title: Peptide-receptor protein relationships: steroid feedback in GnRH stimulation of the anterior pituitary.
abstract: Gonadotropin releasing hormone receptor protein (GnRH.RP) purified to homogeneity has several binding sites for its effector hormone, as evidenced from the concentration dependence binding curve. Binding of a fully biologically active iodinated GnRH decreased (P less than 0.001) by pretreatment of immobilized receptor protein with physiological concentrations of both main sex steroids, testosterone and estradiol 17-beta. With increasing concentrations of the steroids the binding of 125I-GnRH decreased biphasically for testosterone and multiphasically for estradiol 17-beta. The findings are conducive to an allosteric receptor model.
mesh_terms: D000818:Animals; D002369:Castration; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D005246:Feedback; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D011966:Receptors, LHRH; D013739:Testosterone / Q000494:pharmacology
chemical_list: D011956:Receptors, Cell Surface; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone