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Tune JD, Warne CM, Essajee SI, Tucker SM, Figueroa CA, Dick GM, Beard DA. Unraveling the Gordian knot of coronary pressure-flow autoregulation. J Mol Cell Cardiol 2024; 190:82-91. [PMID: 38608928 DOI: 10.1016/j.yjmcc.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 03/27/2024] [Accepted: 04/09/2024] [Indexed: 04/14/2024]
Abstract
The coronary circulation has the inherent ability to maintain myocardial perfusion constant over a wide range of perfusion pressures. The phenomenon of pressure-flow autoregulation is crucial in response to flow-limiting atherosclerotic lesions which diminish coronary driving pressure and increase risk of myocardial ischemia and infarction. Despite well over half a century of devoted research, understanding of the mechanisms responsible for autoregulation remains one of the most fundamental and contested questions in the field today. The purpose of this review is to highlight current knowledge regarding the complex interrelationship between the pathways and mechanisms proposed to dictate the degree of coronary pressure-flow autoregulation. Our group recently likened the intertwined nature of the essential determinants of coronary flow control to the symbolically unsolvable "Gordian knot". To further efforts to unravel the autoregulatory "knot", we consider recent challenges to the local metabolic and myogenic hypotheses and the complicated dynamic structural and functional heterogeneity unique to the heart and coronary circulation. Additional consideration is given to interrogation of putative mediators, role of K+ and Ca2+ channels, and recent insights from computational modeling studies. Improved understanding of how specific vasoactive mediators, pathways, and underlying disease states influence coronary pressure-flow relations stands to significantly reduce morbidity and mortality for what remains the leading cause of death worldwide.
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Affiliation(s)
- Johnathan D Tune
- Department of Physiology and Anatomy, University of North Texas Health Science Center, USA.
| | - Cooper M Warne
- Department of Physiology and Anatomy, University of North Texas Health Science Center, USA
| | - Salman I Essajee
- Department of Physiology and Anatomy, University of North Texas Health Science Center, USA
| | - Selina M Tucker
- Department of Physiology and Anatomy, University of North Texas Health Science Center, USA
| | - C Alberto Figueroa
- Section of Vascular Surgery, Department of Surgery, University of Michigan, USA; Department of Biomedical Engineering, University of Michigan, USA
| | - Gregory M Dick
- Department of Physiology and Anatomy, University of North Texas Health Science Center, USA
| | - Daniel A Beard
- Department of Molecular and Integrative Physiology, University of Michigan, USA
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Warne CM, Essajee SI, Tucker SM, Figueroa CA, Beard DA, Dick GM, Tune JD. Oxygen-sensing pathways below autoregulatory threshold act to sustain myocardial oxygen delivery during reductions in perfusion pressure. Basic Res Cardiol 2023; 118:12. [PMID: 36988670 PMCID: PMC10797605 DOI: 10.1007/s00395-023-00985-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/13/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023]
Abstract
The coronary circulation has an innate ability to maintain constant blood flow over a wide range of perfusion pressures. However, the mechanisms responsible for coronary autoregulation remain a fundamental and highly contested question. This study interrogated the local metabolic hypothesis of autoregulation by testing the hypothesis that hypoxemia-induced exaggeration of the metabolic error signal improves the autoregulatory response. Experiments were performed on open-chest anesthetized swine during stepwise changes in coronary perfusion pressure (CPP) from 140 to 40 mmHg under normoxic (n = 15) and hypoxemic (n = 8) conditions, in the absence and presence of dobutamine-induced increases in myocardial oxygen consumption (MVO2) (n = 5-7). Hypoxemia (PaO2 < 40 mmHg) decreased coronary venous PO2 (CvPO2) ~ 30% (P < 0.001) and increased coronary blood flow ~ 100% (P < 0.001), sufficient to maintain myocardial oxygen delivery (P = 0.14) over a wide range of CPPs. Autoregulatory responsiveness during hypoxemia-induced reductions in CvPO2 were associated with increases of autoregulatory gain (Gc; P = 0.033) but not slope (P = 0.585) over a CPP range of 120 to 60 mmHg. Preservation of autoregulatory Gc (P = 0.069) and slope (P = 0.264) was observed during dobutamine administration ± hypoxemia. Reductions in coronary resistance in response to decreases in CPP predominantly occurred below CvPO2 values of ~ 25 mmHg, irrespective of underlying vasomotor reserve. These findings support the presence of an autoregulatory threshold under which oxygen-sensing pathway(s) act to preserve sufficient myocardial oxygen delivery as CPP is reduced during increases in MVO2 and/or reductions in arterial oxygen content.
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Affiliation(s)
- Cooper M Warne
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., TX, 76107, Fort Worth, USA
| | - Salman I Essajee
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., TX, 76107, Fort Worth, USA
| | - Selina M Tucker
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., TX, 76107, Fort Worth, USA
| | - C Alberto Figueroa
- Section of Vascular Surgery, Department of Surgery, University of Michigan, Ann Arbor, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, USA
| | - Daniel A Beard
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, USA
| | - Gregory M Dick
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., TX, 76107, Fort Worth, USA
| | - Johnathan D Tune
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., TX, 76107, Fort Worth, USA.
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Tune JD, Goodwill AG, Baker HE, Dick GM, Warne CM, Tucker SM, Essajee SI, Bailey CA, Klasing JA, Russell JJ, McCallinhart PE, Trask AJ, Bender SB. Chronic high-rate pacing induces heart failure with preserved ejection fraction-like phenotype in Ossabaw swine. Basic Res Cardiol 2022; 117:50. [PMID: 36222894 DOI: 10.1007/s00395-022-00958-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 09/12/2022] [Accepted: 09/28/2022] [Indexed: 01/31/2023]
Abstract
The lack of pre-clinical large animal models of heart failure with preserved ejection fraction (HFpEF) remains a growing, yet unmet obstacle to improving understanding of this complex condition. We examined whether chronic cardiometabolic stress in Ossabaw swine, which possess a genetic propensity for obesity and cardiovascular complications, produces an HFpEF-like phenotype. Swine were fed standard chow (lean; n = 13) or an excess calorie, high-fat, high-fructose diet (obese; n = 16) for ~ 18 weeks with lean (n = 5) and obese (n = 8) swine subjected to right ventricular pacing (180 beats/min for ~ 4 weeks) to induce heart failure (HF). Baseline blood pressure, heart rate, LV end-diastolic volume, and ejection fraction were similar between groups. High-rate pacing increased LV end-diastolic pressure from ~ 11 ± 1 mmHg in lean and obese swine to ~ 26 ± 2 mmHg in lean HF and obese HF swine. Regression analyses revealed an upward shift in LV diastolic pressure vs. diastolic volume in paced swine that was associated with an ~ twofold increase in myocardial fibrosis and an ~ 50% reduction in myocardial capillary density. Hemodynamic responses to graded hemorrhage revealed an ~ 40% decrease in the chronotropic response to reductions in blood pressure in lean HF and obese HF swine without appreciable changes in myocardial oxygen delivery or transmural perfusion. These findings support that high-rate ventricular pacing of lean and obese Ossabaw swine initiates underlying cardiac remodeling accompanied by elevated LV filling pressures with normal ejection fraction. This distinct pre-clinical tool provides a unique platform for further mechanistic and therapeutic studies of this highly complex syndrome.
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Affiliation(s)
- Johnathan D Tune
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA.
| | - Adam G Goodwill
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Hana E Baker
- Diabetes and Complications Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Gregory M Dick
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Cooper M Warne
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Selina M Tucker
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Salman I Essajee
- Department of Physiology and Anatomy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Chastidy A Bailey
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Jessica A Klasing
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Jacob J Russell
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
| | - Patricia E McCallinhart
- Center for Cardiovascular Research, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Aaron J Trask
- Center for Cardiovascular Research, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Shawn B Bender
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
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Warne CM, Essajee SI, Dick GM, Tune JD. Hypoxemia Augments the Local Metabolic Error Signal and Improves Coronary Pressure‐Flow Autoregulation. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r3725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Cooper M. Warne
- Department of Physiology and AnatomyUniversity of North Texas Health Science CenterFort WorthTX
| | - Sal I. Essajee
- Department of Physiology and AnatomyUniversity of North Texas Health Science CenterFort WorthTX
| | - Gregory M. Dick
- Department of Physiology and AnatomyUniversity of North Texas Health Science CenterFort WorthTX
| | - Johnathan D. Tune
- Department of Physiology and AnatomyUniversity of North Texas Health Science CenterFort WorthTX
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Tune JD, Goodwill AG, Baker HE, Dick GM, Warne CM, Bailey CA, Klasing JA, Russell JJ, McCallinhart PE, Trask AJ, Bender SB. Chronic High‐Rate Pacing Induces Heart Failure with Preserved Ejection Fraction‐Like Phenotype in Obese Ossabaw Swine. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r3827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Johnathan D. Tune
- Physiology and AnatomyUniversity of North Texas Health Sciences CenterFort WorthTX
| | - Adam G. Goodwill
- Department of Integrative Medical SciencesNortheast Ohio Medical UniversityRootstownOH
| | - Hana E. Baker
- Diabetes and Complications ResearchEli Lilly and CompanyIndianapolisIN
| | - Gregory M. Dick
- Physiology and AnatomyUniversity of North Texas Health Sciences CenterFort WorthTX
| | - Cooper M. Warne
- Physiology and AnatomyUniversity of North Texas Health Sciences CenterFort WorthTX
| | | | | | - Jacob J. Russell
- Department of Biomedical SciencesUniversity of MissouriColumbiaMO
| | - Patricia E. McCallinhart
- Center for Cardiovascular ResearchThe Abigail Wexner Research Institute at Nationwide Children’s HospitalColumbusOH
| | - Aaron J. Trask
- Center for Cardiovascular ResearchThe Abigail Wexner Research Institute at Nationwide Children’s HospitalColumbusOH
| | - Shawn B. Bender
- Department of Biomedical SciencesUniversity of MissouriColumbiaMO
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Fu L, Jiang G, Weng H, Dick GM, Chang Y, Kassab GS. Cerebrovascular miRNAs correlate with the clearance of Aβ through perivascular route in younger 3xTg-AD mice. Brain Pathol 2019; 30:92-105. [PMID: 31206909 DOI: 10.1111/bpa.12759] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/04/2019] [Indexed: 12/14/2022] Open
Abstract
The "two-hit vascular hypothesis for Alzheimer's disease (AD)" and amyloid-β (Aβ) oligomer hypothesis suggest that impaired soluble Aβ oligomers clearance through the cerebral vasculature may be an initial step of the AD process. Soluble Aβ oligomers are driven into perivascular spaces from the brain parenchyma and toward peripheral blood flow. The underlying vascular-based mechanism, however, has not been defined. Given that microRNAs (miRNAs), emerging as novel modulators, are involved in numerous physiological and pathological processes, we hypothesized that cerebrovascular miRNAs may regulate the activities of brain blood vessels, which further affects the concentration of Aβ in the AD brain. In this study, perivascular Aβ deposits, higher vascular activation, increased pericyte coverage and up-regulated capillaries miRNAs at 6 months old (6 mo) were found to correlate with the lower Aβ levels of middle AD stage (9 mo) in 3xTg-AD (3xTg) mice. It is implicated that at the early stage of AD when intracellular Aβ appeared, higher expression of vessel-specific miRNAs, elevated pericyte coverage, and activated endothelium facilitate Aβ oligomer clearance through the perivascular route, resulting in a transient reduction of Aβ oligomers at 9 mo. Additionally, ghrelin-induced upregulation of capillary miRNAs and increased pericyte coverage attenuated Aβ burden at 9 mo, in further support of the relationship between vascular miRNAs and Aβ clearance. This work suggests a cerebral microvessel miRNA may boost endothelial highly activated phenotypes to promote elimination of Aβ oligomers through the perivascular drainage pathway and contribute to AD progression. The targeting of brain vessel-specific miRNAs may provide a new rationale for the development of innovative therapeutic strategies for AD treatment.
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Affiliation(s)
- Lijuan Fu
- California Medical Innovations Institute, San Diego, USA
| | - Ge Jiang
- California Medical Innovations Institute, San Diego, USA
| | - Hope Weng
- California Medical Innovations Institute, San Diego, USA
| | - Gregory M Dick
- California Medical Innovations Institute, San Diego, USA
| | - Yanzhong Chang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, Shijiazhuang, China
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Kiel AM, Goodwill AG, Baker HE, Dick GM, Tune JD. Local metabolic hypothesis is not sufficient to explain coronary autoregulatory behavior. Basic Res Cardiol 2018; 113:33. [PMID: 30073416 DOI: 10.1007/s00395-018-0691-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 06/19/2018] [Accepted: 07/04/2018] [Indexed: 01/21/2023]
Abstract
The local metabolic hypothesis proposes that myocardial oxygen tension determines the degree of autoregulation by increasing the production of vasodilator metabolites as perfusion pressure is reduced. Thus, normal physiologic levels of coronary venous PO2, an index of myocardial oxygenation, are proposed to be required for effective autoregulation. The present study challenged this hypothesis through determination of coronary responses to changes in coronary perfusion pressure (CPP 140-40 mmHg) in open-chest swine in the absence (n = 7) and presence of euvolemic hemodilution (~ 50% reduction in hematocrit), with (n = 5) and without (n = 6) infusion of dobutamine to augment MVO2. Coronary venous PO2 decreased over similar ranges (~ 28-15 mmHg) as CPP was lowered from 140 to 40 mmHg in each of the groups. However, coronary venous PO2 was not associated with changes in coronary blood flow (r = - 0.11; P = 0.29) or autoregulatory gain (r = - 0.29; P = 0.12). Coronary zero-flow pressure (Pzf) was measured in 20 mmHg increments and determined to be directly related to vascular resistance (r = 0.71; P < 0.001). Further analysis demonstrated that changes in coronary blood flow remained minimal at Pzf > 20 mmHg, but progressively increased as Pzf decreased below this threshold value (r = 0.68; P < 0.001). Coronary Pzf was also positively correlated with autoregulatory gain (r = 0.43; P = 0.001). These findings support that coronary autoregulatory behavior is predominantly dependent on an adequate degree of underlying vasomotor tone, independent of normal myocardial oxygen tension.
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Affiliation(s)
- Alexander M Kiel
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN, 46202, USA.,Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN, 47907, USA
| | - Adam G Goodwill
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN, 46202, USA
| | - Hana E Baker
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN, 46202, USA
| | - Gregory M Dick
- California Medical Innovations Institute, 11107 Roselle Street, San Diego, CA, 92121, USA
| | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN, 46202, USA.
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Dick GM, Namani R, Patel B, Kassab GS. Role of Coronary Myogenic Response in Pressure-Flow Autoregulation in Swine: A Meta-Analysis With Coronary Flow Modeling. Front Physiol 2018; 9:580. [PMID: 29875686 PMCID: PMC5974144 DOI: 10.3389/fphys.2018.00580] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/01/2018] [Indexed: 11/23/2022] Open
Abstract
Myogenic responses (pressure-dependent contractions) of coronary arterioles play a role in autoregulation (relatively constant flow vs. pressure). Publications on myogenic reactivity in swine coronaries vary in caliber, analysis, and degree of responsiveness. Further, data on myogenic responses and autoregulation in swine have not been completely compiled, compared, and modeled. Thus, it has been difficult to understand these physiological phenomena. Our purpose was to: (a) analyze myogenic data with standard criteria; (b) assign results to diameter categories defined by morphometry; and (c) use our novel multiscale flow model to determine the extent to which ex vivo myogenic reactivity can explain autoregulation in vivo. When myogenic responses from the literature are an input for our model, the predicted coronary autoregulation approaches in vivo observations. More complete and appropriate data are now available to investigate the regulation of coronary blood flow in swine, a highly relevant model for human physiology and disease.
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Affiliation(s)
- Gregory M Dick
- California Medical Innovations Institute, San Diego, CA, United States
| | - Ravi Namani
- California Medical Innovations Institute, San Diego, CA, United States
| | - Bhavesh Patel
- California Medical Innovations Institute, San Diego, CA, United States
| | - Ghassan S Kassab
- California Medical Innovations Institute, San Diego, CA, United States
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Dick GM, Tune JD. Dynamic Regulation of the Subunit Composition of BK Channels in Smooth Muscle. Circ Res 2017; 121:594-595. [PMID: 28860314 DOI: 10.1161/circresaha.117.311723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Gregory M Dick
- From the California Medical Innovations Institute, San Diego (G.M.D.); and Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis (J.D.T.)
| | - Johnathan D Tune
- From the California Medical Innovations Institute, San Diego (G.M.D.); and Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis (J.D.T.).
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Abstract
The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. © 2017 American Physiological Society. Compr Physiol 7:321-382, 2017.
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Affiliation(s)
- Adam G Goodwill
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
| | - Gregory M Dick
- California Medical Innovations Institute, 872 Towne Center Drive, Pomona, CA
| | - Alexander M Kiel
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, Lafayette, IN
| | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN
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Goodwill AG, Fu L, Noblet JN, Casalini ED, Sassoon D, Berwick ZC, Kassab GS, Tune JD, Dick GM. KV7 channels contribute to paracrine, but not metabolic or ischemic, regulation of coronary vascular reactivity in swine. Am J Physiol Heart Circ Physiol 2016; 310:H693-704. [PMID: 26825518 DOI: 10.1152/ajpheart.00688.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/20/2016] [Indexed: 12/30/2022]
Abstract
Hydrogen peroxide (H2O2) and voltage-dependent K(+) (KV) channels play key roles in regulating coronary blood flow in response to metabolic, ischemic, and paracrine stimuli. The KV channels responsible have not been identified, but KV7 channels are possible candidates. Existing data regarding KV7 channel function in the coronary circulation (limited to ex vivo assessments) are mixed. Thus we examined the hypothesis that KV7 channels are present in cells of the coronary vascular wall and regulate vasodilation in swine. We performed a variety of molecular, biochemical, and functional (in vivo and ex vivo) studies. Coronary arteries expressed KCNQ genes (quantitative PCR) and KV7.4 protein (Western blot). Immunostaining demonstrated KV7.4 expression in conduit and resistance vessels, perhaps most prominently in the endothelial and adventitial layers. Flupirtine, a KV7 opener, relaxed coronary artery rings, and this was attenuated by linopirdine, a KV7 blocker. Endothelial denudation inhibited the flupirtine-induced and linopirdine-sensitive relaxation of coronary artery rings. Moreover, linopirdine diminished bradykinin-induced endothelial-dependent relaxation of coronary artery rings. There was no effect of intracoronary flupirtine or linopirdine on coronary blood flow at the resting heart rate in vivo. Linopirdine had no effect on coronary vasodilation in vivo elicited by ischemia, H2O2, or tachycardia. However, bradykinin increased coronary blood flow in vivo, and this was attenuated by linopirdine. These data indicate that KV7 channels are expressed in some coronary cell type(s) and influence endothelial function. Other physiological functions of coronary vascular KV7 channels remain unclear, but they do appear to contribute to endothelium-dependent responses to paracrine stimuli.
