Production and characterization of antibodies to gonadotropin-releasing hormone receptor.
Antibodies to the gonadotropin-releasing hormone (GnRH) receptor of bovine pituitary membranes have been raised in rabbits by immunization with affinity-purified receptor preparations. These antibodies did not compete with 125I-labeled GnRH analog (Buserelin) for binding to the receptors but did precipitate rat and bovine solubilized receptors labeled with 125I-Buserelin. Binding of the antibodies to the receptors was also demonstrated by immunoprecipitation of 125I-labeled purified receptors and photoaffinity-labeled receptors. The antibodies did not have a GnRH-like activity but rather inhibited, in a dose-dependent manner, GnRH-stimulated luteinizing hormone release from cultured rat pituitary cells. In addition, the antibodies did not inhibit luteinizing hormone release stimulated by high K+ concentration. This suggests that the antibodies recognize domains of the receptor other than the binding site of the hormone and thereby inhibit the biological response. These GnRH receptor antibodies provide a useful tool for studying GnRH receptor structure, function, localization, and biosynthesis.
D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex; D002064:Buserelin / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000378:metabolism; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011966:Receptors, LHRH / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*
D000906:Antibodies; D000936:Antigen-Antibody Complex; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D002064:Buserelin; D011188:Potassium