Kashiwagi A, Harano Y, Kosugi K, Nakano T, Hidaka H, Shigeta Y
J Biochem. 1985 Feb;97(2):679-84. doi: 10.1093/oxfordjournals.jbchem.a135104.
The specific [125I]insulin binding to primary cultured hepatocytes was significantly greater than that to freshly isolated hepatocytes. Low affinity insulin binding sites in cultured cells were 6-fold greater in number than those of freshly isolated cells without a significant change in high affinity sites. However, both sensitivity (insulin concentration for half maximum stimulation) and responsiveness (% of increase above the basal level) to insulin for the stimulation of ODC activity were similar for isolated and cultured cells indicating an important role of high affinity sites in the insulin action. On the other hand, the specific [125I]glucagon binding to cultured cells was significantly decreased. Low affinity glucagon binding sites in cultured cells decreased by about 50% in cultured cells without a significant change in high affinity sites. Both sensitivity and responsiveness to glucagon for the stimulation of ketogenesis from palmitate also decreased as compared with those of isolated cells, indicating an important role of low affinity sites in the glucagon action. These results indicate that insulin and glucagon receptors were reciprocally changed in cultured cells, as compared with isolated cells.
与新鲜分离的肝细胞相比，原代培养肝细胞对[125I]胰岛素的特异性结合显著增加。培养细胞中低亲和力胰岛素结合位点的数量比新鲜分离细胞多6倍，而高亲和力位点没有显著变化。然而，分离的细胞和培养的细胞对胰岛素刺激鸟氨酸脱羧酶（ODC）活性的敏感性（半数最大刺激的胰岛素浓度）和反应性（高于基础水平的增加百分比）相似，表明高亲和力位点在胰岛素作用中起重要作用。另一方面，培养细胞对[125I]胰高血糖素的特异性结合显著降低。培养细胞中低亲和力胰高血糖素结合位点减少约50%，而高亲和力位点没有显著变化。与分离的细胞相比，培养细胞对胰高血糖素刺激棕榈酸生酮作用的敏感性和反应性也降低，表明低亲和力位点在胰高血糖素作用中起重要作用。这些结果表明，与分离的细胞相比，培养细胞中的胰岛素和胰高血糖素受体发生了相互变化。
