Quinolinic acid (pyridine-cr , /3-dicarboxylic acid) has been isolated from rat urine after administration of tryptophan to rats (1). It has been suggested that quinolinic acid is formed via 3-hydroxyanthranilic acid by oxidative cleavage of the benzene ring in the 3-4 position, followed by closure incorporating the amino nitrogen in a pyridine ring (1). In this paper are reported the results o...

Previous results suggest that the tryptophan metabolite, picolinic acid may have the unusual properties of antagonizing the neurotoxic but not the neuroexcitant effects of another tryptophan metabolite, quinolinic acid in the central nervous system. The present experiments tested this possibility utilizing behavioural and tyrosine hydroxylase immunohistochemical techniques. In the first series ...

objective(s): quinolinic acid (qa)-mediated excitotoxicity has been widely used as a model for studying neurodegenerative disorders. recent studies suggested that saffron (crocus sativus) or its active metabolite, i.e. safranal, exerts pharmacological actions on central nervous system including anxiolytic, anticonvulsant, and neuroprotective properties. the present study aimed to investigate th...

In order to clarify the mechanism by polyphenols of protective effects against oxidative damage or by quinolinic acid of its neurotoxic and inflammatory actions, effects of polyphenols or quinolinic acid on the radical formation were examined. The ESR measurements showed that some polyphenols such as caffeic acid, catechol, gallic acid, D-(+)-catechin, L-dopa, chlorogenic acid and L-noradrenali...

In vivo release of [3H]-purines from the cortex of anaesthetized rats was measured and the actions of excitatory amino acids and analogues investigated. High KCl, N-methyl-DL-aspartate (NMDLA) and quinolinic acid produced a large increase in basal release of labelled materials. Glutamate, quisqualate and kainate had less effect. The N-methyl-D-aspartic acid (NMDA)-preferring receptor antagonist...

The participation of 3-hydroxyanthranilic acid as an intermediate in the biosynthesis of nicotinic acid from tryptophan was first demonstrated in certain mutant strains of Neurospora in 1948 by Bonner (1) and by Mitchell and Nyc (2). In addition, Mitchell et al. (3) found that 3-hydroxyanthranilic acid can replace nicotinic acid in the nutrition of the rat. In 1946 Singal et al. (4) noted a sub...

The ricinine content of etiolated seedlings of Ricinus communis increased nearly 12-fold over a 4-day period. In plants quinolinic acid is an intermediate in the de novo pathway for the synthesis of pyridine nucleotides. The only known enzyme in the de novo pathway for pyridine nucleotide biosynthesis, quinolinic acid phosphoribosyltransferase, increased 6-fold in activity over a 4-day period w...

Striatal binding of labeled glutamate to N-methyl-D-aspartate (NMDA) receptors, D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) to quisqualate receptors and kainate to kainate receptors was examined in rats which had received unilateral decortications or unilateral striatal quinolinic acid lesions. One week after decortication, there were no significant changes in NMDA, qui...

Glutamate, the major transmitter of the corticostriatal pathway, is present in abundance in the striatum. 3-Hydroxyanthranilic acid oxygenase (3HAO) is the biosynthetic enzyme for quinolinic acid, an endogenous agonist of the NMDA glutamate receptor subtype and a potent neurotoxin. In order to explore the anatomical basis of possible functional interactions between glutamate and quinolinic acid...