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探讨~（１２５）Ｉ－血管活性肠肽（ＶＩＰ）与人胃腺癌及癌旁组织细胞膜、结肠腺癌及癌旁组织细胞膜的体外受体结合特性。~（１２５）Ｉ－ＶＩＰ采用ＣＨ－Ｔ法制备， Ｓｅｐｈａｄｅｘ Ｇ－５０柱层析纯化，硅胶６０Ｆ_（２５４）薄板层析（ＴＬＣ）检测。~（１２５）－Ｉ－ＶＩＰ与人胃肠腺癌及癌旁组织细胞膜进行体外时间－温度结合实验、饱和结合实验和竞争结合实验。结果显示：碘标记率７０％，~（１２５）Ｉ－ＶＩＰ比活度１８ＴＢｑ／ｍｍｏｌ，放射化学纯度９８％；~（１２５）Ｉ－ＶＩＰ与人胃腺癌及癌旁组织细胞膜、结肠腺癌及癌旁组织细胞膜的结合具有温度与时间依赖性、可饱和性及特异性；Ｓｃａｔｃｈａｒｄ作图均为一直线，提示上述组织细胞膜含有单一位点ＶＩＰ受体；胃腺癌细胞膜及癌周组织细胞膜、结肠腺癌细胞膜及癌周组织细胞膜上ＶＩＰ受体的Ｋ_ｄ值分别为１．９１、１．２６、０．９７、１．５３ｎｍｏｌ／Ｌ；Ｂ_（ｍａｘ）分别为３３９、１５６、３０４、 １５１ｆｍｏｌ／ｍｇ。研究结果表明人胃肠腺癌细胞膜与其癌旁组织细胞膜相比， ＶＩＰ受体亲和力无明显变化，最大结合容量明显增加，为ＶＩＰ受体显像奠定了直接的实验依据。
To investigate the in vitro receptor binding characteristics of ~ (125) I-vasoactive intestinal peptide (VIP) and human gastric adenocarcinoma and adjacent noncancerous cell membrane, colon adenocarcinoma and para-carcinoma cell membrane. ~ (125) I-VIP was prepared by CH-T method, purified by Sephadex G-50 column chromatography and detected by thin layer chromatography (TLC) on silica gel 60F_ (254). ~ (125) -I-VIP and human gastrointestinal adenocarcinoma and paracancerous tissue membrane in vitro time-temperature binding experiments, saturation binding experiments and competition binding experiments. The results showed that the iodine labeling rate was 70%, the specific activity of ~ (125) I-VIP was 18TBq / mmol and the radiochemical purity was 98%. The expressions of ~ (125) I-VIP and human gastric adenocarcinoma and paracancerous cell membrane, Paratumor tissue cell membrane binding temperature and time-dependent, saturability and specificity; Scatchard plot are a straight line, suggesting that the organization of the membrane contains a single site VIP receptor; gastric adenocarcinoma cell membrane and peritumoral tissue cell membrane, colon The K_d values of VIP receptors on the cell membrane of adenocarcinoma and peritumoral tissues were 1.91,1.26,0.97 and 1.53nmol / L, respectively, and the B max values were 339,156,304 and 151fmol / mg . The results showed that human gastric adenocarcinoma cell membrane compared with its adjacent cell membrane, VIP receptor affinity did not change significantly, the maximum binding capacity increased significantly for the VIP receptor imaging has laid a direct experimental basis.