Binding characteristics of pancreatic polypeptide receptors on rat hepatic membranes  

Binding characteristics of pancreatic polypeptide receptors on rat hepatic membranes 1

作　　者：张新堂[1] 姚矢音[1] 许英镐[1] 朱尚权[1] 

机构地区：[1]中国科学院上海生物化学研究所

出　　处：《中国药理学报》1999年第1期59-64,共6页Acta Pharmacologica Sinica

摘　　要：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５４ｎｍｏｌ·Ｌ－１和１５８ｎｍｏｌ·Ｌ－１．结论：大鼠肝膜存在胰多肽的专一结合受体。AIM: To study the binding characteristics of pancreatic polypeptide(PP) receptors on rat hepatic membranes. METHODS: 125 I PP suitable to study interaction between ligand and receptors were prepared. 125 I porcine PP and 125 I duck PP were used to study PP receptor binding in the controlled conditions. RE￣SULTS: The binding of 125 I porcine PP to receptors on rat hepatic membranes was time and temperature dependent. The specific binding of 125 I porcine PP was inhibited by unlabeled porcine PP in a concentration dependent manner, whereas duck PP was only partially inhibited in the high concentration (>500 nmol·L -1 ). Scatchard analysis produced a curvilinear plot, suggesting multiple affinity binding sites, ie, high affinity and low affinity with dissociation constants ( K d) 5 4 and 158 nmol·L -1 , respectively. CON￣CLU￣SION: Rat hepatic membranes possessed specific PP receptors and porcine PP binding activity was much higher than that of duck PP.

关 键 词：胰多肽 胰腺激素 受体 结合位点 肝细胞膜 

分 类 号：Q578[生物学—生物化学]