Specific estrogen binding sites in human lymphoid cells and thymic cells.

The binding of estrogen in preparations of human peripheral blood mononuclear cells, as well as by splenic and thymic cells is demonstrated by three different approaches (Dextran-coated charcoal method, whole cell assay, and gel filtration on a sepharose 4B column). Scatchard's analysis of [3H]-moxestrol (R2858) and [3H]-estradiol binding proves the existence of a single class of receptor sites having a dissociation constant of 0.18-2.4 X 10(-9) M. Physicochemical properties of the binder, including binding capacity and steroid specificity, are quite similar to those reported for the thymus of small mammalian species or human thymoma.