title: Interstitial concentrations of amino acids in the rat striatum during global forebrain ischemia and potassium-evoked spreading depression.
abstract: The early detection and appropriate treatment of brain ischemia is of paramount importance. The interstitial concentrations of neurotransmitter amino acids are often used as an index of neuronal injury. However, monitoring of non-neurotransmitter amino acids may be equally important. We have studied the behavior of 10 amino acids during K(+)-induced spreading depression (application of 70 mM KCl during 40 min) and global forebrain ischemia (two-vessel occlusion with hypotension during 20 min). The concentrations of glutamate, aspartate, taurine, GABA, glycine, and alanine, measured in the rat striatum by microdialysis, increased during both ischemia and spreading depression, whereas glutamine concentrations decreased in both cases. Only ischemia, but not spreading depression, led to enhanced release of serine, threonine, and asparagine. We thus conclude that an elevation in the interstitial concentrations of non-neurotransmitter amino acids is specific to deep ischemic injury to nervous tissue. We propose the monitoring of serine, asparagine, and threonine, together with excitatory amino acids, as an index of the degree of ischemic brain injury.
authors.affiliation: Brain Research Center, Medical School, FIN-33014 University of Tampere, Finland. svetlana.molchanova@uta.fi
authors.forename: Svetlana
authors.initials: S
authors.lastname: Molchanova
authors.forename: Peeter
authors.initials: P
authors.lastname: Kööbi
authors.forename: Simo S
authors.initials: SS
authors.lastname: Oja
authors.forename: Pirjo
authors.initials: P
authors.lastname: Saransaari
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology*; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D013181:Cortical Spreading Depression / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology*; D016548:Prosencephalon / Q000502:physiology* / Q000503:physiopathology; D051381:Rats
chemical_list: D000596:Amino Acids; D011188:Potassium