Figure 3.

The effect of E2 or NAC on the osteoclastic bone resorption in ovariectomized mice. A. Representative photomicrographs of paraffin sections of tibias from 16-week-old mice of each group stained histochemically for TRAP. B. The number of TRAP-positive osteoclasts (N.Oc) per mm bone perimeter (B.Pm) was measured and presented. C. Osteoclast surface relative to bone surface (Oc.S/B.S, %). Real-time RT-PCR was performed on bone tissue extracts from 16-week-old mice of each group. D. Gene expression of RANKL/OPG ratio are shown. Messenger RNA expression, assessed by real-time RT-PCR analysis, was calculated as a ratio to the GAPDH mRNA level and expressed relative to levels in sham mice. Data are presented as the mean ± SEM of determinations, each data point is the mean of five specimens. **P<0.01, versus sham mice. ##P<0.01 versus OVX mice. A. Magnification, 200×.