Identification of androgen receptors in normal human osteoblast-like cells.

The sex steroids, androgens and estrogens, are major regulators of bone metabolism. However, whether these hormones act on bone cells through direct or indirect mechanisms has remained unclear. A nuclear binding assay recently used to demonstrate estrogen receptors in bone Eriksen, E.F., Colvard, D.S., Berg, N.J., Graham, M.L., Mann, K.G., Spelsberg, T.C. the concentration of bound estradiol receptor was 1537 +/- 221 molecules per cell nucleus. The concentrations of nuclear binding sites were similar in males and females for both [3HR1881 and 3Hestradiol. We conclude that both androgens and estrogens act directly on human bone cells through their respective receptor-mediated mechanisms.