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Palacios-Ramírez R, Hernanz R, Martín A, Pérez-Girón JV, Barrús MT, González-Carnicero Z, Aguado A, Jaisser F, Briones AM, Salaices M, Alonso MJ. Pioglitazone Modulates the Vascular Contractility in Hypertension by Interference with ET-1 Pathway. Sci Rep 2019; 9:16461. [PMID: 31712626 PMCID: PMC6848177 DOI: 10.1038/s41598-019-52839-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 09/11/2019] [Indexed: 02/07/2023] Open
Abstract
Endothelin-1 (ET-1) is an important modulator of the vascular tone and a proinflammatory molecule that contributes to the vascular damage observed in hypertension. Peroxisome-proliferator activated receptors-γ (PPARγ) agonists show cardioprotective properties by decreasing inflammatory molecules such as COX-2 and reactive oxygen species (ROS), among others. We investigated the possible modulatory effect of PPARγ activation on the vascular effects of ET-1 in hypertension. In spontaneously hypertensive rats (SHR), but not in normotensive rats, ET-1 enhanced phenylephrine-induced contraction through ETA by a mechanism dependent on activation of TP receptors by COX-2-derived prostacyclin and reduction in NO bioavailability due to enhanced ROS production. In SHR, the PPARγ agonist pioglitazone (2.5 mg/Kg·day, 28 days) reduced the increased ETA levels and increased those of ETB. After pioglitazone treatment of SHR, ET-1 through ETB decreased ROS levels that resulted in increased NO bioavailability and diminished phenylephrine contraction. In vascular smooth muscle cells from SHR, ET-1 increased ROS production through AP-1 and NFκB activation, leading to enhanced COX-2 expression. These effects were blocked by pioglitazone. In summary, in hypertension, pioglitazone shifts the vascular ETA/ETB ratio, reduces ROS/COX-2 activation and increases NO availability; these changes explain the effect of ET-1 decreasing phenylephrine-induced contraction.
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Affiliation(s)
- Roberto Palacios-Ramírez
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain.,Institut National de la Santé et de la Recherche Médicale Inserm U1138, Cordeliers Institute, Paris VI-University, Paris, France
| | - Raquel Hernanz
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - Angela Martín
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - José V Pérez-Girón
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain
| | - María T Barrús
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - Zoe González-Carnicero
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain
| | - Andrea Aguado
- Depto. de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPaz), Madrid, Spain
| | - Frederic Jaisser
- Institut National de la Santé et de la Recherche Médicale Inserm U1138, Cordeliers Institute, Paris VI-University, Paris, France
| | - Ana M Briones
- CIBER de Enfermedades Cardiovasculares, Madrid, Spain.,Depto. de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPaz), Madrid, Spain
| | - Mercedes Salaices
- CIBER de Enfermedades Cardiovasculares, Madrid, Spain.,Depto. de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPaz), Madrid, Spain
| | - María J Alonso
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain. .,CIBER de Enfermedades Cardiovasculares, Madrid, Spain.
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2
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Pialoux V, Poulin MJ, Hemmelgarn BR, Muruve DA, Chirico EN, Faes C, Sola DY, Ahmed SB. Cyclooxygenase-2 Inhibition Limits Angiotensin II-Induced DNA Oxidation and Protein Nitration in Humans. Front Physiol 2017; 8:138. [PMID: 28344559 PMCID: PMC5344903 DOI: 10.3389/fphys.2017.00138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 02/23/2017] [Indexed: 01/03/2023] Open
Abstract
Compared to other cyclooxygenase-2 inhibitors, celecoxib is associated with a lower cardiovascular risk, though the mechanism remains unclear. Angiotensin II is an important mediator of oxidative stress in the pathophysiology of vascular disease. Cyclooxygenase-2 may modify the effects of angiotensin II though this has never been studied in humans. The purpose of the study was to test the effects of selective cyclooxygenase-2 inhibition on plasma measures of oxidative stress, the vasoconstrictor endothelin-1, and nitric oxide metabolites, both at baseline and in respose to Angiotensin II challenge in healthy humans. Measures of 8-hydroxydeoxyguanosine, advanced oxidation protein products, nitrotyrosine, endothelin-1, and nitric oxide metabolites were assessed from plasma samples drawn at baseline and in response to graded angiotensin II infusion (3 ng/kg/min × 30 min, 6 ng/kg/min × 30 min) before and after 14 days of cyclooxygenase-2 inhibition in 14 healthy subjects (eight male, six female) in high salt balance, a state of maximal renin angiotensin system suppression. Angiotensin II infusion significantly increased plasma oxidative stress compared to baseline (8-hydroxydeoxyguanosine; +17%; advanced oxidation protein products; +16%), nitrotyrosine (+76%). Furthermore, levels of endothelin-1 levels were significantly increased (+115%) and nitric oxide metabolites were significantly decreased (−20%). Cycloxygenase-2 inhibition significantly limited the increase in 8-hydroxydeoxyguanosine, nitrotyrosine and the decrease in nitric oxide metabolites induced by angiotensin II infusion, though no changes in advanced oxidation protein products and endothelin-1 concentrations were observed. Cyclooxygenase-2 inhibition with celecoxib partially limited the angiotensin II-mediated increases in markers of oxidative stress in humans, offering a potential physiological pathway for the improved cardiovascular risk profile of this drug.