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Affiliation(s)
- Adam G Goodwill
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Lijuan Fu
- California Medical Innovations Institute, San Diego, California
| | - Jillian N Noblet
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Eli D Casalini
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Daniel Sassoon
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | | | | | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Gregory M Dick
- California Medical Innovations Institute, San Diego, California
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Fancher IS, Butcher JT, Brooks SD, Rottgen TS, Skaff PR, Frisbee JC, Dick GM. Diphenyl phosphine oxide-1-sensitive K(+) channels contribute to the vascular tone and reactivity of resistance arteries from brain and skeletal muscle. Microcirculation 2016; 22:315-25. [PMID: 25808400 DOI: 10.1111/micc.12201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 03/17/2015] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Many types of vascular smooth muscle cells exhibit prominent KDR currents. These KDR currents may be mediated, at least in part, by KV1.5 channels, which are sensitive to inhibition by DPO-1. We tested the hypothesis that DPO-1-sensitive KDR channels regulate the tone and reactivity of resistance-sized vessels from rat brain (MCA) and skeletal muscle (GA). METHODS Middle cerebral and gracilis arteries were isolated and subjected to three kinds of experimental analysis: (i) western blot/immunocytochemistry; (ii) patch clamp electrophysiology; and (iii) pressure myography. RESULTS Western blot and immunocytochemistry experiments demonstrated KV1.5 immunoreactivity in arteries and smooth muscle cells isolated from them. Whole-cell patch clamp experiments revealed smooth muscle cells from resistance-sized arteries to possess a KDR current that was blocked by DPO-1. Resistance arteries constricted in response to increasing concentrations of DPO-1. DPO-1 enhanced constrictions to PE and serotonin in gracilis and middle cerebral arteries, respectively. When examining the myogenic response, we found that DPO-1 reduced the diameter at any given pressure. Dilations in response to ACh and SNP were reduced by DPO-1. CONCLUSION We suggest that KV1.5, a DPO-1-sensitive KDR channel, plays a major role in determining microvascular tone and the response to vasoconstrictors and vasodilators.
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Affiliation(s)
- Ibra S Fancher
- Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, Morgantown, West Virginia, USA
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Shepherd DL, Nichols CE, Croston TL, McLaughlin SL, Petrone AB, Lewis SE, Thapa D, Long DM, Dick GM, Hollander JM. Early detection of cardiac dysfunction in the type 1 diabetic heart using speckle-tracking based strain imaging. J Mol Cell Cardiol 2015; 90:74-83. [PMID: 26654913 DOI: 10.1016/j.yjmcc.2015.12.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/11/2015] [Accepted: 12/02/2015] [Indexed: 12/14/2022]
Abstract
Enhanced sensitivity in echocardiographic analyses may allow for early detection of changes in cardiac function beyond the detection limits of conventional echocardiographic analyses, particularly in a small animal model. The goal of this study was to compare conventional echocardiographic measurements and speckle-tracking based strain imaging analyses in a small animal model of type 1 diabetes mellitus. Conventional analyses revealed differences in ejection fraction, fractional shortening, cardiac output, and stroke volume in diabetic animals relative to controls at 6-weeks post-diabetic onset. In contrast, when assessing short- and long-axis speckle-tracking based strain analyses, diabetic mice showed changes in average systolic radial strain, radial strain rate, radial displacement, and radial velocity, as well as decreased circumferential and longitudinal strain rate, as early as 1-week post-diabetic onset and persisting throughout the diabetic study. Further, we performed regional analyses for the LV and found that the free wall region was affected in both the short- and long-axis when assessing radial dimension parameters. These changes began 1-week post-diabetic onset and remained throughout the progression of the disease. These findings demonstrate the use of speckle-tracking based strain as an approach to elucidate cardiac dysfunction from a global perspective, identifying left ventricular cardiac regions affected during the progression of type 1 diabetes mellitus earlier than contractile changes detected by conventional echocardiographic measurements.
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Affiliation(s)
- Danielle L Shepherd
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States
| | - Cody E Nichols
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States
| | - Tara L Croston
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States
| | - Sarah L McLaughlin
- Department of Cancer Cell Biology, School of Medicine, West Virginia University, Morgantown, WV 26505, United States
| | - Ashley B Petrone
- Department of Neurobiology and Anatomy, School of Medicine, West Virginia University, Morgantown, WV 26505, United States
| | - Sara E Lewis
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States
| | - Dharendra Thapa
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States
| | - Dustin M Long
- Department of Biostatistics, School of Public Health, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, United States
| | - Gregory M Dick
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States
| | - John M Hollander
- Department of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, School of Medicine, West Virginia University, Morgantown, WV, 26505, United States.
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14
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Rottgen TS, Fancher IS, Asano S, Widlanski TS, Dick GM. Bisphenol A activates BK channels through effects on α and β1 subunits. Channels (Austin) 2015; 8:249-57. [PMID: 24476761 PMCID: PMC4203754 DOI: 10.4161/chan.27709] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We demonstrated previously that BK (K(Ca)1.1) channel activity (NP(o)) increases in response to bisphenol A (BPA). Moreover, BK channels containing regulatory β1 subunits were more sensitive to the stimulatory effect of BPA. How BPA increases BK channel NPo remains mostly unknown. Estradiol activates BK channels by binding to an extracellular site, but neither the existence nor location of a BPA binding site has been demonstrated. We tested the hypothesis that an extracellular binding site is responsible for activation of BK channels by BPA. We synthesized membrane-impermeant BPA-monosulfate (BPA-MS) and used patch clamp electrophysiology to study channels composed of α or α + β1 subunits in cell-attached (C-A), whole-cell (W-C), and inside-out (I-O) patches. In C-A patches, bath application of BPA-MS (100 μM) had no effect on the NP(o) of BK channels, regardless of their subunit composition. Importantly, however, subsequent addition of membrane-permeant BPA (100 μM) increased the NP(o) of both α and α + β1 channels in C-A patches. The C-A data indicate that in order to alter BK channel NP(o), BPA must interact with the channel itself (or some closely associated partner) and diffusible messengers are not involved. In W-C patches, 100 μM BPA-MS activated current in cells expressingα subunits, whereas cells expressing α + β1 subunits responded similarly to a log-order lower concentration (10 μM). The W-C data suggest that an extracellular activation site exists, but do not eliminate the possibility that an intracellular site may also be present. In I-O patches, where the cytoplasmic face was exposed to the bath, BPA-MS had no effect on the NP(o) of BK α subunits, but BPA increased it. BPA-MS increased the NP(o) of α + β1 channels in I-O patches, but not as much as BPA. We conclude that BPA activates BK α via an extracellular site and that BPA-sensitivity is increased by the β1 subunit, which may also constitute part of an intracellular binding site.
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15
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Manoharan P, Gayam S, Arthur S, Palaniappan B, Singh S, Dick GM, Sundaram U. Chronic and selective inhibition of basolateral membrane Na-K-ATPase uniquely regulates brush border membrane Na absorption in intestinal epithelial cells. Am J Physiol Cell Physiol 2015; 308:C650-6. [PMID: 25652450 DOI: 10.1152/ajpcell.00355.2014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/30/2015] [Indexed: 11/22/2022]
Abstract
Na-K-ATPase, an integral membrane protein in mammalian cells, is responsible for maintaining the favorable intracellular Na gradient necessary to promote Na-coupled solute cotransport processes [e.g., Na-glucose cotransport (SGLT1)]. Inhibition of brush border membrane (BBM) SGLT1 is, at least in part, due to the diminished Na-K-ATPase in villus cells from chronically inflamed rabbit intestine. The aim of the present study was to determine the effect of Na-K-ATPase inhibition on the two major BBM Na absorptive pathways, specifically Na-glucose cotransport and Na/H exchange (NHE), in intestinal epithelial (IEC-18) cells. Na-K-ATPase was inhibited using 1 mM ouabain or siRNA for Na-K-ATPase-α1 in IEC-18 cells. SGLT1 activity was determined as 3-O-methyl-D-[(3)H]glucose uptake. Na-K-ATPase activity was measured as the amount of inorganic phosphate released. Treatment with ouabain resulted in SGLT1 inhibition at 1 h but stimulation at 24 h. To further characterize this unexpected stimulation of SGLT1, siRNA silencing was utilized to inhibit Na-K-ATPase-α1. SGLT1 activity was significantly upregulated by Na-K-ATPase silencing, while NHE3 activity remained unaltered. Kinetics showed that the mechanism of stimulation of SGLT1 activity was secondary to an increase in affinity of the cotransporter for glucose without a change in the number of cotransporters. Molecular studies demonstrated that the mechanism of stimulation was not secondary to altered BBM SGLT1 protein levels. Chronic and direct silencing of basolateral Na-K-ATPase uniquely regulates BBM Na absorptive pathways in intestinal epithelial cells. Specifically, while BBM NHE3 is unaffected, SGLT1 is stimulated secondary to enhanced affinity of the cotransporter.
