Appearance of exogenous epidermal growth factor in liver, bile, and intestinal lumen of suckling rats.
Appearance of exogenous epidermal growth factor in liver, bile, and intestinal lumen of suckling rats.
复制标题
乳鼠肝脏、胆汁和肠腔中外源性表皮生长因子的出现。
DOI：
10.1016/0016-5085(92)90117-h
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发表时间：
1992
期刊：
影响因子：
29.4
通讯作者：
Rao,RK
中科院分区：
文献类型：
--
作者：
Kong,WY;Koldovský,O;Rao,RK
本实验研究了静脉注射[125I]大鼠表皮生长因子（rEGF）在哺乳大鼠肝脏和胃肠道中的分布和降解情况。麻醉大鼠胆管插管，将[125I]rEGF（含或不含2500倍过量未标记rEGF）注入股静脉。5、30、60、120分钟后，测定肝脏、胃、小肠、血液、肾脏、胆汁及胃、小肠内腔内容物的放射性。然后通过免疫亲和层析分析提取的放射性并与egf特异性受体结合。5分钟后，肝脏（占总剂量的57%）和小肠（10%）的放射性水平较高，逐渐下降。与此相反，随着时间的延长，胆汁和小肠内的放射性物质呈增加趋势。在60分钟和120分钟内，胆汁中的放射性分别占总剂量的2.4%和4.5%。在最初的60分钟内，肝脏、小肠、胆汁和肠道内容物中90%以上的放射性物质具有免疫反应性。胆汁和肝脏中34% - 70%的放射性物质以及小肠壁和内容物中20%-41%的放射性物质能够与egf特异性受体结合。在肝脏、胆汁、小肠和肠道内容物中检测到的放射性被过量注射未标记的EGF大大降低。这些研究表明，静脉给药[125I]rEGF被肝脏和胃肠道迅速吸收，并以能够结合抗egf抗体和egf特异性受体的形式分泌到哺乳大鼠的胆汁和肠腔内容物中。肝和小肠的摄取和分泌似乎是受体介导的。
This study was performed to investigate the distribution and the degradation of IV administered [125I]rat epidermal growth factor (rEGF) in the liver and gastrointestinal tract of suckling rats. The bile duct of anesthetized rats was cannulated, and [125I]rEGF was injected (with or without 2500-fold excess unlabeled rEGF) into the femoral vein. After 5, 30, 60, and 120 minutes, the radioactivity in the liver, stomach, small intestine, blood, kidney, bile, and luminal contents of the stomach and small intestine was measured. The extracted radioactivity was then analyzed by immunoaffinity chromatography and binding to EGF-specific receptors. High levels of radioactivity were found in the liver (57% of total administered) and small intestine (10%) at 5 minutes, which gradually decreased. On the contrary, radioactivity secreted in the bile and luminal contents of the small intestine increased with time. The radioactivity in the bile represented 2.4% and 4.5% of the total administered at 60 and 120 minutes, respectively. During the first 60 minutes, more than 90% of the radioactivity in the liver, small intestine, bile, and intestinal contents was immunoreactive. Thirty-four to seventy percent of the radioactivity in the bile and liver and 20%–41% of radioactivity in the small intestinal wall and contents were capable of binding to EGF-specific receptors. Radioactivity detected in the liver, bile, small intestine, and intestinal contents was profoundly reduced by the coinjection excess of unlabeled EGF. These studies show that IV administered [125I]rEGF is rapidly taken up by the liver and the gastrointestinal tract and secreted into the bile and intestinal luminal contents of suckling rats in form(s) capable of binding to anti-EGF antibody and EGF-specific receptors. The uptake and secretion by the liver and the small intestine appear to be receptor mediated.