title: Role of renal vascular potassium channels in physiology and pathophysiology.
abstract: The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+conductance is a major factor in the regulation of the membrane potential (Vm) in vascular smooth muscle (VSMC) and endothelial cells (EC). The vascular tone is controlled by Vmvia its effect on the opening probability of voltage-operated Ca2+channels (VOCC) in VSMC. When K+conductance increases Vmbecomes more negative and vasodilation follows, while deactivation of K+channels leads to depolarization and vasoconstriction. K+channels in EC indirectly participate in the control of vascular tone by endothelium-derived vasodilation. Therefore, by regulating the tone of renal resistance vessels, K+channels have a potential role in the control of fluid homoeostasis and blood pressure as well as in the protection of the renal parenchyma. The main classes of K+channels (calcium activated (KCa), inward rectifier (Kir), voltage activated (Kv) and ATP sensitive (KATP)) have been found in the renal vessels. In this review, we summarize results available in the literature and our own studies in the field. We compare the ambiguous in vitro and in vivo results. We discuss the role of single types of K+channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+channels in the pathophysiology of hypertension, diabetes mellitus and sepsis.
authors.affiliation: Medical Ward 12, Trelleborg Hospital, Trelleborg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Salomonsson
authors.affiliation: Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
authors.forename: J C
authors.initials: JC
authors.lastname: Brasen
authors.affiliation: Department of Biomedical Sciences, Division of Renal and Vascular Physiology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: C M
authors.initials: CM
authors.lastname: Sorensen
mesh_terms: D000818:Animals; D006801:Humans; D007668:Kidney / Q000098:blood supply* / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D015221:Potassium Channels / Q000378:metabolism*; D014661:Vasoconstriction / Q000502:physiology; D014664:Vasodilation / Q000502:physiology
chemical_list: D015221:Potassium Channels
keywords: 
  in vivo
  ; afferent arteriole; renal blood flow; renal vascular resistance; vasoconstriction; vasodilation