Delayed increases in regional brain quinolinic acid follow transient ischemia in the gerbil

M. P. Heyes, Thaddeus Nowak

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Excessive activity or release of excitatory amino acids has been implicated in the neuronal injury that follows transient cerebral ischemia. To investigate the metabolism of the endogenous excitotoxin, quinolinic acid, and its potential for mediating cell loss following ischemia, the concentrations of quinolinic acid, L-tryptophan, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid were quantified in gerbil brain regions at different times after 5 or 15 min of ischemia induced by bilateral carotid artery occlusion. Significant elevation of brain tryptophan levels, accompanied by increased 5-hydroxyindoleacetic acid concentrations, occurred during the first several hours of recirculation, but regional brain quinolinic acid concentrations were found either to decrease or remain unchanged during the first 24 h after the ischemic insult. However, significant increases in quinolinic acid concentrations occurred in striatum and hippocampus at 2 days of recirculation after 5 min of ischemia. After a further 4 and 7 days, strikingly large increases in quinolinic acid concentrations were observed in all regions examined, with the highest levels observed in the hippocampus and striatum, regions that also show the most severe ischemic injury. These delayed increases in brain quinolinic acid concentrations are suggested to reflect the presence of activated macrophages, reactive astrocytes, and/or microglia in vulnerable regions during and subsequent to ischemic injury. While the results do not support a role for increased quinolinic acid concentrations in early excitotoxic neuronal damage, the role of the delayed increases in brain quinolinic acid in the progresssion of postischemic injury and its relevance to postischemic brain funciton remain to be established.

Original languageEnglish (US)
Pages (from-to)660-667
Number of pages8
JournalJournal of Cerebral Blood Flow and Metabolism
Volume10
Issue number5
DOIs
StatePublished - Jan 1 1990

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Quinolinic Acid
Gerbillinae
Ischemia
Brain
Hydroxyindoleacetic Acid
Wounds and Injuries
Tryptophan
Hippocampus
Excitatory Amino Acids
Transient Ischemic Attack
Neurotoxins
Microglia
Carotid Arteries
Astrocytes
Serotonin
Macrophages

All Science Journal Classification (ASJC) codes

  • Neurology
  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine

Cite this

Delayed increases in regional brain quinolinic acid follow transient ischemia in the gerbil. / Heyes, M. P.; Nowak, Thaddeus.

In: Journal of Cerebral Blood Flow and Metabolism, Vol. 10, No. 5, 01.01.1990, p. 660-667.

Research output: Contribution to journalArticle

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