Figure 1.

Ovariectomy fails to increase osteoclast formation in cultures of bone marrow cells from nude mice. Mean (± SEM) number of osteoclasts from three independent experiments (n = 6 wells per group). ^AP < 0.05 compared to estrogen replete mice. (a) Unfractionated bone marrow cells (10⁶ cells/well) from OVX and estrogen-replete nude and euthymic mice were harvested 4 weeks after surgery and cultured for 7 days with 1,25(OH)₂D₃ (10^–8M) to induce osteoclast formation. (b) Bone marrow cells were depleted of stromal cells by adherence for 12 hours. Nonadherent bone marrow cells (10⁶ cells/well) were cultured for 7 days with optimal osteoclastogenic concentrations of M-CSF (25 ng/ml) and RANKL (100 ng/ml). OC, osteoclast.