Na+ modulates the affinity of the lutropin/choriogonadotropin receptor.
The studies presented herein were designed to assess the effects of Na+ on the affinity of the lutropin/choriogonadotropin (LH/CG) receptor. We performed competition binding experiments in buffers containing NaCl or an isosmolar concentration of an appropriate Na+ substitute. The results presented show that Na+ decreases the affinity of LH, but not that of CG, in intact cells and membranes. In detergent-solubilized receptors, however, the affinity of LH is higher than that of CG and is not influenced by Na+. In addition, we show that Na+ does not affect the number of LH/CG receptors.
D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D006063:Chorionic Gonadotropin / Q000378:metabolism*; D003338:Corpus Luteum / Q000378:metabolism; D005260:Female; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D011974:Receptors, LH; D012964:Sodium / Q000494:pharmacology*; D013552:Swine; D014325:Tromethamine / Q000494:pharmacology
D006063:Chorionic Gonadotropin; D011956:Receptors, Cell Surface; D011974:Receptors, LH; D014325:Tromethamine; D007986:Luteinizing Hormone; D012964:Sodium