Histamine activates whole cell K+ currents in swine carotid arterial smooth muscle cell.
1. The effects of histamine on whole cell K+ currents were evaluated in cultured smooth muscle cells that were derived from explants of swine carotid artery. These cells exhibited cytoplasmic protein and agonist-induced calcium responses typical of noncultured smooth muscle cells. 2. Upon obtaining whole cell configuration, depolarization from a holding potential of -80 mV elicited a slowly inactivating voltage-dependent outward current that was sensitive to tetraethylammonium and 4-aminopyridine. 3. These K+ currents were at least partially Ca2+ dependent since they were inhibited by extracellular bath application of verapamil or by substitution of external Ca2+ with Co2+. 4. The addition of extracellular histamine increased the outward current both in the presence and absence of extracellular Ca2+ and this response was blocked by (+/-)chlorpheniramine. 5. We conclude that swine carotid arterial smooth muscle cells exhibit voltage and calcium dependent potassium current and that these currents are modified by histamine stimulation.
Hashemzadeh-Gargari
H
H
Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
Rembold
C M
CM
D000818:Animals; D002118:Calcium / Q000502:physiology; D002339:Carotid Arteries / Q000502:physiology; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D006632:Histamine / Q000502:physiology*; D007211:Indoles; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000502:physiology*; D015221:Potassium Channels / Q000502:physiology*; D013552:Swine / Q000502:physiology*
D005456:Fluorescent Dyes; D007211:Indoles; D015221:Potassium Channels; D006632:Histamine; C048960:indo-1; D002118:Calcium