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Affiliation(s)
- Vincent Pialoux
- Laboratoire Interuniversitaire de Biologie de la Motricité EA7424, Université de Lyon, Université Claude Bernard Lyon 1 Villeurbanne, France
| | - Marc J Poulin
- Faculty of Medicine, Hotchkiss Brain Institute, University of CalgaryCalgary, AB, Canada; Department of Physiology and Pharmacology, Faculty of Medicine, University of CalgaryCalgary, AB, Canada; Faculty of Medicine, Libin Cardiovascular Institute of Alberta, University of CalgaryCalgary, AB, Canada; Department of Clinical Neurosciences, Cumming School of Medicine, University of CalgaryCalgary, AB, Canada; Faculty of Kinesiology, University of CalgaryCalgary, AB, Canada
| | - Brenda R Hemmelgarn
- Faculty of Medicine, Libin Cardiovascular Institute of Alberta, University of CalgaryCalgary, AB, Canada; Department of Medicine, Faculty of Medicine, University of CalgaryCalgary, AB, Canada
| | - Daniel A Muruve
- Department of Medicine, Faculty of Medicine, University of Calgary Calgary, AB, Canada
| | - Erica N Chirico
- Laboratoire Interuniversitaire de Biologie de la Motricité EA7424, Université de Lyon, Université Claude Bernard Lyon 1Villeurbanne, France; Department of Biomedical Sciences, Cooper Medical School of Rowan UniversityCamden, NJ, USA
| | - Camille Faes
- Laboratoire Interuniversitaire de Biologie de la Motricité EA7424, Université de Lyon, Université Claude Bernard Lyon 1 Villeurbanne, France
| | - Darlene Y Sola
- Faculty of Medicine, Libin Cardiovascular Institute of Alberta, University of CalgaryCalgary, AB, Canada; Department of Medicine, Faculty of Medicine, University of CalgaryCalgary, AB, Canada
| | - Sofia B Ahmed
- Faculty of Medicine, Libin Cardiovascular Institute of Alberta, University of CalgaryCalgary, AB, Canada; Department of Medicine, Faculty of Medicine, University of CalgaryCalgary, AB, Canada
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3
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Pérez-Girón JV, Palacios R, Martín A, Hernanz R, Aguado A, Martínez-Revelles S, Barrús MT, Salaices M, Alonso MJ. Pioglitazone reduces angiotensin II-induced COX-2 expression through inhibition of ROS production and ET-1 transcription in vascular cells from spontaneously hypertensive rats. Am J Physiol Heart Circ Physiol 2014; 306:H1582-93. [PMID: 24727493 DOI: 10.1152/ajpheart.00924.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glitazones have anti-inflammatory properties by interfering with the transcription of proinflammatory genes, such as cyclooxygenase (COX)-2, and with ROS production, which are increased in hypertension. This study analyzed whether pioglitazone modulates COX-2 expression in hypertension by interfering with ROS and endothelin (ET)-1. In vivo, pioglitazone (2.5 mg·kg(-1)·day(-1), 28 days) reduced the greater levels of COX-2, pre-pro-ET-1, and NADPH oxidase (NOX) expression and activity as well as O2 (·-) production found in aortas from spontaneously hypertensive rats (SHRs). ANG II increased COX-2 and pre-pro-ET-1 levels more in cultured vascular smooth muscle cells from hypertensive rats compared with normotensive rats. The ETA receptor antagonist BQ-123 reduced ANG II-induced COX-2 expression in SHR cells. ANG II also increased NOX-1 expression, NOX activity, and superoxide production in SHR cells; the selective NOX-1 inhibitor ML-171 and catalase reduced ANG II-induced COX-2 and ET-1 transcription. ANG II also increased c-Jun transcription and phospho-JNK1/2, phospho-c-Jun, and p65 NF-κB subunit nuclear protein expression. SP-600125 and lactacystin, JNK and NF-κB inhibitors, respectively, reduced ANG II-induced ET-1, COX-2, and NOX-1 levels and NOX activity. Pioglitazone reduced the effects of ANG II on NOX activity, NOX-1, pre-pro-ET-1, COX-2, and c-Jun mRNA levels, JNK activation, and nuclear phospho-c-Jun and p65 expression. In conclusion, ROS production and ET-1 are involved in ANG II-induced COX-2 expression in SHRs, explaining the greater COX-2 expression observed in this strain. Furthermore, pioglitazone inhibits ANG II-induced COX-2 expression likely by interfering with NF-κB and activator protein-1 proinflammatory pathways and downregulating ROS production and ET-1 transcription, thus contributing to the anti-inflammatory properties of glitazones.
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Affiliation(s)
- Jose V Pérez-Girón
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Alcorcón, Spain; and
| | - Roberto Palacios
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Alcorcón, Spain; and
| | - Angela Martín
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Alcorcón, Spain; and
| | - Raquel Hernanz
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Alcorcón, Spain; and
| | - Andrea Aguado
- Departamento de Farmacología, Universidad Autónoma de Madrid, Instituto de Investigación Hospital Universitario La Paz, Madrid, Spain
| | - Sonia Martínez-Revelles
- Departamento de Farmacología, Universidad Autónoma de Madrid, Instituto de Investigación Hospital Universitario La Paz, Madrid, Spain
| | - María T Barrús
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Alcorcón, Spain; and
| | - Mercedes Salaices
- Departamento de Farmacología, Universidad Autónoma de Madrid, Instituto de Investigación Hospital Universitario La Paz, Madrid, Spain
| | - María J Alonso
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Alcorcón, Spain; and
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Houde M, Jamain MD, Labonté J, Desbiens L, Pejler G, Gurish M, Takai S, D'Orléans-Juste P. Pivotal role of mouse mast cell protease 4 in the conversion and pressor properties of Big-endothelin-1. J Pharmacol Exp Ther 2013; 346:31-7. [PMID: 23596057 DOI: 10.1124/jpet.112.202275] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The serine protease chymase has been reported to generate intracardiac angiotensin-II (Ang-II) from Ang-I as well as an intermediate precursor of endothelin-1 (ET-1), ET-1 (1-31) from Big-ET-1. Although humans possess only one chymase, several murine isoforms are documented, each with its own specific catalytic activity. Among these, mouse mast cell protease 4 (mMCP-4) is the isoform most similar to the human chymase for its activity. The aim of this study was to characterize the capacity of mMCP-4 to convert Big-ET-1 into its bioactive metabolite, ET-1, in vitro and in vivo in the mouse model. Basal mean arterial pressure did not differ between wild-type (WT) and mMCP-4(-/-) mice. Systemic administration of Big-ET-1 triggered pressor responses and increased blood levels of immunoreactive (IR) ET-1 (1-31) and ET-1 that were reduced by more than 50% in mMCP-4 knockout (-/-) mice compared with WT controls. Residual responses to Big-ET-1 in mMCP-4(-/-) mice were insensitive to the enkephalinase/neutral endopeptidase inhibitor thiorphan and the specific chymase inhibitor TY-51469 {2-[4-(5-fluoro-3-methylbenzo[b]thiophen-2-yl)sulfonamido-3-methanesulfonylphenyl]thiazole-4-carboxylic acid}. Soluble fractions from the lungs, left cardiac ventricle, aorta, and kidneys of WT but not mMCP-4(-/-) mice generated ET-1 (1-31) from exogenous Big-ET-1 in a TY-51469-sensitive fashion as detected by high-performance liquid chromatography/ matrix-assisted laser desorption/ionization-mass spectrometry. Finally, pulmonary endogenous levels of IR-ET-1 were reduced by more than 40% in tissues derived from mMCP-4(-/-) mice compared with WT mice. Our results show that mMCP-4 plays a pivotal role in the dynamic conversion of systemic Big-ET-1 to ET-1 in the mouse model.
