Immunoreactive component resembling cholecystokinin octapeptide in intestine
Immunoreactive component resembling cholecystokinin octapeptide in intestine
复制标题
肠道中类似缩胆囊素八肽的免疫反应成分
作者：
G. Dockray
许多激素以多种分子形式存在。肠道激素胆囊收缩素以 33 和 39 个氨基酸残基（CCK33 和 CCK39）1-4 的肽形式从猪十二指肠中分离出来。猪大脑皮层提取物已被证明含有具有 CCK 样免疫反应性的成分5，但经凝胶过滤，大脑中的主要成分具有 CCK33 和 CCK395 的 COOH 末端八肽 (CCK8) 的特性。其他几种激素和相关肽可能以相同的形式存在于大脑和肠道中，因此似乎在肠道中也发现了 CCK8 样因子。已知合成的 CCK8 在激素的主要靶器官（胆囊和外分泌胰腺）7 上的摩尔浓度约为 CCK33 的两倍，因此 CCK8 在肠道中的可能存在具有生理意义。我们研究了猪十二指肠和空肠提取物中的免疫反应性 CCK 样因子，并在此报告了相对高浓度的 CCK8 样成分的存在。用于纯化 CCK33 和 CCK39 的方法很难提取该因子，这可能解释了为什么它以前被忽视。
MANY hormones exist in several molecular forms. The intestinal hormone cholecystokinin has been isolated from hog duodenum in the form of peptides of 33 and 39 amino acid residues (CCK33 and CCK39)1–4. Extracts of hog cerebral cortex have been shown to contain components with CCK-like immunoreactivity5, but on gel filtration the main component in brain had the properties of the COOH-terminal octapeptide (CCK8) of CCK33 and CCK395. Several other hormonal and related peptides probably occur in identical forms in brain and gut6, so it seemed possible that a CCK8-like factor would also be found in intestine. Synthetic CCK8 is known to be about twice as potent on a molar basis as CCK33 on the main target organs of the hormone (gall bladder and exocrine pancreas)7 so that the possible existence of CCK8 in the intestine is of physiological significance. We have studied immunoreactive CCK-like factors in extracts of hog duodenum and jejunum and we report here the presence of relatively high concentrations of a CCK8-like component. This factor was poorly extracted by the method used to purify CCK33 and CCK39 which may explain why it was previously overlooked.