大鼠大脑皮质胆囊收缩素受体的体外结合分析法研究  

Study on the Radioligand Binding Assay of Cholecystokinin Receptor in Rat Cerebral Cortex

作　　者：项鹏[1] 陈曼玲[1] 谭天秩[1] 史育红 

机构地区：[1]华西医科大学基础医学院生物化学教研室

出　　处：《华西医科大学学报》1999年第2期214-216,221,共4页Journal of West China University of Medical Sciences

摘　　要：用Ｂｏｌｔｏｎ－Ｈｕｎｔｅｒ试剂联结法标记胆囊收缩素（ＣＣＫ８），得１２５Ｉ－ＢＨ－ＣＣＫ８，其比放射性为３．４ＴＢｑ／ｍｍｏｌ，放射化学纯度大于９６％。取其与自制的大鼠大脑皮质细胞膜进行受体放射分析，发现标记配体与大鼠大脑皮质ＣＣＫ受体的结合具有温度和时间依赖性，可饱和性，可逆性及特异性。经Ｓｃａｔｃｈａｒｄ分析获大鼠大脑皮质细胞膜ＣＣＫ受体Ｋｄ值为１．０９８ｎｍｏｌ／Ｌ，Ｂｍａｘ为１９７．５ｆｍｏｌ／ｍｇ蛋白。A radioligand binding assay system for determining the characterization of CCK receptor is presented. Using BoltonHunter reagent, we prepared a biologically active, specific125IBHCCK8. The iodination mixture was then transferred to a column of Sephadex G25 and examined by silica thin layer chromatography. Its specific activity and radiochemical purity were 3.4 TBq/mmol and 96% respectively. Binding of125IBHCCK8 to the membrane of rat cerebral cortex was rapid, reversible, timetemperature dependent, saturable and specific. The labeled CCK was shown to have biological activity as measured by the CCK receptor radioassay. Under our laboratorial conditions, the CCK binding required an hour to reach equilibrium at 4. We chose polyethylene glycol 6 000 and globulin protein for the separation of B and F. Scatchard plot of CCK binding was linear with a Kd value of 1.098nmol/L and Bmax of 197.5 fmol/mg protein.The results of this study support the standpoint that CCK may function as a regulatory peptide in Receptor radioassaybrain and hence may be of use for clarifying the CCK receptor's function in central nervous system.

关 键 词：CCK8 放射分析 胆囊收缩素 受体 大鼠 

分 类 号：Q579.23[生物学—生物化学]