Specific binding of estrogen to osteoclast surfaces.

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