Orskov C, Holst J J
Scand J Clin Lab Invest. 1987 Apr;47(2):165-74.
Gene-sequencing studies have shown that the glucagon precursor contains two additional glucagon-like sequences, the so-called glucagon-like peptides 1 and 2 (GLP-1 and GLP-2). We developed radio-immunoassays against synthetic peptides corresponding to these sequences. Antisera were raised in rabbits after carbodiimide conjugation of peptides to BSA. The selected antisera showed neither mutual cross-reactivity nor cross-reacted with any other peptide of the glucagon family. Trypsin digestion experiments showed that both antisera were directed against the C-terminus of the antigen peptides. Labelling was performed with chloramine T, and separation with plasma-coated charcoal. The detection limit was 7 and 25 pmol/l for GLP-1 and GLP-2. Accurate measurement of both peptides in plasma required extraction. Optimum recovery was obtained with ethanol at 75% (final concentration). The concentrations measured in fasting plasma from 10 normal subjects were 107 +/- 7 pmol/l and 151 +/- 14 pmol/l for GLP-1 and GLP-2, respectively. After a mixed meal the concentrations rose slowly for 2 h reaching 145 +/- 13 and 225 +/- 15 pmol/l.
基因测序研究表明，胰高血糖素前体包含另外两个类胰高血糖素序列，即所谓的胰高血糖素样肽1和2（GLP-1和GLP-2）。我们针对与这些序列对应的合成肽开发了放射免疫测定法。在将肽与牛血清白蛋白（BSA）通过碳二亚胺偶联后，在兔体内产生抗血清。所选抗血清既不相互交叉反应，也不与胰高血糖素家族的任何其他肽交叉反应。胰蛋白酶消化实验表明，两种抗血清均针对抗原肽的C末端。用氯胺T进行标记，并用血浆包被的活性炭进行分离。GLP-1和GLP-2的检测限分别为7和25 pmol/l。准确测量血浆中的两种肽需要进行提取。用75%（终浓度）的乙醇可获得最佳回收率。10名正常受试者空腹血浆中测得的GLP-1和GLP-2浓度分别为107±7 pmol/l和151±14 pmol/l。混合餐后，浓度在2小时内缓慢上升，分别达到145±13和225±15 pmol/l。
