FIGURE 6.

Pb inhibits osteogenesis and is rescued, in part, in cells from SOST knock-out mice. Bone marrow was harvested from 3-month-old WT and SOST-KO mice treated with 0, 50, or 500 ppm of Pb in drinking water. A, mesenchymal cells were induced by osteogenic medium to form bone nodules. Left, representative alkaline phosphatase staining on day 14 of differentiation. Right, quantification. B, osteoclastogenesis was initiated in marrow cells for 7 days. Left, representative osteoclasts are presented; right, TRAP-positive stains were quantified. Data represent mean ± S.E. for three trials. *, p < 0.05 versus WT control, #, p < 0.05 versus KO control.