Glutamate Uptake Impairment and Neuronal Damage in Young and Aged Rats In Vivo
Article first published online: 18 NOV 2002
Journal of Neurochemistry
Volume 69, Issue 3, pages 1151–1160, September 1997
How to Cite
Massieu, L. and Tapia, R. (1997), Glutamate Uptake Impairment and Neuronal Damage in Young and Aged Rats In Vivo. Journal of Neurochemistry, 69: 1151–1160. doi: 10.1046/j.1471-4159.1997.69031151.x
- Issue published online: 18 NOV 2002
- Article first published online: 18 NOV 2002
- Received November 5, 1996; revised manuscript received March 14, 1997; accepted April 16, 1997.
- Glutamate uptake;
- Neuronal damage;
- Pyrrolidine dicarboxylate;
Abstract: The extracellular concentration of glutamate increases during hypoxia/ischemia probably due to deficient uptake. Glutamate might contribute to neuronal damage associated with this disorder and to neurodegeneration during aging. In the present study, we have tested the effect of two inhibitors of glutamate transport, l-trans-pyrrolidine-2,4-dicarboxylate and dihydrokainate, on the extracellular levels of glutamate and on neuronal damage, which was quantitatively studied by image analysis of histological brain sections. Drugs were administered by microdialysis and glutamate concentration was determined by HPLC in the striatum and the hippocampus of 3-month-old and 22–24-month-old rats. In both regions studied, the basal concentration of extracellular glutamate was higher in aged than in young rats. Pyrrolidine dicarboxylate induced a substantial elevation of extracellular glutamate in both regions, and although this increase was almost twofold higher in old than in young animals, no neuronal damage was observed. In contrast, dihydrokainate had a poor effect on glutamate levels, but induced clear neuronal damage in the striatum and the hippocampus in both groups of rats. The present results suggest that age appears not to be a significant factor in the sensitivity of neurons to the toxic effect of extracellular glutamate increase via blockade of its transport system.