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Elijovich F, Kirabo A, Laffer CL. Salt Sensitivity of Blood Pressure in Black People: The Need to Sort Out Ancestry Versus Epigenetic Versus Social Determinants of Its Causation. Hypertension 2024; 81:456-467. [PMID: 37767696 PMCID: PMC10922075 DOI: 10.1161/hypertensionaha.123.17951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Race is a social construct, but self-identified Black people are known to have higher prevalence and worse outcomes of hypertension than White people. This may be partly due to the disproportionate incidence of salt sensitivity of blood pressure in Black people, a cardiovascular risk factor that is independent of blood pressure and has no proven therapy. We review the multiple physiological systems involved in regulation of blood pressure, discuss what, if anything is known about the differences between Black and White people in these systems and how they affect salt sensitivity of blood pressure. The contributions of genetics, epigenetics, environment, and social determinants of health are briefly touched on, with the hope of stimulating further work in the field.
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Affiliation(s)
- Fernando Elijovich
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Cheryl L Laffer
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
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Oppelaar JJ, Bouwmeester TA, Silova AA, Collard D, Wouda RD, van Duin RE, Rorije NMG, Olde Engberink RHG, Danser AHJ, van den Born BJH, Vogt L. Salt-sensitive trait of normotensive individuals is associated with altered autonomous cardiac regulation: a randomized controlled intervention study. Am J Physiol Renal Physiol 2023; 325:F707-F716. [PMID: 37795535 DOI: 10.1152/ajprenal.00076.2023] [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] [Received: 03/30/2023] [Revised: 09/07/2023] [Accepted: 09/27/2023] [Indexed: 10/06/2023] Open
Abstract
Blood pressure (BP) responses to sodium intake show great variation, discriminating salt-sensitive (SS) from salt-resistant (SR) individuals. The pathophysiology behind salt sensitivity is still not fully elucidated. We aimed to investigate salt-induced effects on body fluid, vascular tone, and autonomic cardiac response with regard to BP change in healthy normotensive individuals. We performed a randomized crossover study in 51 normotensive individuals with normal body mass index and estimated glomerular filtration rate. Subjects followed both a low-Na+ diet (LSD, <50 mmol/day) and a high-Na+ diet (HSD, >200 mmol/day). Cardiac output, systemic vascular resistance (SVR), and cardiac autonomous activity, through heart rate variability and cross-correlation baroreflex sensitivity (xBRS), were assessed with noninvasive continuous finger BP measurements. In a subset, extracellular volume (ECV) was assessed by iohexol measurements. Subjects were characterized as SS if mean arterial pressure (MAP) increased ≥3 mmHg after HSD. After HSD, SS subjects (25%) showed a 6.1-mmHg (SD 1.9) increase in MAP. No differences between SS and SR in body weight, cardiac output, or ECV were found. SVR was positively correlated with Delta BP (r = 0.31, P = 0.03). xBRS and heart rate variability were significantly higher in SS participants compared to SR participants after both HSD and LSD. Sodium loading did not alter heart rate variability within groups. Salt sensitivity in normotensive individuals is associated with an inability to decrease SVR upon high salt intake that is accompanied by alterations in autonomous cardiac regulation, as reflected by decreased xBRS and heart rate variability. No discriminatory changes upon high salt were observed among salt-sensitive individuals in body weight and ECV.NEW & NOTEWORTHY Extracellular fluid expansion in normotensive individuals after salt loading is present in both salt-sensitive and salt-resistant individuals and is not discriminatory to the blood pressure response to sodium loading in a steady-state measurement. In normotensive subjects, the ability to sufficiently vasodilate seems to play a pivotal role in salt sensitivity. In a normotensive cohort, differences in sympathovagal balance are also present in low-salt conditions rather than being affected by salt loading. Whereas treatment and prevention of salt-sensitive blood pressure increase are mostly focused on renal sodium handling and extracellular volume regulation, our study suggests that an inability to adequately vasodilate and altered autonomous cardiac functioning are additional key players in the pathophysiology of salt-sensitive blood pressure increase.
