Chloride transport in embryonic cells: effect of ethanol and GABA.
Ethanol and GABA (gamma-aminobutyric acid) and their interaction on 36Cl-influx were analyzed in cultured embryonic palate and limb mesenchymal cells in order to determine whether ethanol exerts its teratogenic action through a GABA receptor involved in embryogenesis. Cl- transport in secondary cultures of C57BL/6 palate mesenchymal cells was shown to consist of three systems including the electroneutral Cl-/HCO3- exchange (50%) and Na+/K+/Cl- cotransport (30%) pathways and the voltage-dependent Cl- channel (20%). Treatment with DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid) or SITS (4-acetamido-4'-isocyano-stilbene-2,2' disulfonic acid) in SWV palate cells inhibited the Cl-/HCO3- exchange pathway, while treatment with DIDS and bumetanide inhibited both the exchange and cation cotransport pathways, the residual Cl- influx inferred to be the electrogenic pathway. Inhibition of Cl- transport by anthracene-9-carboxylic acid confirmed the presence of the electrogenic Cl- pathway. It was observed that the rate of Cl- transport was significantly greater in palate cells of C57BL/6 mice than those of SWV mice. Also the rate of Cl- transport was significantly greater in secondary cultures of palate cells from C57BL/6 mice than from primary cultures of limb cells from the same strain. No evidence could be obtained that ethanol (10 to 100 mM) or GABA (3 X 10(-5) M) or their combination stimulated total Cl- influx in either C57BL/6 or SWV palate mesenchymal cells, putative voltage-dependent Cl- influx in C57BL/6 palate cells, or total Cl- influx in primary cultures of C57BL/6 limb mesenchymal cells.
Zimmerman
E F
EF
Division of Basic Science Research, Children's Hospital Research Foundation, Cincinnati, Ohio 45229.
Collins
M
M
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001386:Azides / Q000494:pharmacology; D001569:Benzodiazepines / Q000494:pharmacology; D001693:Biological Transport, Active; D002034:Bumetanide / Q000494:pharmacology; D002478:Cells, Cultured; D002712:Chlorides / Q000493:pharmacokinetics*; D004622:Embryo, Mammalian / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D005121:Extremities; D005665:Furosemide / Q000494:pharmacology; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D001386:Azides; D002712:Chlorides; D002034:Bumetanide; D001569:Benzodiazepines; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D000431:Ethanol; D005680:gamma-Aminobutyric Acid; D005665:Furosemide; C042957:Ro 15-4513; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid