Hwang D L, Lev-Ran A
Department of Diabetes, Endocrinology and Metabolism, City of Hope National Medical Center, Duarte, CA 91010.
Regul Pept. 1990 Jul 30;29(2-3):103-8. doi: 10.1016/0167-0115(90)90073-6.
Anesthetized mice were infused into the tail vein with 7.5% mannitol in saline (0.1 ml/min for 60 min) alone or with EGF at 0.5 microgram/min. Urine was collected every 10 min starting 20 min after the beginning of the infusion and ending 20 min after its termination. EGF concentration in the serum of mice infused with EGF increased from the baseline level of 0.6 +/- 0.4 to 70.7 +/- 16.0 ng/ml at 80 min. Total excretion of EGF for 80 min was 117 +/- 49 ng with mannitol alone and 1916 +/- 420 ng (6.4% of the EGF infused) after mannitol with EGF. Serum and urine EGF was indistinguishable from the native mouse EGF by its radioimmunoassay and HPLC characteristics. Intact labeled EGF was also found in urine when mice were infused with 125I-EGF (1 x 10(6) cpm/ml) in mannitol. After 5 min infusion with 125I-EGF (6 x 10(6) cpm/ml in saline), more than 80% of the label was found in the liver and kidneys and more than 90% of it was intact EGF. However, 30 min after infusion more than 95% of the labeled EGF was degraded. We conclude that at least part of the urinary EGF in mice originates in blood and that liver and kidneys are the main organs of EGF degradation.
将麻醉的小鼠经尾静脉单独输注生理盐水（0.1毫升/分钟，共60分钟）或同时输注0.5微克/分钟的表皮生长因子（EGF）。从输注开始20分钟后至结束后20分钟，每隔10分钟收集尿液。输注EGF的小鼠血清中EGF浓度在80分钟时从基线水平0.6±0.4升高至70.7±16.0纳克/毫升。单独输注甘露醇时，80分钟内EGF的总排泄量为117±49纳克；输注甘露醇并同时输注EGF后，总排泄量为1916±420纳克（占输注EGF的6.4%）。通过放射免疫分析和高效液相色谱特性，血清和尿液中的EGF与天然小鼠EGF无法区分。当给小鼠输注甘露醇中含有的125I - EGF（1×10⁶ 计数每分钟/毫升）时，尿液中也发现了完整的标记EGF。在以125I - EGF（6×10⁶ 计数每分钟/毫升于生理盐水中）输注5分钟后，超过80%的标记物存在于肝脏和肾脏中，且其中超过90%为完整的EGF。然而，输注30分钟后，超过95%的标记EGF被降解。我们得出结论，小鼠尿液中的EGF至少部分来源于血液，且肝脏和肾脏是EGF降解的主要器官。
