Eberlein G A, Eysselein V E, Hesse W H, Goebell H, Schaefer M, Reeve J R
Department of Gastroenterology, University of Essen, Federal Republic of Germany.
Am J Physiol. 1987 Oct;253(4 Pt 1):G477-82. doi: 10.1152/ajpgi.1987.253.4.G477.
Although cholecystokinin-58 (CCK-58) is a major molecular form stored in the intestine, it has not yet been shown to be released into the circulation. This report describes in vitro degradation of CCK-58 in human blood and plasma and the molecular forms detected when this degradation is inhibited. After incubation of CCK-58 for 150 min between 20 and 24 degrees C, approximately 60% of immunoreactivity recovered was degraded to smaller immunoreactive forms. Storage of the 150-min incubate at -20 degrees C for 3 days greatly increased the observed degradation to 85%. When CCK-58 was added in vitro to blood, similar degradation occurred. Degradation of CCK-58 could be inhibited by addition of acid. Blood was obtained 1 h after a test meal designed to stimulate CCK release. The pH was lowered during collection and processing of blood and plasma to inhibit in vitro degradation of cholecystokinin. This method permitted the detection of significant amounts of CCK-58 in circulation.
尽管胆囊收缩素-58（CCK-58）是储存在肠道中的主要分子形式，但尚未证明它会释放到循环系统中。本报告描述了CCK-58在人血液和血浆中的体外降解情况，以及在抑制这种降解时检测到的分子形式。将CCK-58在20至24摄氏度下孵育150分钟后，回收的免疫反应性中约60%降解为较小的免疫反应性形式。将150分钟孵育物在-20摄氏度下储存3天，观察到的降解率大幅增加至85%。当将CCK-58体外添加到血液中时，也会发生类似的降解。添加酸可抑制CCK-58的降解。在一顿旨在刺激CCK释放的试验餐后1小时采集血液。在血液和血浆的采集及处理过程中降低pH值，以抑制胆囊收缩素的体外降解。该方法能够检测到循环系统中大量的CCK-58。
