An ATP-driven Cl- pump regulates Cl- concentrations in rat hippocampal neurons.
To investigate the role of Cl(-)-stimulated Mg(2+)-ATPase (Cl(-)-ATPase) in neurons, we examined the effects of ethacrynic acid (0.3 mM), which completely inhibits Cl(-)-ATPase on the intracellular Cl- concentrations of cultured rat hippocampal neurons, using Cl(-)-sensitive fluorescent probes. Ethacrynic acid and ATP consuming treatment increased the intracellular Cl- concentration, but elevation of the extracellular K+ concentration up to 10 mM, inhibition of Na+/K(+)-ATPase, or dissolution of H+ gradients had no effect. Furosemide (0.1 mM), an inhibitor of Na+/K+/Cl- co-transport, decreased the intracellular Cl- concentrations. These results indicate that an ethacrynic acid-sensitive and ATP-driven Cl- pump functions to reduce intraneural Cl- concentrations.
Inoue
M
M
Department of Pharmacology, Kansai Medical University, Osaka, Japan.
Hara
M
M
Zeng
X T
XT
Hirose
T
T
Ohnishi
S
S
Yasukura
T
T
Uriu
T
T
Omori
K
K
Minato
A
A
Inagaki
C
C
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000502:physiology*; D000818:Animals; D027321:Anion Transport Proteins; D001693:Biological Transport, Active / Q000187:drug effects; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors / Q000502:physiology*; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism*; D004976:Ethacrynic Acid / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D006624:Hippocampus / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains / Q000196:embryology / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
D027321:Anion Transport Proteins; D002712:Chlorides; D005665:Furosemide; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; C031652:anion-sensitive ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D004976:Ethacrynic Acid; D011188:Potassium