Subchronic -acetylcysteine Treatment Decreases Brain Kynurenic Acid Levels and Improves Cognitive Performance in Mice.

The tryptophan (Trp) metabolite kynurenic acid (KYNA) is an α7-nicotinic and -methyl-d-aspartate receptor antagonist. Elevated brain KYNA levels are commonly seen in psychiatric disorders and neurodegenerative diseases and may be related to cognitive impairments. Recently, we showed that -acetylcysteine (NAC) inhibits kynurenine aminotransferase II (KAT II), KYNA's key biosynthetic enzyme, and reduces KYNA neosynthesis in rats .