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Affiliation(s)
- Jetta J Oppelaar
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Microcirculation, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Thomas A Bouwmeester
- Section of Vascular Medicine, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Atherosclerosis and Ischemic Syndromes, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Anastasia A Silova
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
| | - Didier Collard
- Section of Vascular Medicine, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Atherosclerosis and Ischemic Syndromes, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Rosa D Wouda
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Microcirculation, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Robert E van Duin
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Microcirculation, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Nienke M G Rorije
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Microcirculation, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Rik H G Olde Engberink
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Microcirculation, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - A H Jan Danser
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Bert-Jan H van den Born
- Section of Vascular Medicine, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Atherosclerosis and Ischemic Syndromes, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Liffert Vogt
- Section of Nephrology, Department of Internal Medicine, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
- Microcirculation, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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Kolwelter J, Kannenkeril D, Linz P, Jung S, Nagel AM, Bosch A, Ott C, Bramlage P, Nöh L, Schiffer M, Uder M, Achenbach S, Schmieder RE. The SGLT2 inhibitor empagliflozin reduces tissue sodium content in patients with chronic heart failure: results from a placebo-controlled randomised trial. Clin Res Cardiol 2023; 112:134-144. [PMID: 36289063 PMCID: PMC9849317 DOI: 10.1007/s00392-022-02119-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/17/2022] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Sodium-glucose co-transporter 2 (SGLT2) inhibitors have cardiovascular protective properties in addition to the metabolic effects and represent a cornerstone of treating patients with chronic heart failure (CHF). We hypothesised that empagliflozin reduces tissue sodium content in patients with CHF. METHODS In a double-blind, randomised (2:1), placebo-controlled, parallel-group, clinical trial, 74 patients with NYHA class II-III CHF and an ejection fraction of 49% or less received empagliflozin 10 mg once daily or placebo for 3 months. In each patient, tissue sodium content of the lower leg was assessed non-invasively by sodium-MRI (23Na-MRI) at baseline, after 1 and 3 months of treatment. RESULTS After 1 and 3 months treatment with empagliflozin (n = 48), a significant decrease in skin sodium content was observed (1 month: 22.8 ± 6.1 vs. 21.6 ± 6.0 AU, p = 0.039; 3 months: 22.9 ± 6.1 vs. 21.6 ± 6.1 AU, p = 0.013), while there was no change in muscle sodium and muscle water content. In direct comparison, the change in skin sodium content between baseline and 3 months was - 1.3 ± 3.5 AU in the empagliflozin group versus 0.6 ± 3.5 AU in the placebo group (p for between-group difference = 0.022). No significant difference regarding change in muscle sodium and in muscle water content was observed after 3 months treatment between the two groups. CONCLUSION This trial showed a significant decrease in skin sodium content after 1 and 3 months of treatment with empagliflozin. The decrease in skin sodium content may reflect a decrease in subclinical micro-oedema or/and in non-osmotic bound tissue sodium, both reported to impair left ventricular function. TRIAL REGISTRATION NUMBER NCT03128528 ( http://www. CLINICALTRIALS gov ). TRIAL REGISTRATION DATE 25th April 2017.
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Affiliation(s)
- Julie Kolwelter
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany ,grid.5330.50000 0001 2107 3311Department of Cardiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Dennis Kannenkeril
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany
| | - Peter Linz
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany ,grid.5330.50000 0001 2107 3311Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Susanne Jung
- grid.5330.50000 0001 2107 3311Department of Cardiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Armin M. Nagel
- grid.5330.50000 0001 2107 3311Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany ,grid.7497.d0000 0004 0492 0584Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Agnes Bosch
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany
| | - Christian Ott
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany ,grid.511981.5Department of Nephrology and Hypertension, Paracelsus Medical University, Nuremberg, Germany
| | - Peter Bramlage
- grid.476473.50000 0004 8389 0378Institute for Pharmacology and Preventive Medicine, Cloppenburg, Germany
| | - Lisa Nöh
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany
| | - Mario Schiffer
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany
| | - Michael Uder
- grid.5330.50000 0001 2107 3311Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Stephan Achenbach
- grid.5330.50000 0001 2107 3311Department of Cardiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Roland E. Schmieder
- grid.5330.50000 0001 2107 3311Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Ulmenweg 18, 91054 Erlangen, Germany
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Lu X, Crowley SD. The Immune System in Hypertension: a Lost Shaker of Salt 2021 Lewis K. Dahl Memorial Lecture. Hypertension 2022; 79:1339-1347. [PMID: 35545942 DOI: 10.1161/hypertensionaha.122.18554] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The seminal observations of Dr Lewis Dahl regarding renal mechanisms of hypertension remain highly relevant in light of more recent experiments showing that immune system dysfunction contributes to hypertension pathogenesis. Dr Dahl established that inappropriate salt retention in the kidney plays a central role via Ohm's Law in permitting blood pressure elevation. Nevertheless, inflammatory cytokines whose expression is induced in the early stages of hypertension can alter renal blood flow and sodium transporter expression and activity to foster renal sodium retention. By elaborating these cytokines and reactive oxygen species, myeloid cells and T lymphocytes can connect systemic inflammatory signals to aberrant kidney functions that allow sustained hypertension. By activating T lymphocytes, antigen-presenting cells such as dendritic cells represent an afferent sensing mechanism triggering T cell activation, cytokine generation, and renal salt and water reabsorption. Manipulating these inflammatory signals to attenuate hypertension without causing prohibitive systemic immunosuppression will pose a challenge, but disrupting actions of inflammatory mediators locally within the kidney may offer a path through which to target immune-mediated mechanisms of hypertension while capitalizing on Dr Dahl's key recognition of the kidney's importance in blood pressure regulation.
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Affiliation(s)
- Xiaohan Lu
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, NC
| | - Steven D Crowley
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, NC
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Kurtz T, Pravenec M, DiCarlo S. Mechanism-based strategies to prevent salt sensitivity and salt-induced hypertension. Clin Sci (Lond) 2022; 136:599-620. [PMID: 35452099 PMCID: PMC9069470 DOI: 10.1042/cs20210566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 12/15/2022]
Abstract
High-salt diets are a major cause of hypertension and cardiovascular (CV) disease. Many governments are interested in using food salt reduction programs to reduce the risk for salt-induced increases in blood pressure and CV events. It is assumed that reducing the salt concentration of processed foods will substantially reduce mean salt intake in the general population. However, contrary to expectations, reducing the sodium density of nearly all foods consumed in England by 21% had little or no effect on salt intake in the general population. This may be due to the fact that in England, as in other countries including the U.S.A., mean salt intake is already close to the lower normal physiologic limit for mean salt intake of free-living populations. Thus, mechanism-based strategies for preventing salt-induced increases in blood pressure that do not solely depend on reducing salt intake merit attention. It is now recognized that the initiation of salt-induced increases in blood pressure often involves a combination of normal increases in sodium balance, blood volume and cardiac output together with abnormal vascular resistance responses to increased salt intake. Therefore, preventing either the normal increases in sodium balance and cardiac output, or the abnormal vascular resistance responses to salt, can prevent salt-induced increases in blood pressure. Suboptimal nutrient intake is a common cause of the hemodynamic disturbances mediating salt-induced hypertension. Accordingly, efforts to identify and correct the nutrient deficiencies that promote salt sensitivity hold promise for decreasing population risk of salt-induced hypertension without requiring reductions in salt intake.
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Affiliation(s)
- Theodore W. Kurtz
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94017-0134, U.S.A
| | - Michal Pravenec
- Institute of Physiology, Czech Academy of Sciences, Prague 14220, Czech Republic
| | - Stephen E. DiCarlo
- Department of Physiology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, U.S.A
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6
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Kovarik JJ, Morisawa N, Wild J, Marton A, Takase‐Minegishi K, Minegishi S, Daub S, Sands JM, Klein JD, Bailey JL, Kovalik J, Rauh M, Karbach S, Hilgers KF, Luft F, Nishiyama A, Nakano D, Kitada K, Titze J. Adaptive physiological water conservation explains hypertension and muscle catabolism in experimental chronic renal failure. Acta Physiol (Oxf) 2021; 232:e13629. [PMID: 33590667 PMCID: PMC8244025 DOI: 10.1111/apha.13629] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 02/11/2021] [Accepted: 02/11/2021] [Indexed: 12/22/2022]
Abstract
Aim We have reported earlier that a high salt intake triggered an aestivation‐like natriuretic‐ureotelic body water conservation response that lowered muscle mass and increased blood pressure. Here, we tested the hypothesis that a similar adaptive water conservation response occurs in experimental chronic renal failure. Methods In four subsequent experiments in Sprague Dawley rats, we used surgical 5/6 renal mass reduction (5/6 Nx) to induce chronic renal failure. We studied solute and water excretion in 24‐hour metabolic cage experiments, chronic blood pressure by radiotelemetry, chronic metabolic adjustment in liver and skeletal muscle by metabolomics and selected enzyme activity measurements, body Na+, K+ and water by dry ashing, and acute transepidermal water loss in conjunction with skin blood flow and intra‐arterial blood pressure. Results 5/6 Nx rats were polyuric, because their kidneys could not sufficiently concentrate the urine. Physiological adaptation to this renal water loss included mobilization of nitrogen and energy from muscle for organic osmolyte production, elevated norepinephrine and copeptin levels with reduced skin blood flow, which by means of compensation reduced their transepidermal water loss. This complex physiologic‐metabolic adjustment across multiple organs allowed the rats to stabilize their body water content despite persisting renal water loss, albeit at the expense of hypertension and catabolic mobilization of muscle protein. Conclusion Physiological adaptation to body water loss, termed aestivation, is an evolutionary conserved survival strategy and an under‐studied research area in medical physiology, which besides hypertension and muscle mass loss in chronic renal failure may explain many otherwise unexplainable phenomena in medicine.
