Radioimmunoassay for neurotensin, a hypothalamic peptide.
Radioimmunoassay for neurotensin, a hypothalamic peptide.
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神经降压素（一种下丘脑肽）的放射免疫测定。
DOI：
10.1016/s0021-9258(17)32937-x
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
S. Leeman
中科院分区：
文献类型：
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作者：
R. Carraway;S. Leeman
利用125I标记的神经降压素和人工合成神经降压素的兔抗血清，建立了一种高灵敏度和特异性的神经降压素放射免疫分析方法。所描述的三种抗血清具有不同的特异性，但主要针对神经降压素的COOH末端区域，这是分子的生物活性部分。其中两种抗血清Poly(Glu60，Lys40)(来自4号动物)和Keyhole Limet血蓝蛋白(来自8号动物)与神经降压素的COOH末端部分序列完全交叉反应，而抗血清Poly(Glu60，Lys40)(来自6号动物)需要整个分子才能完全识别。该方法可以检测到低于3fmol的神经降压素，无论使用何种抗血清，合成神经降压素和天然神经降压素的剂量-反应曲线都是可叠加的。利用这些检测系统，对45公斤牛下丘脑的酸/丙酮提取物中的免疫活性进行了纯化，结果表明免疫活性来自完整的神经降压素，而不是神经降压素的片段或相关分子。从牛、大鼠、豚鼠和兔下丘脑中获得的放射免疫可分析神经降压素(R-NT)也给出了与神经降压素平行的剂量-反应曲线，每克湿组织中的神经降压素当量在45至70pmol/g范围内。三种抗血清的测量结果是一致的，特别是在Sephadex G-25层析后；这些下丘脑提取物中的R-NT也被已知的裂解神经降压素的各种酶处理而破坏。
A highly sensitive and specific radioimmunoassay for neurotensin has been developed which utilizes 125I-labeled neurotensin and rabbit antisera raised toward synthetic neurotensin which has been coupled specifically through its lysine side chain to several proteins. The three antisera described have different specificities but are directed primarily towards the COOH-terminal region of neurotensin which is the biologically active portion of the molecule. Two of the antisera, poly(Glu60, Lys40) (from animal no. 4) and keyhole limpet hemocyanin (from animal no. 8), cross-react fully with COOH-terminal partial sequences of neurotensin while antiserum poly(Glu60, Lys40) (from animal no. 6) requires the entire molecule for full recognition. The assay can detect less than 3 fmol of neurotensin and the dose-response curves for synthetic and native neurotensin are superimposable, irrespective of the antiserum employed. Using these assay systems, the immunoactivity in acid/acetone extracts of 45 kg of bovine hypothalami was purified to homogeneity and shown to be attributable to intact neurotensin and not to fragments of neurotensin nor to related molecules. Radioimmunoassayable neurotensin (R-NT) obtained from bovine, rat, guinea pig, and rabbit hypothalami also gave dose-response curves which paralleled that of neurotensin and the neurotensin equivalents per g of wet tissue were in the range 45 to 70 pmol/g. Measurements with the three antisera were in agreement, especially after the extracts were chromatographed on Sephadex G-25; R-NT in these hypothalamic extracts has also been shown to be destroyed by treatment with various enzymes known to cleave neurotensin.