Bone mineral content and density

The BMC (g) and BMD (g/cm²) of the rats were measured by DXA with a small-animal high-resolution collimator (Discovery A/SL/W/C; Hologic, Bedford, MA, USA). The rats were anaesthetized as described previously, and then were positioned on the DXA table in prone position with legs separated from the trunk to scan the whole bodies. After the scan, the regions of interest (ROIs) were marked across the entire L6 regions. Analyses were performed using the small-animal mode of the software supplied with the collimator (v. 13.2:3; Hologic), which was calibrated at the start of each experiment.