Effect of ethanol on gamma-aminobutyric acid and glycine receptor-coupled Cl- fluxes in rat brain synaptoneurosomes.
Chloride fluxes in synaptoneurosomes in response to additions of gamma-aminobutyric acid, glycine, and ethanol were measured using a chloride-sensitive fluorescent probe 6-methoxy-N-(3-sulfopropyl)quinolinium (SPQ). The Cl- gradient was directed outward by bathing cells in a medium low in Cl- concentration. The synaptoneurosomes responded to both gamma-aminobutyric acid and glycine by outflow of Cl- ions, as judged from an increase in SPQ fluorescence. These effects were inhibited by picrotoxin and strychnine, respectively. Ethanol also produced an outflow of Cl- ions from the synaptoneurosomes. Both picrotoxin and strychnine inhibited this effect. When the antagonists were used together, the inhibiting effect was additive. These results indicate that ethanol affects both gamma-aminobutyric acid and glycine receptor-linked chloride fluxes in the rat brain.
Engblom
A C
AC
Department of Biochemistry and Pharmacy, Abo Akademi, Finland.
Akerman
K E
KE
D000818:Animals; D001921:Brain / Q000502:physiology*; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D005998:Glycine / Q000378:metabolism / Q000494:pharmacology*; D007473:Ion Channels / Q000502:physiology; D007700:Kinetics; D008565:Membrane Proteins / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*; D018009:Receptors, Glycine; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D013574:Synaptosomes / Q000187:drug effects / Q000502:physiology*; D014220:Trialkyltin Compounds / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D018118:Chloride Channels; D002712:Chlorides; D007473:Ion Channels; D008565:Membrane Proteins; D011963:Receptors, GABA-A; D018009:Receptors, Glycine; D017981:Receptors, Neurotransmitter; D014220:Trialkyltin Compounds; D000431:Ethanol; C011559:tributyltin; D005680:gamma-Aminobutyric Acid; D005998:Glycine