Kanthan R, Shuaib A, Griebel R, el-Alazounni H, Miyashita H, Kalra J
Department of Medicine (Neurology), Royal University Hospital Saskatoon, SK.
Neurochem Res. 1996 May;21(5):563-6. doi: 10.1007/BF02527754.
The release of neurotransmitters principally glutamate during cerebral ischemia has been extensively studied. It is well recognized that ischemia induced release of glutamate plays a key role in "excitotoxic" neuronal death. The role of monoaminergic neurotransmitters is however unclear. The purpose of this study was to evaluate the extracellular norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA) and serotonin (5-HT) under varied degrees of ischemia in the acute focal ischemic model of the human brain by in-vivo microdialysis. The ischemic response of these amines was correlated with the glutamate levels. Our study concludes that these amines and metabolites can be detected in the human "stroke" model. No marked fluctuations were noted in the levels of norepinephrine and DOPAC. However, significant changes to partial and total ischemia were noted in the extracellular levels of 5-HIAA and 5-HT. These compounds showed a dramatic increase with the onset of ischemia with higher detectable levels in the partial ischemic state in comparison to the total ischemic dialysate levels. The exact role played by the differential increase in the levels of 5-HT to the other catecholamines in the pathogenesis of ischemic neuronal damage remains unclear and warrants further study.
脑缺血期间主要神经递质谷氨酸的释放已得到广泛研究。众所周知，缺血诱导的谷氨酸释放 在 “兴奋性毒性” 神经元死亡中起关键作用。然而，单胺能神经递质的作用尚不清楚。本研究的目的是通过体内微透析评估人脑急性局灶性缺血模型中不同程度缺血下细胞外去甲肾上腺素、3,4-二羟基苯乙酸（DOPAC）、5-羟基吲哚乙酸（5-HIAA）和5-羟色胺（5-HT）的情况。这些胺类的缺血反应与谷氨酸水平相关。我们的研究得出结论，这些胺类和代谢产物可在人类 “中风” 模型中检测到。去甲肾上腺素和DOPAC水平未发现明显波动。然而，5-HIAA和5-HT的细胞外水平在部分缺血和完全缺血时出现了显著变化。这些化合物在缺血开始时急剧增加，与完全缺血透析液水平相比，部分缺血状态下可检测到更高水平。5-HT水平相对于其他儿茶酚胺的差异增加在缺血性神经元损伤发病机制中的确切作用尚不清楚，值得进一步研究。
