Temporal changes in proton MRS metabolites after kainic acid-induced seizures in rat brain.
Epilepsia
; 38(1): 87-94, 1997 Jan.
Article
em En
| MEDLINE
| ID: mdl-9024189
ABSTRACT
PURPOSE:
In situ 1H-magnetic resonance spectroscopy (MRS) was used to study temporal metabolic changes in a rat model of temporal lobe epilepsy (TLE) by using kainic acid (KA).METHODS:
Rat brains were scanned at the level of the hippocampal body for MRS measurements. Relative ratios of N-acetyl groups (NA N-acetylaspartate and N-acetylaspartyl glutamate), choline, and lactate (Lac) over creatine (Cr) were calculated.RESULTS:
NA/Cr ratios increased significantly during the ictal phase. During the postictal and interictal phases, the NA/Cr ratio decreased. There was a significant and prolonged increase of the lactate/Cr ratio in the hippocampi of rats that started 1 h after the onset of KA-induced seizure activity and persisted up to 24 h after the injection. The prolonged lactate/Cr increase in an area susceptible to neuronal damage (e.g., hippocampus) correlated with the onset of seizure activity but remained elevated thereafter.CONCLUSIONS:
The ictal and early postictal increase in lactate ratios may reflect increased cellular activity and metabolism resulting from KA excitotoxicity. Assuming that the changes in NA/Cr ratios are due to NAA increase, we speculate that an activation of the N-acetylaspartylglutamate (NAAG) dipeptidase pathway may explain the ictal increase in NA/Cr ratios. The late postictal decrease in NA/Cr ratios is a reflection of KA-induced neuronal cell loss.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Convulsões
/
Encéfalo
/
Espectroscopia de Ressonância Magnética
/
Ácido Caínico
Limite:
Animals
Idioma:
En
Revista:
Epilepsia
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos