title: Impaired function of coronary BK(Ca) channels in metabolic syndrome.
abstract: The role of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in regulation of coronary microvascular function is widely appreciated, but molecular and functional changes underlying the deleterious influence of metabolic syndrome (MetS) have not been determined. Male Ossabaw miniature swine consumed for 3-6 mo a normal diet (11% kcal from fat) or an excess-calorie atherogenic diet that induces MetS (45% kcal from fat, 2% cholesterol, 20% kcal from fructose). MetS significantly impaired coronary vasodilation to the BK(Ca) opener NS-1619 in vivo (30-100 microg) and reduced the contribution of these channels to adenosine-induced microvascular vasodilation in vitro (1-100 microM). MetS reduced whole cell penitrem A (1 microM)-sensitive K(+) current and NS-1619-activated (10 microM) current in isolated coronary vascular smooth muscle cells. MetS increased the concentration of free intracellular Ca(2+) and augmented coronary vasoconstriction to the L-type Ca(2+) channel agonist BAY K 8644 (10 pM-10 nM). BK(Ca) channel alpha and beta(1) protein expression was increased in coronary arteries from MetS swine. Coronary vascular dysfunction in MetS is related to impaired BK(Ca) channel function and is accompanied by significant increases in L-type Ca(2+) channel-mediated coronary vasoconstriction.
authors.affiliation: Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Léna
authors.initials: L
authors.lastname: Borbouse
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Dick
authors.forename: Shinichi
authors.initials: S
authors.lastname: Asano
authors.forename: Shawn B
authors.initials: SB
authors.lastname: Bender
authors.forename: U Deniz
authors.initials: UD
authors.lastname: Dincer
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Payne
authors.forename: Zachary P
authors.initials: ZP
authors.lastname: Neeb
authors.forename: Ian N
authors.initials: IN
authors.lastname: Bratz
authors.forename: Michael
authors.initials: M
authors.lastname: Sturek
authors.forename: Johnathan D
authors.initials: JD
authors.lastname: Tune
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D015762:2-Chloroadenosine / Q000494:pharmacology; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D001160:Arterioles / Q000378:metabolism / Q000503:physiopathology; D001562:Benzimidazoles / Q000494:pharmacology; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000378:metabolism; D020013:Calcium Signaling; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000378:metabolism / Q000503:physiopathology; D004036:Diet, Atherogenic; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000378:metabolism; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits / Q000378:metabolism; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials; D024821:Metabolic Syndrome / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D008833:Microcirculation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D009183:Mycotoxins / Q000494:pharmacology; D009529:Nicardipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D010641:Phenotype; D026902:Potassium Channel Blockers / Q000494:pharmacology; D013552:Swine; D013556:Swine, Miniature; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001562:Benzimidazoles; D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051038:Large-Conductance Calcium-Activated Potassium Channel beta Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D009183:Mycotoxins; D010455:Peptides; D026902:Potassium Channel Blockers; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D015762:2-Chloroadenosine; C086491:NS 1619; C003626:tremortin; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C064719:iberiotoxin; D009529:Nicardipine