Nexø E, Kryger-Baggesen N
Department of Clinical Chemistry, Central Hospital, Hillerød, Denmark.
Regul Pept. 1989 Aug;26(1):1-8. doi: 10.1016/0167-0115(89)90098-0.
In animals a pharmacological doses of the growth-promoting peptide epidermal growth factor (EGF) has an effect on the growth and/or maturation of several organs such as the lung, the kidney, the liver and the gastrointestinal tract. Since EGF elicits its function via binding to specific cellular receptors the presence of these receptors predicts a possible physiological role for EGF and EGF agonists. We have studied the presence of the EGF-receptor on human fetal membrane preparations from the kidney, the liver, the lung and the placenta (gestational age 13-20 weeks). The 4 membrane preparations all bind labeled EGF thus allowing us to calculate the apparent affinity constant and the number of receptors present per mg of membrane protein. The apparent affinity constant (gestational age 13-20 weeks) varies between 0.5 and 3.5 X 10(9) mol-1, median 1.3 X 10(9) mol-1 (n = 40). No difference is observed for the 4 tissues examined, and no difference is found as a function of the gestational age. The number of receptors present per mg of membrane protein (gestational age 16-20 weeks) are (range and (median) 90-220 (130) fmol, n = 10 for the kidney, 80-480 (250) fmol, n = 9 for the liver, 90-690 (300) fmol, n = 10 for the lung, and 2100-4200 (3400) fmol, n = 7 for the placenta. Results for a fetus of gestational age 13 weeks show high values for kidney receptors (240 fmol) and lung receptors (800 fmol) and low values for the placenta receptors (410 fmol).
在动物中,药理剂量的促生长肽表皮生长因子(EGF)对多个器官的生长和/或成熟有影响,如肺、肾、肝和胃肠道。由于EGF通过与特定细胞受体结合来发挥其功能,这些受体的存在预示着EGF和EGF激动剂可能具有生理作用。我们研究了来自肾、肝、肺和胎盘(妊娠13 - 20周)的人胎膜制剂上EGF受体的存在情况。这4种膜制剂均能结合标记的EGF,从而使我们能够计算出表观亲和常数以及每毫克膜蛋白中存在的受体数量。表观亲和常数(妊娠13 - 20周)在0.5至3.5×10⁹ mol⁻¹之间变化,中位数为1.3×10⁹ mol⁻¹(n = 40)。在所检查的4种组织中未观察到差异,也未发现其随妊娠年龄的变化而有差异。每毫克膜蛋白中存在的受体数量(妊娠16 - 20周)分别为:肾90 - 220(130)fmol,n = 10;肝80 - 480(250)fmol,n = 9;肺90 - 690(300)fmol,n = 10;胎盘2100 - 4200(3400)fmol,n = 7。妊娠13周胎儿的结果显示,肾受体(240 fmol)和肺受体(800 fmol)的值较高,胎盘受体(410 fmol)的值较低。