title: Characterization of an inhibitor for luteinizing hormone receptor site binding.
abstract: An inhibitor for luteinizing hormone (LH) receptor site binding has been partially purified from aqueous extracts of ovaries from pseudo-pregnant or pregnant rats. The LH receptor binding inhibitor (LH-RBI) was heat-resistant, partially inactivated by trypsin or pronase digestion, and had a molecular weight of approximately 3800 daltons. The LH-RBI was not found in the ovary of mature non-pregnant rats or immature rats, nor was it found in testis or liver extracts. The LH-RBI strongly inhibited the in vitro binding of 125I-labeled ovine LH to ovarian LH receptors but did not inhibit 125I-labeled ovine prolactin binding to ovarian PRL receptors.
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000187:drug effects*; D002850:Chromatography, Gel; D003270:Contraceptive Agents / Q000494:pharmacology; D006224:Cricetinae; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins; D007986:Luteinizing Hormone / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors*; D010053:Ovary / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology*; D011247:Pregnancy; D011555:Pseudopregnancy; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects*; D012756:Sheep; D014020:Tissue Extracts / Q000494:pharmacology
chemical_list: D003270:Contraceptive Agents; D036341:Intercellular Signaling Peptides and Proteins; C011898:LH receptor binding inhibitor; D010455:Peptides; D011956:Receptors, Cell Surface; D014020:Tissue Extracts; D007986:Luteinizing Hormone