Stone Trevor W, Mackay Gillian M, Forrest Caroline M, Clark Catherine J, Darlington L Gail
Institute of Biomedical & Life Sciences,Division of Neuroscience & Biomedical Systems, West Medical Building, University of Glasgow, Glasgow, UK.
Clin Chem Lab Med. 2003 Jul;41(7):852-9. doi: 10.1515/CCLM.2003.129.
Tryptophan is metabolised primarily along the kynurenine pathway, of which two components are now known to have marked effects on neurons in the central nervous system. Quinolinic acid is an agonist at the population of glutamate receptors which are sensitive to N-methyl-D-aspartate (NMDA), and kynurenic acid is an antagonist at several glutamate receptors. Consequently quinolinic acid can act as a neurotoxin while kynurenic acid is neuroprotectant. A third kynurenine, 3-hydroxykynurenine, can generate free radicals and contribute to, or exacerbate, neuronal damage. Changes in the absolute or relative concentrations of these kynurenines have been implicated in a variety of central nervous system disorders such as the AIDS-dementia complex and Huntington's disease, raising the possibility that interference with their actions or synthesis could lead to new forms of pharmacotherapy for these conditions.
色氨酸主要沿犬尿氨酸途径代谢，目前已知该途径的两个成分对中枢神经系统的神经元有显著影响。喹啉酸是对N-甲基-D-天冬氨酸（NMDA）敏感的谷氨酸受体群体的激动剂，而犬尿喹啉酸是几种谷氨酸受体的拮抗剂。因此，喹啉酸可作为神经毒素，而犬尿喹啉酸具有神经保护作用。第三种犬尿氨酸，即3-羟基犬尿氨酸，可产生自由基并导致或加剧神经元损伤。这些犬尿氨酸的绝对或相对浓度变化与多种中枢神经系统疾病有关，如艾滋病痴呆综合征和亨廷顿舞蹈症，这增加了干扰它们的作用或合成可能会为这些疾病带来新的药物治疗形式的可能性。
