Role of the liver in regulating somatomedin activity: hormonal effects on the synthesis and release of insulin-like growth factor and its carrier protein by the isolated perfused rat liver.
Role of the liver in regulating somatomedin activity: hormonal effects on the synthesis and release of insulin-like growth factor and its carrier protein by the isolated perfused rat liver.
复制标题
肝脏在调节生长调节素活性中的作用：激素对离体灌注大鼠肝脏合成和释放胰岛素样生长因子及其载体蛋白的影响。
作者：
Don S. Schalch;Udo E. Heinrich;Boris Draznin;Carolyn J. Johnson;Leon L. Miller
以往的研究表明，一个或多个生长激素依赖的生长激素(Sm)是由肝脏合成或至少释放的。采用大鼠离体肝灌流技术和竞争性蛋白结合试验，研究了胰岛素样生长因子(IGF)及其载体蛋白(CP)在正常大鼠和去垂体大鼠肝脏中的净累积释放量。7个正常肝脏的灌流液中的IGF浓度在最初的2小时内迅速增加，在12小时的其余时间内更加缓慢。12h的平均净累积释放量为5620±740μU/300cm2(供体表面积)。与IGF的释放模式相反，CP的释放最初非常缓慢，但在12h后迅速增加，达到5.0±0.9 mg/300cm2。在6只正常肝脏灌流中加入牛生长激素后，胰岛素样生长因子的释放量显著增加(9210±850μU/300cm2)，而CP的释放量却没有显著增加(5.4cm2±0.07cm2).
Previous studies have indicated that one or more GH-dependen t somatomedins (SMs) are either synthesized or at least released by the liver. Employing the isolated rat liver perfusion technique and a competitive protein-binding assay to measure one of the SMs [insulin-like growth factor (IGF)] and its carrier protein (CP), the net cumulative release of these peptides from normal and hypophysectomized (hypox) rat livers has been studied. The IGF concentration in the perfusates of seven normal livers increased rapidly during the initial 2 h and more gradually during the remainder of a 12-h perfusion. The mean (± SEM) net cumulative release of IGF at 12 h was 5620 ± 740 μU/300 cm2 (donor body surface area). In contrast to the pattern of IGF release, the release of CP was very slow initially but increased rapidly by the 12th h to 5.0 ± 0.9 mg/300 cm2. The addition of bovine GH to the perfusions of six normal livers caused a significant increase in the release of IGF(9210 ± 850 μU/300 cm2) but not of CP (5.4 ± ...