title: The effects of Na(+)-K(+)-Cl- co-transport and Cl(-)-HCO3-exchange blockade on the membrane potential and intracellular chloride levels of rat arterial smooth muscle, in vitro.
abstract: Membrane potential and intracellular chloride levels have been measured simultaneously in vascular smooth muscle from the femoral artery of the rat, in vitro, using double-barrelled chloride-sensitive microelectrodes. These values are compared in the presence and absence of bicarbonate, and inhibitors of Cl(-)-HCO3- exchange and Na(+)-K(+)-Cl- co-transport. Both DIDS and bumetanide caused a hyperpolarization of membrane potential (Em) and a fall in [Cl-]i, in the presence of extracellular HCO3-. The effects of bumetanide were reversible, but those of DIDS were not. The effect of both agents were additive. The results demonstrate that both Cl(-)-HCO3- exchange and Na(+)-K(+)-Cl- co-transport accumulate intracellular chloride in this preparation, and it is suggested that this may allow the modulation of membrane potential (and hence excitability) of smooth muscle.
authors: Department of Anatomy and Physiology, University of Dundee.
authors: J P
authors: JP
authors: Davis
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000378:metabolism*; D001639:Bicarbonates / Q000494:pharmacology; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides / Q000378:metabolism*; D046508:Culture Techniques; D004338:Drug Combinations; D007425:Intracellular Membranes / Q000378:metabolism*; D008564:Membrane Potentials; D009130:Muscle, Smooth / Q000378:metabolism*; D051381:Rats; D028021:Sodium-Potassium-Chloride Symporters
chemical_list: D001639:Bicarbonates; D002352:Carrier Proteins; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides; D004338:Drug Combinations; D028021:Sodium-Potassium-Chloride Symporters; D002034:Bumetanide; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid