title: Ethanol differentially increases alpha 2-adrenergic and muscarinic acetylcholine receptor gene expression in NG108-15 cells.
abstract: Modulation of alpha 2-adrenergic and opioid neurotransmission may contribute to ethanol intoxication, tolerance, and physical dependence. We showed previously that ethanol increased the expression of functional delta-opioid receptors in NG108-15 cells (Charness, M. E., Querimit, L. A., and Diamond, I. (1986) J. Biol. Chem. 261, 3164-3169). Here we report that long-term (2 days) treatment of NG108-15 cells with ethanol increased the binding of the alpha 2-adrenergic receptor (alpha 2AR) antagonist [3H]rauwolscine and the muscarinic acetylcholine receptor (mAChR) antagonist [3H]quinuclidinyl benzilate by 2.8- and 1.4-fold, respectively. Increased receptor expression was associated with a proportionate increase in the potency of oxymetazoline and carbachol in inhibiting cAMP accumulation. Ethanol did not change the expression of G alpha i2 and reduced levels of G alpha s. Pertussis toxin pretreatment did not prevent the ethanol-induced increase in alpha 2AR, mAChR, and delta-opioid receptor expression. Ethanol caused a large (3.6-fold), dose-dependent increase in the abundance of alpha 2BAR mRNA (rat cDNA probe RNG, 4.1-kb transcript). Ethanol-induced increases in alpha 2BAR and alpha 2CAR (rat probe RG10, 2.5-kb transcript) mRNAs were first detected after 6 h of exposure to 100 mM ethanol, became maximal after 24 h, and persisted for up to 5 days. In contrast, ethanol caused only a small (1.3-fold) increase in the abundance of hm4 mAChR mRNA and did not change levels of G alpha i2 and G alpha s mRNAs. Our data indicate that clinically attainable concentrations of ethanol regulate alpha 2AR gene expression within the time frame of a single session of drinking.
authors.affiliation: Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: G
authors.initials: G
authors.lastname: Hu
authors.forename: L A
authors.initials: LA
authors.lastname: Querimit
authors.forename: L A
authors.initials: LA
authors.lastname: Downing
authors.forename: M E
authors.initials: ME
authors.lastname: Charness
mesh_terms: D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D037342:Pertussis Toxin; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000145:classification / Q000235:genetics*; D011976:Receptors, Muscarinic / Q000235:genetics*; D013997:Time Factors; D014018:Tissue Distribution; D015854:Up-Regulation / Q000187:drug effects; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D011942:Receptors, Adrenergic, alpha; D011976:Receptors, Muscarinic; D010566:Virulence Factors, Bordetella; D000431:Ethanol; D000242:Cyclic AMP; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins