Korf J, de Boer J, Baarsma R, Venema K, Okken A
Department of Biological Psychiatry, Groningen University, The Netherlands.
Dev Neurosci. 1993;15(3-5):240-6. doi: 10.1159/000111340.
Methods for the continuous in vivo monitoring of glucose and lactate were applied in man for studies of peripheral metabolism and, in rats, for cerebral examinations. Lactate ('lactography') and glucose were continuously measured by the enzyme formation of NADH or NADPH using appropriate dehydrogenases. Glucose was monitored with a transcutaneous probe in neonates or with probes placed directly in the brain of conscious rats. In neonates a high correlation was seen between the dialysate and blood levels. A correlation between the age of the neonates and glucose levels in the dialysate was found, suggesting that the thickness of the skin determined to a large extent the diffusion of glucose into the probe. In the rat brain transient changes in the extracellular glucose levels were seen during electroconvulsive shock and immobilization stress. Lactography was applied to striatum or hippocampus during stress, electroconvulsive shock or systemic and intracerebral drug applications. Extracellular lactate decreased during intracerebral deoxyglucose infusion and was increased by excitatory neuronal activity and the presence of glucose in the perfusion medium. The present studies show that microdialysis in combination with continuous flow analysis can be used to study metabolic trafficking in vivo and in clinical studies. In the brain both neurons and glia may contribute to extracellular lactate levels.
用于葡萄糖和乳酸连续体内监测的方法被应用于人体外周代谢研究，以及大鼠的脑部检查。使用适当的脱氢酶通过NADH或NADPH的酶形成来连续测量乳酸（“乳酸成像”）和葡萄糖。在新生儿中使用经皮探头监测葡萄糖，在清醒大鼠的大脑中直接放置探头监测葡萄糖。在新生儿中，透析液和血液水平之间存在高度相关性。发现新生儿年龄与透析液中葡萄糖水平之间存在相关性，这表明皮肤厚度在很大程度上决定了葡萄糖向探头的扩散。在大鼠脑中，在电惊厥休克和固定应激期间观察到细胞外葡萄糖水平的短暂变化。在应激、电惊厥休克或全身及脑内药物应用期间，将乳酸成像应用于纹状体或海马体。脑内注入脱氧葡萄糖期间细胞外乳酸减少，兴奋性神经元活动以及灌注介质中存在葡萄糖会使其增加。目前的研究表明，微透析结合连续流动分析可用于体内和临床研究中的代谢转运研究。在大脑中，神经元和神经胶质细胞都可能对外细胞乳酸水平有影响。
