Alpha-Aminoadipic Acid (aAAA)

α-Aminoadipic acid is an intermediate in the α-Aminoadipic acid pathway for the metabolism of lysine and saccharopine. It is synthesised from homoisocitrate by aminoadipate aminotransferase and reduced by aminoadipate reductase to form the semialdehyde. L-alpha-Aminoadipic acid is a lysine metabolite with neuroexcitatory properties, and has previously been shown to inhibit the production of the broad spectrum excitatory amino acid receptor antagonist kynurenic acid in brain tissue slices. The effects of L-alpha-aminoadipic acid on the levels of extracellular kynurenic acid were now studied by microdialysis in the dorsal hippocampus of freely moving rats. Application of L-alpha-aminoadipic acid through the microdialysis probe dose dependently decreased both the concentration of endogenous kynurenic acid and of kynurenic acid which was produced de novo from its bioprecursor L-kynurenine.