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Affiliation(s)
- Palanikumar Manoharan
- Department of Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio
| | - Swapna Gayam
- Section of Digestive Diseases, West Virginia University, Morgantown, West Virginia
| | - Subha Arthur
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Balasubramanian Palaniappan
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Soudamani Singh
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
| | - Gregory M Dick
- Center for Cardiovascular and Respiratory Sciences, West Virginia University, Morgantown, West Virginia
| | - Uma Sundaram
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia; and
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16
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Berwick ZC, Dick GM, O'Leary HA, Bender SB, Goodwill AG, Moberly SP, Owen MK, Miller SJ, Obukhov AG, Tune JD. Contribution of electromechanical coupling between Kv and Ca v1.2 channels to coronary dysfunction in obesity. Basic Res Cardiol 2013; 108:370. [PMID: 23856709 DOI: 10.1007/s00395-013-0370-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/12/2013] [Accepted: 06/27/2013] [Indexed: 12/22/2022]
Abstract
Previous investigations indicate that diminished functional expression of voltage-dependent K(+) (KV) channels impairs control of coronary blood flow in obesity/metabolic syndrome. The goal of this investigation was to test the hypothesis that KV channels are electromechanically coupled to CaV1.2 channels and that coronary microvascular dysfunction in obesity is related to subsequent increases in CaV1.2 channel activity. Initial studies revealed that inhibition of KV channels with 4-aminopyridine (4AP, 0.3 mM) increased intracellular [Ca(2+)], contracted isolated coronary arterioles and decreased coronary reactive hyperemia. These effects were reversed by blockade of CaV1.2 channels. Further studies in chronically instrumented Ossabaw swine showed that inhibition of CaV1.2 channels with nifedipine (10 μg/kg, iv) had no effect on coronary blood flow at rest or during exercise in lean swine. However, inhibition of CaV1.2 channels significantly increased coronary blood flow, conductance, and the balance between coronary flow and metabolism in obese swine (P < 0.05). These changes were associated with a ~50 % increase in inward CaV1.2 current and elevations in expression of the pore-forming subunit (α1c) of CaV1.2 channels in coronary smooth muscle cells from obese swine. Taken together, these findings indicate that electromechanical coupling between KV and CaV1.2 channels is involved in the regulation of coronary vasomotor tone and that increases in CaV1.2 channel activity contribute to coronary microvascular dysfunction in the setting of obesity.
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Affiliation(s)
- Zachary C Berwick
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
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17
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Kunduri SS, Dick GM, Nayeem MA, Mustafa SJ. Adenosine A
1
receptor signaling inhibits BK channels. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.877.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Owen MK, Krenzke R, Dick GM, Tune JD. Perivascular adipose tissue impairs H2O2‐mediated vasodilation in the coronary circulation. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1195.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Rebecca Krenzke
- Cellular and Integrative PhysiologyIU School of MedicineIndianapolisIN
| | - Gregory M Dick
- Exercise PhysiologyWest Virginia UniversityMorgantownWV
- Center for Cardiovascular and Respiratory ScienceWest Virginia UniversityMorgantownWV
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19
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Goodwill AG, Casalini ED, Owen MK, Conteh A, Sassoon D, Shatagopam K, Dick GM, Tune JD. Role of Voltage‐dependent Kv7 Channels in the Regulation of Coronary Blood Flow. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1185.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Adam G Goodwill
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Eli D Casalini
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Meredith K Owen
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Abass Conteh
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Daniel Sassoon
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Kashyap Shatagopam
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory M Dick
- Department of Exercise PhysiologyWest Virginia UniversityMorgantownWV
- Center for Cardiovascular and Respiratory SciencesWest Virginia UniversityMorgantownWV
| | - Johnathan D Tune
- Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
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20
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Fancher IS, Croston T, Shepherd D, Dick GM, Hollander JM. Cardiac interfibrillar mitoK
ATP
channels are sensitive to diazoxide and have a regulatory subunit profile distinct from subsarcolemmal mitoK
ATP. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1209.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Tara Croston
- Exercise PhysiologyWest Virginia UniverstiyMorgantownWV
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21
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Sharifi-Sanjani M, Zhou X, Asano S, Tilley S, Ledent C, Teng B, Dick GM, Mustafa SJ. Interactions between A(2A) adenosine receptors, hydrogen peroxide, and KATP channels in coronary reactive hyperemia. Am J Physiol Heart Circ Physiol 2013; 304:H1294-301. [PMID: 23525711 DOI: 10.1152/ajpheart.00637.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Myocardial metabolites such as adenosine mediate reactive hyperemia, in part, by activating ATP-dependent K(+) (K(ATP)) channels in coronary smooth muscle. In this study, we investigated the role of adenosine A(2A) and A(2B) receptors and their signaling mechanisms in reactive hyperemia. We hypothesized that coronary reactive hyperemia involves A(2A) receptors, hydrogen peroxide (H(2)O(2)), and KATP channels. We used A(2A) and A(2B) knockout (KO) and A(2A/2B) double KO (DKO) mouse hearts for Langendorff experiments. Flow debt for a 15-s occlusion was repaid 128 ± 8% in hearts from wild-type (WT) mice; this was reduced in hearts from A(2A) KO and A(2A)/(2B) DKO mice (98 ± 9 and 105 ± 6%; P < 0.05), but not A(2B) KO mice (123 ± 13%). Patch-clamp experiments demonstrated that adenosine activated glibenclamide-sensitive KATP current in smooth muscle cells from WT and A(2B) KO mice (90 ± 23% of WT) but not A(2A) KO or A(2A)/A(2B) DKO mice (30 ± 4 and 35 ± 8% of WT; P < 0.05). Additionally, H(2)O(2) activated KATP current in smooth muscle cells (358 ± 99%; P < 0.05). Catalase, an enzyme that breaks down H(2)O(2), attenuated adenosine-induced coronary vasodilation, reducing the percent increase in flow from 284 ± 53 to 89 ± 13% (P < 0.05). Catalase reduced the repayment of flow debt in hearts from WT mice (84 ± 9%; P < 0.05) but had no effect on the already diminished repayment in hearts from A(2A) KO mice (98 ± 7%). Our findings suggest that adenosine A(2A) receptors are coupled to smooth muscle KATP channels in reactive hyperemia via the production of H(2)O(2) as a signaling intermediate.
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Affiliation(s)
- Maryam Sharifi-Sanjani
- Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV 26506, USA
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22
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Asano S, Bratz IN, Berwick ZC, Fancher IS, Tune JD, Dick GM. Penitrem A as a tool for understanding the role of large conductance Ca(2+)/voltage-sensitive K(+) channels in vascular function. J Pharmacol Exp Ther 2012; 342:453-60. [PMID: 22580348 DOI: 10.1124/jpet.111.191072] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Large conductance, Ca(2+)/voltage-sensitive K(+) channels (BK channels) are well characterized, but their physiological roles, often determined through pharmacological manipulation, are less clear. Iberiotoxin is considered the "gold standard" antagonist, but cost and membrane-impermeability limit its usefulness. Economical and membrane-permeable alternatives could facilitate the study of BK channels. Thus, we characterized the effect of penitrem A, a tremorigenic mycotoxin, on BK channels and demonstrate its utility for studying vascular function in vitro and in vivo. Whole-cell currents from human embryonic kidney 293 cells transfected with hSlo α or α + β1 were blocked >95% by penitrem A (IC(50) 6.4 versus 64.4 nM; p < 0.05). Furthermore, penitrem A inhibited BK channels in inside-out and cell-attached patches, whereas iberiotoxin could not. Inhibitory effects of penitrem A on whole-cell K(+) currents were equivalent to iberiotoxin in canine coronary smooth muscle cells. As for specificity, penitrem A had no effect on native delayed rectifier K(+) currents, cloned voltage-dependent Kv1.5 channels, or native ATP-dependent K(ATP) current. Penitrem A enhanced the sensitivity to K(+)-induced contraction in canine coronary arteries by 23 ± 5% (p < 0.05) and increased the blood pressure response to phenylephrine in anesthetized mice by 36 ± 11% (p < 0.05). Our data indicate that penitrem A is a useful tool for studying the role of BK channels in vascular function and is practical for cell and tissue (in vitro) studies as well as anesthetized animal (in vivo) experiments.
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Affiliation(s)
- Shinichi Asano
- Division of Exercise Physiology, Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, Morgantown, West Virginia 26506, USA
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23
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Fancher IS, Baseler WA, Croston TL, Thapa D, Shepherd D, Nichols C, Lewis S, Jagannathan R, Asano S, Dick GM, Hollander JM. Differential expression of mitoK
ATP
subunits in cardiac mitochondrial subpopulations and the influence of Type I diabetes. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1057.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | - Cody Nichols
- Exercise PhysiologyWest Virginia UniversityMorgantownWV
| | - Sara Lewis
- Exercise PhysiologyWest Virginia UniversityMorgantownWV
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24
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Asano S, Fancher IS, Dick GM. Bisphenol A decreases BK channel expression in rat aorta via genomic mechanisms. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1140.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Abstract
Metabolic syndrome (MetS) is a collection of risk factors including obesity, dyslipidemia, insulin resistance/impaired glucose tolerance, and/or hypertension. The incidence of obesity has reached pandemic levels, as ~20-30% of adults in most developed countries can be classified as having MetS. This increased prevalence of MetS is critical as it is associated with a two-fold elevated risk for cardiovascular disease. Although the pathophysiology underlying this increase in disease has not been clearly defined, recent evidence indicates that alterations in the control of coronary blood flow could play an important role. The purpose of this review is to highlight current understanding of the effects of MetS on regulation of coronary blood flow and to outline the potential mechanisms involved. In particular, the role of neurohumoral modulation via sympathetic α-adrenoceptors and the renin-angiotensin-aldosterone system (RAAS) are explored. Alterations in the contribution of end-effector K(+), Ca(2+), and transient receptor potential (TRP) channels are also addressed. Finally, future perspectives and potential therapeutic targeting of the microcirculation in MetS are discussed. This article is part of a Special Issue entitled "Coronary Blood Flow".
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Affiliation(s)
- Zachary C. Berwick
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Gregory M. Dick
- Department of Exercise Physiology Center for Cardiovascular and Respiratory Sciences West Virginia University School of Medicine
| | - Johnathan D. Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202
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26
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Berwick ZC, Dick GM, Bender SB, Moberly SP, Kohr MC, Goodwill AG, Obukhov AG, Tune JD. Contribution of Cav1.2 Channels to Coronary Microvascular Dysfunction in Metabolic Syndrome. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.860.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zachary C Berwick
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory M Dick
- Exercise PhysiologyWest Virginia School of MedicineMorgantownWV
| | - Shawn B Bender
- Internal MedicineUniversity of Missouri School of MedicineColumbiaMO
| | - Steven P Moberly
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Meredith C Kohr
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Adam G Goodwill
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Alexander G Obukhov
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Johnathan D Tune
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
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27
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Berwick ZC, Moberly SP, Kohr MC, Morrical EB, Kurian MM, Dick GM, Tune JD. Contribution of voltage-dependent K+ and Ca2+ channels to coronary pressure-flow autoregulation. Basic Res Cardiol 2012; 107:264. [PMID: 22466959 DOI: 10.1007/s00395-012-0264-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/21/2012] [Accepted: 03/08/2012] [Indexed: 11/30/2022]
Abstract
The mechanisms responsible for coronary pressure-flow autoregulation, a critical physiologic phenomenon that maintains coronary blood flow relatively constant in the presence of changes in perfusion pressure, remain poorly understood. This investigation tested the hypothesis that voltage-sensitive K(+) (K(V)) and Ca(2+) (Ca(V)1.2) channels play a critical role in coronary pressure-flow autoregulation in vivo. Experiments were performed in open-chest, anesthetized Ossabaw swine during step changes in coronary perfusion pressure (CPP) from 40 to 140 mmHg before and during inhibition of K(V) channels with 4-aminopyridine (4AP, 0.3 mM, ic) or Ca(V)1.2 channels with diltiazem (10 μg/min, ic). 4AP significantly decreased vasodilatory responses to H(2)O(2) (0.3-10 μM, ic) and coronary flow at CPPs = 60-140 mmHg. This decrease in coronary flow was associated with diminished ventricular contractile function (dP/dT) and myocardial oxygen consumption. However, the overall sensitivity to changes in CPP from 60 to 100 mmHg (i.e. autoregulatory gain; Gc) was unaltered by 4-AP administration (Gc = 0.46 ± 0.11 control vs. 0.46 ± 0.06 4-AP). In contrast, inhibition of Ca(V)1.2 channels progressively increased coronary blood flow at CPPs > 80 mmHg and substantially diminished coronary Gc to -0.20 ± 0.11 (P < 0.01), with no effect on contractile function or oxygen consumption. Taken together, these findings demonstrate that (1) K(V) channels tonically contribute to the control of microvascular resistance over a wide range of CPPs, but do not contribute to coronary responses to changes in pressure; (2) progressive activation of Ca(V)1.2 channels with increases in CPP represents a critical mechanism of coronary pressure-flow autoregulation.
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Affiliation(s)
- Zachary C Berwick
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, 46202, USA
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28
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Berwick ZC, Dick GM, Moberly SP, Kohr MC, Sturek M, Tune JD. Contribution of voltage-dependent K⁺ channels to metabolic control of coronary blood flow. J Mol Cell Cardiol 2011; 52:912-9. [PMID: 21771599 DOI: 10.1016/j.yjmcc.2011.07.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 06/27/2011] [Accepted: 07/02/2011] [Indexed: 01/12/2023]
Abstract
The purpose of this investigation was to test the hypothesis that K(V) channels contribute to metabolic control of coronary blood flow and that decreases in K(V) channel function and/or expression significantly attenuate myocardial oxygen supply-demand balance in the metabolic syndrome (MetS). Experiments were conducted in conscious, chronically instrumented Ossabaw swine fed either a normal maintenance diet or an excess calorie atherogenic diet that produces the clinical phenotype of early MetS. Data were obtained under resting conditions and during graded treadmill exercise before and after inhibition of K(V) channels with 4-aminopyridine (4-AP, 0.3mg/kg, iv). In lean-control swine, 4-AP reduced coronary blood flow ~15% at rest and ~20% during exercise. Inhibition of K(V) channels also increased aortic pressure (P<0.01) while reducing coronary venous PO(2) (P<0.01) at a given level of myocardial oxygen consumption (MVO(2)). Administration of 4-AP had no effect on coronary blood flow, aortic pressure, or coronary venous PO(2) in swine with MetS. The lack of response to 4-AP in MetS swine was associated with a ~20% reduction in coronary K(V) current (P<0.01) and decreased expression of K(V)1.5 channels in coronary arteries (P<0.01). Together, these data demonstrate that K(V) channels play an important role in balancing myocardial oxygen delivery with metabolism at rest and during exercise-induced increases in MVO(2). Our findings also indicate that decreases in K(V) channel current and expression contribute to impaired control of coronary blood flow in the MetS. This article is part of a Special Issue entitled "Coronary Blood Flow".
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Affiliation(s)
- Zachary C Berwick
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Asano S, Dick GM. Sensitivity to block by penitrem A is reduced in human BK channels containing the β1 subunit. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1021.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shinichi Asano
- Exercise PhysiologyCenter for Cardiovascular and Respiratory SciencesWest Virginia University School of MedicneMorgantownWV
| | - Gregory M. Dick
- Exercise PhysiologyCenter for Cardiovascular and Respiratory SciencesWest Virginia University School of MedicneMorgantownWV
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Berwick ZC, Payne GA, Lynch B, Dick GM, Sturek M, Tune JD. Contribution of adenosine A(2A) and A(2B) receptors to ischemic coronary dilation: role of K(V) and K(ATP) channels. Microcirculation 2011; 17:600-7. [PMID: 21044214 DOI: 10.1111/j.1549-8719.2010.00054.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study was designed to elucidate the contribution of adenosine A(2A) and A(2B) receptors to coronary reactive hyperemia and downstream K(+) channels involved. Coronary blood flow was measured in open-chest anesthetized dogs. Adenosine dose-dependently increased coronary flow from 0.72 ± 0.1 to 2.6 ± 0.5 mL/minute/g under control conditions. Inhibition of A(2A) receptors with SCH58261 (1 μm) attenuated adenosine-induced dilation by ∼50%, while combined administration with the A(2B) receptor antagonist alloxazine (3 μm) produced no additional effect. SCH58261 significantly reduced reactive hyperemia in response to a transient 15 second occlusion; debt/repayment ratio decreased from 343 ± 63 to 232 ± 44%. Alloxazine alone attenuated adenosine-induced increases in coronary blood flow by ∼30% but failed to alter reactive hyperemia. A(2A) receptor agonist CGS21680 (10 μg bolus) increased coronary blood flow by 3.08 ± 0.31 mL/minute/g. This dilator response was attenuated to 0.76 ± 0.14 mL/minute/g by inhibition of K(V) channels with 4-aminopyridine (0.3mm) and to 0.11 ± 0.31 mL/minute/g by inhibition of K(ATP) channels with glibenclamide (3 mg/kg). Combined administration abolished vasodilation to CGS21680. These data indicate that A(2A) receptors contribute to coronary vasodilation in response to cardiac ischemia via activation of K(V) and K(ATP) channels.
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Affiliation(s)
- Zachary C Berwick
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Asano S, Dick GM. Bisphenol A activates Maxi‐K channels in coronary smooth muscle. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.986.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
BACKGROUND AND PURPOSE Bisphenol A (BPA) is used to manufacture plastics, including containers for food into which it may leach. High levels of exposure to this oestrogenic endocrine disruptor are associated with diabetes and heart disease. Oestrogen and oestrogen receptor modulators increase the activity of large conductance Ca(2+)/voltage-sensitive K(+) (Maxi-K; K(Ca)1.1) channels, but the effects of BPA on Maxi-K channels are unknown. We tested the hypothesis that BPA activates Maxi-K channels through a mechanism that depends upon the regulatory beta1 subunit. EXPERIMENTAL APPROACH Patch-clamp recordings of Maxi-K channels were made in human and canine coronary smooth muscle cells as well as in AD-293 cells expressing pore-forming alpha or alpha plus beta1 subunits. KEY RESULTS BPA (10 microM) activated an outward current in smooth muscle cells that was inhibited by penitrem A (1 microM), a Maxi-K blocker. BPA increased Maxi-K activity in inside-out patches from coronary smooth muscle, but had no effect on single channel conductance. In AD-293 cells with Maxi-K channels composed of alpha subunits alone, 10 microM BPA did not affect channel activity. When channels in AD-293 cells contained beta1 subunits, 10 microM BPA increased channel activity. Effects of BPA were rapid (<1 min) and reversible. A higher concentration of BPA (100 microM) increased Maxi-K current independent of the beta1 subunit. CONCLUSIONS AND IMPLICATIONS Our data indicate that BPA increased the activity of Maxi-K channels and may represent a basis for some potential toxicological effects.
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Affiliation(s)
- Shinichi Asano
- Division of Exercise Physiology, Center for Cardiovascular & Respiratory Sciences, West Virginia University School of Medicine, Morgantown, WV, USA
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Borbouse L, Dick GM, Payne GA, Berwick ZC, Neeb ZP, Alloosh M, Bratz IN, Sturek M, Tune JD. Metabolic syndrome reduces the contribution of K+ channels to ischemic coronary vasodilation. Am J Physiol Heart Circ Physiol 2010; 298:H1182-9. [PMID: 20118408 DOI: 10.1152/ajpheart.00888.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This investigation tested the hypothesis that metabolic syndrome decreases the relative contribution of specific K(+) channels to coronary reactive hyperemia. Ca(2+)-activated (BK(Ca)), voltage-activated (K(V)), and ATP-dependent (K(ATP)) K(+) channels were investigated. Studies were conducted in anesthetized miniature Ossabaw swine fed a normal maintenance diet (11% kcal from fat) or an excess calorie atherogenic diet (43% kcal from fat, 2% cholesterol, 20% kcal from fructose) for 20 wk. The latter diet induces metabolic syndrome, increasing body weight, fasting glucose, total cholesterol, and triglyceride levels. Ischemic vasodilation was determined by the coronary flow response to a 15-s occlusion before and after cumulative administration of antagonists for BK(Ca) (penitrem A; 10 microg/kg iv), K(V) (4-aminopyridine; 0.3 mg/kg iv) and K(ATP) (glibenclamide; 1 mg/kg iv) channels. Coronary reactive hyperemia was diminished by metabolic syndrome as the repayment of flow debt was reduced approximately 30% compared with lean swine. Inhibition of BK(Ca) channels had no effect on reactive hyperemia in either lean or metabolic syndrome swine. Subsequent inhibition of K(V) channels significantly reduced the repayment of flow debt ( approximately 25%) in both lean and metabolic syndrome swine. Additional blockade of K(ATP) channels further diminished ( approximately 45%) the repayment of flow debt in lean but not metabolic syndrome swine. These data indicate that the metabolic syndrome impairs coronary vasodilation in response to cardiac ischemia via reductions in the contribution of K(+) channels to reactive hyperemia.
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Affiliation(s)
- Léna Borbouse
- Dept. of Cellular and Integrative Physiology, Indiana Univ. School of Medicine, Indianapolis, 46202, USA
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Abstract
K+ channels in coronary arterial smooth muscle cells (CASMC) determine the resting membrane potential ( Em) and serve as targets of endogenous and therapeutic vasodilators. Em in CASMC is in the voltage range for activation of L-type Ca2+ channels; therefore, when K+ channel activity changes, Ca2+ influx and arterial tone change. This is why both Ca2+ channel blockers and K+ channel openers have such profound effects on coronary blood flow; the former directly inhibits Ca2+ influx through L-type Ca2+ channels, while the latter indirectly inhibits Ca2+ influx by hyperpolarizing Em and reducing Ca2+ channel activity. K+ channels in CASMC play important roles in vasodilation to endothelial, ischemic and metabolic stimuli. The purpose of this article is to review the types of K+ channels expressed in CASMC, discuss the regulation of their activity by physiological mechanisms and examine impairments related to cardiovascular disease.
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Affiliation(s)
- Gregory M Dick
- Department of Exercise Physiology and Center for Cardiovascular & Respiratory Sciences, West Virginia University School of Medicine, Morgantown, WV 26506
| | - Johnathan D Tune
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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35
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Borbouse L, Dick GM, Payne GA, Payne BD, Svendsen MC, Neeb ZP, Alloosh M, Bratz IN, Sturek M, Tune JD. Contribution of BK(Ca) channels to local metabolic coronary vasodilation: Effects of metabolic syndrome. Am J Physiol Heart Circ Physiol 2009; 298:H966-73. [PMID: 20044440 DOI: 10.1152/ajpheart.00876.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This investigation was designed to examine the hypothesis that impaired function of coronary microvascular large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels in metabolic syndrome (MetS) significantly attenuates the balance between myocardial oxygen delivery and metabolism at rest and during exercise-induced increases in myocardial oxygen consumption (MVo(2)). Studies were conducted in conscious, chronically instrumented Ossabaw swine fed a normal maintenance diet (11% kcal from fat) or an excess calorie atherogenic diet (43% kcal from fat, 2% cholesterol, 20% kcal from fructose) that induces many common features of MetS. Data were collected under baseline/resting conditions and during graded treadmill exercise before and after selective blockade of BK(Ca) channels with penitrem A (10 microg/kg iv). We found that the exercise-induced increases in blood pressure were significantly elevated in MetS swine. No differences in baseline cardiac function or heart rate were noted. Induction of MetS produced a parallel downward shift in the relationship between coronary venous Po(2) and MVo(2) (P < 0.001) that was accompanied by a marked release of lactate (negative lactate uptake) as MVo(2) was increased with exercise (P < 0.005). Inhibition of BK(Ca) channels with penitrem A did not significantly affect blood pressure, heart rate, or the relationship between coronary venous Po(2) and MVo(2) in lean or MetS swine. These data indicate that BK(Ca) channels are not required for local metabolic control of coronary blood flow under physiological (lean) or pathophysiological (MetS) conditions. Therefore, diminished function of BK(Ca) channels does not contribute to the impairment of myocardial oxygen-supply demand balance in MetS.
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Affiliation(s)
- Léna Borbouse
- Dept. of Cellular and Integrative Physiology, Indiana Univ. School of Medicine, Indianapolis, 46202, USA
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36
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Borbouse L, Dick GM, Asano S, Bender SB, Dincer UD, Payne GA, Neeb ZP, Bratz IN, Sturek M, Tune JD. Impaired function of coronary BK(Ca) channels in metabolic syndrome. Am J Physiol Heart Circ Physiol 2009; 297:H1629-37. [PMID: 19749164 DOI: 10.1152/ajpheart.00466.2009] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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.
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Affiliation(s)
- Léna Borbouse
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana
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Kang LS, Kim S, Dominguez JM, Sindler AL, Dick GM, Muller-Delp JM. Aging and muscle fiber type alter K+ channel contributions to the myogenic response in skeletal muscle arterioles. J Appl Physiol (1985) 2009; 107:389-98. [PMID: 19407249 DOI: 10.1152/japplphysiol.91245.2008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Aging diminishes myogenic tone in arterioles from skeletal muscle. Recent evidence indicates that both large-conductance Ca2+-activated (BKCa) and voltage-dependent (KV) K+ channels mediate negative feedback control of the myogenic response. Thus we tested the hypothesis that aging increases the contributions of KV and BKCa channels to myogenic regulation of vascular tone. Because myogenic responsiveness differs between oxidative and glycolytic muscles, we predicted that KV and BKCa channel contributions to myogenic responsiveness vary with fiber type. Myogenic responses of first-order arterioles from the gastrocnemius and soleus muscles of 4- and 24-mo-old Fischer 344 rats were evaluated in the presence and absence of 4-aminopyridine (5 mM) or iberiotoxin (30 nM), inhibitors of KV and BKCa, respectively. 4-Aminopyridine enhanced myogenic tone with aging and normalized age-related differences in both muscle types. By contrast, iberiotoxin eliminated age-related differences in soleus arterioles and had no effect in gastrocnemius vessels. KV1.5 is an integral component of KV channels in vascular smooth muscle; therefore, we determined the relative protein expression of KV1.5, as well as BKCa, in soleus and gastrocnemius arterioles. Immunoblot analysis revealed no differences in KV1.5 protein with aging or between variant fiber types, whereas BKCa protein levels declined with age in arterioles from both muscle groups. Collectively, these results suggest that the contribution of BKCa to myogenic regulation of vascular tone changes with age in soleus muscle arterioles, whereas increased KV channel expression and negative feedback regulation of myogenic tone increases with advancing age in arterioles from both oxidative and glycolytic muscles.
