Ballard F J, Gunn J M
Horm Metab Res. 1980 Jan;12(1):10-4. doi: 10.1055/s-2007-996184.
The apparent Ki for insulin binding to Reuber H35 hepatoma, rat hepatocytes, 3T3 and SV403T3 cells in monolayer culture was approximately 2 x 10(-9) M. Since insulin concentrations of 2 x 10(-12) M and 6 x 10(-11) M inhibit half-maximally intracellular protein degradation in the H35 hepatoma and SV403T3 cells respectively, it is apparent that very few insulin molecules are bound at such concentrations. The calculated number of insulin molecules bound per cell under these conditions is 45 in the H35 hepatoma and 180 in SV403T3. On the other hand, 36,000 and 2100 and molecules are bound per cell respectively at insulin concentrations which inhibit half-maximally intracellular protein degradation in hepatocytes and 3T3 cells. Measurements of insulin degradation show rates about five times greater in the H35 hepatoma as compared to hepatocytes, thus eliminating a more rapid breakdown of insulin as an explanation of the lower insulin sensitivity in hepatocytes.
胰岛素与单层培养的鲁伯H35肝癌细胞、大鼠肝细胞、3T3细胞和SV40 3T3细胞结合的表观解离常数（Ki）约为2×10⁻⁹ M。由于2×10⁻¹² M和6×10⁻¹¹ M的胰岛素浓度分别可半最大程度抑制H35肝癌细胞和SV40 3T3细胞内的蛋白质降解，显然在这些浓度下结合的胰岛素分子极少。在这些条件下，计算得出H35肝癌细胞每个细胞结合的胰岛素分子数为45个，SV40 3T3细胞为180个。另一方面，在可半最大程度抑制肝细胞和3T3细胞内蛋白质降解的胰岛素浓度下，每个细胞分别结合36000个和2100个分子。胰岛素降解的测量结果显示，H35肝癌细胞中的降解速率约为肝细胞的五倍，因此排除了胰岛素更快降解是肝细胞胰岛素敏感性较低的原因。
