Na(+)-K(+)-Cl- cotransport system in brain capillary endothelial cells: response to endothelin and hypoxia.
Effect of endothelin-1 and chemically induced hypoxia on Na(+)-K(+)-Cl- cotransport activity in cultured rat brain capillary endothelial cells was examined by using 86Rb+ as a tracer for K+; bumetanide-sensitive K+ uptake was defined as Na(+)-K(+)-Cl- cotransport activity. Endothelin-1, phorbol 12-myristate 13-acetate (PMA), or thapsigargin increased Na(+)-K(+)-Cl- cotransport activity. A protein kinase C inhibitor, bisindolylmaleimide, inhibited PMA- and endothelin-1- (but not thapsigargin-) induced Na(+)-K(+)-Cl- cotransport activity, indicating the presence of both protein kinase C-dependent regulatory mechanisms and protein kinase C-independent mechanisms which involve intracellular Ca2+. Oligomycin, sodium azide, or antimycin A increased Na(+)-K(+)-Cl- cotransport activity by 80-200%. Oligomycin-induced Na(+)-K(+)-Cl- cotransport activity was reduced by an intracellular Ca2+ chelator (BAPTA/AM) but not affected by bisindolylmaleimide, suggesting the involvement of intracellular Ca2+, and not protein kinase C, in hypoxia-induced Na(+)-K(+)-Cl- cotransport activity.
Kawai
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N
Stroke Branch, National Institute of Neurological Disease and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4128, USA.
McCarron
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RM
Spatz
M
M
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D019332:Endothelin-1 / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D002534:Hypoxia, Brain / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology
D002352:Carrier Proteins; D002712:Chlorides; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D007211:Indoles; D008301:Maleimides; D008565:Membrane Proteins; D028021:Sodium-Potassium-Chloride Symporters; D019284:Thapsigargin; D012964:Sodium; C088060:bisindolylmaleimide; D013755:Tetradecanoylphorbol Acetate; D011188:Potassium