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Affiliation(s)
- Johannes J. Kovarik
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Clinical Division of Nephrology and Dialysis Department of Internal Medicine III Medical University of Vienna Vienna Austria
| | - Norihiko Morisawa
- Department of Pharmacology Faculty of Medicine Kagawa University Kagawa Japan
| | - Johannes Wild
- Division for Cardiology 1 Centre for Cardiology Johannes Gutenberg‐University Mainz Mainz Germany
| | - Adriana Marton
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
| | - Kaoru Takase‐Minegishi
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Department of Stem Cell and Immune Regulation Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Shintaro Minegishi
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Steffen Daub
- Division for Cardiology 1 Centre for Cardiology Johannes Gutenberg‐University Mainz Mainz Germany
| | - Jeff M. Sands
- Renal Division Department of Medicine Emory University Atlanta GA USA
| | - Janet D. Klein
- Renal Division Department of Medicine Emory University Atlanta GA USA
| | - James L. Bailey
- Renal Division Department of Medicine Emory University Atlanta GA USA
| | - Jean‐Paul Kovalik
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
| | - Manfred Rauh
- Division of Paediatrics Research Laboratory Erlangen Germany
| | - Susanne Karbach
- Division for Cardiology 1 Centre for Cardiology Johannes Gutenberg‐University Mainz Mainz Germany
| | - Karl F. Hilgers
- Division of Nephrology and Hypertension University Clinic Erlangen Erlangen Germany
| | - Friedrich Luft
- Experimental and Clinical Research Center Max Delbrück Center for Molecular Medicine Berlin Germany
| | - Akira Nishiyama
- Department of Pharmacology Faculty of Medicine Kagawa University Kagawa Japan
| | - Daisuke Nakano
- Department of Pharmacology Faculty of Medicine Kagawa University Kagawa Japan
| | - Kento Kitada
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- JSPS Overseas Research Fellow Japan Society for the Promotion of Science Tokyo Japan
| | - Jens Titze
- Programme in Cardiovascular and Metabolic DisordersDuke‐NUS Medical School Singapore Singapore
- Division of Nephrology and Hypertension University Clinic Erlangen Erlangen Germany
- Division of Nephrology Duke University School of Medicine Durham NC USA
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Wild J, Wenzel P. Myeloid cells, tissue homeostasis, and anatomical barriers as innate immune effectors in arterial hypertension. J Mol Med (Berl) 2021; 99:315-326. [PMID: 33443617 PMCID: PMC7899956 DOI: 10.1007/s00109-020-02019-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 11/18/2020] [Indexed: 11/29/2022]
Abstract
Although essential hypertension affects a large proportion of the human population and is one of the key drivers of cardiovascular mortality worldwide, we still do not have a complete understanding of its pathophysiology. More than 50 years ago, the immune system has been identified as an important part of the pathogenesis of arterial hypertension. An exceeding variety of recent publications deals with the interplay between the numerous different components of the immune system and mechanisms of arterial hypertension and has substantially contributed to our understanding of the role of immunity and inflammation in the pathogenesis of the disease. In this review, we focus on myeloid cells and anatomical barriers as particular aspects of innate immunity in arterial hypertension. Since it represents a first line of defense protecting against pathogens and maintaining tissue homeostasis, innate immunity provides many mechanistic hinge points in the area of hypertension.
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Affiliation(s)
- Johannes Wild
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany.,Center for Cardiology - Cardiology I and CTH Professorship "Vascular Inflammation", University Medical Center Mainz, Langenbeckstr. 1, 55131, Mainz, Germany.,German Center for Cardiovascular Research (DZHK) - Partner site RheinMain, Berlin, Germany
| | - Philip Wenzel
- Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany. .,Center for Cardiology - Cardiology I and CTH Professorship "Vascular Inflammation", University Medical Center Mainz, Langenbeckstr. 1, 55131, Mainz, Germany. .,German Center for Cardiovascular Research (DZHK) - Partner site RheinMain, Berlin, Germany.
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8
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Salt-sensitive blood pressure rise in type 1 diabetes patients is accompanied by disturbed skin macrophage influx and lymphatic dilation-a proof-of-concept study. Transl Res 2020; 217:23-32. [PMID: 31883728 DOI: 10.1016/j.trsl.2019.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 02/08/2023]
Abstract
Type 1 diabetes patients are more prone to have hypertension than healthy individuals, possibly mediated by increased blood pressure (BP) sensitivity to high salt intake. The classical concept proposes that the kidney is central in salt-mediated BP rises, by insufficient renal sodium excretion leading to extracellular fluid volume expansion. Recent animal-derived findings, however, propose a causal role for disturbance of macrophage-mediated lymphangiogenesis. Its relevance for humans, specifically type 1 diabetes patients, is unknown. The present study aimed to assess responses of type 1 diabetes patients to a dietary salt load with regard to BP, extracellular fluid volume (using precise iohexol measurements), and CD163+ macrophage and lymphatic capillary density in skin biopsies. Also, macrophage expression of HLA-DR (a proinflammatory marker) and CD206 (an anti-inflammatory marker) was assessed. Type 1 diabetes patients (n = 8) showed a salt-sensitive BP increase without extracellular fluid volume expansion. Whereas healthy controls (n = 12), who had no BP increase, showed increased skin CD163+ and HLA-DR+ macrophages and dilation of lymphatic skin vasculature after the dietary salt load, these changes were absent (and in case of HLA-DR more heterogenic) in type 1 diabetes patients. In conclusion, we show that salt sensitivity in type 1 diabetes patients cannot be explained by the classical concept of extracellular fluid volume expansion. Rather, we open up a potential role for macrophages and the lymphatic system. Future studies on hypertension and diabetes need to scrutinize these phenomena.