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Affiliation(s)
- Martin Houde
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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5
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Angiotensin II contributes to the increased baseline leg vascular resistance in spinal cord-injured individuals. J Hypertens 2010; 28:2094-101. [DOI: 10.1097/hjh.0b013e32833cd2f4] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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Biggi A, Musiari L, Iori M, De Iaco G, Magnani G, Pelloni I, Pinelli S, Pelà GM, Novarini A, Cabassi A, Montanari A. Contribution of bradykinin B2 receptors to the inhibition by valsartan of systemic and renal effects of exogenous angiotensin II in salt-repleted humans. J Pharmacol Exp Ther 2010; 334:911-6. [PMID: 20504911 DOI: 10.1124/jpet.110.166942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
To investigate whether bradykinin (BK) participates in the inhibition of renal effects of exogenous angiotensin II (AngII) by AngII type 1 receptor (AT1R) blockade, eight salt-repleted volunteers underwent four p-aminohippurate- and inulin-based renal studies of AngII infusion at increasing rates of 0.625, 1.25, and 2.5 ng.kg.min(-1) for 30 min. Studies 1 and 2 were preceded by 3 days of placebo, whereas studies 3 and 4 used 240 to 320 mg.day(-1) valsartan. Bradykinin B2-type receptor (BKB2R) antagonist icatibant (50 mug.kg(-1)) was coinfused in studies 2 and 4. Mean blood pressure (MBP), glomerular filtration rate (GFR), renal blood flow (RBF), and renal sodium excretion (UNaV) were measured. In study 1, MBP rose by 12.8%, UNaV decreased by 68%, and GFR and RBF also fell (p < 0.001 for all). In study 2, GFR and RBF fell as in study 1, but the rise in MBP and the fall in UNaV were accentuated [+20.0%, analysis of variance (ANOVA), p < 0.02 versus study 1 and -80.0%, p < 0.05, respectively]. In study 3, AngII had no effects, and in study 4, renal hemodynamics remained unaffected, but MBP still rose and UNaV fell (ANOVA, p < 0.02 and 0.005 versus study 3, respectively). Icatibant accentuated AngII-induced changes in MBP and UNaV. Previous AT1R blockade prevented any systemic and renal effects of AngII, but significant changes in MBP and UNaV still followed AngII plus icatibant even after AT1R blockade. BK, through BKB2Rs, participates in the inhibitory action of AT1R blockers toward actions of exogenous AngII on MBP and UNaV in healthy humans.
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Affiliation(s)
- Almerina Biggi
- Department of Clinical Sciences, University of Parma Medical School, Parma, Italy
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7
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8
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Gupta R, Mohanan A, Joshi D. Development and Validation of a Rat Model for Examining the AT1 and ETA Receptor-Blocking Activity of Dual AT1 and ETA Receptor Blockers. High Blood Press Cardiovasc Prev 2009. [DOI: 10.2165/00151642-200916020-00002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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9
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D'Orléans-Juste P, Houde M, Rae G, Bkaily G, Carrier E, Simard E. Endothelin-1 (1–31): From chymase-dependent synthesis to cardiovascular pathologies. Vascul Pharmacol 2008; 49:51-62. [DOI: 10.1016/j.vph.2008.06.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 06/30/2008] [Indexed: 12/11/2022]
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Sudano I, Hermann M, Ruschitzka FT. Endothelin-receptor antagonists in arterial hypertension: Further indications? Curr Hypertens Rep 2007; 9:59-65. [PMID: 17362673 DOI: 10.1007/s11906-007-0011-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Endothelin-1 exerts vasoactive, pro-inflammatory, hypertrophic, and profibrotic properties on the heart, kidney, and blood vessels. Hence, endothelin-receptor antagonists hold the potential to reduce blood pressure and to prevent complications of hypertension, atherosclerosis, and diabetes through blood pressure-independent effects on cardiovascular growth, inflammation, and fibrosis. These potentially important effects of endothelin antagonism may contribute to its therapeutic potential in hypertension and other cardiovascular disorders, including chronic renal failure and diabetes. First clinical trial evidence demonstrates a moderate reduction in blood pressure in studies of patients with mild-to-moderate essential hypertension and patients with resistant hypertension. Future large-scale randomized clinical trials will provide more insight into whether the blood-pressure reduction and promising pleiotropic effects observed with several members of this novel class of drugs, which are already established therapy in pulmonary hypertension, will translate into clinical benefit in patients with arterial hypertension.
