本文采用差速离心法制备胎盘微绒毛膜，用125I－Hunter试剂联接标记铁蛋白，在国内首次建立了胎盘微绒毛膜铁蛋白受体放射配体分析法，并进行了最适反应条件及铁蛋白受体的特性研究。所标记的125I一铁蛋白放化纯达95％以上，且免疫活性和生物活性均较好。用放射配体受体分析测定了11例正常足月孕妇胎盘微绒毛膜铁蛋白受体数为（3．534土1．105）×1012位点／毫克膜蛋白，亲和力常数Ka为（2．203土0．622）×107mol-1．L。实验条件为：膜蛋白160ug，125I互铁蛋白与游离铁蛋白分离的PEG浓度为12％。对铁蛋白受体特性研究表明：铁蛋白受体与铁蛋白结合具有高度特异性、可饱和性和中度亲和力。 In this paper, differential centrifugation was used to prepare placental microvilli, and 125I-Hunter reagent was used to label ferritin. The method of radioligand analysis of placental microvillioferritin receptor was established for the first time in China. The optimum reaction conditions and iron Study on the Characteristics of Protein Receptors. The labeled 125I ferritin was purely up to 95%, with good immunocompetence and biological activity. Radioligand receptor assay was used to determine the number of placental microvillioferritin receptors (3.534 ± 1.105) × 1012 sites per milligram of membrane protein in 11 normal term pregnancies and the affinity constant Ka was (2). 203 soil 0.622) × 107 mol-1. L. The experimental conditions were: membrane protein 160ug, 12% PEG concentration of 125I cofferrin isolated from free ferritin. Studies on the properties of ferritin receptors show that the binding of ferritin receptors to ferritin is highly specific, saturable and moderately affinitive.