Fig. 3

A–D Representative histological images of Safranin-O-stained femora of controls (A, B) and PTH-treated mice (C, D) at 2 (A, C) and 10 weeks (B, D) after surgery. Fibrous tissue (ft), cartilaginous tissue (ct), woven bone (wb) and cortical bone (cb) are indicated. Scale bars: 0.5 mm. E, F Callus composition (%), including fibrous tissue (white), cartilaginous tissue (gray) and osseous tissue (black), of the callus of controls (n = 5 at 2 weeks after surgery, n = 9 at 10 weeks after surgery) and PTH-treated mice (n = 5 at 2 weeks after surgery, n = 9 at 10 weeks after surgery) at 2 (E) and 10 (F) weeks after surgery, as assessed by histomorphometric analysis. G Representative histological images of TRAP-positive osteoclasts (arrowheads) within the callus tissue of controls and PTH-treated mice at 2 and 10 weeks after surgery. Scale bars: 25 μm. H TRAP-positive osteoclasts/HPF within the callus tissue of controls (white bars, n = 5 at 2 weeks after surgery, n = 9 at 10 weeks after surgery) and PTH-treated mice (black bars, n = 5 at 2 weeks after surgery, n = 9 at 10 weeks after surgery) at 2 and 10 weeks after surgery, as assessed by histological analysis. Mean ± SEM; *p < 0.05 vs. control