Ischemic flow threshold for extracellular glutamate increase in cat cortex.
Extracellular glutamate (Glu), cerebral blood flow (CBF), and auditory-evoked potentials (AEPs) were measured concurrently using microdialysis and hydrogen clearance in the auditory cortex of anesthetized cats during global ischemia of various severities. A threshold-type relationship was observed between extracellular Glu and CBF: Glu increased at CBF levels below about 20 ml/100 g/min. The Glu increase was related to the impairment of AEPs. The results suggest that Glu neurotoxicity is an important factor for ischemic neuronal injury even in penumbra.
Shimada
N
N
Max-Planck-Institut für Neurologische Forschung, Köln, Federal Republic of Germany.
Graf
R
R
Rosner
G
G
Wakayama
A
A
George
C P
CP
Heiss
W D
WD
D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology*; D002415:Cats; D002540:Cerebral Cortex / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D004056:Differential Threshold; D005072:Evoked Potentials, Auditory; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D008297:Male; D009994:Osmolar Concentration
D005971:Glutamates; D018698:Glutamic Acid