title: Presence of oestrogen receptors in human blood mononuclear cells and thymocytes.
abstract: We studied oestrogen binding sites in blood mononuclear cells from healthy blood donors, patients with leukaemia or systemic lupus erythematosus, and in thymocytes, using the dextran-coated charcoal assay and Scatchard analysis of binding data. Using 3H-labelled oestradiol as ligand, inaccurate results were obtained which could be related to the low amounts of binding sites. Using 125I-labelled ligand, saturable oestradiol binding sites could be demonstrated in low amount (mean value 2.1 fmol/mg of cytosolic protein) and high affinity (mean Kd value 0.26 nM; mean Ka value 3.85 X 10(9) M-1). The binding could be inhibited by unlabelled oestradiol but not with oestrone, dihydrotestosterone, cortisol and the progestin-receptor ligand Org 2058. We conclude that blood mononuclear cells and thymocytes contain true oestrogen receptors. This conclusion supports current hypotheses on the involvement of such receptors in oestrogen-mediated modulation of the immune system.
mesh_terms: D000328:Adult; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D007938:Leukemia / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D011869:Radioligand Assay; D011960:Receptors, Estrogen / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D011960:Receptors, Estrogen; D004958:Estradiol