title: Contribution of Kv7 channels to natriuretic peptide mediated vasodilation in normal and hypertensive rats.
abstract: The Kv7 family of voltage-gated potassium channels are expressed within the vasculature where they are key regulators of vascular tone and mediate cAMP-linked endogenous vasodilator responses, a pathway that is compromised in hypertension. However, the role of Kv7 channels in non-cAMP-linked vasodilator pathways has not been investigated. Natriuretic peptides are potent vasodilators, which operate primarily through the activation of a cGMP-dependent signaling pathway. This study investigated the putative role of Kv7 channels in natriuretic peptide-dependent relaxations in the vasculature of normal and hypertensive animals. Relaxant responses of rat aorta to both atrial and C-type natriuretic peptides and the nitric oxide donor sodium nitroprusside were impaired by the Kv7 blocker linopirdine (10 μmol/L) but not by the Kv7.1-specific blocker HMR1556 (10 μmol/L) and other K(+) channel blockers. In contrast, only the atrial natriuretic peptide response was sensitive to linopirdine in the renal artery. These Kv7-mediated responses were attenuated in arteries from hypertensive rats. Quantitative polymerase chain reaction showed that A- and B-type natriuretic peptide receptors were expressed at high levels in the aorta and renal artery from normal and spontaneously hypertensive rats. This study provides the first evidence that natriuretic peptide responses are impaired in hypertension and that recruitment of Kv7 channels is a key component of natriuretic peptide-dependent vasodilations.
authors.affiliation: From the Vascular Biology Research Centre, Institute for Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom (J.B.S., V.B., E.V.L., I.A.G.); and Ion Channels Group, Institute of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark (T.A.J.).
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Stott
authors.affiliation: From the Vascular Biology Research Centre, Institute for Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom (J.B.S., V.B., E.V.L., I.A.G.); and Ion Channels Group, Institute of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark (T.A.J.).
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barrese
authors.affiliation: From the Vascular Biology Research Centre, Institute for Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom (J.B.S., V.B., E.V.L., I.A.G.); and Ion Channels Group, Institute of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark (T.A.J.).
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Jepps
authors.affiliation: From the Vascular Biology Research Centre, Institute for Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom (J.B.S., V.B., E.V.L., I.A.G.); and Ion Channels Group, Institute of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark (T.A.J.).
authors.forename: Emma V
authors.initials: EV
authors.lastname: Leighton
authors.affiliation: From the Vascular Biology Research Centre, Institute for Cardiovascular and Cell Sciences, St George's University of London, London, United Kingdom (J.B.S., V.B., E.V.L., I.A.G.); and Ion Channels Group, Institute of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark (T.A.J.). i.greenwood@sgul.ac.uk.
authors.forename: Iain A
authors.initials: IA
authors.lastname: Greenwood
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000503:physiopathology; D002839:Chromans / Q000494:pharmacology; D006152:Cyclic GMP / Q000502:physiology; D004195:Disease Models, Animal; D006973:Hypertension / Q000503:physiopathology*; D007211:Indoles / Q000494:pharmacology; D051656:KCNQ Potassium Channels / Q000502:physiology*; D051657:KCNQ1 Potassium Channel / Q000502:physiology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000503:physiopathology; D045265:Natriuretic Peptides / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D012077:Renal Artery / Q000187:drug effects / Q000503:physiopathology; D015398:Signal Transduction / Q000502:physiology; D013449:Sulfonamides / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology*
chemical_list: D002839:Chromans; C420023:HMR 1556; D007211:Indoles; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C492166:Kcnq4 protein, rat; D045265:Natriuretic Peptides; D026902:Potassium Channel Blockers; D011725:Pyridines; D013449:Sulfonamides; D009599:Nitroprusside; D006152:Cyclic GMP; C061017:linopirdine
keywords: KCNQ potassium channels; cyclic GMP; muscle, smooth, vascular; natriuretic peptides