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作者对人体胃粘膜、十二指肠粘膜、结肠粘膜或胰腺组织的外科手术标本以~(125)Ⅰ标记的胃泌素17(~(125)Ⅰ-G17)进行特异性结合(specific binding)的研究(译者注:这些标本捣碎离心后获得细胞膜碎片,其中含有G-17的受体和其他膜蛋白质。加入~(125)Ⅰ-G 17后,部分与受体结合,称特异性结合,部分与其他膜蛋白质结合,称非特异性结合,故混合物离心后对沉渣所测得的放射性(cpm)为总结合;如以G-17或五肽胃泌素先加入与受体结合使之饱和,然后加入~(125)Ⅰ-G 17,则~(125)Ⅰ-G 17只与膜蛋白质结合,此时对沉渣所测得的放射性为非特异性结合,总结合减去非特异性结合即得特异性结合。)对胃底腺粘膜,研究了受体结合的标准。结果如下:(1)证实有饱和性,即有限度的结合能力;(2)与G-17有高度的亲和力,其离解常数为1.6×10~(-9)M,结合能力(bin-ding capacity)为15fmol/mg 蛋白质;(3)组织特异性,证实与胃底腺粘膜有高度的结合力;(4)激素特异性,证实与G-17及五肽胃泌素有高度特异性。标记物与十二
The authors specifically bind the gastrin 17 (~(125)I-G17) labeled with ~(125)I to surgical specimens of the human gastric mucosa, duodenal mucosa, colon mucosa, or pancreatic tissue. Research (Translator’s Note: These specimens were crushed and centrifuged to obtain cell membrane debris containing G-17 receptors and other membrane proteins. After the addition of ~(125)I-G 17, some of them bind to receptors, The binding, partly combined with other membrane proteins, is called non-specific binding, so the measured radioactivity (cpm) of the mixture after centrifugation is the total binding; for example, G-17 or pentagastrin is first added to bind to the receptor. Saturation, and then added ~ (125) I-G 17, then ~ (125) I-G 17 only with the membrane protein binding, the radioactivity measured on the sediment is non-specific binding, total binding minus non-specific binding That is, specific binding is achieved.) On the fundic glandular mucosa, the criteria for receptor binding have been studied. The results are as follows: (1) Saturation, ie, limited binding ability; (2) High affinity with G-17, dissociation constant of 1.6×10 -9 M, binding ability (bin-ding) (15) capacity (15 fmol/mg protein); (3) tissue specificity, confirming a high degree of binding to the gastric gland mucosa; (4) hormone specificity, confirming high specificity with G-17 and pentagastrin. Markers and Twelve