Possible Interaction: Kynurenic Acid and Niacin

“The tryptophan metabolite kynurenic acid (KYNA), which is produced enzymatically by the irreversible transamination of l‐kynurenine, is an antagonist of α7 nicotinic and NMDA receptors and may thus modulate cholinergic and glutamatergic neurotransmission.”

“ Kynurenic acid , a metabolite of the kynurenine pathway of tryptophan degradation, acts as an endogenous antagonist of alpha7 nicotinic and NMDA receptors and is implicated in a number of neurophysiological and neuropathological processes including cognition and neurodegenerative events.”

“Altogether, these data strongly suggest that KYNA , in addition to be a well-known antagonist acting on nicotinic and NMDA receptors, can be considered as a potential endogenous antioxidant.”

“It is suggested that blockade of nicotinic synaptic transmission may be relevant to the actions of kynurenic acid in the hippocampus, but that in the intact brain this activity is likely to be comparable in importance to the blockade of glutamate‐mediated transmission.”

“The amplitudes of nicotinic spontaneous miniature EPSPs were also reduced by methyl‐lycaconitine and kynurenic acid.”

“The results show that kynurenic acid is more potent in blocking nicotinic EPSPs compared with the full, glutamate‐mediated EPSPs, but it was substantially less potent than has been reported in cultures, possibly because of differences in the accessibility of synaptic and extrasynaptic receptors.”

“Prolonged (3 d) exposure of cultured hippocampal neurons to KYNA increased their nicotinic sensitivity, apparently by enhancing alpha4beta2 nAChR expression.”

“The α-7 nicotinic and the NMDA receptors may counteract the effects of kynurenic acid (KYNA) resulting in cognitive enhancement.”