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Canaud B, Kooman J, Selby NM, Taal M, Francis S, Kopperschmidt P, Maierhofer A, Kotanko P, Titze J. Sodium and water handling during hemodialysis: new pathophysiologic insights and management approaches for improving outcomes in end-stage kidney disease. Kidney Int 2020; 95:296-309. [PMID: 30665570 DOI: 10.1016/j.kint.2018.09.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/22/2018] [Accepted: 09/24/2018] [Indexed: 02/07/2023]
Abstract
Space medicine and new technology such as magnetic resonance imaging of tissue sodium stores (23NaMRI) have changed our understanding of human sodium homeostasis and pathophysiology. It has become evident that body sodium comprises 3 main components. Two compartments have been traditionally recognized, namely one that is circulating and systemically active via its osmotic action, and one slowly exchangeable pool located in the bones. The third, recently described pool represents sodium stored in skin and muscle interstitium, and it is implicated in cell and biologic activities via local hypertonicity and sodium clearance mechanisms. This in-depth review provides a comprehensive view on the pathophysiology and existing knowledge gaps of systemic hemodynamic and tissue sodium accumulation in dialysis patients. Furthermore, we discuss how the combination of novel technologies to quantitate tissue salt accumulation (e.g., 23NaMRI) with devices to facilitate the precise attainment of a prescribed hemodialytic sodium mass balance (e.g., sodium and water balancing modules) will improve our therapeutic approach to sodium management in dialysis patients. While prospective studies are required, we think that these new diagnostic and sodium balancing tools will enhance our ability to pursue more personalized therapeutic interventions on sodium and water management, with the eventual goal of improving dialysis patient outcomes.
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Affiliation(s)
- Bernard Canaud
- Centre for Medical Excellence, Fresenius Medical Care Deutschland, Bad Homburg, Germany; Montpellier University, Montpellier, France.
| | - Jeroen Kooman
- Maastricht Universitair Medisch Centrum - Maastricht, Netherlands
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Derby, UK
| | - Maarten Taal
- Centre for Kidney Research and Innovation, University of Nottingham, Royal Derby Hospital Campus, Derby, UK
| | - Susan Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, UK
| | | | | | - Peter Kotanko
- Renal Research Institute, New York, New York, USA; Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jens Titze
- Division of Cardiovascular and Metabolic Disease, Duke-NUS, Singapore; Division of Nephrology, Duke University Medical Center, Durham, North Carolina, USA; Division of Nephrology and Hypertension, University Clinic Erlangen, Germany
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10
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Oppelaar JJ, Vogt L. Body Fluid-Independent Effects of Dietary Salt Consumption in Chronic Kidney Disease. Nutrients 2019; 11:E2779. [PMID: 31731658 PMCID: PMC6893804 DOI: 10.3390/nu11112779] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 02/07/2023] Open
Abstract
The average dietary salt (i.e., sodium chloride) intake in Western society is about 10 g per day. This greatly exceeds the lifestyle recommendations by the WHO to limit dietary salt intake to 5 g. There is robust evidence that excess salt intake is associated with deleterious effects including hypertension, kidney damage and adverse cardiovascular health. In patients with chronic kidney disease, moderate reduction of dietary salt intake has important renoprotective effects and positively influences the efficacy of common pharmacological treatment regimens. During the past several years, it has become clear that besides influencing body fluid volume high salt also induces tissue remodelling and activates immune cell homeostasis. The exact pathophysiological pathway in which these salt-induced fluid-independent effects contribute to CKD is not fully elucidated, nonetheless it is clear that inflammation and the development of fibrosis play a major role in the pathogenic mechanisms of renal diseases. This review focuses on body fluid-independent effects of salt contributing to CKD pathogenesis and cardiovascular health. Additionally, the question whether better understanding of these pathophysiological pathways, related to high salt consumption, might identify new potential treatment options will be discussed.
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Affiliation(s)
| | - Liffert Vogt
- Section of Nephrology, Department of Internal Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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Naser AM, Rahman M, Unicomb L, Doza S, Anand S, Chang HH, Luby SP, Clasen TF, Narayan KV. Comparison of Urinary Sodium and Blood Pressure Relationship From the Spot Versus 24-Hour Urine Samples. J Am Heart Assoc 2019; 8:e013287. [PMID: 31615314 PMCID: PMC6898815 DOI: 10.1161/jaha.119.013287] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/09/2019] [Indexed: 01/10/2023]
Abstract
Background We compared the relationship between sodium (Na) intake and blood pressure when Na intake was estimated from first- and second-morning spot urine samples using the INTERSALT (International Study on Salt and Blood Pressure) formula, versus directly measured 24-hour samples. Methods and Results We collected 24-hour urine and first- and second-morning voids of 383 participants in coastal Bangladesh for 2 visits. We measured participants' blood pressure using an Omron® HEM-907 monitor. To assess the shape of the relationship between urinary Na and blood pressure, we created restricted cubic spline plots adjusted for age, sex, body mass index, smoking and alcohol consumption, physical activities, religion, sleep hours, and household wealth. To assess multicollinearity, we reported variance inflation factors, tolerances, and Leamer's and Klein's statistics following linear regression models. The mean daily urinary Na was 122 (SD 26) mmol/d for the first; 122 (SD 27) mmol/d for the second; and 134 (SD 70) mmol/d for the 24-hour samples. The restricted cubic spline plots illustrated no association between first-morning urinary Na and systolic blood pressure until the 90th percentile distribution followed by a downward relationship; a nonlinear inverse-V-shaped relationship between second-morning urinary Na and systolic blood pressure; and a monotonic upward relationship between 24-hour urinary Na and systolic blood pressure. We found no evidence of multicollinearity for the 24-hour urinary Na model. Conclusions The urinary Na and systolic blood pressure relationship varied for 3 urinary Na measurements. Twenty-four-hour urinary Na captured more variability of Na intake compared with spot urine samples, and its regression models were not affected by multicollinearity.
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Affiliation(s)
- Abu Mohd Naser
- Department of Environmental Health SciencesRollins School of Public HealthEmory UniversityAtlantaGA
- Emory Global Diabetes Research CenterHubert Department of Global HealthRollins School of Public HealthEmory UniversityAtlantaGA
| | - Mahbubur Rahman
- International Centre for Diarrhoeal Disease ResearchBangladesh (icddr,b)DhakaBangladesh
| | - Leanne Unicomb
- International Centre for Diarrhoeal Disease ResearchBangladesh (icddr,b)DhakaBangladesh
| | - Solaiman Doza
- International Centre for Diarrhoeal Disease ResearchBangladesh (icddr,b)DhakaBangladesh
| | - Shuchi Anand
- Division of NephrologySchool of MedicineStanford UniversityStanfordCA
| | - Howard H. Chang
- Department of Biostatistics and BioinformaticsRollins School of Public HealthEmory UniversityAtlantaGA
| | - Stephen P. Luby
- Woods Institute for the EnvironmentStanford UniversityStanfordCA
| | - Thomas F. Clasen
- Department of Environmental Health SciencesRollins School of Public HealthEmory UniversityAtlantaGA
| | - K.M. Venkat Narayan
- Emory Global Diabetes Research CenterHubert Department of Global HealthRollins School of Public HealthEmory UniversityAtlantaGA
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12
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Sodium Intake and Hypertension. Nutrients 2019; 11:nu11091970. [PMID: 31438636 PMCID: PMC6770596 DOI: 10.3390/nu11091970] [Citation(s) in RCA: 294] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/24/2022] Open
Abstract
The close relationship between hypertension and dietary sodium intake is widely recognized and supported by several studies. A reduction in dietary sodium not only decreases the blood pressure and the incidence of hypertension, but is also associated with a reduction in morbidity and mortality from cardiovascular diseases. Prolonged modest reduction in salt intake induces a relevant fall in blood pressure in both hypertensive and normotensive individuals, irrespective of sex and ethnic group, with larger falls in systolic blood pressure for larger reductions in dietary salt. The high sodium intake and the increase in blood pressure levels are related to water retention, increase in systemic peripheral resistance, alterations in the endothelial function, changes in the structure and function of large elastic arteries, modification in sympathetic activity, and in the autonomic neuronal modulation of the cardiovascular system. In this review, we have focused on the effects of sodium intake on vascular hemodynamics and their implication in the pathogenesis of hypertension.
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13
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Abstract
Purpose of Review Dietary sodium is an important trigger for hypertension and humans show a heterogeneous blood pressure response to salt intake. The precise mechanisms for this have not been fully explained although renal sodium handling has traditionally been considered to play a central role. Recent Findings Animal studies have shown that dietary salt loading results in non-osmotic sodium accumulation via glycosaminoglycans and lymphangiogenesis in skin mediated by vascular endothelial growth factor-C, both processes attenuating the rise in BP. Studies in humans have shown that skin could be a buffer for sodium and that skin sodium could be a marker of hypertension and salt sensitivity. Summary Skin sodium storage could represent an additional system influencing the response to salt load and blood pressure in humans.
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Affiliation(s)
- Viknesh Selvarajah
- Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, Box 98, Addenbrookes Hospital, Cambridge, CB2 0QQ, UK.
| | - Kathleen Connolly
- Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, Box 98, Addenbrookes Hospital, Cambridge, CB2 0QQ, UK
| | - Carmel McEniery
- Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, Box 98, Addenbrookes Hospital, Cambridge, CB2 0QQ, UK
| | - Ian Wilkinson
- Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, Box 98, Addenbrookes Hospital, Cambridge, CB2 0QQ, UK
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14
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Affiliation(s)
- Eliane F.E. Wenstedt
- From the Division of Nephrology, Department of Internal Medicine, Amsterdam Cardiovascular Sciences, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Rik H.G. Olde Engberink
- From the Division of Nephrology, Department of Internal Medicine, Amsterdam Cardiovascular Sciences, Academic Medical Center, University of Amsterdam, The Netherlands
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15
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Wiig H, Luft FC, Titze JM. The interstitium conducts extrarenal storage of sodium and represents a third compartment essential for extracellular volume and blood pressure homeostasis. Acta Physiol (Oxf) 2018; 222. [PMID: 29193764 DOI: 10.1111/apha.13006] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/31/2017] [Accepted: 11/23/2017] [Indexed: 12/15/2022]
Abstract
The role of salt in the pathogenesis of arterial hypertension is not well understood. According to the current understanding, the central mechanism for blood pressure (BP) regulation relies on classical studies linking BP and Na+ balance, placing the kidney at the very centre of long-term BP regulation. To maintain BP homeostasis, the effective circulating fluid volume and thereby body Na+ content has to be maintained within very narrow limits. From recent work in humans and rats, the notion has emerged that Na+ could be stored somewhere in the body without commensurate water retention to buffer free extracellular Na+ and that previously unidentified extrarenal, tissue-specific regulatory mechanisms are operative regulating the release and storage of Na+ from a kidney-independent reservoir. Moreover, immune cells from the mononuclear phagocyte system not only function as local on-site sensors of interstitial electrolyte concentration, but also, together with lymphatics, act as systemic regulators of body fluid volume and BP. These studies have established new and unexpected targets in studies of BP control and thus the pathophysiology of hypertension: the interstitium/extracellular matrix of the skin, its inherent interstitial fluid and the lymphatic vasculature forming a vessel network in the interstitium. Aspects of the interstitium in relation to Na+ balance and hypertension are the focus of this review. Taken together, observations of salt storage in the skin to buffer free extracellular Na+ and macrophage modulation of the extracellular matrix and lymphatics suggest that electrolyte homeostasis in the body cannot be achieved by renal excretion alone, but also relies on extrarenal regulatory mechanisms.
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Affiliation(s)
- H. Wiig
- Department of Biomedicine; University of Bergen; Bergen Norway
| | - F. C. Luft
- Experimental and Clinical Research Center; Max-Delbrück Center for Molecular Medicine; Charité Medical Faculty; Berlin Germany
- Division of Clinical Pharmacology; Department of Medicine; Vanderbilt University School of Medicine; Nashville TN USA
| | - J. M. Titze
- Division of Clinical Pharmacology; Department of Medicine; Vanderbilt University School of Medicine; Nashville TN USA
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16
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Abstract
The link between inappropriate salt retention in the kidney and hypertension is well recognized. However, growing evidence suggests that the immune system can play surprising roles in sodium homeostasis, such that the study of inflammatory cells and their secreted effectors has provided important insights into salt sensitivity. As part of the innate immune system, myeloid cells have diverse roles in blood pressure regulation, ranging from prohypertensive actions in the kidney, vasculature, and brain, to effects in the skin that attenuate blood pressure elevation. In parallel, T lymphocyte subsets, as key constituents of the adaptive immune compartment, have variable effects on renal sodium handling and the hypertensive response, accruing from the functions of the cytokines that they produce. Conversely, salt can directly modulate the phenotypes of myeloid and T cells, illustrating bidirectional regulatory mechanisms through which sodium and the immune system coordinately impact blood pressure. This review details the complex interplay between myeloid cells, T cells, and salt in the pathogenesis of essential hypertension.
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Affiliation(s)
- A Justin Rucker
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA
| | - Nathan P Rudemiller
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA
| | - Steven D Crowley
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA
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17
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Hammon M, Grossmann S, Linz P, Seuss H, Hammon R, Rosenhauer D, Janka R, Cavallaro A, Luft FC, Titze J, Uder M, Dahlmann A. 3 Tesla 23Na Magnetic Resonance Imaging During Acute Kidney Injury. Acad Radiol 2017; 24:1086-1093. [PMID: 28495210 DOI: 10.1016/j.acra.2017.03.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/08/2017] [Accepted: 03/11/2017] [Indexed: 10/19/2022]
Abstract
RATIONALE AND OBJECTIVES Sodium and proton magnetic resonance imaging (23Na/1H-MRI) have shown that muscle and skin can store Na+ without water. In chronic renal failure and in heart failure, Na+ mobilization occurs, but is variable depending on age, dialysis vintage, and other features. Na+ storage depots have not been studied in patients with acute kidney injury (AKI). MATERIALS AND METHODS We studied 7 patients with AKI (mean age: 51.7 years; range: 25-84) and 14 age-matched and gender-matched healthy controls. All underwent 23Na/1H-MRI at the calf. Patients were studied before and after acute hemodialysis therapy within 5-6 days. The 23Na-MRI produced grayscale images containing Na+ phantoms, which served to quantify Na+ contents. A fat-suppressed inversion recovery sequence was used to quantify H2O content. RESULTS Plasma Na+ levels did not change. Mean Na+ contents in muscle and skin did not significantly change following four to five cycles of hemodialysis treatment (before therapy: 32.7 ± 6.9 and 44.2 ± 13.5 mmol/L, respectively; after dialysis: 31.7 ± 10.2 and 42.8 ± 11.8 mmol/L, respectively; P > .05). Water content measurements did not differ significantly before and after hemodialysis in muscle and skin (P > .05). Na+ contents in calf muscle and skin of patients before hemodialysis were significantly higher than in healthy subjects (16.6 ± 2.1 and 17.9 ± 3.2) and remained significantly elevated after hemodialysis. CONCLUSIONS Na+ in muscle and skin accumulates in patients with AKI and, in contrast to patients receiving chronic hemodialysis and those with acute heart failure, is not mobilized with hemodialysis within 5-6 days.
