title: Further characterization of estrogen receptors in the human oviduct.
abstract: Estrogen binding in human oviducts was studied in vitro by the dextran-coated charcoal assay and sucrose density ultracentrifugation. Estrogen binds with high affinity and limited capacity to cytosol of the human oviduct. The concentration of competitive inhibitors to produce 50% reduction in estrogen binding was 8 x 10(-8) M for the antiestrogen CI-628, 8 x 10(-7) M for the progestogen norethynodrel, and 3 x 10(-6) M for the testosterone derivative danazol at the ligand concentration of 1 nM estradiol. Nuclear estrogen binding was not inhibited by a 100-fold excess of progesterone or by a 10-fold excess of norethynodrel. Estrogen-binding protein with a sedimentation coefficient of 4S was seen in oviductal cytosol of all three anatomic segments. The nuclear 4S peak of estrogen binding was demonstrated in the ampullary tubal segment.
mesh_terms: D001667:Binding, Competitive; D002467:Cell Nucleus / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D002606:Charcoal; D003600:Cytosol / Q000378:metabolism; D003613:Danazol / Q000378:metabolism; D003911:Dextrans; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D009641:Norethynodrel / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism*
chemical_list: D003911:Dextrans; D011960:Receptors, Estrogen; D002606:Charcoal; D009641:Norethynodrel; D003613:Danazol