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Affiliation(s)
- Isabella Sudano
- Department of Cardiology, University Hospital, Rämistrasse 100, 8091 Zurich, Switzerland
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11
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Biggi A, Carra N, Cabassi A, Barilli AL, Musiari L, Iori M, De Iaco G, Azzarone M, Novarini A, Montanari A. Impaired renal haemodynamic response to L-arginine in essential hypertension: role of buffering anion and tubuloglomerular feedback. J Hypertens 2007; 25:679-88. [PMID: 17278985 DOI: 10.1097/hjh.0b013e3280117550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To investigate whether changes in tubuloglomerular feedback (TGF) dependent upon the tubular effects of buffering anions affect the renal haemodynamic response to L-arginine in healthy (control) individuals and patients with essential hypertension. METHODS Mean arterial pressure (MAP), glomerular filtration rate (GFR), renal blood flow (RBF) and fractional excretion of sodium (FENa), chloride (FECl) and lithium (FELi) were measured in 10 control individuals and 10 hypertensive patients during two 3-h infusions of 0.012 mmol/kg per min L-arginine buffered with either HCl or citric acid. RESULTS FELi, FECl and FENa increased (P < 0.001) comparably in controls and hypertensive individuals with arginine-HCl and decreased with arginine-citrate (P < 0.001). MAP was unchanged in controls with arginine-HCl and decreased by 3% with arginine-citrate (P < 0.001), and decreased in hypertensive individuals with both arginine-HCl and arginine-citrate (by 3 and 7%, respectively; P < 0.001). GFR increased with arginine-citrate in controls and hypertensive individuals (by 6.1 and 5.4%, respectively; P < 0.001), but did not change with arginine-HCl in controls and declined by 4.6% in hypertensive individuals (P < 0.05). RBF increased equally after arginine-citrate in controls and hypertensive individuals (by 34 and 33%, respectively; P < 0.001); it also increased after arginine-HCl (22 and 13%, respectively; P < 0.001), but less than after arginine-citrate (P < 0.001), and 41% less in hypertensive individuals than in controls (P < 0.001). DISCUSSION Because arginine-HCl, unlike arginine-citrate, inhibits tubular reabsorption and elicits much less renal vasodilatation than does arginine-citrate, renal haemodynamics in response to L-arginine are modulated by changes in reabsorption and TGF according to the tubular effects of the attendant anion. As renal vasodilatation in hypertensive individuals was reduced only with arginine-HCl, which activates TGF, the blunted vasodilatation of the hypertensive kidney in response to arginine-HCl reflects an exaggerated response to an activated TGF.
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Affiliation(s)
- Almerina Biggi
- Department of Clinical Sciences, University of Parma, Parma, Italy
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12
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Van de Wal RMA, Voors AA, Gansevoort RT. Urinary albumin excretion and the renin-angiotensin system in cardiovascular risk management. Expert Opin Pharmacother 2007; 7:2505-20. [PMID: 17150005 DOI: 10.1517/14656566.7.18.2505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Microalbuminuria has been shown to be a strong predictor of cardiovascular morbidity and mortality in diabetic and hypertensive patients, but also in the general population. Moreover, several reports suggest that reduction of urinary albumin excretion (UAE) is associated with improvement of cardiovascular prognosis. Reduction of UAE can be achieved by lowering arterial blood pressure, but blockers of the renin-angiotensin system (RAS) with their specific renal actions have demonstrated to be able to reduce UAE more than might be expected from reduction of blood pressure alone. Consequently, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may also provide superior cardiovascular protection, especially in subjects with higher levels of albuminuria, but evidence is still scarce. The ability of both angiotensin-converting enzyme inhibitors and angiotensin receptor blockers to reduce UAE and provide cardiovascular protection suggests that the RAS may play a central role. New developments in this area include the use of aldosterone antagonists in albuminuric/proteinuric subjects, and the development of oral renin inhibitors. Combinations of the aforementioned drugs may have the ability to fully block the RAS, potentially avoiding all detrimental effects of this hormonal cascade. However, combination therapy is expected to also increase the incidence of side effects, such as hyperkalaemia and acute renal insufficiency. The current knowledge of microalbuminuria represents the proverbial tip of the iceberg, and future studies should focus on the underlying pathophysiological mechanism of urinary albumin excretion in relation to cardiovascular protection. Only then can a better understanding of the problem be achieved and the optimal pharmacological approach be ascertained.
