The effects of chronic ethanol exposure on N-methyl-D-aspartate-stimulated overflow of [3H]catecholamines from rat brain.
The effects of acute and chronic ethanol administration on N-methyl-D-aspartate-stimulated catecholamine overflow were examined. Three groups of male Sprague-Dawley rats were used. The first group received a chronic liquid diet containing ethanol (37%) for 3 weeks. The second group was pair-fed a liquid diet with dextrin substituted for ethanol isocalorically. The third group received Purina rat lab chow and water ad libitum. N-methyl-D-aspartate-stimulated [3H]catecholamine overflow from brain tissue slices was determined. N-methyl-D-aspartate (50-2000 microM) produced a concentration-dependent increase in [3H]norepinephrine overflow from cortical and hippocampal slices with no significant alteration of the response following chronic ethanol treatment. [3H]Dopamine overflow from striatal slices of the chronic ethanol group was significantly different at 1000 microM N-methyl-D-aspartate. The response of the chronic ethanol-treated group at the 1000 microM N-methyl-D-aspartate concentration was 30% and 40% lower than the pair-fed and ad libitum controls, respectively. Ethanol when added in vitro (30-200 mM) produced a concentration-dependent inhibition of N-methyl-D-aspartate (150 microM) stimulated efflux in all brain regions, and chronic ethanol treatment did not alter the inhibitory response. These results indicate an apparant lack of adaptation in N-methyl-D-aspartate-stimulated transmitter release following chronic ethanol treatment in this particular paradigm.
Brown
L M
LM
Institute for Neuroscience, University of Texas, Austin 78713.
Leslie
S W
SW
Gonzales
R A
RA
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D008297:Male; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014316:Tritium
D014316:Tritium; D000431:Ethanol; D016202:N-Methylaspartate; D004298:Dopamine; D009638:Norepinephrine