Ethanol acutely decreases astroglial gap junction permeability in primary cultures from defined brain regions.
The acute effect of hyperosmotic ethanol on gap junction permeability was examined in astroglial cells in primary culture from five different brain regions. Gap junction permeability was analyzed by measuring dye spreading from cell to cell with the low molecular weight dye Lucifer Yellow. Ethanol concentrations 25-300 mM significantly decreased dye spreading in cultures from the cerebral cortex in a dose-dependent but time-independent manner for up to 60 min. Besides cerebral cortex, exposure to 150 mM ethanol decreased dye spreading in astroglial cultures from the hippocampus and from the brain stem, while cultures from the olfactory bulb and from the hypothalamus were not significantly affected. The ethanol-induced decrease in dye spreading in cultures from the cerebral cortex was not mediated through changes in cell volume, osmolarity, protein kinase C (PKC) phosphorylation, intracellular pH, or intracellular calcium concentration ([Ca(2+)](i)). The decrease in dye spreading was abolished upon incubation in sodium-reduced buffer, and after blockage of the Na(+)/K(+)/2Cl(-) cotransporter with furosemide. The results presented here indicate that ethanol-mediated decrease in dye spreading is directly or indirectly dependent on sodium.
Adermark
Louise
L
Institute of Clinical Neuroscience, Göteborg University, Box 420, SE 405 30 Göteborg, Sweden. louise.adermark@neuro.gu.se
Olsson
Torsten
T
Hansson
Elisabeth
E
D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage*; D017629:Gap Junctions / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D000431:Ethanol