comscantechno) scanning was accomplished to investigate micro architectue of right halves of femurs and mandibles using a 3D structural analysis software (TRI/3D-BON, RATOC). Trabecular bone volume (TBV) and cortical bone volume (CBV) were measured separately in the epiphysis of femurs. For measurement of TBV of mandibles, the region of interesting (ROI) was determined in the frontal section at the second molar. Results: In femurs, TBV of the femoral metaphysis were obviously smaller in WF group than that in PS group (p=0.03). In mandibles, a tendency of TBV to decrease was seen in WF group, but significant difference was not found in comparison with PS groups. In WF group, a correlation of TBV of femurs with TBV of mandibles was found (Pearson's correlation coefficient: 0.758, p=0.029). Conclusion: These results suggest that TBV of femurs and mandibles of rats are reduced in 4 weeks by daily administration of warfarin.