Turski W A, Schwarcz R
Maryland Psychiatric Research Center, Baltimore 21228.
Exp Brain Res. 1988;71(3):563-7. doi: 10.1007/BF00248748.
The disposition of kynurenic acid (KYNA), a tryptophan metabolite and broad spectrum antagonist at excitatory amino acid receptors, was studied following the unilateral intrahippocampal injection of 3H-KYNA in the rat. KYNA was rapidly cleared from the injected hippocampus. Similar decay curves were observed in several brain regions ipsi- and contralateral to the injection site as well as in serum and renal tissue. The radioactivity retained in tissue or excreted in urine for the first two hours after a 3H-KYNA injection was identified as unmetabolized KYNA. Moreover, direct measurement in hippocampal slices failed to provide evidence for the presence of specific cellular uptake mechanisms for KYNA. The present results do not support a neurotransmitter function for KYNA in the rat brain. However, they do not rule out a role of KYNA in the pathogenesis of neurodegenerative and seizure disorders.
犬尿喹啉酸（KYNA）是一种色氨酸代谢产物，也是兴奋性氨基酸受体的广谱拮抗剂。在大鼠海马单侧注射³H-KYNA后，对其在体内的处置情况进行了研究。KYNA从注射的海马中迅速清除。在注射部位同侧和对侧的几个脑区以及血清和肾组织中观察到了相似的衰减曲线。³H-KYNA注射后最初两小时内保留在组织中或经尿液排泄的放射性被鉴定为未代谢的KYNA。此外，在海马切片中的直接测量未能提供证据证明存在针对KYNA的特定细胞摄取机制。目前的结果不支持KYNA在大鼠脑中具有神经递质功能。然而，它们并不排除KYNA在神经退行性疾病和癫痫疾病发病机制中的作用。
