Garofalo O, Cox D W, Bachelard H S
Division of Biochemistry, U.M.D.S. (St. Thomas's), London, England.
J Neurochem. 1988 Jul;51(1):172-6. doi: 10.1111/j.1471-4159.1988.tb04851.x.
The effects of hypoxia and hypoglycaemia on the redox state in vitro have been studied. NADH and NAD+ were extracted simultaneously from superfused cerebral cortex slices and assayed by bioluminescence. The results show a nonsignificant increase in NADH and the redox ratio in "mild hypoxia," whereas "severe hypoxia" produced an increase of over 200% in NADH and in the NADH/NAD+ ratio. When the glucose in the incubation medium was reduced from its control value of 10 mM to 0.5 mM, significant decreases in NADH and the redox ratio to 60% of control value were observed. Further decreasing the glucose to 0.2 mM gave lower levels of NADH and the redox ratio (40% of control). The effects on the redox state of alternative substrates to glucose were also tested. Replacement of glucose by 10 mM pyruvate decreased the NADH by 77% and the NADH/NAD+ ratio by 79%. Replacement of glucose with 10 mM lactate gave decreases of 70% and 71%, respectively, whereas in the presence of 15 mM 2-deoxyglucose and 5 mM glucose, the NADH was decreased by 56% and the ratio by 50%. The results are discussed in relation to levels of creatine phosphate and ATP, as well as evoked action potentials, observed from parallel studies.
已经研究了缺氧和低血糖对体外氧化还原状态的影响。从超融合的大脑皮层切片中同时提取NADH和NAD⁺，并通过生物发光法进行测定。结果显示，在“轻度缺氧”时，NADH和氧化还原比无显著增加，而“重度缺氧”使NADH和NADH/NAD⁺比增加超过200%。当孵育培养基中的葡萄糖从其10 mM的对照值降至0.5 mM时，观察到NADH和氧化还原比显著降低至对照值的60%。进一步将葡萄糖降至0.2 mM，NADH和氧化还原比水平更低（对照值的40%）。还测试了葡萄糖替代底物对氧化还原状态的影响。用10 mM丙酮酸替代葡萄糖使NADH降低77%，NADH/NAD⁺比降低79%。用10 mM乳酸替代葡萄糖分别使NADH和NADH/NAD⁺比降低70%和71%，而在存在15 mM 2-脱氧葡萄糖和5 mM葡萄糖的情况下，NADH降低56%，该比例降低50%。结合平行研究中观察到的磷酸肌酸和ATP水平以及诱发动作电位对结果进行了讨论。
