Pentylenetetrazole decreases metabolic glutamate turnover in rat brain
Pentylenetetrazole decreases metabolic glutamate turnover in rat brain
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DOI：
10.1046/j.1471-4159.2003.01781.x
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发表时间：
2003-06-01
影响因子：
4.7
通讯作者：
Sonnewald, U
中科院分区：
文献类型：
--
作者：
Eloqayli, H;Dahl, CB;Sonnewald, U
腹腔注射戊四唑（PTZ，70 mg/kg）诱导大鼠癫痫发作，30 min后注射1-（13）C葡萄糖和1，2-（13）C醋酸盐。使用（13）C磁共振波谱和HPLC对皮质、皮质下和小脑的提取物进行分析。这表明PTZ对不同脑区的影响不同。谷氨酸、谷氨酰胺、GABA、天冬氨酸和牛磺酸的总量在小脑中减少，而在其他脑区中不变。皮质和皮质下的GABA能神经元没有受到影响，而小脑中的GABA能神经元的合成明显减少。然而，所有脑区的谷氨酸能神经元显示谷氨酸标记减少，此外小脑营业额减少。可以表明，这种减少是在谷氨酸盐的代谢池中，而谷氨酸盐的释放不受影响，因为谷氨酸盐的谷氨酰胺标记未发生变化。所有脑区的天冬氨酸周转率也降低。未检测到星形胶质细胞代谢的变化，表明PTZ在发作后早期对星形胶质细胞代谢没有影响。
Seizures were induced in rats by intraperitoneal injection of pentylenetetrazole (PTZ, 70 mg/kg), followed, 30 min later, by injection of [1-(13) C]glucose and [1,2-(13) C]acetate. Analyses of extracts from cortex, subcortex and cerebellum were performed using (13) C magnetic resonance spectroscopy and HPLC. It could be shown that PTZ affected different brain regions differently. The total amounts of glutamate, glutamine, GABA, aspartate and taurine were decreased in the cerebellum and unchanged in the other brain regions. GABAergic neurones in the cortex and subcortex were not affected, whereas those in the cerebellum showed a pronounced decrease of GABA synthesis. However, glutamatergic neurones in all brain regions showed a decrease in glutamate labelling and in addition a decreased turnover in cerebellum. It could be shown that this decrease was in the metabolic pool of glutamate whereas release of glutamate was unaffected since glutamine labelling from glutamate was unchanged. Aspartate turnover was also decreased in all brain regions. Changes in astrocyte metabolism were not detected, indicating that PTZ had no effect on astrocyte metabolism in the early postictal stage.