Evidence against tight channelling of NADH in hepatocytes.
Evidence against tight channelling of NADH in hepatocytes.
复制标题
反对肝细胞中 NADH 紧密通道的证据。
DOI：
10.1016/0003-9861(91)90079-x
复制
发表时间：
1991
影响因子：
3.9
通讯作者：
Rognstad,R
中科院分区：
文献类型：
--
作者：
Rognstad,R
在示踪剂水平的氚化底物与大鼠肝细胞加10 mml-乳酸盐孵育，并在葡萄糖和水中的氚的产量，以及在C-6和C-4的葡萄糖，确定的氚分布。胞质A型NAD-连接的脱氢酶的底物显示出对葡萄糖的C-6的某些优先标记（涉及A型苹果酸脱氢酶的途径），而胞质B型NAD-连接的脱氢酶的底物显示出对葡萄糖的C-4的某些优先标记（涉及B型甘油醛-3 P脱氢酶的途径）。发现的结果与经典的NADH代谢扩散模型一致，并且与Srivastava假说（基于分离的酶研究）不一致，该假说表明NADH的直接转移可以发生在许多NAD连接的酶之间，但仅当它们具有相反的（A或B）特异性时。
Tritiated substrates at tracer levels were incubated with rat hepatocytes plus 10 mml-lactate, and the yields of tritium in glucose and water, as well as the tritium distribution on C-6 and C-4 of glucose, determined. Substrates of cytosolic type A NAD-linked dehydrogenases showed some preferential labeling of C-6 of glucose (the pathway involving type A malate dehydrogenase), whereas substrates of cytosolic type B NAD-linked dehydrogenases showed some preferential labeling of C-4 of glucose (the pathway involving type B glyceraldehyde-3P dehydrogenase). The results found are consistent with a classical diffusion model of NADH metabolism, and are at odds with the Srivastava hypothesis (based on isolated enzyme studies) which indicated that direct transfer of NADH can occur between many NAD-linked enzymes, but only when they are of opposite (A or B) specificity.