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Indole-3-Pyruvic Acid as a Direct Precursor of Kynurenic Acid

  • V. Politi
  • M. V. Lavaggi
  • G. Di Stazio
  • A. Margonelli
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 294)

Abstract

Kynurenic acid (KYNA) is found in large amounts after tryptophan load, because tryptophan-2, 3-dioxygenase (EC 1.13.11.11), present in the liver, opens its indole ring, while kynurenine transaminase (EC 2.6.1.7) is able to catalyze the transformation of kynurenine to KYNA. In the last few years, it was demonstrated that KYNA is an important endogenous antagonist of excitatory amino acid receptors (Ganong et al., 1983; Stone and Burton, 1988) and that it reduces cerebral ischemic effects when administered at high dosages in vivo (Germano et al., 1987). Unfortunately, tryptophan is not a good precursor of cerebral KYNA, because it simultaneously increases kynurenine and quinolinic acid, two well-known pro-convulsant agents (Lapin, 1983; Foster et al., 1984). On the other hand, indole-3-pyruvic acid (IPA), the keto-analog of tryptophan, increases KYNA content in several rat organs after i.p. injection (Russi et al., 1989). Inside the brain, conversion to KYNA appears more effective for IPA than for tryptophan, suggesting a different metabolic pathway. Experiments were therefore performed in order to find the new pathway leading from IPA to KYNA.

Keywords

Brain Homogenate Quinolinic Acid Indole Ring Kynurenic Acid Glyoxylic Acid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Plenum Press, New York 1991

Authors and Affiliations

  • V. Politi
    • 1
  • M. V. Lavaggi
    • 1
  • G. Di Stazio
    • 1
  • A. Margonelli
    • 1
  1. 1.Polifarma Research CentreRomaItaly

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