Effects of Various Kynurenine Metabolites on Respiratory Parameters of Rat Brain, Liver and Heart Mitochondria:

International Journal of Tryptophan Research

HalinaBaran*¹ 

关键词: respiratory parameters of mitochondria;    brain;    heart;    liver;    kynurenine metabolites;    xanthurenic acid;    misfoldome;    dementia;   

DOI  :  10.4137/IJTR.S37973

学科分类：生物科学（综合）

来源: Sage Journals

【 摘 要 】

Previously, we demonstrated that the endogenous glutamate receptor antagonist kynurenic acid dose-dependently and significantly affected rat heart mitochondria. Now we have investigated the effects of L-tryptophan, L-kynurenine, 3-hydroxykynurenine and kynurenic, anthranilic, 3-hydroxyanthranilic, xanthurenic and quinolinic acids on respiratory parameters (ie, state 2, state 3), respiratory control index (RC) and ADP/oxygen ratio in brain, liver and heart mitochondria of adult rats. Mitochondria were incubated with glutamate/malate (5 mM) or succinate (10 mM) and in the presence of L-tryptophan metabolites (1 mM) or in the absence, as control. Kynurenic and anthranilic acids significantly reduced RC values of heart mitochondria in the presence of glutamate/malate. Xanthurenic acid significantly reduced RC values of brain mitochondria in the presence of glutamate/malate. Furthermore, 3-hydroxykynurenine and 3-hydroxyanthranilic acid decreased RC values of brain, liver and heart mitochondria using glutamate/malate. In the presence of succinate, 3-hydroxykynurenine and 3-hydroxyanthranilic acid affected RC values of brain mitochondria, whereas in liver and heart mitochondria only 3-hydroxykynurenine lowered RC values significantly. Furthermore, lowered ADP/oxygen ratios were observed in brain mitochondria in the presence of succinate with 3-hydroxykynurenine and 3-hydroxyanthranilic acid, and to a lesser extent with glutamate/malate. In addition, 3-hydroxyanthranilic acid significantly lowered the ADP/oxygen ratio in heart mitochondria exposed to glutamate/malate, while in the liver mitochondria only a mild reduction was found. Tests of the influence of L-tryptophan and its metabolites on complex I in liver mitochondria showed that only 3-hydroxykynurenine, 3-hydroxyanthranilic acid and L-kynurenine led to a significant acceleration of NADH-driven complex I activities. The data indicate that L-tryptophan metabolites had different effects on brain, liver and heart mitochondria. Alterations of L-tryptophan metabolism might have an impact on the bioenergetic activities of brain, liver and/or heart mitochondria and might be involved in the development of clinical symptoms such as cardiomyopathy, hepatopathy and dementia.

【 授权许可】

CC BY