Striking differences in glucose and lactate levels between brain extracellular fluid and plasma in conscious human subjects: Effects of hyperglycemia and hypoglycemia
Striking differences in glucose and lactate levels between brain extracellular fluid and plasma in conscious human subjects: Effects of hyperglycemia and hypoglycemia
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DOI：
10.1097/00004647-200203000-00004
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发表时间：
2002-03-01
影响因子：
6.3
通讯作者：
Sherwin, RS
中科院分区：
文献类型：
--
作者：
Abi-Saab, WM;Maggs, DG;Sherwin, RS
细胞外液（ECF）中的葡萄糖和乳酸的脑水平反映了神经元所暴露的环境，从未在人类中研究过不同条件下的脑水平。作者在接受电生理学评价的清醒人类受试者中使用脑内微透析治疗药物难治性癫痫，并在基础条件下和高血糖-低血糖钳夹研究期间测量葡萄糖和乳酸的ECF水平。仅包括非致癫痫区域的测量值。在基础条件下，作者发现大脑中的代谢环境与循环中的代谢环境截然不同。与血浆相比，脑ECF中的乳酸水平比葡萄糖高三倍。大鼠补充研究的结果与人体数据一致。在高血糖-低血糖钳夹研究期间，血浆和脑ECF葡萄糖水平之间的关系保持相似，但脑ECF葡萄糖的变化滞后于血浆变化约30分钟。这些数据表明，大脑暴露于比血浆中低得多的葡萄糖水平和高得多的乳酸水平;此外，大脑似乎是一个显着的无氧糖酵解的位点，提高了葡萄糖衍生的乳酸是大脑重要燃料的可能性。
Brain levels of glucose and lactate in the extracellular fluid (ECF), which reflects the environment to which neurons are exposed, have never been studied in humans under conditions of varying glycemia. The authors used intracerebral microdialysis in conscious human subjects undergoing electrophysiologic evaluation for medically intractable epilepsy and measured ECF levels of glucose and lactate under basal conditions and during a hyperglycemia-hypoglycemia clamp study. Only measurements from nonepileptogenic areas were included. Under basal conditions, the authors found the metabolic milieu in the brain to be strikingly different from that in the circulation. In contrast to plasma, lactate levels in brain ECF were threefold higher than glucose. Results from complementary studies in rats were consistent with the human data. During the hyperglycemia-hypoglycemia clamp study the relationship between plasma and brain ECF levels of glucose remained similar, but changes in brain ECF glucose lagged approximately 30 minutes behind changes in plasma. The data demonstrate that the brain is exposed to substantially lower levels of glucose and higher levels of lactate than those in plasma; moreover, the brain appears to be a site of significant anaerobic glycolysis, raising the possibility that glucose-derived lactate is an important fuel for the brain.