Nadi A B, Olivares E, Malaisse W J
Laboratory of Experimental Medicine, Brussels Free University, Belgium.
Mol Cell Biochem. 2000 Jul;210(1-2):167-72. doi: 10.1023/a:1007106529644.
The metabolism of D-glucose was characterized in both normal dispersed rat islet cells and the 2-mercaptoethanol-dependent insulin-secreting cells of the INS-1 line. The normal and tumoral islet cells differed from one another by the relative magnitude, concentration dependency and hierarchy of the increase in the production of 3HOH from D-[5-(3)H]glucose and 14C-labelled CO2, acidic metabolites and amino acids from D-[U-14C]glucose at increasing concentrations of the hexose. For instance, whilst the paired ratio between D-[U-14C]glucose oxidation and D-[5-(3)H]glucose utilization augmented in a typical sigmoidal manner in normal islet cells exposed to increasing concentrations of D-glucose, it progressively decreased under the same experimental conditions in INS-1 cells. Nevertheless, the absolute values and concentration-response relationship for the increase in ATP generation rate attributable to the catabolism of D-glucose were virtually identical in normal and tumoral cells. These findings indicate that the analogy in the secretory response to D-glucose of normal and INS-1 islet cells, although coinciding with a comparable response to the hexose in terms of ATP generation, contrasts with a vastly different pattern of D-glucose metabolism in these two cell types.
在正常分散的大鼠胰岛细胞和INS-1系的2-巯基乙醇依赖性胰岛素分泌细胞中，对D-葡萄糖的代谢进行了表征。正常胰岛细胞和肿瘤性胰岛细胞的差异在于，随着己糖浓度的增加，D-[5-(³H)]葡萄糖生成3H OH以及D-[U-¹⁴C]葡萄糖生成¹⁴C标记的CO₂、酸性代谢产物和氨基酸的产量增加的相对幅度、浓度依赖性和层级关系。例如，在暴露于浓度不断增加的D-葡萄糖的正常胰岛细胞中，D-[U-¹⁴C]葡萄糖氧化与D-[5-(³H)]葡萄糖利用之间的配对比率以典型的S形方式增加，而在相同实验条件下，INS-1细胞中的该比率则逐渐降低。然而，正常细胞和肿瘤细胞中，由D-葡萄糖分解代谢导致的ATP生成速率增加的绝对值和浓度-反应关系实际上是相同的。这些发现表明，正常胰岛细胞和INS-1胰岛细胞对D-葡萄糖的分泌反应虽然在ATP生成方面与对己糖的可比反应一致，但在这两种细胞类型中，D-葡萄糖代谢模式却大不相同。