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Affiliation(s)
- R M A Van de Wal
- St Antonius Hospital, Department of Cardiology, Nieuwegein, The Netherlands
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13
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Castro-Chaves P, Roncon-Albuquerque R, Leite-Moreira AF. Endothelin ETA receptors and endothelium partially mediate the positive inotropic and lusitropic effects of angiotensin II. Eur J Pharmacol 2006; 544:91-6. [PMID: 16842775 DOI: 10.1016/j.ejphar.2006.06.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 06/08/2006] [Accepted: 06/12/2006] [Indexed: 10/24/2022]
Abstract
We analyzed the influence of endothelin-1 and endocardial endothelium on the myocardial effects of angiotensin-II. Angiotensin-II (10(-9)-10(-5) M) was tested in rabbit right papillary muscles in absence (Protocol-A) or presence of PD-145065 (10(-7) M; Protocol-B), BQ-123 (10(-7) M; Protocol-C) or losartan (10(-6) M; Protocol-E), as well as, after removing the endocardial endothelium with Triton X-100 0.5% (Protocol-D). In Protocol-F increasing concentrations of endothelin-1 (10(-10)-10(-8) M) were added in presence of angiotensin-II (10(-7) M) after selective removal of the endocardial endothelium. In Protocol-A, angiotensin-II had dose-dependent positive inotropic and lusitropic effects, maximal at 10(-6) M increasing 122+/-13% active tension, 117+/-16% dT/dtmax and 86+/-9% dT/dtmin. In Protocols B, C and D the inotropic and lusitropic effects of angiotensin-II were significantly attenuated. The same concentration (10(-6) M) of angiotensin-II increased respectively 48+/-11%, 59+/-27% and 72+/-16% active tension; 54+/-14%, 54+/-20% and 32+/-9% dT/dtmax; and 39+/-8%, 48+/-19% and 59+/-11% dT/dtmin; and 40+/-10%. EC(50) for active tension significantly increased from -7.8+/-0.1 logM in Protocol A to -7.1+/-0.3, -6.7+/-0.4 and -6.8+/-0.3 logM in Protocols B, C and D respectively, while Emax decreased from 106+/-14% in Protocol A to 50+/-14 and 51+/-19% in Protocols B and C respectively, but did not significantly change in Protocol D (114+/-25%). Losartan completely blocked the inotropic and lusitropic effects of angiotensin-II, while the attenuation of these effects after the selective removal of the endocardial endothelium was blunted by concomitant administration of endothelin-1 (Protocol F). In conclusion, angiotensin-II has a dose-dependent positive inotropic effect that depends, to a great extent, on endothelin ETA receptor activation and intact endocardial endothelium.
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Affiliation(s)
- Paulo Castro-Chaves
- Department of Physiology, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
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14
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Schiffrin EL. Vascular endothelin in hypertension. Vascul Pharmacol 2005; 43:19-29. [PMID: 15955745 DOI: 10.1016/j.vph.2005.03.004] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 01/17/2005] [Accepted: 03/01/2005] [Indexed: 12/31/2022]
Abstract
Endothelins are powerful vasoconstrictor peptides that also play numerous other functions in many different organs. Endothelin-1 (ET-1) is the most abundant and important of this family of peptides in blood vessels. Production of ET-1 is increased in the endothelium and the kidney in salt-dependent models of hypertension (e.g.: DOCA-salt rats and Dahl salt-sensitive rats, in salt-loaded SHR-SP, in angiotensin II-infused and in diabetic rats). ET-1 elicits an inflammatory response by increasing oxidant stress in the vascular wall, which induces vascular remodeling and endothelial dysfunction found in the hypertensive models that exhibit an endothelin-mediated component. Endothelin receptor antagonism reduces blood pressure and vascular hypertrophic remodeling present in these hypertensive models. Patients with stage 2 hypertension have enhanced vascular expression of ET-1. Endothelin receptor antagonists lower blood pressure in hypertensive patients. They could become therapeutic agents for prevention of target organ damage in hypertension and in type 2 diabetes, chronic renal failure and congestive heart failure. Side effects of endothelin receptor blockers have prevented up to the present their development for these indications. New endothelin antagonists devoid of these side effects, or alternatively inhibitors of the endothelin converting enzymes that generate ET-1 may in the future become available to block the endothelin system. However, to date endothelin antagonists have been approved only for the treatment of primary pulmonary hypertension, a rapidly fatal condition in which the endothelin system plays an important role and endothelin antagonists exert favorable effects.
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Affiliation(s)
- Ernesto L Schiffrin
- CIHR Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada.
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Affiliation(s)
- David M Pollock
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912-2500, USA.
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