Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
Cytotechnology. 2000 Oct;34(1-2):47-57. doi: 10.1023/A:1008154615643.
The effects of media concentrations of glucose andglutamine on the intracellular nucleotide pools andoxygen uptake rates of a murine antibody-secretinghybridoma cell line were investigated. Cells takenfrom mid-exponential phase of growth were incubated inmedium containing varying concentrations of glucose(0-25 mM) and glutamine (0-9 mM). The intracellularconcentrations of ATP, GTP, UTP and CTP, and theadenylate energy charge increased concomitantly withthe medium glucose concentration. The total adenylatenucleotide concentration did not change over a glucose concentration range of 1-25 mM but therelative levels of AMP, ADP and ATP changed as theenergy charge increased from 0.36 to 0.96. Themaximum oxygen uptake rate (OUR) was obtained in thepresence of 0.1-1 mM glucose. However at glucoseconcentrations >1 mM the OUR decreased suggestinga lower level of aerobic metabolism as a result of theCrabtree effect.A low concentration of glutamine (0.5 mM) caused asignificant increase (45-128%) in the ATP, GTP,CTP, UTP, UDP-GNac, and NAD pools and a doubling ofthe OUR compared to glutamine-free cultures. Theminimal concentration of glutamine also caused anincrease in the total adenylate pool indicating thatthe amino acid may stimulate thede novosynthesis of nucleotides. However, all nucleotidepools and the OUR remained unchanged within the rangeof 0.5-9 mM glutamine.Glucose was shown to be the major substrate forenergy metabolism. It was estimated that in thepresence of high concentrations of glucose (10-25 mM),glutamine provided the energy for the maintenance ofup to 28% of the intracellular ATP pool, whereas theremainder was provided by glucose metabolism.
研究了葡萄糖和谷氨酰胺的介质浓度对鼠抗体分泌杂交瘤细胞系细胞内核苷酸池和耗氧率的影响。从中期指数生长期取出的细胞在含有不同浓度葡萄糖（0-25mM）和谷氨酰胺（0-9mM）的培养基中孵育。细胞内 ATP、GTP、UTP 和 CTP 的浓度以及腺苷酸能荷与培养基葡萄糖浓度呈正相关。在 1-25mM 葡萄糖浓度范围内，总腺苷酸核苷酸浓度没有变化，但 AMP、ADP 和 ATP 的相对水平随着能荷从 0.36 增加到 0.96 而变化。在 0.1-1mM 葡萄糖存在下，最大耗氧率（OUR）最高。然而，在葡萄糖浓度>1mM 时，OUR 降低，表明由于 Crabtree 效应，有氧代谢水平较低。低浓度谷氨酰胺（0.5mM）导致 ATP、GTP、CTP、UTP、UDP-GNac 和 NAD 池显著增加（45-128%），OUR 与无谷氨酰胺培养物相比增加了一倍。最低谷氨酰胺浓度也导致总腺苷酸池增加，表明该氨基酸可能刺激核苷酸的从头合成。然而，在 0.5-9mM 谷氨酰胺范围内，所有核苷酸池和 OUR 保持不变。葡萄糖被证明是能量代谢的主要底物。据估计，在高浓度葡萄糖（10-25mM）存在下，谷氨酰胺为维持高达 28%的细胞内 ATP 池提供能量，而其余部分由葡萄糖代谢提供。
