Specific Binding of Estrogen to Osteoclast Surfaces

Specific plasma membrane binding sites for 17β-estradiol were shown to exist on avian osteoclasts by the use of a fluorescent conjugated estrogen, 17β-estradiol -6- carboxymethyloxime- bovine serum albumin fluorescein isothiocyanate. Binding was dose and time dependent, as well as specific, since 17β-estradiol blocked the binding of the complex. Tamoxifen was also an effective blocking agent. Rapid responses to 17β-estradiol included decreased acid production (41.5%) and distinct cell shape changes.