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Schiffrin EL, Pollock DM. Endothelin System in Hypertension and Chronic Kidney Disease. Hypertension 2024; 81:691-701. [PMID: 38059359 PMCID: PMC10954415 DOI: 10.1161/hypertensionaha.123.21716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
ET (endothelin) is a powerful vasoconstrictor 21-amino acid peptide present in many tissues, which exerts many physiological functions across the body and participates as a mediator in many pathological conditions. ETs exert their effects through ETA and ETB receptors, which can be blocked by selective receptor antagonists. ETs were shown to play important roles among others, in systemic hypertension, particularly when resistant or difficult to control, and in pulmonary hypertension, atherosclerosis, cardiac hypertrophy, subarachnoid hemorrhage, chronic kidney disease, diabetic cardiovascular disease, scleroderma, some cancers, etc. To date, ET antagonists are only approved for the treatment of primary pulmonary hypertension and recently for IgA nephropathy and used in the treatment of digital ulcers in scleroderma. However, they may soon be approved for the treatment of patients with resistant hypertension and different types of nephropathy. Here, the role of ETs is reviewed with a special emphasis on participation in and treatment of hypertension and chronic kidney disease.
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Affiliation(s)
- Ernesto L. Schiffrin
- Lady Davis Institute for Medical Research, and Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital, McGill University
| | - David M. Pollock
- Section of Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL
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Billaud M, Chiu YH, Lohman AW, Parpaite T, Butcher JT, Mutchler SM, DeLalio LJ, Artamonov MV, Sandilos JK, Best AK, Somlyo AV, Thompson RJ, Le TH, Ravichandran KS, Bayliss DA, Isakson BE. A molecular signature in the pannexin1 intracellular loop confers channel activation by the α1 adrenoreceptor in smooth muscle cells. Sci Signal 2015; 8:ra17. [PMID: 25690012 DOI: 10.1126/scisignal.2005824] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Both purinergic signaling through nucleotides such as ATP (adenosine 5'-triphosphate) and noradrenergic signaling through molecules such as norepinephrine regulate vascular tone and blood pressure. Pannexin1 (Panx1), which forms large-pore, ATP-releasing channels, is present in vascular smooth muscle cells in peripheral blood vessels and participates in noradrenergic responses. Using pharmacological approaches and mice conditionally lacking Panx1 in smooth muscle cells, we found that Panx1 contributed to vasoconstriction mediated by the α1 adrenoreceptor (α1AR), whereas vasoconstriction in response to serotonin or endothelin-1 was independent of Panx1. Analysis of the Panx1-deficient mice showed that Panx1 contributed to blood pressure regulation especially during the night cycle when sympathetic nervous activity is highest. Using mimetic peptides and site-directed mutagenesis, we identified a specific amino acid sequence in the Panx1 intracellular loop that is essential for activation by α1AR signaling. Collectively, these data describe a specific link between noradrenergic and purinergic signaling in blood pressure homeostasis.
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Affiliation(s)
- Marie Billaud
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yu-Hsin Chiu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Alexander W Lohman
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Thibaud Parpaite
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Joshua T Butcher
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Stephanie M Mutchler
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Leon J DeLalio
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Mykhaylo V Artamonov
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Joanna K Sandilos
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Angela K Best
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Avril V Somlyo
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Roger J Thompson
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Thu H Le
- Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Kodi S Ravichandran
- Center for Cell Clearance, University of Virginia, Charlottesville, VA 22908, USA. Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA. Beirne B. Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA 22908, USA. Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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3
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Compeer MG, Janssen GMJ, De Mey JGR. Endothelin-1 and endothelin-2 initiate and maintain contractile responses by different mechanisms in rat mesenteric and cerebral arteries. Br J Pharmacol 2014; 170:1199-209. [PMID: 23941276 DOI: 10.1111/bph.12332] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/29/2013] [Accepted: 08/01/2013] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Endothelin (ET)-1 and ET-2 cause potent long-lasting vasoconstrictions by tight binding to smooth muscle ETA receptors. We tested the hypotheses that different mechanisms mediate initiation and maintenance of arterial contractile responses to ET-1 and ET-2 and that this differs among vascular beds. EXPERIMENTAL APPROACH Segments of rat mesenteric resistance artery (MRA) and basilar artery (BA) were studied in wire myographs with and without functional antagonists. KEY RESULTS Sensitivity and maximum of MRA contractile responses to ET-1 were not, or only moderately, reduced by stimulation of soluble GC, AC or K(+) -channels and by an inhibitor of receptor-operated ion channels. However, each of these reduced maintenance of ET-1 effects and relaxed ET-1-induced contractions in MRA. A calcium channel antagonist did not alter sensitivity, maximum and maintenance of ET-1 effects, but relaxed ET-1-induced contractions in MRA. A PLC inhibitor prevented contractile responses to ET-1 and ET-2 in MRA and BA, and relaxed ET-1- and ET-2-induced responses in MRA and ET-1 effects in BA. A Rho-kinase inhibitor did not modify sensitivity, maximum and maintenance of responses to both peptides in both arteries but relaxed ET-2, but not ET-1, effects in MRA and ET-1 effects in BA. CONCLUSIONS AND IMPLICATIONS PLC played a key role in arterial contractile responses to ETs, but ET-1 and ET-2 initiated and maintained vasoconstriction through different mechanisms, and these differed between MRA and BA. Selective functional antagonism may be considered for agonist- and vascular bed selective pharmacotherapy of ET-related diseases.
