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目的：研究大鼠肝膜胰多肽受体的结合特性．方法：在控制条件下，用１２５Ｉ标记的胰多肽进行胰多肽受体的结合特性研究．结果：制备了适用于进行配体和受体相互作用研究的１２５Ｉ标记的猪胰多肽和鸭胰多肽．１２５Ｉ猪胰多肽与大鼠肝膜胰多肽受体结合依赖于时间和温度，而这一专一结合能被未标记的猪胰多肽以剂量关系所抑制．鸭胰多肽只有在高浓度下才显示出部分抑制作用．Ｓｃａｔｃｈａｒｄ作图分析表明大鼠肝膜存在两种胰多肽的结合位点，高亲和结合位点和低亲和结合位点．它们的结合解离常数Ｋｄ分别为５４ｎｍｏｌ·Ｌ－１和１５８ｎｍｏｌ·Ｌ－１．结论：大鼠肝膜存在胰多肽的专一结合受体，而且猪胰多肽对这些受体的结合活性要比鸭胰多肽高得多
Objective: To study the binding characteristics of rat hepatic membrane pancreatic polypeptide receptor. Methods: Under the controlled conditions, the binding properties of pancreatic polypeptide receptor were studied with 125I-labeled pancreatic polypeptide. Results: 125I-labeled porcine pancreatic polypeptide and duck pancreatic polypeptide suitable for ligand-receptor interaction studies were prepared. The binding of 125I porcine pancreatic polypeptide to the rat hepatic membrane pancreatic polypeptide receptor depends on time and temperature and this specific binding can be dose-dependently inhibited by unlabeled porcine pancreatic polypeptide. Duck pancreatic peptides showed partial inhibition only at high concentrations. Scatchard mapping analysis showed that there are two pancreatic polypeptide binding sites, high affinity binding sites and low affinity binding sites in rat hepatic membranes. Their dissociation constants Kd were 54nmol·L-1 and 158nmol·L-1, respectively. CONCLUSIONS: There is a specific binding partner of pancreatic polypeptide in rat liver membrane, and the binding activity of porcine pancreatic polypeptide to these receptors is much higher than that of duck pancreatic polypeptide