Keilacker H, Ziegler M, Knospe S, Ziegler B, Besch W
Acta Biol Med Ger. 1978;37(4):601-11.
Using mono-125I-insulin the hormone receptor binding on cultivated rat hepatocytes cultivated rat fibroblasts and freshly isolated adipocytes of wistar rat and man were characterized. No specific insulin binding was obtained in the case of long time cultivated hepatocytes. The fibroblasts show a low specific insulin binding with an affinity constant of K = 0.75. 10(9)M-1 and a binding capacity of q = 4000 binding sites per cell, and also an insulin response measureable by the lactate production. In agreement with a strong stimulation effect of insulin on the conversion of glucose to CO2 und triglycerides the freshly isolated adipocytes bind insulin with high affinity and capacity in comparison with the fibroblasts. For the high affinity population of insulin receptors at the adipocytes of wistar rat we found K = 2.8 . 10(9) M-1 and q = 22000 binding sites per cell, whereas 20 per cent of saturation of the receptors cause 90 per cent of the maximal stimulation effect on the bio-conversion of glucose. This shift of the binding curve to higher concentrations may be important for the ability of insulin to regulate the carbohydrate metabolism.
使用单碘-125胰岛素对培养的大鼠肝细胞、培养的大鼠成纤维细胞以及Wistar大鼠和人的新鲜分离脂肪细胞上的激素受体结合进行了表征。长时间培养的肝细胞未获得特异性胰岛素结合。成纤维细胞显示出低特异性胰岛素结合，其亲和常数K = 0.75×10⁹M⁻¹，结合容量q = 4000个结合位点/细胞，并且还具有可通过乳酸产生来测量的胰岛素反应。与胰岛素对葡萄糖转化为二氧化碳和甘油三酯的强烈刺激作用一致，与成纤维细胞相比，新鲜分离的脂肪细胞以高亲和力和容量结合胰岛素。对于Wistar大鼠脂肪细胞上的高亲和力胰岛素受体群体，我们发现K = 2.8×10⁹M⁻¹，q = 22000个结合位点/细胞，而受体饱和度的20%会导致对葡萄糖生物转化的最大刺激作用的90%。结合曲线向更高浓度的这种偏移对于胰岛素调节碳水化合物代谢的能力可能很重要。
