Kover K, Moore W V
Horm Metab Res. 1984 Apr;16(4):193-7. doi: 10.1055/s-2007-1014740.
The binding characteristics of hGH to rat liver macrophages ( Kupfer cells) and hepatocytes have been compared to determine the role of each in the binding of hGH to liver tissue. The time course of binding, displacement of bound 125I-hGH and effect of pH on binding was qualitatively similar for macrophages and hepatocytes. Since the macrophage isolation depends upon their phagocytosis of iron particles, we determined that exposure of the isolated hepatocytes to the iron did not affect their binding of 125I-hGH. The relative capacity of the macrophage preparations was two-fold less than the hepatocyte preparations. This indicated that the hepatocyte is responsible for the majority of the hGH binding by the liver. In contrast, the cell surface concentration of the hGH receptor on the macrophage is greater than the hepatocyte. Ovine prolactin and hPrl were equipotent in competing for the binding of 125I-hGH to the macrophage receptor while only oPrl was significantly competitive in the hepatocytes. Bovine GH and hPI exhibited minimal interaction for 125I-hGH binding in both cell preparations. We conclude that even though significant differences in 125I-hGH binding do exist between hepatocytes and liver macrophages, the macrophages contribute significantly to hGH binding by hepatic tissue. The demonstration of somatomedin production by fibroblasts in culture suggest a possible role of the hepatic macrophage in GH responsiveness of the liver.
已比较了人生长激素（hGH）与大鼠肝脏巨噬细胞（库普弗细胞）及肝细胞的结合特性，以确定二者在hGH与肝脏组织结合过程中各自所起的作用。巨噬细胞和肝细胞在结合的时间进程、结合的125I-hGH的置换以及pH对结合的影响方面在性质上相似。由于巨噬细胞的分离依赖于它们对铁颗粒的吞噬作用，我们确定将分离出的肝细胞暴露于铁中并不影响其对125I-hGH的结合。巨噬细胞制剂的相对结合能力比肝细胞制剂低两倍。这表明肝细胞是肝脏中hGH结合的主要负责者。相反，巨噬细胞上hGH受体的细胞表面浓度高于肝细胞。绵羊催乳素和人催乳素在竞争125I-hGH与巨噬细胞受体的结合方面效力相当，而在肝细胞中只有绵羊催乳素具有显著的竞争性。牛生长激素和人胎盘催乳素在两种细胞制剂中对125I-hGH结合的相互作用最小。我们得出结论，尽管肝细胞和肝脏巨噬细胞在125I-hGH结合方面确实存在显著差异，但巨噬细胞对肝脏组织中hGH的结合有显著贡献。培养的成纤维细胞产生生长调节素的现象表明肝脏巨噬细胞在肝脏对生长激素的反应性中可能起作用。
