Abstract：
This research aimed to explore the potential influence of mitochondria on the rate of anaerobic glycolysis. We hypothesized that mitochondria could reduce the rate of anaerobic glycolysis and pH decline by metabolizing a portion of glycolytic pyruvate. We utilized an in vitro model and incorporated CPI-613 and Avidin to inhibit pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC), respectively. Four treatments were tested: 400 μM CPI-613, 1.5 U/ml Avidin, 400 μM CPI-613 + 1.5 U/ml Avidin, or control. Glycolytic metabolites and pH of the in vitro model were evaluated throughout a 1440-min incubation period. CPI-613-containing treatments, with or without Avidin, decreased pH levels and increased glycogen degradation and lactate accumulation compared to the control and Avidin treatments (P < 0.05), indicating increased glycolytic flux. In a different experiment, two treatments, 400 μM CPI-613 or control, were employed to track the fates of pyruvate using [13C6]glucose. CPI-613 reduced the contribution of glucose carbon to tricarboxylic acid cycle intermediates compared to control (P < 0.05). To test whether the acceleration of acidification in reactions containing CPI-613 was due to an increase in the activity of key enzymes of glycogenolysis and glycolysis, we evaluated the activities of glycogen phosphorylase, phosphofructokinase, and pyruvate kinase in the presence or absence of 400 μM CPI-613. The CPI-613 treatment did not elicit an alteration in the activity of these three enzymes. These findings indicate that inhibiting PDH increases the rate of anaerobic glycolysis and pH decline, suggesting that mitochondria are potential regulators of postmortem metabolism.
摘要：
本研究旨在探讨线粒体对厌氧糖酵解速率的潜在影响。我们假设线粒体可以通过代谢一部分糖酵解丙酮酸来降低厌氧糖酵解和pH下降的速率。我们利用体外模型并掺入CPI-613和抗生物素蛋白来抑制丙酮酸脱氢酶（PDH）和丙酮酸羧化酶（PC），分别。测试了四种处理：400μMCPI-613，1.5U/ml抗生物素蛋白，400μMCPI-613+1.5U/ml抗生物素蛋白，或控制。在整个1440分钟的孵育期间评估体外模型的糖酵解代谢物和pH。含CPI-613的处理，有或没有亲和素，与对照和抗生物素蛋白处理相比，pH水平降低，糖原降解和乳酸积累增加（P<0.05），表明糖酵解通量增加。在另一个实验中，两种治疗,400μMCPI-613或对照，使用[13C6]葡萄糖追踪丙酮酸的命运。与对照相比,CPI-613降低了葡萄糖碳对三羧酸循环中间体的贡献(P<0.05)。为了测试在含有CPI-613的反应中酸化的加速是否是由于糖原分解和糖酵解的关键酶的活性增加,我们评估了糖原磷酸化酶的活性，磷酸果糖激酶，和丙酮酸激酶在存在或不存在400μMCPI-613的情况下。CPI-613处理没有引起这三种酶活性的改变。这些发现表明，抑制PDH增加了厌氧糖酵解和pH下降的速率，表明线粒体是死后代谢的潜在调节因子。