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Affiliation(s)
- Lori S Kang
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
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Payne GA, Borbouse L, Bratz IN, Roell WC, Bohlen HG, Dick GM, Tune JD. Endogenous adipose-derived factors diminish coronary endothelial function via inhibition of nitric oxide synthase. Microcirculation 2008; 15:417-26. [PMID: 18574744 DOI: 10.1080/10739680701858447] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Adipocytokines may be the molecular link between obesity and vascular disease. However, the effects of these factors on coronary vascular function have not been discerned. Accordingly, the goal of this investigation was to delineate the mechanisms by which endogenous adipose-derived factors affect coronary vascular endothelial function. Both isolated canine coronary arteries and coronary blood flow in anesthetized dogs were studied with and without exposure to adipose tissue. Infusion of adipose-conditioned buffer directly into the coronary circulation did not change baseline hemodynamics; however, endothelial-dependent vasodilation to bradykinin was impaired both in vitro and in vivo. Coronary vasodilation to sodium nitroprusside was unaltered by adipose tissue. Oxygen radical formation did not cause the impairment because quantified dihydroethidium staining was decreased by adipose tissue and neither a superoxide dismutase mimetic nor catalase improved endothelial function. Inhibition of nitric oxide (NO) synthase with L-NAME diminished bradykinin-mediated relaxations and eliminated the subsequent vascular effects of adipose tissue. In vitro measurement of NO demonstrated that adipose tissue exposure quickly lowered baseline NO and abolished bradykinin-induced NO production. The results indicate that adipose tissue releases factor(s) that selectively impair endothelial-dependent dilation via inhibition of NO synthase-mediated NO production.
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Affiliation(s)
- Gregory A Payne
- Department of Cellular and Integrative Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
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39
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Bratz IN, Dick GM, Tune JD, Edwards JM, Neeb ZP, Dincer UD, Sturek M. Impaired capsaicin-induced relaxation of coronary arteries in a porcine model of the metabolic syndrome. Am J Physiol Heart Circ Physiol 2008; 294:H2489-96. [PMID: 18390821 DOI: 10.1152/ajpheart.01191.2007] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies implicate channels of the transient receptor potential vanilloid family (e.g., TRPV1) in regulating vascular tone; however, little is known about these channels in the coronary circulation. Furthermore, it is unclear whether metabolic syndrome alters the function and/or expression of TRPV1. We tested the hypothesis that TRPV1 mediates coronary vasodilation through endothelium-dependent mechanisms that are impaired by the metabolic syndrome. Studies were conducted on coronary arteries from lean and obese male Ossabaw miniature swine. In lean pigs, capsaicin, a TRPV1 agonist, relaxed arteries in a dose-dependent manner (EC50 = 116 +/- 41 nM). Capsaicin-induced relaxation was blocked by the TRPV1 antagonist capsazepine, endothelial denudation, inhibition of nitric oxide synthase, and K+ channel antagonists. Capsaicin-induced relaxation was impaired in rings from pigs with metabolic syndrome (91 +/- 4% vs. 51 +/- 10% relaxation at 100 microM). TRPV1 immunoreactivity was prominent in coronary endothelial cells. TRPV1 protein expression was decreased 40 +/- 11% in obese pigs. Capsaicin (100 microM) elicited divalent cation influx that was abolished in endothelial cells from obese pigs. These data indicate that TRPV1 channels are functionally expressed in the coronary circulation and mediate endothelium-dependent vasodilation through a mechanism involving nitric oxide and K+ channels. Impaired capsaicin-induced vasodilation in the metabolic syndrome is associated with decreased expression of TRPV1 and cation influx.
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Affiliation(s)
- Ian N Bratz
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5120, USA.
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40
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Dick GM, Bratz IN, Borbouse L, Payne GA, Dincer UD, Knudson JD, Rogers PA, Tune JD. Voltage-dependent K+ channels regulate the duration of reactive hyperemia in the canine coronary circulation. Am J Physiol Heart Circ Physiol 2008; 294:H2371-81. [PMID: 18375717 DOI: 10.1152/ajpheart.01279.2007] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously demonstrated a role for voltage-dependent K(+) (K(V)) channels in coronary vasodilation elicited by myocardial metabolism and exogenous H(2)O(2), as responses were attenuated by the K(V) channel blocker 4-aminopyridine (4-AP). Here we tested the hypothesis that K(V) channels participate in coronary reactive hyperemia and examined the role of K(V) channels in responses to nitric oxide (NO) and adenosine, two putative mediators. Reactive hyperemia (30-s occlusion) was measured in open-chest dogs before and during 4-AP treatment [intracoronary (ic), plasma concentration 0.3 mM]. 4-AP reduced baseline flow 34 +/- 5% and inhibited hyperemic volume 32 +/- 5%. Administration of 8-phenyltheophylline (8-PT; 0.3 mM ic or 5 mg/kg iv) or N(G)-nitro-L-arginine methyl ester (L-NAME; 1 mg/min ic) inhibited early and late portions of hyperemic flow, supporting roles for adenosine and NO. 4-AP further inhibited hyperemia in the presence of 8-PT or L-NAME. Adenosine-induced blood flow responses were attenuated by 4-AP (52 +/- 6% block at 9 microg/min). Dilation of arterioles to adenosine was attenuated by 0.3 mM 4-AP and 1 microM correolide, a selective K(V)1 antagonist (76 +/- 7% and 47 +/- 2% block, respectively, at 1 microM). Dilation in response to sodium nitroprusside, an NO donor, was attenuated by 4-AP in vivo (41 +/- 6% block at 10 microg/min) and by correolide in vitro (29 +/- 4% block at 1 microM). K(V) current in smooth muscle cells was inhibited by 4-AP (IC(50) 1.1 +/- 0.1 mM) and virtually eliminated by correolide. Expression of mRNA for K(V)1 family members was detected in coronary arteries. Our data indicate that K(V) channels play an important role in regulating resting coronary blood flow, determining duration of reactive hyperemia, and mediating adenosine- and NO-induced vasodilation.
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Affiliation(s)
- Gregory M Dick
- Department of Exercise Physiology, Center for Interdisciplinary Research in Cardiovascular Sciences, West Virginia University School of Medicine, Morgantown, WV, USA
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Payne GA, Borbouse L, Dincer UD, Bohlen HG, Dick GM, Tune JD. Perivascular adipose tissue impairs coronary endothelial function via protein kinase C‐beta dependent phosphorylation of nitric oxide synthase. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.743.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Gregory Allen Payne
- Department of Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Lena Borbouse
- Department of Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - U. Deniz Dincer
- Department of Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - H. Glenn Bohlen
- Department of Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory M. Dick
- Department of Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Johnathan D. Tune
- Department of Cellular and Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
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42
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Borbouse L, Payne GA, Dick GM, Aloosh M, Sturek M, Tune JD. Role of large conductance Ca
2+
‐activated K
+
(BK
Ca
) channels in local metabolic coronary vasodilation in Ossabaw swine with metabolic syndrome. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1152.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lena Borbouse
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory A. Payne
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory M. Dick
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Mouhamad Aloosh
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Michael Sturek
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Johnathan D. Tune
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
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43
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Borbouse L, Payne GA, Dick GM, Sturek M, Tune JD. Impaired contribution of voltage‐dependent K
+
channels to ischemic coronary vasodilation in Ossabaw swine with metabolic syndrome. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1152.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lena Borbouse
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory A. Payne
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Gregory M. Dick
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Michael Sturek
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
| | - Johnathan D. Tune
- Cellular & Integrative PhysiologyIndiana University School of MedicineIndianapolisIN
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Saitoh SI, Kiyooka T, Rocic P, Rogers PA, Zhang C, Swafford A, Dick GM, Viswanathan C, Park Y, Chilian WM. Redox-dependent coronary metabolic dilation. Am J Physiol Heart Circ Physiol 2007; 293:H3720-5. [PMID: 17965288 DOI: 10.1152/ajpheart.00436.2007] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have observed that hydrogen peroxide (H2O2), the dismutated product of superoxide, is a coronary metabolic dilator and couples myocardial oxygen consumption to coronary blood flow. Because the chemical activity of H2O2 favors its role as an oxidant, and thiol groups are susceptible to oxidation, we hypothesized that coronary metabolic dilation occurs via a redox mechanism involving thiol oxidation. To test this hypothesis, we studied the mechanisms of dilation of isolated coronary arterioles to metabolites released by metabolically active (paced at 400 min) isolated cardiac myocytes and directly compared these responses with authentic H2O2. Studies were performed under control conditions and using interventions designed to reduce oxidized thiols [0.1 microM dithiothreitol (DTT) and 10 mM N-acetyl-L-cysteine (NAC)]. Aliquots of the conditioned buffer from paced myocytes produced vasodilation of isolated arterioles (peak response, 71% +/- 6% of maximal dilation), whereas H2O2 produced complete dilation (92% +/- 7%). Dilation to either the conditioned buffer or to H2O2 was significantly reduced by the administration of either NAC or DTT. The location of the thiols oxidized by the conditioned buffer or of H2O2 was determined by the administration of the fluorochromes monochlorobimane (20 microM) or monobromotrimethylammoniobimane (20 microM), which covalently label the reduced total or extracellular-reduced thiols, respectively. H2O2 or the conditioned buffer predominantly oxidized intracellular thiols since the fluorescent signal from monochlorobimane was reduced more than that of monobromotrimethylammoniobimane. To determine whether one of the intracellular targets of thiol oxidation that leads to dilation is the redox-sensitive kinase p38 mitogen-activated protein (MAP) kinase, we evaluated dilation following the administration of the p38 inhibitor SB-203580 (10 microM). The inhibition of p38 attenuated dilation to either H2O2 or to the conditioned buffer from stimulated myocytes by a similar degree, but SB-203580 did not attenuate dilation to nitroprusside. Western blot analysis for the activated form of p38 (phospho-p38) in the isolated aortae revealed robust activation of this enzyme by H2O2. Taken together, our results show that an active component of cardiac metabolic dilation, like that of H2O2, produces dilation by the oxidation of thiols, which are predominantly intracellular and dependent activation on the p38 MAP kinase. Thus coronary metabolic dilation appears to be mediated by redox-dependent signals.
