Dockray G J, Taylor I L
Gastroenterology. 1976 Dec;71(6):971-7.
The characteristics are described of an antibody (designated L6) which has virtually absolute specificity for heptadecapeptide gastrin. This antibody binds G17, but does not bind peptide fragments or molecular forms of gastrin comprising G17 with either amino acid deletions, or additions, at the carboxyl- and amino-terminals. In serum from patients with Zollinger-Ellison syndrome the only form of gastrin revealed by L6 was compatible with G17, and there was good agreement between estimated G17 concentrations in serum analyzed by gel filtration and by direct radioimmunoassay using L6. Using L6 in conjunction with antibodies specific for carboxyl- and amino-terminals of G17 it has been possible to measure concentrations of different forms of gastrin in serum of normal subjects after a meal in greater detail than previously possible. After a light meal consisting of eggs, toast, and Oxo, serum concentrations of G17 measured by L6 increased to a peak 20 min after feeding (delta gastrin, 19 pmoles per liter; n = 17). In contrast, concentration of G34 peaked at 50 min (delta gastrin, 27 pmoles per liter). Small amounts of amino-terminal fragments of G17 were present throughout the digestive period. Applying the known ratio of biological potencies of G34 and G17 for stimulation of acid secretion in man, it is estimated that G17 accounts for about 75% of the biological activity in blood after a meal, even though G34 is present in higher molar concentrations.
本文描述了一种对十七肽胃泌素具有几乎绝对特异性的抗体（命名为L6）的特性。该抗体可结合G17，但不结合胃泌素的肽片段或包含G17且在羧基末端和氨基末端有氨基酸缺失或添加的分子形式。在卓-艾综合征患者的血清中，L6检测到的唯一胃泌素形式与G17相符，通过凝胶过滤分析的血清中G17估计浓度与使用L6进行的直接放射免疫测定结果之间具有良好的一致性。将L6与针对G17羧基末端和氨基末端的特异性抗体结合使用，可以比以前更详细地测量正常受试者餐后血清中不同形式胃泌素的浓度。进食由鸡蛋、烤面包和牛肉精组成的清淡餐后，用L6检测到的G17血清浓度在进食后20分钟升至峰值（胃泌素增量为19皮摩尔/升；n = 17）。相比之下，G34浓度在50分钟时达到峰值（胃泌素增量为27皮摩尔/升）。在整个消化期均存在少量G17的氨基末端片段。应用已知的G34和G17对人胃酸分泌刺激的生物效价比，估计餐后血液中约75%的生物活性由G17介导，尽管G34的摩尔浓度更高。
