title: The endocrine background of human renal cell carcinoma. I. Binding of the highly potent progestin R 5020 by tumour cytosol.
abstract: Based on the potential sensitivity of the growth of human renal cell carcinoma, tumour tissue from 88 patients was analysed for progestin receptors. With the dextran-coated charcoal assay, cytoplasmic components which bound the potent progestin R 5020 specifically and with high affinity could be detected in 42% of the carcinomas. The apparent dissociation constant of the R-5020-binder complex amounted to 3.1 +/- 1.2 X 10(-8) mol/l. Sedimentation in sucrose gradients revealed the bulk of these components to be in the 4-S region. The ligand specificity for binding to these sites indicated a requirement for progestins. Despite the enormous case material investigated, we were unable to confirm the presence of the high receptor concentrations reported in the literature.
mesh_terms: D000230:Adenocarcinoma / Q000032:analysis* / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007680:Kidney Neoplasms / Q000032:analysis* / Q000378:metabolism; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism; D009649:Norpregnadienes / Q000378:metabolism*; D011397:Promegestone / Q000378:metabolism*; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000032:analysis*
chemical_list: D009649:Norpregnadienes; D011956:Receptors, Cell Surface; D011397:Promegestone