Figure 2.

Osteoclast stimulation increases angiogenesis in bone explants. (A) PTHrP stimulates angiogenic outgrowth from metatarsal explants by a mechanism requiring osteoclasts. Whole-mount fetal metatarsal explants from outbred mice cultured for 15 days with 3 μg/mL rh OPG-Fc or 100nM PTHrP as indicated. Images acquired as whole mounts in water with an Olympus IX71 microscope with a Plan N 2x objective, NA of 0.06, and a Spot RTKE camera with Spot Advanced software (original magnification × 2). (B) Quantification of angiogenic response to PTHrP and OPG. Angiogenesis was quantified by measurements of total CD31⁺ area (i) or angiogenic tube formation (branches; ii). Data are mean ± SEM. *P < .05. Similar results were seen in 2 experiments. Results are from 1 representative experiment of 2 performed.