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Affiliation(s)
- M G Compeer
- Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
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4
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Yoon N, Lteif AA, Han K, Mather KJ. Endothelin contributes differently to peripheral vascular tone and blood pressure in human obesity and diabetes. ACTA ACUST UNITED AC 2008; 2:182-91. [DOI: 10.1016/j.jash.2007.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 10/05/2007] [Accepted: 10/10/2007] [Indexed: 01/08/2023]
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Wendel M, Kummer W, Knels L, Schmeck J, Koch T. Muscular ETB receptors develop postnatally and are differentially distributed in specific segments of the rat vasculature. J Histochem Cytochem 2005; 53:187-96. [PMID: 15684331 DOI: 10.1369/jhc.4a6474.2005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The endothelin/endothelin-receptor system is a key player in the regulation of vascular tone in mammals. We raised and characterized an antiserum against rat ETB receptor and investigated the distribution of ETB receptors in different vascular beds during postnatal development (day 0 through day 28) and in the adult rat. We report the tissue-specific and age-dependent presence of vasoconstrictor ETB receptors. At the time of birth, vascular smooth muscle cells from all tissues examined did not exhibit ETB receptor immunoreactivity. The occurrence of ETB receptor immunoreactivity in the postnatal development was time dependent and started in small coronary and meningeal arteries at day 5, followed by small mesenteric arteries as well as brachial artery and vein at day 14. At day 21, ETB receptors were present in the media of muscular segments of pulmonary artery, large coronary arteries, and intracerebral arterioles. At day 28, ETB receptor immunoreactivity was evident in interlobular renal arteries, vas afferens, and efferens. Large renal arteries, mesenteric artery, and elastic segments of pulmonary arteries, as well as coronary and mesenteric veins, did not exhibit ETB receptor immunoreactivity. These data demonstrate the age-dependent and tissue-specific presence of ETB receptors, mainly on arterial smooth muscle cells in the vascular system of the rat.
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Affiliation(s)
- Martina Wendel
- Department of Anesthesiology and Intensive Care Medicine, Technical University of Dresden, Dresden, Germany.
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Claing A, Shbaklo H, Plante M, Bkaily G, D'Orléans-Juste P. Comparison of the contractile and calcium-increasing properties of platelet-activating factor and endothelin-1 in the rat mesenteric artery and vein. Br J Pharmacol 2002; 135:433-43. [PMID: 11815379 PMCID: PMC1573133 DOI: 10.1038/sj.bjp.0704441] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In the present study, the properties of endothelin-1 (ET-1) and platelet-activating factor (PAF) in inducing contraction and increased intracellular-free calcium level in rat mesenteric arteries and veins were studied. Furthermore, measurements of cytosolic ([Ca](c)) and nuclear ([Ca](n)) Ca(2+) were performed by confocal microscopy. PAF, at a concentration of 1 microM, and the selective ET(B) agonists, IRL-1620 and sarafotoxin S6C (100 nM), induced a marked constriction and increase in [Ca](i) in the mesenteric vein but not in the artery. On the other hand, endothelin-1 (1 - 100 nM) induced a significant concentration-dependent nifedipine-insensitive increase in tension and [Ca](i) in both arteries and veins. Those responses to endothelin-1 were significantly reduced by the ET(A) receptor antagonist, BQ-123 (10(-6) M), on both types of vessels, whereas the selective ET(B) receptor antagonist, BQ-788, inhibited only the venous responses. The mixed ET(A)/ET(B) receptor antagonist, SB 209670, reduced the ET-1-induced venous responses to the same level of that found in presence of BQ-123 or BQ-788. However, concomitant applications of BQ-123 and BQ-788 reduced the vasoconstriction below to that induced by ET(A) or ET(B) blockade without further affecting [Ca](i). PAF and the selective ET(B) agonists IRL-1620, induced a sustained increase of [Ca](c) and [Ca](n) solely in venous cells and ET-1 in both arterial and venous smooth muscle cells. Thus, PAF increases total intracellular calcium concentration and tension on the smooth muscle cells from venous origin only. Furthermore, ET-1-induced vasoactive as well as [Ca](i) and [Ca](n) increasing effects are mediated by distinct receptors on venous and arterial smooth muscles.
