摘要
目的探讨高比活度１２５Ｉ血管活性肠肽（ＶＩＰ）的制备及其与人ＳＧＣ７９０１胃腺癌细胞受体体外结合特性。方法１２５ＩＶＩＰ采用氯胺Ｔ法标记，ＳｅｐｈａｄｅｘＧ５０柱层析分离纯化，硅胶６０Ｆ２５４薄板层析检测。１２５ＩＶＩＰ与ＳＧＣ７９０１细胞进行体外时间温度结合实验、可逆结合实验、饱和结合实验和竞争结合实验，通过１２５ＩＵｄＲ参入实验与ｃＡＭＰ生成实验评价ＶＩＰ对ＳＧＣ７９０１细胞的生物效应。结果１２５Ｉ标记率为７３８％，１２５ＩＶＩＰ比活度为１８２ＴＢｑ／ｍｍｏｌ，放射化学纯度（ＲＣＰ）为９８２％，－８０℃贮存４８天后ＲＣＰ仍有９６３％；１２５ＩＶＩＰ与ＳＧＣ７９０１细胞结合具有温度与时间依赖性、可饱和性、可逆性及特异性，Ｓｃａｔｃｈａｒｄ作图提示ＳＧＣ７９０１细胞含有高低亲和力两种ＶＩＰ受体，Ｋｄ分别为０２３０与２７８８ｎｍｏｌ／Ｌ，Ｂｍａｘ为０１２０与５６０７ｐｍｏｌ／１０６细胞；ＶＩＰ以剂量依赖方式促进ＳＧＣ７９０１细胞ｃＡＭＰ产生和ＤＮＡ的合成。结论制备的１２５ＩＶＩＰ符合作为ＶＩＰ受体特异性配体的标准，碘标记ＶＩＰ并不改变与其受体的结合活性；首次证实ＳＧＣ７９０?
Purpose To investigate the preparation of 125 I vasoactive intestinal peptide (VIP) and its characters of binding to SGC7901 cell receptors Methods VIP was labeled with Na 125 I using chloramine T method, then isolated by sephadex G 50 column chromatography and examined by silica 60F 254 thin layer chromatography (TLC) The tests of time temperature binding, reversible binding, saturable binding and competition binding between SGC7901 cells and 125 I VIP were carried out Results The labelling rate of 125 I was 73 8%, the specific activity of 125 I VIP was 18 2TBq/mmol, the radiochemical purity was over 98 2% and remained 96 3% after a 48 days' storage at -80℃ The results demonstrated that the binding of 125 I VIP to SGC7901 cells possessed the reversibility, specificity, saturability, and was time temperature dependent It was confirmed that VIP promoted the production of cAMP and the synthesis of DNA in SGC7901 cells dose dependently Scatchard plotting suggested that SGC7901 cells contained two types of VIP receptors, high affinity receptor and low affinity receptor The concentrations of Kd and B max were 0 230nmol/L and 0 120pmol/10 6 cells for high affinity receptor, 2 788nmol/L and 5 607pmol/10 6 cells for low affinity receptor Conclusions The present study indicates that the labeled 125 I VIP can be used for receptor analysis and the iodination of VIP does not change its binding to VIP receptor We are the first who have confirmed that the SGC7901 cell line expresses VIP receptors of high density and affinity
出处
《中华核医学杂志》
CAS
CSCD
北大核心
1998年第2期73-76,共4页
Chinese Journal of Nuclear Medicine
基金
国家自然科学基金
关键词
胃癌
腺癌
血管活性肠肽
碘125
Vasoactive intestinal peptide Iodine radioisotopes Isotope labeling Receptor Stomach neoplasms
