Estrogen and Testosterone Use Different Cellular Pathways to Inhibit Osteoclastogenesis and Bone Resorption

Using human peripheral blood CD14(+) osteoclast precursors, we show that testosterone directly inhibits osteoclast formation and bone resorption at physiological concentrations. Instead, estrogen has no direct effects, whereas its action seems to be mediated through osteoblasts by producing osteoprotegerin. Both estrogen and testosterone acts through their cognate receptors.