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MESH Headings
- Animals
- Calcium/metabolism
- Cells, Cultured
- Dose-Response Relationship, Drug
- Endothelin Receptor Antagonists
- Endothelin-1/pharmacology
- Endothelin-1/physiology
- Male
- Mesenteric Arteries/cytology
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/physiology
- Mesenteric Veins/cytology
- Mesenteric Veins/drug effects
- Mesenteric Veins/physiology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Platelet Activating Factor/pharmacology
- Platelet Activating Factor/physiology
- Rats
- Rats, Wistar
- Receptor, Endothelin A
- Receptor, Endothelin B
- Receptors, Endothelin/agonists
- Receptors, Endothelin/physiology
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
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Affiliation(s)
- Audrey Claing
- CIHR Group in Immuno-Cardiovascular Interaction, Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke (Québec) J1H 5N4, Canada
| | - Hadia Shbaklo
- CIHR Group in Immuno-Cardiovascular Interaction, Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke (Québec) J1H 5N4, Canada
| | - Mirco Plante
- CIHR Group in Immuno-Cardiovascular Interaction, Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke (Québec) J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke (Québec) J1H 5N4, Canada
| | - Pedro D'Orléans-Juste
- CIHR Group in Immuno-Cardiovascular Interaction, Department of Pharmacology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke (Québec) J1H 5N4, Canada
- Author for correspondence:
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Moreau P, Dao HH. An update on the status of endothelin receptor antagonists for hypertension. Expert Opin Investig Drugs 2001; 10:1937-46. [PMID: 11772297 DOI: 10.1517/13543784.10.11.1937] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Endothelin receptor antagonists (ETRA) are actively developed by the pharmaceutical industry for several cardiovascular indications. In the context of hypertension, preclinical studies are increasingly focused on prevention or regression of end-organ damage and drug combination than on control of arterial pressure in monotherapy, as most experimental models have already been studied. In general, the antihypertensive effect of ETRA is limited but the overwhelming efficacy of this class of drugs to prevent several end-organ damages warrants judicious combination. However, the few studies looking at regression of hypertension-induced cardiovascular alterations proved less successful, suggesting that ETRA should be used early in the treatment of hypertension to obtain full benefit. Judging from the progression of ongoing trials and the development of new trials patients suffering from pulmonary hypertension and heart failure may be the first to benefit from this new class of drugs. However, it is expected that once on the market, responsive subsets of hypertensive patients will be identified and will benefit from end-organ protection.
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Affiliation(s)
- P Moreau
- Laboratory of Vascualar Pharmacology, Faculty of Pharmacy, Université de Montréal, P.O. Box 6128, Stn 'Centre-ville,' Montréal, Quebec, H3C 3J7, Canada.
