Lipkin E W, Teller D C, de Haën C
Biochemistry. 1983 Feb 15;22(4):792-9. doi: 10.1021/bi00273a013.
Glucose oxidation to CO2 was investigated in isolated perifused rat epididymal fat cells. Insulin stimulated rates of oxidation up to 30-fold. Multiple pulses of insulin or prolonged perifusion with the hormone led to a time-dependent desensitization of the cells. The action of insulin could be mimicked by H2O2. Reversal of H2O2 effects was associated with a damped oscillation of large initial amplitude. Initiation of perifusion with insulin induced rates of glucose oxidation that oscillated around a mean elevated rate with an amplitude of about +/- 4% of the mean, significantly larger than the measurement error. Basal rates did not show clear oscillations. The oscillations after insulin had a statistically significant period of around 14 min. The results were the same with C1- or C6-labeled glucose and occurred in the presence of both 0.275 and 5.5 mM glucose in the perifusion medium. The oscillations were interpreted as the result of insulin- or H2O2-induced synchronization of oscillatory glycolysis by individual fat cells. The similarity of the observed oscillatory period with the period of oscillatory insulin secretion by pancreatic beta cells suggests that oscillatory glycolysis may constitute the internal pacemaker for the latter process.
在分离的经灌流的大鼠附睾脂肪细胞中研究了葡萄糖氧化为二氧化碳的过程。胰岛素刺激氧化速率提高了30倍。多次注射胰岛素或用该激素进行长时间灌流会导致细胞出现时间依赖性脱敏。过氧化氢可模拟胰岛素的作用。过氧化氢作用的逆转与初始振幅较大的衰减振荡有关。用胰岛素开始灌流会诱导葡萄糖氧化速率围绕平均升高速率振荡，振幅约为平均速率的±4%，明显大于测量误差。基础速率未显示出明显的振荡。胰岛素作用后的振荡在统计学上有一个约14分钟的显著周期。用C1或C6标记的葡萄糖得到的结果相同，且在灌流培养基中0.275 mM和5.5 mM葡萄糖存在的情况下均会出现。这些振荡被解释为胰岛素或过氧化氢诱导单个脂肪细胞中振荡性糖酵解同步化的结果。观察到的振荡周期与胰腺β细胞振荡性胰岛素分泌的周期相似，这表明振荡性糖酵解可能构成了后者过程的内部起搏器。
