ISSN:
1573-6903
Keywords:
Glutamate
;
vitamin E
;
oxidative stress
;
synaptosomes
;
aging
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We examined the influence of aging upon the uptake of glutamate by synaptosomes, and the oxidation of Synaptosomal vitamin E. Synaptosomes isolated from the cerebral hemispheres of Fischer 344 rats, 4 and 24 months old, were suspended at 37°C in buffer (pH 7.4) simulating extracellular fluid containing 10 mM glucose. The Km for the high affinity uptake of tritium labeled glutamate was ∼10 μM. The uptake of glutamate was lower in synaptosomes from older animals than those from younger animals for periods of up to 20 minutes. Upon incubation with a mixture of ferrous iron and ascorbate, more of the alpha tocopherol in synaptosomes derived from older rats was oxidized than in those derived from younger ones. Older animals may be more susceptible to excitotoxicity because: a) Synaptosomal reuptake of glutamate is less efficient and b) oxidative stress induced by various agents including glutamate may be higher in synaptosomes from the older animal.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022495804817
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