Muscarinic-activated K+ current in bovine aortic endothelial cells.
Isolated, cultured arterial endothelial cells express an acetylcholine (ACh)-activated K+ current in addition to an inward rectifier current whose conductance is unaffected by ACh. The cholinergic K+ current is specifically blocked by atropine (1 microM) and shows single saturation kinetics with ACh (half-maximal stimulation 51 nM ACh). Unlike the cardiac muscarinic receptor-gated K+ channel, its stimulation appears independent of a pertussis toxin-sensitive GTP-binding protein. Activation of the endothelial muscarinic K+ current resulting in hyperpolarization may represent an initial component of the vasodilatory effect of ACh.
Olesen
S P
SP
Department of Pathology, Brigham and Women's Hospital, Boston.
Davies
P F
PF
Clapham
D E
DE
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D019204:GTP-Binding Proteins / Q000378:metabolism; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials; D011188:Potassium / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism / Q000502:physiology*
D007473:Ion Channels; D011976:Receptors, Muscarinic; D019204:GTP-Binding Proteins; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium