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van der Horst J, Rognant S, Hellsten Y, Aalkjær C, Jepps TA. Dynein Coordinates β2-Adrenoceptor-Mediated Relaxation in Normotensive and Hypertensive Rat Mesenteric Arteries. Hypertension 2022; 79:2214-2227. [PMID: 35929419 DOI: 10.1161/hypertensionaha.122.19351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The voltage-gated potassium channel (Kv)7.4 and Kv7.5 channels contribute to the β-adrenoceptor-mediated vasodilatation. In arteries from hypertensive rodents, the Kv7.4 channel is downregulated and function attenuated, which contributes to the reduced β-adrenoceptor-mediated vasodilatation observed in these arteries. Recently, we showed that disruption of the microtubule network, with colchicine, or inhibition of the microtubule motor protein, dynein, with ciliobrevin D, enhanced the membrane abundance and function of Kv7.4 channels in rat mesenteric arteries. This study aimed to determine whether these pharmacological compounds can improve Kv7.4 function in third-order mesenteric arteries from the spontaneously hypertensive rat, thereby restoring the β-adrenoceptor-mediated vasodilatation. METHODS Wire and intravital myography was performed on normotensive and hypertensive male rat mesenteric arteries and immunostaining was performed on isolated smooth muscle cells from the same arteries. RESULTS Using wire and intravital microscopy, we show that ciliobrevin D enhanced the β-adrenoceptor-mediated vasodilatation by isoprenaline. This effect was inhibited partially by the Kv7 channel blocker linopirdine and was dependent on an increased functional contribution of the β2-adrenoceptor to the isoprenaline-mediated relaxation. In mesenteric arteries from the spontaneously hypertensive rat, ciliobrevin D and colchicine both improved the isoprenaline-mediated vasorelaxation and relaxation to the Kv7.2 -7.5 activator, ML213. Immunostaining confirmed ciliobrevin D enhanced the membrane abundance of Kv7.4. As well as an increase in the function of Kv7.4, the functional changes were associated with an increase in the contribution of β2-adrenoceptor following isoprenaline treatment. Immunostaining experiments showed ciliobrevin D prevented isoprenaline-mediated internalizationof the β2-adrenoceptor. CONCLUSIONS Overall, these data show that colchicine and ciliobrevin D can induce a β2-adrenoceptor-mediated vasodilatation in arteries from the spontaneously hypertensive rat as well as reinstating Kv7.4 channel function.
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Affiliation(s)
- Jennifer van der Horst
- Department of Biomedical Sciences (J.v.d.H., S.R., C.A., T.A.J.), University of Copenhagen, Denmark.,The August Krogh Section for Human Physiology, Department of Nutrition, Exercise and Sports (J.v.d.H., Y.H.), University of Copenhagen, Denmark
| | - Salomé Rognant
- Department of Biomedical Sciences (J.v.d.H., S.R., C.A., T.A.J.), University of Copenhagen, Denmark
| | - Ylva Hellsten
- The August Krogh Section for Human Physiology, Department of Nutrition, Exercise and Sports (J.v.d.H., Y.H.), University of Copenhagen, Denmark
| | - Christian Aalkjær
- Department of Biomedical Sciences (J.v.d.H., S.R., C.A., T.A.J.), University of Copenhagen, Denmark.,Department of Biomedicine, Aarhus University, Denmark (C.A.)
| | - Thomas A Jepps
- Department of Biomedical Sciences (J.v.d.H., S.R., C.A., T.A.J.), University of Copenhagen, Denmark
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Boguslavskyi A, Tokar S, Prysyazhna O, Rudyk O, Sanchez-Tatay D, Lemmey HA, Dora KA, Garland CJ, Warren HR, Doney A, Palmer CN, Caulfield MJ, Vlachaki Walker J, Howie J, Fuller W, Shattock MJ. Phospholemman Phosphorylation Regulates Vascular Tone, Blood Pressure, and Hypertension in Mice and Humans. Circulation 2021; 143:1123-1138. [PMID: 33334125 PMCID: PMC7969167 DOI: 10.1161/circulationaha.119.040557] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 12/09/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Although it has long been recognized that smooth muscle Na/K ATPase modulates vascular tone and blood pressure (BP), the role of its accessory protein phospholemman has not been characterized. The aim of this study was to test the hypothesis that phospholemman phosphorylation regulates vascular tone in vitro and that this mechanism plays an important role in modulation of vascular function and BP in experimental models in vivo and in humans. METHODS In mouse studies, phospholemman knock-in mice (PLM3SA; phospholemman [FXYD1] in which the 3 phosphorylation sites on serines 63, 68, and 69 are mutated to alanines), in which phospholemman is rendered unphosphorylatable, were used to assess the role of phospholemman phosphorylation in vitro in aortic and mesenteric vessels using wire myography and membrane potential measurements. In vivo BP and regional blood flow were assessed using Doppler flow and telemetry in young (14-16 weeks) and old (57-60 weeks) wild-type and transgenic mice. In human studies, we searched human genomic databases for mutations in phospholemman in the region of the phosphorylation sites and performed analyses within 2 human data cohorts (UK Biobank and GoDARTS [Genetics of Diabetes Audit and Research in Tayside]) to assess the impact of an identified single nucleotide polymorphism on BP. This single nucleotide polymorphism was expressed in human embryonic kidney cells, and its effect on phospholemman phosphorylation was determined using Western blotting. RESULTS Phospholemman phosphorylation at Ser63 and Ser68 limited vascular constriction in response to phenylephrine. This effect was blocked by ouabain. Prevention of phospholemman phosphorylation in the PLM3SA mouse profoundly enhanced vascular responses to phenylephrine both in vitro and in vivo. In aging wild-type mice, phospholemman was hypophosphorylated, and this correlated with the development of aging-induced essential hypertension. In humans, we identified a nonsynonymous coding variant, single nucleotide polymorphism rs61753924, which causes the substitution R70C in phospholemman. In human embryonic kidney cells, the R70C mutation prevented phospholemman phosphorylation at Ser68. This variant's rare allele is significantly associated with increased BP in middle-aged men. CONCLUSIONS These studies demonstrate the importance of phospholemman phosphorylation in the regulation of vascular tone and BP and suggest a novel mechanism, and therapeutic target, for aging-induced essential hypertension in humans.
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Affiliation(s)
- Andrii Boguslavskyi
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Sergiy Tokar
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Oleksandra Prysyazhna
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Olena Rudyk
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - David Sanchez-Tatay
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Hamish A.L. Lemmey
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Kim A. Dora
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Christopher J. Garland
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Helen R. Warren
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Alexander Doney
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Colin N.A. Palmer
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Mark J. Caulfield
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Julia Vlachaki Walker
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Jacqueline Howie
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - William Fuller
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Michael J. Shattock
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
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Saunders SL, Hutchinson DS, Britton FC, Liu L, Markus I, Sandow SL, Murphy TV. Effect of β 1 /β 2 -adrenoceptor blockade on β 3 -adrenoceptor activity in the rat cremaster muscle artery. Br J Pharmacol 2021; 178:1789-1804. [PMID: 33506492 DOI: 10.1111/bph.15398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND AND PURPOSE The physiological role of vascular β3 -adrenoceptors is not fully understood. Recent evidence suggests cardiac β3 -adrenoceptors are functionally effective after down-regulation of β1 /β2 -adrenoceptors. The functional interaction between the β3 -adrenoceptor and other β-adrenoceptor subtypes in rat striated muscle arteries was investigated. EXPERIMENTAL APPROACH Studies were performed in cremaster muscle arteries isolated from male Sprague-Dawley rats. β-adrenoceptor expression was assessed through RT-PCR and immunofluorescence. Functional effects of β3 -adrenoceptor agonists and antagonists and other β-adrenoceptor ligands were measured using pressure myography. KEY RESULTS All three β-adrenoceptor subtypes were present in the endothelium of the cremaster muscle artery. The β3 -adrenoceptor agonists mirabegron and CL 316,243 had no effect on the diameter of pressurized (70 mmHg) cremaster muscle arterioles with myogenic tone, while the β3 -adrenoceptor agonist SR 58611A and the nonselective β-adrenoceptor agonist isoprenaline caused concentration-dependent dilation. In the presence of β1/2 -adrenoceptor antagonists nadolol (10 μM), atenolol (1 μM) and ICI 118,551 (0.1 μM) both mirabegron and CL 316,243 were effective in causing vasodilation and the potency of SR 58611A was enhanced, while responses to isoprenaline were inhibited. The β3 -adrenoceptor antagonist L 748,337 (1 μM) inhibited vasodilation caused by β3 -adrenoceptor agonists (in the presence of β1/2 -adrenoceptor blockade), but L 748,337 had no effect on isoprenaline-induced vasodilation. CONCLUSION AND IMPLICATIONS All three β-adrenoceptor subtypes were present in the endothelium of the rat cremaster muscle artery, but β3 -adrenoceptor mediated vasodilation was only evident after blockade of β1/2 -adrenoceptors. This suggests constitutive β1/2 -adrenoceptor activity inhibits β3 -adrenoceptor function in the endothelium of skeletal muscle resistance arteries.
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Affiliation(s)
- Samantha L Saunders
- Physiology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Fiona C Britton
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Lu Liu
- Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Irit Markus
- Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Shaun L Sandow
- Physiology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia.,Biomedical Science, School of Health and Sports Science, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Timothy V Murphy
- Physiology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
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Alves JQ, Pernomian L, Silva CD, Gomes MS, de Oliveira AM, da Silva RS. Vascular tone and angiogenesis modulation by catecholamine coordinated to ruthenium. RSC Med Chem 2020; 11:497-510. [PMID: 33479651 DOI: 10.1039/c9md00573k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/12/2020] [Indexed: 01/11/2023] Open
Abstract
Catecholamines participate in angiogenesis, an important tumor development process. However, the way catecholamines interact with their receptors has not been completely elucidated, and doubts still remain as to whether these interactions occur between catechol and/or amine sites and particular amino acid residues on the catecholamine receptors. To evaluate how catechol and amine groups contribute to angiogenesis, we immobilized the catechol site through ruthenium ion (Ru) coordination, to obtain species with the general formula [Ru(NH3)4(catecholamine-R)]Cl. We then assessed the angiogenic activity of the complexes in a chorioallantoic membrane model (CAM) and examined vascular reactivity and calcium mobilization in rat aortas and vascular cells. [Ru(NH3)4(catecholamine-R)]Cl acted as partial agonists and/or antagonists of their respective receptors and induced calcium mobilization. [Ru(NH3)4(isoproterenol)]+ [Ru(NH3)4(noradrenaline)]+, and [Ru(NH3)4(adrenaline)]+ behaved as antiangiogenic complexes, whereas [Ru(NH3)4(dopamine)]+ proved to be a proangiogenic complex. In conclusion, catecholamines and [Ru(NH3)4(catecholamine-R)]Cl can modulate angiogenesis, and catechol group availability can modify the way these complexes impact the vascular tone, suggesting that catecholamines and their receptors interact differently after catecholamine coordination to ruthenium.
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Affiliation(s)
- Jacqueline Querino Alves
- Faculty of Philosophy , Sciences and Letters of Ribeirão Preto - University of São Paulo (USP) , Department of Chemistry , Avenida Bandeirantes, 3900 , postal code 14.040-901 , Ribeirão Preto , São Paulo , Brazil
| | - Laena Pernomian
- Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP) - University of São Paulo (USP) , Department of Physics and Chemistry , Avenida do Café, s/n , postal code 14.040-903 , Ribeirão Preto , São Paulo , Brazil .
| | - Cássia Dias Silva
- Faculty of Philosophy , Sciences and Letters of Ribeirão Preto - University of São Paulo (USP) , Department of Chemistry , Avenida Bandeirantes, 3900 , postal code 14.040-901 , Ribeirão Preto , São Paulo , Brazil
| | - Mayara Santos Gomes
- Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP) - University of São Paulo (USP) , Department of Physics and Chemistry , Avenida do Café, s/n , postal code 14.040-903 , Ribeirão Preto , São Paulo , Brazil .
| | - Ana Maria de Oliveira
- Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP) - University of São Paulo (USP) , Department of Physics and Chemistry , Avenida do Café, s/n , postal code 14.040-903 , Ribeirão Preto , São Paulo , Brazil .
| | - Roberto Santana da Silva
- Faculty of Philosophy , Sciences and Letters of Ribeirão Preto - University of São Paulo (USP) , Department of Chemistry , Avenida Bandeirantes, 3900 , postal code 14.040-901 , Ribeirão Preto , São Paulo , Brazil.,Faculty of Pharmaceutical Sciences of Ribeirão Preto (FCFRP) - University of São Paulo (USP) , Department of Physics and Chemistry , Avenida do Café, s/n , postal code 14.040-903 , Ribeirão Preto , São Paulo , Brazil .
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Manoury B, Idres S, Leblais V, Fischmeister R. Ion channels as effectors of cyclic nucleotide pathways: Functional relevance for arterial tone regulation. Pharmacol Ther 2020; 209:107499. [PMID: 32068004 DOI: 10.1016/j.pharmthera.2020.107499] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
Abstract
Numerous mediators and drugs regulate blood flow or arterial pressure by acting on vascular tone, involving cyclic nucleotide intracellular pathways. These signals lead to regulation of several cellular effectors, including ion channels that tune cell membrane potential, Ca2+ influx and vascular tone. The characterization of these vasocontrictive or vasodilating mechanisms has grown in complexity due to i) the variety of ion channels that are expressed in both vascular endothelial and smooth muscle cells, ii) the heterogeneity of responses among the various vascular beds, and iii) the number of molecular mechanisms involved in cyclic nucleotide signalling in health and disease. This review synthesizes key data from literature that highlight ion channels as physiologically relevant effectors of cyclic nucleotide pathways in the vasculature, including the characterization of the molecular mechanisms involved. In smooth muscle cells, cation influx or chloride efflux through ion channels are associated with vasoconstriction, whereas K+ efflux repolarizes the cell membrane potential and mediates vasodilatation. Both categories of ion currents are under the influence of cAMP and cGMP pathways. Evidence that some ion channels are influenced by CN signalling in endothelial cells will also be presented. Emphasis will also be put on recent data touching a variety of determinants such as phosphodiesterases, EPAC and kinase anchoring, that complicate or even challenge former paradigms.
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Affiliation(s)
- Boris Manoury
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France.
| | - Sarah Idres
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
| | - Véronique Leblais
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
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Bussey CE, Withers SB, Saxton SN, Bodagh N, Aldous RG, Heagerty AM. β 3 -Adrenoceptor stimulation of perivascular adipocytes leads to increased fat cell-derived NO and vascular relaxation in small arteries. Br J Pharmacol 2018; 175:3685-3698. [PMID: 29980164 PMCID: PMC6109217 DOI: 10.1111/bph.14433] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 05/04/2018] [Accepted: 06/19/2018] [Indexed: 01/13/2023] Open
Abstract
Background and Purpose In response to noradrenaline, healthy perivascular adipose tissue (PVAT) exerts an anticontractile effect on adjacent small arterial tissue. Organ bath solution transfer experiments have demonstrated the release of PVAT‐derived relaxing factors that mediate this function. The present studies were designed to investigate the mechanism responsible for the noradrenaline‐induced PVAT anticontractile effect. Experimental Approach In vitro rat small arterial contractile function was assessed using wire myography in the presence and absence of PVAT and the effects of sympathomimetic stimulation on the PVAT environment explored using Western blotting and assays of organ bath buffer. Key Results PVAT elicited an anticontractile effect in response to noradrenaline but not phenylephrine stimulation. In arteries surrounded by intact PVAT, the β3‐adrenoceptor agonist, CL‐316243, reduced the vasoconstrictor effect of phenylephrine but not noradrenaline. Kv7 channel inhibition using XE 991 reversed the noradrenaline‐induced anticontractile effect in exogenously applied PVAT studies. Adrenergic stimulation of PVAT with noradrenaline and CL‐316243, but not phenylephrine, was associated with increased adipocyte‐derived NO production, and the contractile response to noradrenaline was augmented following incubation of exogenous PVAT with L‐NMMA. PVAT from eNOS−/− mice had no anticontractile effect. Assays of adipocyte cAMP demonstrated an increase with noradrenaline stimulation implicating Gαs signalling in this process. Conclusions and Implications We have shown that adipocyte‐located β3‐adrenoceptor stimulation leads to activation of Gαs signalling pathways with increased cAMP and the release of adipocyte‐derived NO. This process is dependent upon Kv7 channel function. We conclude that adipocyte‐derived NO plays a central role in anticontractile activity when rodent PVAT is stimulated by noradrenaline.
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Affiliation(s)
- Charlotte E Bussey
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Sarah B Withers
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK.,Environment and Life Sciences, University of Salford, Salford, UK
| | - Sophie N Saxton
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Neil Bodagh
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Robert G Aldous
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Anthony M Heagerty
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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7
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Dora KA. Endothelial-smooth muscle cell interactions in the regulation of vascular tone in skeletal muscle. Microcirculation 2018; 23:626-630. [PMID: 27653241 DOI: 10.1111/micc.12322] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/19/2016] [Indexed: 11/28/2022]
Abstract
The SMCs of skeletal muscle arterioles are intricately sensitive to changes in membrane potential. Upon increasing luminal pressure, the SMCs depolarize, thereby opening VDCCs, which leads to contraction. Mechanisms that oppose this myogenic tone can involve voltage-dependent and independent dilator pathways, and can be endothelium-dependent or independent. Of particular interest are the pathways leading to hyperpolarization of SMCs, as these can potentially evoke both local and conducted dilation. This review focuses on three agonists that cause local and conducted dilation in skeletal muscle: ACh, ATP, and KCl. The mechanisms for the release of these agonists during motor nerve stimulation and/or hypoxia, and their actions to open either Ca2+ -activated K+ channels (KCa ) or inwardly rectifying K+ channels (KIR ) are described. By causing local and conducted dilation, each agonist has the ability to improve skeletal muscle blood flow during exercise and ischemia.
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Affiliation(s)
- Kim A Dora
- Department of Pharmacology, University of Oxford, Oxford, UK
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8
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Pinkney AMH, Lemmey HAL, Dora KA, Garland CJ. Vasorelaxation to the Nitroxyl Donor Isopropylamine NONOate in Resistance Arteries Does Not Require Perivascular Calcitonin Gene-Related Peptide. Hypertension 2017; 70:HYPERTENSIONAHA.117.09737. [PMID: 28760938 DOI: 10.1161/hypertensionaha.117.09737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 05/28/2017] [Accepted: 07/05/2017] [Indexed: 01/12/2023]
Abstract
Nitroxyl (HNO) donors offer considerable therapeutic potential for the treatment of hypertension-related cardiovascular disorders, particularly heart failure, as they combine an inotropic action with peripheral vasodilation. Angeli's salt is the only HNO donor whose mechanism has been studied in depth, and recently, Angeli's salt vasodilation was suggested to be indirect and caused by calcitonin gene-related peptide (CGRP) released from perivascular nerves after HNO activates TRPA1 (transient receptor potential cation channel subfamily A member 1) channels. We investigated resistance artery vasorelaxation to the HNO donor, isopropylamine NONOate (IPA/NO), one of the structures providing a template for therapeutic development. Wire myography in combination with measurements of smooth muscle membrane potential was used to characterize the effect of IPA/NO in mesenteric resistance arteries. Immunohistochemistry was assessed in pressurized arteries. IPA/NO concentration dependently hyperpolarized and relaxed arteries precontracted with the α1-adrenoreceptor agonist, phenylephrine. These effects were blocked by the soluble guanylyl cyclase inhibitor, ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) but not by the KATP channel inhibitor, glibenclamide. Vasorelaxation persisted in the presence of raised [K+]o, used to block hyperpolarization, capsaicin to deplete perivascular CGRP, or HC030031 (2-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)-N-(4 isopropylphenyl) acetamide) to block TRPA1 receptors. Without preconstriction, hyperpolarization to IPA/NO was suppressed by glibenclamide, capsaicin, or HC030031. Hyperpolarization but not vasorelaxation to exogenous CGRP was inhibited with glibenclamide. Thus, vascular hyperpolarization is not necessary for vasorelaxation to the HNO donor IPA/NO, even though both effects are cGMP dependent. The reduced hyperpolarization after depletion of perivascular CGRP or block of TRPA1 receptors indicates some release of CGRP, but this does not contribute to HNO vasorelaxation. Therefore, HNO-TRPA1-CGRP signaling does not seem important for vasodilation to IPA/NO in resistance arteries.
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Affiliation(s)
- Alice M H Pinkney
- From the Department of Pharmacology, University of Oxford, United Kingdom
| | - Hamish A L Lemmey
- From the Department of Pharmacology, University of Oxford, United Kingdom
| | - Kim A Dora
- From the Department of Pharmacology, University of Oxford, United Kingdom
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9
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Fujii N, McNeely BD, Kenny GP. Nitric oxide synthase and cyclooxygenase modulate β-adrenergic cutaneous vasodilatation and sweating in young men. J Physiol 2017; 595:1173-1184. [PMID: 27779753 DOI: 10.1113/jp273502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/18/2016] [Indexed: 01/10/2023] Open
Abstract
KEY POINTS β-Adrenergic receptor agonists such as isoproterenol induce cutaneous vasodilatation and sweating in humans, but the mechanisms underpinning this response remain unresolved. Using intradermal microdialysis, we evaluated the roles of nitric oxide synthase (NOS) and cyclooxygenase (COX) in β-adrenergic cutaneous vasodilatation and sweating elicited by administration of isoproterenol. We show that while NOS contributes to β-adrenergic cutaneous vasodilatation, COX restricts cutaneous vasodilatation. We also show that combined inhibition of NOS and COX augments β-adrenergic sweating These new findings advance our basic knowledge regarding the physiological control of cutaneous blood flow and sweating, and provide important and new information to better understand the physiological significance of β-adrenergic receptors in the skin. ABSTRACT β-Adrenergic receptor agonists such as isoproterenol can induce cutaneous vasodilatation and sweating in humans, but the mechanisms underpinning this response remain unresolved. We evaluated the hypotheses that (1) nitric oxide synthase (NOS) contributes to β-adrenergic cutaneous vasodilatation, whereas cyclooxygenase (COX) limits the vasodilatation, and (2) COX contributes to β-adrenergic sweating. In 10 young males (25 ± 5 years), cutaneous vascular conductance (CVC) and sweat rate were evaluated at four intradermal forearm skin sites infused with (1) lactated Ringer solution (control), (2) 10 mm Nω -nitro-l-arginine (l-NNA), a non-specific NOS inhibitor, (3) 10 mm ketorolac, a non-specific COX inhibitor, or (4) a combination of l-NNA and ketorolac. All sites were co-administered with a high dose of isoproterenol (100 μm) for 3 min to maximally induce β-adrenergic sweating (β-adrenergic sweating is significantly blunted by subsequent activations). Approximately 60 min after the washout period, three incremental doses of isoproterenol were co-administered (1, 10 and 100 μm each for 25 min). Increases in CVC induced by the first and second 100 μm isoproterenol were attenuated by l-NNA alone, and those in response to all doses of isoproterenol were reduced by l-NNA with co-infusion of ketorolac (all P ≤ 0.05). Ketorolac alone augmented increases in CVC induced by 10 μm and by the second 100 μm isoproterenol (both P ≤ 0.05). While isoproterenol-induced sweating was not affected by the separate administration of l-NNA or ketorolac (all P > 0.05), their combined administration augmented sweating elicited by the first 3 min of 100 μm isoproterenol (P = 0.05). We show that while NOS contributes to β-adrenergic cutaneous vasodilatation, COX restrains the vasodilatation. Finally, combined inhibition of NOS and COX augments β-adrenergic sweating.
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Affiliation(s)
- Naoto Fujii
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
| | - Brendan D McNeely
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
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10
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Stott JB, Barrese V, Greenwood IA. Kv7 Channel Activation Underpins EPAC-Dependent Relaxations of Rat Arteries. Arterioscler Thromb Vasc Biol 2016; 36:2404-2411. [PMID: 27789473 DOI: 10.1161/atvbaha.116.308517] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/11/2016] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To establish the role of Kv7 channels in EPAC (exchange protein directly activated by cAMP)-dependent relaxations of the rat vasculature and to investigate whether this contributes to β-adrenoceptor-mediated vasorelaxations. APPROACH AND RESULTS Isolated rat renal and mesenteric arteries (RA and MA, respectively) were used for isometric tension recording to study the relaxant effects of a specific EPAC activator and the β-adrenoceptor agonist isoproterenol in the presence of potassium channel inhibitors and cell signaling modulators. Isolated myocytes were used in proximity ligation assay studies to detect localization of signaling intermediaries with Kv7.4 before and after cell stimulation. Our studies showed that the EPAC activator (8-pCPT-2Me-cAMP-AM) produced relaxations and enhanced currents of MA and RA that were sensitive to linopirdine (Kv7 inhibitor). Linopirdine also inhibited isoproterenol-mediated relaxations in both RA and MA. In the MA, isoproterenol relaxations were sensitive to EPAC inhibition, but not protein kinase A inhibition. In contrast, isoproterenol relaxations in RA were attenuated by protein kinase A but not by EPAC inhibition. Proximity ligation assay showed a localization of Kv7.4 with A-kinase anchoring protein in both vessels in the basal state, which increased only in the RA with isoproterenol stimulation. In the MA, but not the RA, a localization of Kv7.4 with both Rap1a and Rap2 (downstream of EPAC) increased with isoproterenol stimulation. CONCLUSIONS EPAC-dependent vasorelaxations occur in part via activation of Kv7 channels. This contributes to the isoproterenol-mediated relaxation in mesenteric, but not renal, arteries.
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Affiliation(s)
- Jennifer B Stott
- From the Vascular Biology Research Group, Institute for Cardiovascular and Cell Sciences, St George's University of London, UK
| | - Vincenzo Barrese
- From the Vascular Biology Research Group, Institute for Cardiovascular and Cell Sciences, St George's University of London, UK
| | - Iain A Greenwood
- From the Vascular Biology Research Group, Institute for Cardiovascular and Cell Sciences, St George's University of London, UK.
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11
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Schmidt K, Windler R, de Wit C. Communication Through Gap Junctions in the Endothelium. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 77:209-40. [PMID: 27451099 DOI: 10.1016/bs.apha.2016.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A swarm of fish displays a collective behavior (swarm behavior) and moves "en masse" despite the huge number of individual animals. In analogy, organ function is supported by a huge number of cells that act in an orchestrated fashion and this applies also to vascular cells along the vessel length. It is obvious that communication is required to achieve this vital goal. Gap junctions with their modular bricks, connexins (Cxs), provide channels that interlink the cytosol of adjacent cells by a pore sealed against the extracellular space. This allows the transfer of ions and charge and thereby the travel of membrane potential changes along the vascular wall. The endothelium provides a low-resistance pathway that depends crucially on connexin40 which is required for long-distance conduction of dilator signals in the microcirculation. The experimental evidence for membrane potential changes synchronizing vascular behavior is manifold but the functional verification of a physiologic role is still open. Other molecules may also be exchanged that possibly contribute to the synchronization (eg, Ca(2+)). Recent data suggest that vascular Cxs have more functions than just facilitating communication. As pharmacological tools to modulate gap junctions are lacking, Cx-deficient mice provide currently the standard to unravel their vascular functions. These include arteriolar dilation during functional hyperemia, hypoxic pulmonary vasoconstriction, vascular collateralization after ischemia, and feedback inhibition on renin secretion in the kidney.
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Affiliation(s)
- K Schmidt
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - R Windler
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - C de Wit
- Institut für Physiologie, Universität zu Lübeck, Lübeck, Germany; Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK) e.V. (German Center for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Lübeck, Germany.
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12
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Karlin A. Membrane potential and Ca2+ concentration dependence on pressure and vasoactive agents in arterial smooth muscle: A model. ACTA ACUST UNITED AC 2016; 146:79-96. [PMID: 26123196 PMCID: PMC4485026 DOI: 10.1085/jgp.201511380] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A mathematical model incorporating junctional and stretch-activated microdomains and 37 protein components describes the myogenic response in arterial smooth muscle cells. Arterial smooth muscle (SM) cells respond autonomously to changes in intravascular pressure, adjusting tension to maintain vessel diameter. The values of membrane potential (Vm) and sarcoplasmic Ca2+ concentration (Cain) within minutes of a change in pressure are the results of two opposing pathways, both of which use Ca2+ as a signal. This works because the two Ca2+-signaling pathways are confined to distinct microdomains in which the Ca2+ concentrations needed to activate key channels are transiently higher than Cain. A mathematical model of an isolated arterial SM cell is presented that incorporates the two types of microdomains. The first type consists of junctions between cisternae of the peripheral sarcoplasmic reticulum (SR), containing ryanodine receptors (RyRs), and the sarcolemma, containing voltage- and Ca2+-activated K+ (BK) channels. These junctional microdomains promote hyperpolarization, reduced Cain, and relaxation. The second type is postulated to form around stretch-activated nonspecific cation channels and neighboring Ca2+-activated Cl− channels, and promotes the opposite (depolarization, increased Cain, and contraction). The model includes three additional compartments: the sarcoplasm, the central SR lumen, and the peripheral SR lumen. It incorporates 37 protein components. In addition to pressure, the model accommodates inputs of α- and β-adrenergic agonists, ATP, 11,12-epoxyeicosatrienoic acid, and nitric oxide (NO). The parameters of the equations were adjusted to obtain a close fit to reported Vm and Cain as functions of pressure, which have been determined in cerebral arteries. The simulations were insensitive to ±10% changes in most of the parameters. The model also simulated the effects of inhibiting RyR, BK, or voltage-activated Ca2+ channels on Vm and Cain. Deletion of BK β1 subunits is known to increase arterial–SM tension. In the model, deletion of β1 raised Cain at all pressures, and these increases were reversed by NO.
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Affiliation(s)
- Arthur Karlin
- Department of Biochemistry and Molecular Biophysics, Department of Physiology and Cellular Biophysics, and Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY 10032
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13
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Schepelmann M, Yarova PL, Lopez-Fernandez I, Davies TS, Brennan SC, Edwards PJ, Aggarwal A, Graça J, Rietdorf K, Matchkov V, Fenton RA, Chang W, Krssak M, Stewart A, Broadley KJ, Ward DT, Price SA, Edwards DH, Kemp PJ, Riccardi D. The vascular Ca2+-sensing receptor regulates blood vessel tone and blood pressure. Am J Physiol Cell Physiol 2015; 310:C193-204. [PMID: 26538090 DOI: 10.1152/ajpcell.00248.2015] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/29/2015] [Indexed: 12/28/2022]
Abstract
The extracellular calcium-sensing receptor CaSR is expressed in blood vessels where its role is not completely understood. In this study, we tested the hypothesis that the CaSR expressed in vascular smooth muscle cells (VSMC) is directly involved in regulation of blood pressure and blood vessel tone. Mice with targeted CaSR gene ablation from vascular smooth muscle cells (VSMC) were generated by breeding exon 7 LoxP-CaSR mice with animals in which Cre recombinase is driven by a SM22α promoter (SM22α-Cre). Wire myography performed on Cre-negative [wild-type (WT)] and Cre-positive (SM22α)CaSR(Δflox/Δflox) [knockout (KO)] mice showed an endothelium-independent reduction in aorta and mesenteric artery contractility of KO compared with WT mice in response to KCl and to phenylephrine. Increasing extracellular calcium ion (Ca(2+)) concentrations (1-5 mM) evoked contraction in WT but only relaxation in KO aortas. Accordingly, diastolic and mean arterial blood pressures of KO animals were significantly reduced compared with WT, as measured by both tail cuff and radiotelemetry. This hypotension was mostly pronounced during the animals' active phase and was not rescued by either nitric oxide-synthase inhibition with nitro-l-arginine methyl ester or by a high-salt-supplemented diet. KO animals also exhibited cardiac remodeling, bradycardia, and reduced spontaneous activity in isolated hearts and cardiomyocyte-like cells. Our findings demonstrate a role for CaSR in the cardiovascular system and suggest that physiologically relevant changes in extracellular Ca(2+) concentrations could contribute to setting blood vessel tone levels and heart rate by directly acting on the cardiovascular CaSR.
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Affiliation(s)
- M Schepelmann
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - P L Yarova
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - I Lopez-Fernandez
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Faculty of Pharmacy, Université de Picardie Jules Verne, Amiens, France
| | - T S Davies
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - S C Brennan
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - P J Edwards
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - A Aggarwal
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - J Graça
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Pathology Sciences, AstraZeneca, Macclesfield, Cheshire, United Kingdom
| | - K Rietdorf
- Faculty of Science, Department for Life, Health and Chemical Sciences, The Open University, Milton Keynes, United Kingdom
| | - V Matchkov
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - R A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - W Chang
- Endocrine Research Unit, Department of Veteran Affairs Medical Center, Department of Medicine, University of California, San Francisco, Califonia
| | - M Krssak
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - A Stewart
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - K J Broadley
- School of Pharmacy and Pharmaceutical Sciences, Division of Pharmacology, Cardiff University, Cardiff, United Kingdom
| | - D T Ward
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom; and
| | - S A Price
- Pathology Sciences, AstraZeneca, Macclesfield, Cheshire, United Kingdom
| | - D H Edwards
- Cardiff University, Wales Heart Research Institute, Cardiff, United Kingdom
| | - P J Kemp
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - D Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom;
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14
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Garland CJ, Smirnov SV, Bagher P, Lim CS, Huang CY, Mitchell R, Stanley C, Pinkney A, Dora KA. TRPM4 inhibitor 9-phenanthrol activates endothelial cell intermediate conductance calcium-activated potassium channels in rat isolated mesenteric artery. Br J Pharmacol 2014; 172:1114-23. [PMID: 25323322 DOI: 10.1111/bph.12985] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/08/2014] [Accepted: 10/09/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE Smooth muscle transient receptor potential melastatin 4 (TRPM4) channels play a fundamental role in the development of the myogenic arterial constriction that is necessary for blood flow autoregulation. As TRPM4 channels are present throughout the vasculature, we investigated their potential role in non-myogenic resistance arteries using the TRPM4 inhibitor 9-phenanthrol. EXPERIMENTAL APPROACH Pressure and wire myography were used to assess the reactivity of rat arteries, the latter in combination with measurements of smooth muscle membrane potential. Immunohistochemistry (IHC) and endothelial cell (EC) calcium changes were assessed in pressurized vessels and patch clamp measurements made in isolated ECs. KEY RESULTS The TRPM4 inhibitor 9-phenanthrol reversibly hyperpolarized mesenteric arteries to circa EK and blocked α1 -adrenoceptor-mediated vasoconstriction. Hyperpolarization was abolished and vasoconstriction re-established by damaging the endothelium. In mesenteric and cerebral artery smooth muscle, 9-phenanthrol hyperpolarization was effectively blocked by the KCa 3.1 inhibitor TRAM-34. 9-Phenanthrol did not increase mesenteric EC [Ca(2+)]i , and Na(+) substitution with N-methyl-D-glucamine only increased the muscle resting potential by 10 mV. Immunolabelling for TRPM4 was restricted to the endothelium and perivascular tissue. CONCLUSIONS AND IMPLICATIONS These data reveal a previously unrecognized action of the TRPM4 inhibitor 9-phenanthrol - the ability to act as an activator of EC KCa 3.1 channels. They do not indicate a functionally important role for TRPM4 channels in the reactivity of non-myogenic mesenteric arteries.
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Affiliation(s)
- C J Garland
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
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15
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Yarova PL, Smirnov SV, Dora KA, Garland CJ. β₁-Adrenoceptor stimulation suppresses endothelial IK(Ca)-channel hyperpolarization and associated dilatation in resistance arteries. Br J Pharmacol 2014; 169:875-86. [PMID: 23488860 DOI: 10.1111/bph.12160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 02/01/2013] [Accepted: 02/15/2013] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE In small arteries, small conductance Ca²⁺-activated K⁺ channels (SK(Ca)) and intermediate conductance Ca²⁺-activated K⁺ channels (IK(Ca)) restricted to the vascular endothelium generate hyperpolarization that underpins the NO- and PGI₂-independent, endothelium-derived hyperpolarizing factor response that is the predominate endothelial mechanism for vasodilatation. As neuronal IK(Ca) channels can be negatively regulated by PKA, we investigated whether β-adrenoceptor stimulation, which signals through cAMP/PKA, might influence endothelial cell hyperpolarization and as a result modify the associated vasodilatation. EXPERIMENTAL APPROACH Rat isolated small mesenteric arteries were pressurized to measure vasodilatation and endothelial cell [Ca²⁺]i , mounted in a wire myograph to measure smooth muscle membrane potential or dispersed into endothelial cell sheets for membrane potential recording. KEY RESULTS Intraluminal perfusion of β-adrenoceptor agonists inhibited endothelium-dependent dilatation to ACh (1 nM-10 μM) without modifying the associated changes in endothelial cell [Ca²⁺]i . The inhibitory effect of β-adrenoceptor agonists was mimicked by direct activation of adenylyl cyclase with forskolin, blocked by the β-adrenoceptor antagonists propranolol (non-selective), atenolol (β₁) or the PKA inhibitor KT-5720, but remained unaffected by ICI 118 551 (β₂) or glibenclamide (ATP-sensitive K⁺ channels channel blocker). Endothelium-dependent hyperpolarization to ACh was also inhibited by β-adrenoceptor stimulation in both intact arteries and in endothelial cells sheets. Blocking IK(Ca) {with 1 μM 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34)}, but not SK(Ca) (50 nM apamin) channels prevented β-adrenoceptor agonists from suppressing either hyperpolarization or vasodilatation to ACh. CONCLUSIONS AND IMPLICATIONS In resistance arteries, endothelial cell β₁-adrenoceptors link to inhibit endothelium-dependent hyperpolarization and the resulting vasodilatation to ACh. This effect appears to reflect inhibition of endothelial IK(Ca) channels and may be one consequence of raised circulating catecholamines.
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Affiliation(s)
- P L Yarova
- Department of Pharmacology, University of Oxford, Oxford, UK
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16
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Flacco N, Segura V, Perez-Aso M, Estrada S, Seller JF, Jiménez-Altayó F, Noguera MA, D'Ocon P, Vila E, Ivorra MD. Different β-adrenoceptor subtypes coupling to cAMP or NO/cGMP pathways: implications in the relaxant response of rat conductance and resistance vessels. Br J Pharmacol 2014; 169:413-25. [PMID: 23373597 DOI: 10.1111/bph.12121] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 01/07/2013] [Accepted: 01/18/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE To analyse the relative contribution of β1 -, β2 - and β3 -adrenoceptors (Adrb) to vasodilatation in conductance and resistance vessels, assessing the role of cAMP and/or NO/cGMP signalling pathways. EXPERIMENTAL APPROACH Rat mesenteric resistance artery (MRA) and aorta were used to analyse the Adrb expression by real-time-PCR and immunohistochemistry, and for the pharmacological characterization of Adrb-mediated activity by wire myography and tissue nucleotide accumulation. KEY RESULTS The mRNAs and protein for all Adrb were identified in endothelium and/or smooth muscle cells (SMCs) in both vessels. In MRA, Adrb1 signalled through cAMP, Adrb3 through both cAMP and cGMP, but Adrb2, did not activate nucleotide formation; isoprenaline relaxation was inhibited by propranolol (β1 , β2 ), CGP20712A (β1 ), and SQ22536 (adenylyl cyclase inhibitor), but not by ICI118,551 (β2 ), SR59230A (β3 ), ODQ (soluble guanylyl cyclase inhibitor), L-NAME or endothelium removal. In aorta, Adrb1 signalled through cAMP, while β2 - and β3 -subtypes through cGMP; isoprenaline relaxation was inhibited by propranolol, ICI118,551, ODQ, L-NAME, and to a lesser extent, by endothelium removal. CL316243 (β3 -agonist) relaxed aorta, but not MRA. CONCLUSION AND IMPLICATION Despite all three Adrb subtypes being found in both vessels, Adrb1, located in SMCs and acting through the adenylyl cyclase/cAMP pathway, are primarily responsible for vasodilatation in MRA. However, Adrb-mediated vasodilatation in aorta is driven by endothelial Adrb2 and Adrb3, but also by the Adrb2 present in SMCs, and is coupled to the NO/cGMP pathway. These results could help to understand the different physiological roles played by Adrb signalling in regulating conductance and resistance vessels.
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Affiliation(s)
- N Flacco
- Departament de Farmacologia, Facultat de Farmacia, Universitat de Valencia, Burjassot, Spain
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Pavlov AN, Semyachkina-Glushkovskaya OV, Zhang Y, Bibikova OA, Pavlova ON, Huang Q, Zhu D, Li P, Tuchin VV, Luo Q. Multiresolution analysis of pathological changes in cerebral venous dynamics in newborn mice with intracranial hemorrhage: adrenorelated vasorelaxation. Physiol Meas 2014; 35:1983-99. [PMID: 25238178 DOI: 10.1088/0967-3334/35/10/1983] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Intracranial hemorrhage (ICH) is the major problem of modern neonatal intensive care. Abnormalities of cerebral venous blood flow (CVBF) can play a crucial role in the development of ICH in infants. The mechanisms underlying these pathological processes remain unclear; however it has been established that the activation of the adrenorelated vasorelaxation can be an important reason. Aiming to reach a better understanding of how the adrenodependent relaxation of cerebral veins contributes to the development of ICH in newborns, we study here the effects of pharmacological stimulation of adrenorelated dilation of the sagittal sinus by isoproterenol on the cerebral venous hemodynamics. Our study is performed in newborn mice at different stages of ICH using the laser speckle contrast imaging and wavelet analysis of the vascular dynamics of CVBF. We show that the dilation of the sagittal sinus with the decreased velocity of blood flow presides to the stress-induced ICH in newborn mice. These morphofunctional vascular changes are accompanied by an increased variance of the wavelet-coefficients in the areas of endothelial and non-endothelial (KATP-channels activity of vascular muscle) sympathetic components of the CVBF variability. Changes in the cerebral venous hemodynamics at the latent stage of ICH are associated with a high responsiveness of the sagittal sinus to isoproterenol quantifying by wavelet-coefficients related to a very slow region of the frequency domain. The obtained results certify that a high activation of the adrenergic-related vasodilatory responses to severe stress in newborn mice can be one of the important mechanisms underlying the development of ICH. Thus, the venous insufficiency with the decreased blood outflow from the brain associated with changes in the endothelial and the sympathetic components of CVBF-variability can be treated as prognostic criteria for the risk of ICH during the first days after birth.
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Affiliation(s)
- A N Pavlov
- Department of Physics, Saratov State University, Astrakhanskaya Str. 83, Saratov, 410012, Russia. Saratov State Technical University, Politehnicheskaya Str. 77, Saratov, 410054, Russia. Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
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Chadha PS, Jepps TA, Carr G, Stott JB, Zhu HL, Cole WC, Greenwood IA. Contribution of kv7.4/kv7.5 heteromers to intrinsic and calcitonin gene-related peptide-induced cerebral reactivity. Arterioscler Thromb Vasc Biol 2014; 34:887-93. [PMID: 24558103 DOI: 10.1161/atvbaha.114.303405] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Middle cerebral artery (MCA) diameter is regulated by inherent myogenic activity and the effect of potent vasodilators such as calcitonin gene-related peptide (CGRP). Previous studies showed that MCAs express KCNQ1, 4, and 5 potassium channel genes, and the expression products (Kv7 channels) participate in the myogenic control of MCA diameter. The present study investigated the contribution of Kv7.4 and Kv7.5 isoforms to myogenic and CGRP regulation of MCA diameter and determined whether they were affected in hypertensive animals. APPROACH AND RESULTS Isometric tension recordings performed on MCA from normotensive rats produced CGRP vasodilations that were inhibited by the pan-Kv7 channel blocker linopirdine (P<0.01) and after transfection of arteries with siRNA against KCNQ4 (P<0.01) but not KCNQ5. However, isobaric myography revealed that myogenic constriction in response to increases in intravascular pressure (20-80 mm Hg) was affected by both KCNQ4 and KCNQ5 siRNA. Proximity ligation assay signals were equally abundant for Kv7.4/Kv7.4 or Kv7.4/Kv7.5 antibody combinations but minimal for Kv7.5/Kv7.5 antibodies or Kv7.4/7.1 combinations. In contrast to systemic arteries, Kv7 function and Kv7.4 abundance in MCA were not altered in hypertensive rats. CONCLUSIONS This study reveals, for the first time to our knowledge, that in cerebral arteries, Kv7.4 and Kv7.5 proteins exist predominantly as a functional heterotetramer, which regulates intrinsic myogenicity and vasodilation attributed to CGRP. Surprisingly, unlike systemic arteries, Kv7 activity in MCAs is not affected by the development of hypertension, and CGRP-mediated vasodilation is well maintained. As such, cerebrovascular Kv7 channels could be amenable for therapeutic targeting in conditions such as cerebral vasospasm.
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Affiliation(s)
- Preet S Chadha
- From the Division of Biomedical Sciences, Pharmacology and Cell Physiology Research Group, St George's University of London, London, United Kingdom (P.S.C., T.A.J., G.C., J.B.S., I.A.G.); and The Smooth Muscle Research Group, Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (H.-L.Z., W.C.C.)
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Westcott EB, Segal SS. Perivascular innervation: a multiplicity of roles in vasomotor control and myoendothelial signaling. Microcirculation 2013; 20:217-38. [PMID: 23289720 DOI: 10.1111/micc.12035] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 12/25/2012] [Indexed: 12/30/2022]
Abstract
The control of vascular resistance and tissue perfusion reflect coordinated changes in the diameter of feed arteries and the arteriolar networks they supply. Against a background of myogenic tone and metabolic demand, vasoactive signals originating from perivascular sympathetic and sensory nerves are integrated with endothelium-derived signals to produce vasodilation or vasoconstriction. PVNs release adrenergic, cholinergic, peptidergic, purinergic, and nitrergic neurotransmitters that lead to SMC contraction or relaxation via their actions on SMCs, ECs, or other PVNs. ECs release autacoids that can have opposing actions on SMCs. Respective cell layers are connected directly to each other through GJs at discrete sites via MEJs projecting through holes in the IEL. Whereas studies of intercellular communication in the vascular wall have centered on endothelium-derived signals that govern SMC relaxation, attention has increasingly focused on signaling from SMCs to ECs. Thus, via MEJs, neurotransmission from PVNs can evoke distinct responses from ECs subsequent to acting on SMCs. To integrate this emerging area of investigation in light of vasomotor control, the present review synthesizes current understanding of signaling events that originate within SMCs in response to perivascular neurotransmission in light of EC feedback. Although often ignored in studies of the resistance vasculature, PVNs are integral to blood flow control and can provide a physiological stimulus for myoendothelial communication. Greater understanding of these underlying signaling events and how they may be affected by aging and disease will provide new approaches for selective therapeutic interventions.
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Affiliation(s)
- Erika B Westcott
- Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri 65212, USA
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Abstract
Beta-blockers are widely prescribed for the treatment of a variety of cardiovascular pathologies. Compared to traditional beta-adrenergic antagonists, beta-blockers of the new generation exhibit ancillary properties such as vasodilation through different mechanisms. This translates into a more favorable hemodynamic profile. The relative affinities of beta-adrenoreceptor antagonists towards the three beta-adrenoreceptor isotypes matter for predicting their functional impact on vasomotor control. This review will focus on the mechanisms underlying beta-blocker-evoked vasorelaxation with a specific emphasis on agonist properties of beta(3)-adrenergic receptors.
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Affiliation(s)
- Géraldine Rath
- Pole de Pharmacologie et Thérapeutique (FATH), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, B01.5309, Avenue Mounier 52, 1200, Brussels, Belgium.