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Rizzoni D, Porteri E, Guelfi D, Muiesan ML, Piccoli A, Valentini U, Cimino A, Girelli A, Salvetti M, De Ciuceis C, Tiberio GA, Giulini SM, Sleiman I, Monteduro C, Rosei EA. Endothelial dysfunction in small resistance arteries of patients with non-insulin-dependent diabetes mellitus. J Hypertens 2001; 19:913-9. [PMID: 11393675 DOI: 10.1097/00004872-200105000-00012] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Arterial hypertension is frequently associated with the presence of endothelial dysfunction in human subcutaneous small resistance arteries, as evaluated by responses to acetylcholine or bradykinin; however it is not known whether patients with diabetes mellitus show similar alterations. Therefore, we have investigated endothelial function in subcutaneous arteries of normotensive subjects (NT), of patients with essential hypertension (EH), of patients with non-insulin-dependent diabetes mellitus (NIDDM), as well as of patients with both essential hypertension and non-insulin-dependent diabetes mellitus (NIDDM+EH). PATIENTS AND METHODS All subjects were submitted to a biopsy of the subcutaneous fat Small arteries were dissected and mounted on a micromyograph. The media to lumen ratio (M/L) was calculated. A concentration-response curve to acetylcholine, to bradykinin as well as to the endothelium-independent vasodilator sodium nitroprusside were performed. We also evaluated the contractile response to endothelin-1. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) plasma levels were also measured. RESULTS The vasodilatation to acetylcholine and bradykinin (but not to sodium nitroprusside) was significantly and similarly reduced in EH, in NIDDM, and in NIDDM+EH compared with NT. The contractile response to endothelin-1 was similarly reduced in EH, in NIDDM and in NIDDM+EH. Plasma ICAM-1 and VCAM-1 concentrations were higher in EH, NIDDM and NIDDM+EH than in NT. CONCLUSIONS An evident endothelial dysfunction was detected in patients with NIDDM, and the simultaneous presence of EH did not seem to exert an additive effect. The contractile responses to endothelin-1 were reduced possibly as a consequence of ET(A) receptor down-regulation.
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Affiliation(s)
- D Rizzoni
- Chair of Internal Medicine Department of Medical and Surgical Sciences, University of Brescia, Italy.
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Rizzoni D, Porteri E, Guelfi D, Muiesan ML, Valentini U, Cimino A, Girelli A, Rodella L, Bianchi R, Sleiman I, Rosei EA. Structural alterations in subcutaneous small arteries of normotensive and hypertensive patients with non-insulin-dependent diabetes mellitus. Circulation 2001; 103:1238-44. [PMID: 11238267 DOI: 10.1161/01.cir.103.9.1238] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND It is not presently known whether non-insulin-dependent diabetes mellitus (NIDDM) is associated with the presence of structural alterations in small arteries or whether the combination of hypertension and NIDDM may have an additive effect on endothelial dysfunction. Therefore, we investigated subcutaneous small arteries in 12 normotensive subjects (NT group), 18 patients with essential hypertension (EH group), 13 patients with NIDDM, and 11 patients with NIDDM and EH (NIDDM+EH group). METHODS AND RESULTS Subcutaneous small arteries were evaluated by a micromyographic technique. The internal diameter, the media-to-lumen ratio, remodeling and growth indices, and the collagen-to-elastin ratio were calculated. Concentration-response curves to acetylcholine, bradykinin, the endothelium-independent vasodilator sodium nitroprusside, and endothelin-1 were performed. The media-to-lumen ratio was higher in the EH, NIDDM, and NIDDM+EH groups compared with the NT group. EH patients showed the presence of eutrophic remodeling, whereas NIDDM and NIDDM+EH patients showed 40% to 46% cell growth. The collagen-to-elastin ratio was significantly increased in the EH and NIDDM+EH groups compared with the NT group. The vasodilatation to acetylcholine and bradykinin was similarly reduced in EH, NIDDM, and NIDDM+EH groups compared with the NT group. The contractile responses to endothelin-1 were similarly reduced in EH, NIDDM, and NIDDM+EH patients. CONCLUSIONS Our data suggest that the effects of NIDDM and EH on small artery morphology are quantitatively similar but qualitatively different and that the presence of hypertension in diabetic patients has little additive effect on small artery morphology and none on endothelial dysfunction.
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Affiliation(s)
- D Rizzoni
- Internal Medicine, Department of Medical and Surgical Sciences, University of Brescia, Spedali Civili di Brescia, Italy.
