title: High blood pressure associates with the remodelling of inward rectifier K+ channels in mice mesenteric vascular smooth muscle cells.
abstract: The increased vascular tone that defines essential hypertension is associated with depolarization of vascular smooth muscle cells (VSMCs) and involves a change in the expression profile of ion channels promoting arterial contraction. As a major regulator of VSMC resting membrane potential (V(M)), K(+) channel activity is an important determinant of vascular tone and vessel diameter. However, hypertension-associated changes in the expression and/or modulation of K(+) channels are poorly defined, due to their large molecular diversity and their bed-specific pattern of expression. Moreover, the impact of these changes on the integrated vessel function and their contribution to the development of altered vascular tone under physiological conditions need to be confirmed. Hypertensive (BPH) and normotensive (BPN) mice strains obtained by phenotypic selection were used to explore whether changes in the functional expression of VSMC inward rectifier K(+) channels contribute to the more depolarized resting V(M) and the increased vascular reactivity of hypertensive arteries. We determined the expression levels of inward rectifier K(+) channel mRNA in several vascular beds from BPN and BPH animals, and their functional contribution to VSMC excitability and vascular tone in mesenteric arteries. We found a decrease in the expression of Kir2.1, Kir4.1, Kir6.x and SUR2 mRNA in BPH VSMCs, and a decreased functional contribution of both K(IR) and K(ATP) channels in isolated BPH VSMCs. However, only the effect of K(ATP) channel modulators was impaired when exploring vascular tone, suggesting that decreased functional expression of K(ATP) channels may be an important element in the remodelling of VSMCs in essential hypertension.
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y CSIC, Valladolid, Spain.
authors.forename: Sendoa
authors.initials: S
authors.lastname: Tajada
authors.forename: Pilar
authors.initials: P
authors.lastname: Cidad
authors.forename: Alejandro
authors.initials: A
authors.lastname: Moreno-Domínguez
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Pérez-García
authors.forename: José R
authors.initials: JR
authors.lastname: López-López
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000502:physiology; D000818:Animals; D006973:Hypertension / Q000503:physiopathology*; D008638:Mesenteric Arteries / Q000502:physiology*; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D032389:Myocytes, Smooth Muscle / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying / Q000502:physiology*; D021122:Protein Subunits / Q000502:physiology; D011955:Receptors, Drug / Q000502:physiology; D064233:Sulfonylurea Receptors
chemical_list: D018528:ATP-Binding Cassette Transporters; D024661:Potassium Channels, Inwardly Rectifying; D021122:Protein Subunits; D011955:Receptors, Drug; D064233:Sulfonylurea Receptors