ACTIONS OF l‐GLUTAMATE AND RELATED AMINO ACIDS ON OXYGEN UPTAKE, LACTATE PRODUCTION AND NADH LEVELS OF RAT BRAIN IN VITRO
ACTIONS OF l‐GLUTAMATE AND RELATED AMINO ACIDS ON OXYGEN UPTAKE, LACTATE PRODUCTION AND NADH LEVELS OF RAT BRAIN IN VITRO
复制标题
L-谷氨酸及相关氨基酸对体外大鼠脑摄氧量、乳酸生成和 NADH 水平的作用
DOI：
10.1111/j.1471-4159.1977.tb06518.x
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发表时间：
1977
影响因子：
4.7
通讯作者：
J. Watkins
中科院分区：
文献类型：
--
作者：
D. Cox;R. Osborne;J. Watkins
摘要-一系列酸性氨基酸在（i）它们作为神经元兴奋剂的效力，（ii）它们的运输性质和（iii）它们作为代谢底物的能力方面不同，它们对体外大鼠大脑皮层能量代谢的影响进行了比较。l-谷氨酸，d-和l-同型半胱氨酸，增加组织切片NADH水平，和相同的三种氨基酸，连同d-谷氨酸和红藻氨酸，增加了切片的氧摄取。得出的结论是，这些影响主要是由于神经元去极化和随后激活的离子泵机制。l-谷氨酸、d-谷氨酸和l-同型半胱氨酸增加了切片的乳酸产生，而d-同型半胱氨酸和红藻氨酸则没有。由于后两种氨基酸是最强的神经兴奋性，但可能是最不迅速的运输，这表明，刺激乳酸生产切片的氨基酸兴奋性是一个后果的积极摄取的氨基酸的能量需求，并可能主要发生在神经胶质细胞。虽然l-谷氨酸的代谢似乎不是本工作中观察到的这种氨基酸作用的基本要求，但在切片制备和孵育的次优条件下，这种代谢可能会做出更大的贡献，其中组织的电活动可能会受损。
Abstract— A range of acidic amino acids differing in (i) their potency as neuronal excitants, (ii) their transport properties and (iii) their ability to act as substrates for metabolism have been compared with respect to their effects on energy metabolism of rat cerebral cortex in vitro.l‐Glutamate, and d‐ and l‐homocysteate, increased tissue slice NADH levels, and the same three amino acids, together with d‐glutamate and kainate, increased oxygen uptake by the slices. It was concluded that these effects were predominantly due to neuronal depolarization and the ensuing activation of ion pump mechanisms. l‐Glutamate, d‐glutamate and l‐homocysteate increased lactate production by the slices, whereas d‐homocysteate and kainate did not. Since the two latter amino acids are the strongest neuroexcitants but probably the least rapidly transported, it is suggested that stimulation of lactate production in slices by amino acid excitants is a consequence of the energy requirements of active uptake of the amino acids, and probably occurs mainly in glial cells. Although the metabolism of l‐glutamate appeared not to be an essential requirement for the effects observed with this amino acid in the present work, such metabolism may make a proportionately greater contribution under sub‐optimal conditions of slice preparation and incubation, where electrical activity of the tissue may be impaired.