Prolonged ethanol inhalation decreases gamma-aminobutyric acidA receptor alpha subunit mRNAs in the rat cerebral cortex.
Ethanol administration to rats by ethanol vapor inhalation (14 days) results in a 40-50% reduction in the level of gamma-aminobutyric acidA (GABAA) receptor alpha 1 subunit mRNAs [4.4 and 4.8 kilobases (kb)] in the cerebral cortex. The level of alpha 2 subunit mRNA (8.0 kb) was also reduced by 29%, whereas there was no effect of prolonged ethanol exposure on the level of alpha 3 subunit mRNA (3.1 kb). Ethanol exposure did not alter the steady state levels of cerebral cortical glutamic acid decarboxylase or beta-actin mRNAs. Moreover, no alterations in the levels of total RNA, poly(A)+ RNA, or rRNA were observed, suggesting that the ethanol-induced reductions in GABAA receptor alpha 1 and alpha 2 subunit mRNAs were not the result of a generalized effect of ethanol administration on transcription or mRNA turnover. These ethanol-induced reductions in GABAA receptor alpha subunit mRNAs may underlie alterations in GABAA receptor function or number observed following prolonged ethanol exposure in rats.
Montpied
P
P
Section of Molecular Pharmacology, National Institute of Mental Health, Bethesda, Maryland 20892.
Morrow
A L
AL
Karanian
J W
JW
Ginns
E I
EI
Martin
B M
BM
Paul
S M
SM
D000280:Administration, Inhalation; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008566:Membranes / Q000378:metabolism; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000235:genetics*; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects
D012333:RNA, Messenger; D011963:Receptors, GABA-A; D011061:Poly A; D000431:Ethanol; D012313:RNA