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Affiliation(s)
- Shu-ichi Saitoh
- Department of Integrative Medical Sciences, Northeastern Ohio University College of Medicine, 4209 State Rte. 44, Rootstown, OH 44272-0095, USA
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Abstract
The incidence of obesity and the metabolic syndrome has reached epidemic proportions and alterations in coronary microvascular function could contribute to the increased cardiovascular morbidity and mortality observed in these patients. This review highlights key mechanisms of impaired control of coronary blood flow in the metabolic syndrome. Specifically, coronary endothelial dysfunction, altered neurohumoral control, and the potential roles of smooth muscle ion channels are addressed. Recent studies indicate that alterations in endothelial-dependent vasodilation or endothelial-dependent vasoconstriction contribute little to obesity-induced impairments in coronary vascular control. In contrast, augmented vasoconstriction in response to neurohumoral mediators appears to play a significant role in coronary vascular dysfunction. The authors conclude that coronary dysfunction in the metabolic syndrome is characterized by an imbalance between coronary blood flow and myocardial metabolism that may be mediated by sensitization of vasoconstrictor pathways. Further, they suggest that alterations in smooth muscle ion channels, Ca(2+) handling, and cell signaling may be important mechanisms leading to coronary microvascular dysfunction. Importantly, however, more research is needed to clearly delineate specific mechanisms and identify potential therapeutic targets.
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Affiliation(s)
- Jarrod D Knudson
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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Dincer UD, Dick GM, Obukhov AG, Besch Jr.⁎ HR, Sturek M, Tune JD. Voltage-gated K+ (KV) channels expressed in canine coronary artery. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Knudson JD, Dick GM, Tune JD. Adipokines and coronary vasomotor dysfunction. Exp Biol Med (Maywood) 2007; 232:727-36. [PMID: 17526764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
Research in the last 10-15 years has shown that fat cells (adipocytes) produce and release proteins with specific biologic activities. These proteins, termed adipokines, include the hormones leptin, adiponectin, and resistin. Adipose tissue is now recognized as an active endocrine organ. With the obesity pandemic swelling in the Western world, ongoing research is aimed at determining the biologic links between obesity and cardiovascular disease. This review presents basic historical background information on the major adipokines, introduces findings from clinical studies associating adipokines with cardiovascular disease, and summarizes results from recent basic science research studies of mechanisms of adipokine-induced cardiovascular dysfunction. Particular emphasis is placed on the action of adipokines in the coronary circulation-especially effects of adipokines on endothelial function, as endothelial damage is likely a critical event initiating atherosclerotic coronary artery disease.
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Affiliation(s)
- Jarrod D Knudson
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
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Swafford AN, Harrison-Bernard LM, Dick GM. Knockout mice reveal that the angiotensin II type 1B receptor links to smooth muscle contraction. Am J Hypertens 2007; 20:335-7. [PMID: 17324748 DOI: 10.1016/j.amjhyper.2006.09.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 08/18/2006] [Accepted: 09/11/2006] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Rodents express two isoforms of the angiotensin II type 1 (AT(1)) receptor: AT(1A) and AT(1B). It is unclear which receptor subtype mediates contraction in response to angiotensin II in various arteries. We tested the hypothesis that the AT(1B) receptor is the predominant receptor that mediates contraction in the abdominal aorta in response to angiotensin II. METHODS Isometric tension responses to angiotensin II were determined in abdominal aortic rings obtained from male wild-type and AT(1B) receptor knockout mice. The rings were suspended in an organ bath of a wire myograph and contractions to angiotensin II and other vasoconstrictors were determined. RESULTS Angiotensin II contracted aortic segments from wild-type mice; however, this response was virtually absent in rings obtained from AT(1B) receptor knockout mice. Contractions in response to K(+) and U46619 (thromboxane A(2) mimetic) were not different between rings obtained from wild-type and AT(1B) receptor knockout mice. CONCLUSIONS Reduced angiotensin II contraction is not related to a generalized decrease in smooth muscle function, rather it is specifically due to genetic ablation of the AT(1B) receptor. Our data support the concept that AT(1B) receptors couple to contraction in the mouse abdominal aorta, a function that parallels the single known AT(1) receptor in human vascular smooth muscle.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology
- Angiotensin II/metabolism
- Animals
- Aorta, Abdominal/metabolism
- In Vitro Techniques
- Isometric Contraction
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myography
- Potassium Chloride/pharmacology
- Receptor, Angiotensin, Type 1/deficiency
- Receptor, Angiotensin, Type 1/genetics
- Vasoconstriction/drug effects
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Albert N Swafford
- Physiology, Louisiana State University Health Sciences Center, New Orleans, Louisiana
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Abstract
A popular diet used for weight reduction is the low-carbohydrate diet, which has most calories derived from fat and protein, but effects of this dietary regimen on coronary vascular function have not been identified. We tested the hypothesis that obesity-induced impairment in coronary endothelial function is reversed by a low-carbohydrate diet. We used four groups of male Zucker rats: lean and obese on normal and low-carbohydrate diets. Rats were fed ad libitum for 3 wk; total caloric intake and weight gain were similar in both diets. To assess endothelial and vascular function, coronary arterioles were cannulated and pressurized for diameter measurements during administration of acetylcholine or sodium nitroprusside or during flow. When compared with lean rats, endothelium-dependent acetylcholine-induced vasodilation was impaired by approximately 50% in obese rats (normal diet), but it was restored to normal by the low-carbohydrate diet. When the normal diet was fed, flow-induced dilation (FID) was impaired by >50% in obese compared with lean rats. Similar to acetylcholine, responses to FID were restored to normal by a low-carbohydrate diet. N(omega)-nitro-L-arginine methyl ester (10 microM), an inhibitor of nitric oxide (NO) synthase, inhibited acetylcholine- and flow-induced dilation in lean rats, but it had no effect on acetylcholine- or flow-induced vasodilation in obese rats on a low-carbohydrate diet. Tetraethylammonium, a nonspecific K(+) channel antagonist, blocked flow-dependent dilation in the obese rats, suggesting that the improvement in function was mediated by a hyperpolarizing factor independent of NO. In conclusion, obesity-induced impairment in endothelium-dependent vasodilation of coronary arterioles can be dramatically improved with a low-carbohydrate diet most likely through the production of a hyperpolarizing factor independent of NO.
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Affiliation(s)
- Marta Focardi
- Department of Physiology, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
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Bratz IN, Payne GA, Watanable R, Bohlen HG, Dick GM, Tune JD. PERIVASCULAR ADIPOSE TISSUE ALTERS CORONARY ARTERIAL SMOOTH MUSCLE AND ENDOTHELIAL FUNCTION. FASEB J 2007. [DOI: 10.1096/fasebj.21.6.a1228-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ian N. Bratz
- Cellular and Integrative PhysiologyIndiana University School of Medicine635 Barnhill Dr.IndianapolisIN46202
| | - Gregory A. Payne
- Cellular and Integrative PhysiologyIndiana University School of Medicine635 Barnhill Dr.IndianapolisIN46202
| | - Reina Watanable
- Cellular and Integrative PhysiologyIndiana University School of Medicine635 Barnhill Dr.IndianapolisIN46202
| | - H. Glenn Bohlen
- Cellular and Integrative PhysiologyIndiana University School of Medicine635 Barnhill Dr.IndianapolisIN46202
| | - Gregory M. Dick
- Cellular and Integrative PhysiologyIndiana University School of Medicine635 Barnhill Dr.IndianapolisIN46202
| | - Johnathan D. Tune
- Cellular and Integrative PhysiologyIndiana University School of Medicine635 Barnhill Dr.IndianapolisIN46202
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