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Johnson RJ, Galligan JJ, Fink GD. Effect of an ET(B)-selective and a mixed ET(A/B) endothelin receptor antagonist on venomotor tone in deoxycorticosterone-salt hypertension. J Hypertens 2001; 19:431-40. [PMID: 11288813 DOI: 10.1097/00004872-200103000-00011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Because the ET(B) receptor is important in venoconstriction, we examined the effects of a selective ET(B) receptor antagonist (A-1 92621) and a mixed ET(A/B) receptor antagonist (A-182086) on endogenous endothelin-1 (ET-1) contributions to elevated venomotor tone in deoxycorticosterone acetate-salt (DOCA-salt) hypertension. METHODS Changes in venomotor tone were assessed using repeated measurements of mean circulatory filling pressure (MCFP) in awake, uninephrectomized, DOCA-salt-treated rats and uninephrectomized sham rats following intravenous (i.v.) injections of the ET(B) antagonist (12 mg/kg i.v.) or the ET(A/B) antagonist (12 mg/kg i.v.) alone, or 1 h before ganglion blockade with hexamethonium (30 mg/kg i.v.). RESULTS DOCA-salt rats were hypertensive and exhibited higher MCFP than sham normotensive rats. The ET(A/B) receptor antagonist lowered mean arterial blood pressure (MABP) in DOCA-salt and sham rats, but MCFP fell in DOCA-salt rats only. The ET(B) antagonist produced no changes in MCFP while MABP increased in both groups. Pre-treatment of DOCA-salt rats, but not sham rats, with either antagonist produced greater declines in MCFP following hexamethonium than after hexamethonium alone. CONCLUSIONS The present study confirms previous findings of elevated MCFP in DOCA-salt hypertensive rats compared to normotensive rats, but is the first to show that venomotor tone is affected by the actions of endogenous ET-1 acting at ET(B) receptors to modulate sympathetic input to the veins, as well as direct actions of ET-1 on vascular smooth muscle (VSM) ET(A) receptors. We also showed that mixed ET(A/B) receptor antagonism was effective in lowering MCFP and MABP in DOCA-salt hypertensive rats.
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Affiliation(s)
- R J Johnson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing 48824, USA.
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11
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Dieye AM, Van Overloop B, Gairard A. Endothelin-1 and relaxation of the rat aorta during pregnancy in nitroarginine-induced hypertension. Fundam Clin Pharmacol 1999; 13:204-12. [PMID: 10226765 DOI: 10.1111/j.1472-8206.1999.tb00340.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In pregnant rats during hypertension induced by NO synthase inhibition, endothelin (ET) plasma levels are increased as in some preeclamptic women. Previously, the enhanced vasodepressor effect of endothelin-1 (ET-1) has been observed in this model, thus we decided to study the relaxation induced by ET-1 on the aorta. Non-pregnant or pregnant Wistar rats (n = 7 by group) were fed for 7 days (day 13-day 20) on a nitroarginine-enriched diet (L-NNA, 0.063% i.e. 30 mg/kg/day) or a control diet. Systolic blood pressure, measured by the tail cuff method on conscious rats at day 20 of gestation, was raised by the chronic L-NNA treatment (mean +/- s.e.m., mmHg, p < 0.001: pregnant L-NNA treated, 145 +/- 1.84 vs. pregnant control, 101 +/- 2.00 and non-pregnant L-NNA treated, 148 +/- 3.11 vs. non-pregnant control, 119 +/- 1.80). On day 20 ex vivo aortic ring relaxation was produced by ET-1 in vessels previously precontracted with norepinephrine only when endothelium was present. In control rats, ET-1 (10(-8) to 5 x 10(-8) M) produced a short but significant relaxation (mean value between 4 to 19%) followed by a long-lasting contracting phase, and a higher ET-1 concentration (10(-7) M) only produced contraction. Chronic L-NNA treatment decreased the level of relaxation (at least p < 0.05, in non-pregnant and pregnant rats) and with a 30 min L-NAME (10(-4) M) preincubation, relaxation was completely inhibited in non-pregnant and pregnant rats. BQ-123, an ETA receptor antagonist, did not produce any effect on ET-1 induced relaxation. BQ-788, an ETB receptor antagonist, significantly decreased it. In conclusion, in female rats, as in male rats, ET-1 induces a transient relaxation in the preconstricted aorta which involves endothelial ETB receptors. Despite a decrease in the systemic vascular reactivity during late gestation, the vasodilating and vasoconstricting properties of ET-1 on the aorta are not changed.
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Affiliation(s)
- A M Dieye
- Laboratoire de Pharmacologie et Physiopathologie Cellulaires, CNRS ERS 653, Université Louis Pasteur, Faculté de Pharmacie, Illkirch, France
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