Fonnum F, Paulsen R E
Norwegian Defence Research Establishment, Division for Environmental Toxicology, Kjeller.
J Neurochem. 1990 Apr;54(4):1253-7. doi: 10.1111/j.1471-4159.1990.tb01956.x.
The levels of amino acids in globus pallidus, a structure heavily innervated with gamma-aminobutyric acid (GABA)-ergic terminals but few glutamergic terminals, were compared with the levels in neostriatum, a structure richly innervated with glutamergic terminals but intermediate in GABAergic terminals. The level of glutamate in neostriatum was twice as high as in globus pallidus whereas the level of GABA in globus pallidus was three times higher than in neostriatum. The level of aspartate was similar in both regions whereas the level of glutamine was correlated with the level of glutamate. Methionine sulfoximine, a glutamine synthetase inhibitor, reduced the level of glutamine to 10-20% of control in both structures. This reduction was accompanied by the largest decrease in the level of glutamate in neostriatum, indicating that transmitter glutamate turns over more rapidly than other glutamate pools. Likewise, insulin decreased the levels of glutamate and glutamine more in neostriatum than in globus pallidus. gamma-Vinyl GABA increased the level of GABA in globus pallidus more than in neostriatum although the percent increase was largest in neostriatum. Treatment with gamma-vinyl GABA was accompanied by a large reduction in the level of GABA, indicating that a substantial proportion of the glutamine pool is linked to GABA metabolism.
苍白球是一个由γ-氨基丁酸（GABA）能终末大量支配但谷氨酸能终末较少的结构，将其氨基酸水平与新纹状体进行比较，新纹状体是一个由谷氨酸能终末丰富支配但GABA能终末中等的结构。新纹状体中谷氨酸的水平是苍白球中的两倍，而苍白球中GABA的水平比新纹状体高两倍。两个区域中天冬氨酸的水平相似，而谷氨酰胺的水平与谷氨酸的水平相关。蛋氨酸亚砜胺是一种谷氨酰胺合成酶抑制剂，在两个结构中都将谷氨酰胺水平降低至对照的10% - 20%。这种降低伴随着新纹状体中谷氨酸水平的最大下降，表明递质谷氨酸的周转比其他谷氨酸池更快。同样，胰岛素对新纹状体中谷氨酸和谷氨酰胺水平的降低作用比对苍白球的作用更大。γ-乙烯基GABA使苍白球中GABA的水平升高幅度大于新纹状体，尽管新纹状体中升高的百分比最大。用γ-乙烯基GABA处理伴随着GABA水平的大幅降低，表明相当一部分谷氨酰胺池与GABA代谢相关。