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Influence of Hyperpolarization Caused by High Salt Diet on β-Adrenoceptor–Mediated Responses in Rat Pulmonary Artery. J Cardiovasc Pharmacol 2012; 60:23-32. [DOI: 10.1097/fjc.0b013e3182555097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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23
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Matsumoto T, Szasz T, Tostes RC, Webb RC. Impaired β-adrenoceptor-induced relaxation in small mesenteric arteries from DOCA-salt hypertensive rats is due to reduced K(Ca) channel activity. Pharmacol Res 2012; 65:537-45. [PMID: 22388053 DOI: 10.1016/j.phrs.2012.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 02/07/2012] [Accepted: 02/14/2012] [Indexed: 10/28/2022]
Abstract
β-Adrenoceptor (β-AR)-mediated relaxation plays an important role in the regulation of vascular tone. β-AR-mediated vascular relaxation is reduced in various disease states and aging. We hypothesized that β-AR-mediated vasodilatation is impaired in DOCA-salt hypertension due to alterations in the cAMP pathway. β-AR-mediated relaxation was determined in small mesenteric arteries from DOCA-salt hypertensive and control uninephrectomized (Uni) rats. To exclude nitric oxide (NO) and cyclooxygenase (COX) pathways, relaxation responses were determined in the presence of l-NNA and indomethacin, NO synthase inhibitor and COX inhibitors, respectively. Isoprenaline (ISO)-induced relaxation was reduced in arteries from DOCA-salt compared to Uni rats. Protein kinase A (PKA) inhibitors (H89 or Rp-cAMPS) or adenylyl cyclase inhibitor (SQ22536) did not abolish the difference in ISO-induced relaxation between the groups. Forskolin (adenylyl cyclase activator)-induced relaxation was similar between the groups. The inhibition of IK(Ca)/SK(Ca) channels (TRAM-34 plus UCL1684) or BK(Ca) channels (iberiotoxin) reduced ISO-induced relaxation only in Uni rats and abolished the relaxation differences between the groups. The expression of SK(Ca) channel was decreased in DOCA-salt arteries. The expression of BK(Ca) channel α subunit was increased whereas the expression of BK(Ca) channel β subunit was decreased in DOCA-salt arteries. The expression of receptor for activated C kinase 1 (RACK1), which is a binding protein for BK(Ca) channel and negatively modulates its activity, was increased in DOCA-salt arteries. These results suggest that the impairment of β-AR-mediated relaxation in DOCA-salt mesenteric arteries may be attributable to altered IK(Ca)/SK(Ca) and/or BK(Ca) channels activities rather than cAMP/PKA pathway. Impaired β-AR-stimulated BK(Ca) channel activity may be due to the imbalance between its subunit expressions and RACK1 upregulation.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
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Chadha PS, Zunke F, Zhu HL, Davis AJ, Jepps TA, Olesen SP, Cole WC, Moffatt JD, Greenwood IA. Reduced KCNQ4-encoded voltage-dependent potassium channel activity underlies impaired β-adrenoceptor-mediated relaxation of renal arteries in hypertension. Hypertension 2012; 59:877-84. [PMID: 22353613 DOI: 10.1161/hypertensionaha.111.187427] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
KCNQ4-encoded voltage-dependent potassium (Kv7.4) channels are important regulators of vascular tone that are severely compromised in models of hypertension. However, there is no information as to the role of these channels in responses to endogenous vasodilators. We used a molecular knockdown strategy, as well as pharmacological tools, to examine the hypothesis that Kv7.4 channels contribute to β-adrenoceptor-mediated vasodilation in the renal vasculature and underlie the vascular deficit in spontaneously hypertensive rats. Quantitative PCR and immunohistochemistry confirmed gene and protein expression of KCNQ1, KCNQ3, KCNQ4, KCNQ5, and Kv7.1, Kv7.4, and Kv7.5 in rat renal artery. Isoproterenol produced concentration-dependent relaxation of precontracted renal arteries and increased Kv7 channel currents in isolated smooth muscle cells. Application of the Kv7 blocker linopirdine attenuated isoproterenol-induced relaxation and current. Isoproterenol-induced relaxations were also reduced in arteries incubated with small interference RNAs targeted to KCNQ4 that produced a ≈60% decrease in Kv7.4 protein level. Relaxation to isoproterenol and the Kv7 activator S-1 were abolished in arteries from spontaneously hypertensive rats, which was associated with ≈60% decrease in Kv7.4 abundance. This study provides the first evidence that Kv7 channels contribute to β-adrenoceptor-mediated vasodilation in the renal vasculature and that abrogation of Kv7.4 channels is strongly implicated in the impaired β-adrenoceptor pathway in spontaneously hypertensive rats. These findings may provide a novel pathogenic link between arterial dysfunction and hypertension.
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Affiliation(s)
- Preet S Chadha
- Division of Biomedical Sciences, Pharmacology and Cell Physiology Research Group, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK
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Beleznai TZ, Yarova PL, Yuill KH, Dora KA. Smooth muscle Ca(2+) -activated and voltage-gated K+ channels modulate conducted dilation in rat isolated small mesenteric arteries. Microcirculation 2011; 18:487-500. [PMID: 21535295 PMCID: PMC4826745 DOI: 10.1111/j.1549-8719.2011.00109.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To assess the influence of blocking smooth muscle large conductance Ca(2+) -activated K+ channels and voltage-gated K+ channels on the conducted dilation to ACh and isoproterenol. MATERIALS AND METHODS Rat mesenteric arteries were isolated with a bifurcation, triple-cannulated, pressurized and imaged using confocal microscopy. Phenylephrine was added to the superfusate to generate tone, and agonists perfused into a sidebranch to evoke local dilation and subsequent conducted dilation into the feed artery. RESULTS Both ACh- and isoproterenol-stimulated local and conducted dilation with similar magnitudes of decay with distance along the feed artery (2000μm: ∼15% maximum dilation). The gap junction uncoupler carbenoxolone prevented both conducted dilation and intercellular spread of dye through gap junctions. IbTx, TEA or 4-AP, blockers of large conductance Ca(2+) -activated K+ channels and voltage-gated K+ channels, did not affect conducted dilation to either agonist. A combination of either IbTx or TEA with 4-AP markedly improved the extent of conducted dilation to both agonists (2000μm: >50% maximum dilation). The enhanced conducted dilation was reflected in the hyperpolarization to ACh (2000μm: Control, 4±1 mV, n = 3; TEA with 4-AP, 14±3mV, n=4), and was dependent on the endothelium. CONCLUSIONS These data show that activated BK(Ca) and K(V) -channels serve to reduce the effectiveness of conducted dilation.
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Affiliation(s)
- Timea Z Beleznai
- Department of Pharmacology, University of Oxford, Oxford, UK Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
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Beleznai T, Takano H, Hamill C, Yarova P, Douglas G, Channon K, Dora K. Enhanced K(+)-channel-mediated endothelium-dependent local and conducted dilation of small mesenteric arteries from ApoE(-/-) mice. Cardiovasc Res 2011; 92:199-208. [PMID: 21690174 DOI: 10.1093/cvr/cvr181] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Agonists that evoke smooth muscle cell hyperpolarization have the potential to stimulate both local and conducted dilation. We investigated whether the endothelium-dependent vasodilators acetylcholine (ACh) and SLIGRL stimulated conducted dilation and whether this was altered by deficiency in apolipoprotein E (ApoE(-/-)). METHODS AND RESULTS Isolated mesenteric arteries were cannulated, pressurized, and precontracted with phenylephrine. Agonists were either added to the bath to study local dilation or were restricted to one end of arteries to study conducted dilation. An enhanced sensitivity to both ACh and SLIGRL was observed in mesenteric arteries from ApoE(-/-) mice compared with wild-type controls. Inhibition of nitric oxide (NO) synthase blocked ACh responses, but had no effect on maximum dilation to SLIGRL. SLIGRL increased endothelial cell Ca(2+), hyperpolarized smooth muscle cells, and fully dilated arteries. The NO-independent dilation to SLIGRL was blocked with high [KCl] or Ca(2+)-activated K(+)-channel blockers. The hyperpolarization and dilation to SLIGRL passed through the artery to at least 2.5 mm upstream. The conducted dilation was not affected by a deficit in ApoE and could also be stimulated by ACh, suggesting NO itself could stimulate conducted dilation. CONCLUSION In small mesenteric arteries of ApoE(-/-) mice, NO-independent dilation is enhanced. Since both NO-dependent and -independent pathways can stimulate local and conducted dilation, the potential for reducing vascular resistance is improved in these vessels.
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Affiliation(s)
- Timea Beleznai
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
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