Glutamate transport is downregulated in the cerebral cortex of alcohol-preferring rats.
BACKGROUND
Ethanol (EtOH) affects glutamatergic neurotransmission and this may underlie craving in alcoholics. The present study aimed to further elucidate the EtOH-induced modulation of glutamatergic neurotransmission in a model for alcoholism: the alcohol-preferring cAA rat.


METHODS
Glutamate transporter binding and function was assessed in membrane and synaptosomal preparations from the cerebral cortex of alcohol-preferring cAA rats and alcohol-naive cAA rats.


RESULTS
[3H]L-glutamate transport activity (Vmax) was 699 pmol.min-1.mg-1 in alcohol-naive cAA rats and 487 pmol.min-1.mg-1 in alcohol-preferring cAA rats. The specific binding sites (Bmax) for [3H]D-aspartate were markedly decreased in alcohol-preferring cAA rats (2059 pmol/mg) as compared to alcohol-naive cAA rats (4275 pmol/mg).


CONCLUSIONS
We hypothesize that the reduced density and function of glutamate transporter sites in alcohol-preferring cAA rats may represent an adaptive mechanism in order to counteract suppressed glutamatergic neurotransmission during chronic EtOH exposure.
Schreiber
R
R
Bayer-AG, Aprather Weg 18A, 42096 Wuppertal, Germany. rudy.schrelber.rs1@bayer-ag.ge
Freund
W D
WD
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000437:Alcoholism / Q000378:metabolism* / Q000503:physiopathology; D027322:Amino Acid Transport System X-AG; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects; D000431:Ethanol / Q000633:toxicity; D018698:Glutamic Acid / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects
D018528:ATP-Binding Cassette Transporters; D027322:Amino Acid Transport System X-AG; D016194:Receptors, N-Methyl-D-Aspartate; D000431:Ethanol; D018698:Glutamic Acid