Jørgensen P E, Nexø E, Raaberg L, Rasmussen T N, Poulsen S S
Department B, University of Copenhagen, Denmark.
Regul Pept. 1990 Sep 10;30(2):113-23. doi: 10.1016/0167-0115(90)90052-x.
The 45 kDa epidermal growth factor (EGF-(45 kDa)) has been purified from rat urine. We have investigated the distribution and the processing of i.v. injected 125I-labeled EGF-(45 kDa) in the rat. 2.5 min after the i.v. injection only 12% of the label remained in the blood. Most of the label was found in the liver (54%), in the kidneys (7%) and in the skin (4%). The submandibular glands, stomach, small intestine, colon, spleen and lungs contained 1% or less of the radioactivity. Some of the 125I-EGF-(45 kDa) was processed to 125I-EGF-(6 kDa) immunoreactivity in the liver and in the kidneys. The kidneys excreted 125I-EGF-(45 kDa) in the urine, but we were not able to demonstrate 125I-EGF-(6 kDa) in urine. In conclusion, this study shows that homologous EGF-(45 kDa) is cleared from the circulation of rats within a few minutes, mainly by the liver and the kidneys. In vivo both the liver and the kidneys are able to process some of the EGF-(45 kDa) to EGF-(6 kDa) immunoreactivity.
45 kDa表皮生长因子（EGF-(45 kDa)）已从大鼠尿液中纯化出来。我们研究了静脉注射125I标记的EGF-(45 kDa)在大鼠体内的分布及代谢情况。静脉注射后2.5分钟，仅12%的标记物仍留在血液中。大部分标记物存在于肝脏（54%）、肾脏（7%）和皮肤（4%）中。下颌下腺、胃、小肠、结肠、脾脏和肺中的放射性物质含量为1%或更低。部分125I-EGF-(45 kDa)在肝脏和肾脏中被加工成具有125I-EGF-(6 kDa)免疫反应性的物质。肾脏将125I-EGF-(45 kDa)排泄到尿液中，但我们未能在尿液中检测到125I-EGF-(6 kDa)。总之，本研究表明，同源EGF-(45 kDa)在几分钟内就从大鼠循环中清除，主要是通过肝脏和肾脏。在体内，肝脏和肾脏都能够将部分EGF-(45 kDa)加工成具有EGF-(6 kDa)免疫反应性的物质。
