Triflocin, a novel inhibitor for the Na-HCO3 symport in the proximal tubule.
1. Triflocin, applied at millimolar concentration hyperpolarizes the basolateral membrane of Necturus proximal convoluted tubular cells, in vivo. 2. Barium, 2.5 x 10(-3) M, ouabain, 10(-3) M, or amiloride 10(-4) M, fail to prevent this hyperpolarization. 3. Triflocin has no effect on the intracellular chloride activity. 4. In physiological acid base conditions, Triflocin increases intracellular pH. 5. Upon an acute isohydric hypercapnia, Triflocin depolarizes the basolateral membrane potential. 6. It is concluded that, Triflocin inhibits the basolateral electrogenic Na-(HCO3)n > 1 cotransport in proximal tubules.
Belachgar
F
F
INSERM U. 323, CHU Necker Enfants-Malades, Paris, France.
Hulin
P
P
Anagnostopoulos
T
T
Planelles
G
G
D000818:Animals; D001834:Body Water / Q000378:metabolism; D002352:Carrier Proteins / Q000037:antagonists & inhibitors*; D002712:Chlorides / Q000378:metabolism; D004232:Diuretics / Q000494:pharmacology*; D004594:Electrophysiology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009338:Necturus maculosus; D009539:Nicotinic Acids / Q000494:pharmacology*; D027982:Sodium-Bicarbonate Symporters; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects / Q000378:metabolism
D002352:Carrier Proteins; D002712:Chlorides; D004232:Diuretics; D009539:Nicotinic Acids; D027982:Sodium-Bicarbonate Symporters; D000254:Sodium-Potassium-Exchanging ATPase; C047090:triflocin