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18
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Lecocq M, Bernard C, Felix MS, Linares JM, Chaves-Jacob J, Decherchi P, Dousset E. Biocompatibility of Four Common Orthopedic Biomaterials Following a High-Salt Diet: An In Vivo Study. Int J Mol Sci 2017; 18:ijms18071489. [PMID: 28696371 PMCID: PMC5535979 DOI: 10.3390/ijms18071489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/03/2017] [Accepted: 07/08/2017] [Indexed: 01/13/2023] Open
Abstract
Nowadays, salt consumption appears to be drastically above the recommended level in industrialized countries. The health consequences of this overconsumption are heavy since high-salt intake induces cardiovascular disease, kidney dysfunction, and stroke. Moreover, harmful interaction may also occur with orthopaedic devices because overconsumption of salt reinforces the corrosive aspect of biological tissues and favors bone resorption process. In the present study, we aimed to assess the in vivo effect of three weeks of a high-salt diet, associated (or not) with two weeks of the neuro-myoelectrostimulation (NMES) rehabilitation program on the biocompatibility of four biomaterials used in the manufacture of arthroplasty implants. Thus, two non-metallic (PEEK and Al2O3) and two metallic (Ti6Al4V and CrCo) compounds were implanted in the rat tibial crest, and the implant-to-bone adhesion and cell viability of two surrounded muscles, the Flexor Digitorum (FD) and Tibialis Anterior (TA), were assessed at the end of the experiment. Results indicated lower adhesion strength for the PEEK implant compared to other biomaterials. An effect of NMES and a high-salt diet was only identified for Al2O3 and Ti6Al4V implants, respectively. Moreover, compared to a normal diet, a high-salt diet induced a higher number of dead cells on both muscles for all biomaterials, which was further increased for PEEK, Al2O3, and CrCo materials with NMES application. Finally, except for Ti6Al4V, NMES induced a higher number of dead cells in the directly stimulated muscle (FD) compared to the indirectly stimulated one (TA). This in vivo experiment highlights the potential harmful effect of a high-salt diet for people who have undergone arthroplasty, and a rehabilitation program based on NMES.
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Affiliation(s)
- Mathieu Lecocq
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Plasticité des Systèmes Nerveux et Musculaire (PSNM), Faculté des Sciences du Sport, CC910, 163, Avenue de Luminy, 13288 Marseille CEDEX 09, France.
| | - Cécile Bernard
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Plasticité des Systèmes Nerveux et Musculaire (PSNM), Faculté des Sciences du Sport, CC910, 163, Avenue de Luminy, 13288 Marseille CEDEX 09, France.
| | - Marie Solenne Felix
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Plasticité des Systèmes Nerveux et Musculaire (PSNM), Faculté des Sciences du Sport, CC910, 163, Avenue de Luminy, 13288 Marseille CEDEX 09, France.
| | - Jean-Marc Linares
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Conception Bio-Inspirée (CBI), IUT d'Aix-en-Provence 413, avenue Gaston Berger, 13625 Aix-en-Provence CEDEX, France.
| | - Julien Chaves-Jacob
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Conception Bio-Inspirée (CBI), IUT d'Aix-en-Provence 413, avenue Gaston Berger, 13625 Aix-en-Provence CEDEX, France.
| | - Patrick Decherchi
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Plasticité des Systèmes Nerveux et Musculaire (PSNM), Faculté des Sciences du Sport, CC910, 163, Avenue de Luminy, 13288 Marseille CEDEX 09, France.
| | - Erick Dousset
- Aix-Marseille Université, CNRS, Institut des Sciences du Mouvement: Etienne-Jules MAREY (UMR 7287), Equipe Plasticité des Systèmes Nerveux et Musculaire (PSNM), Faculté des Sciences du Sport, CC910, 163, Avenue de Luminy, 13288 Marseille CEDEX 09, France.
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19
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Abstract
PURPOSE OF REVIEW Textbook theory holds that blood pressure (BP) is regulated by the brain, by blood vessels, or by the kidney. Recent evidence suggests that BP could be regulated in the skin. RECENT FINDINGS The skin holds a complex capillary counter current system, which controls body temperature, skin perfusion, and apparently systemic BP. Epidemiological data suggest that sunlight exposure plays a role in controlling BP. Ultraviolet A radiation produces vasodilation and a fall in BP. Keratinocytes and immune cells control blood flow in the extensive countercurrent loop system of the skin by producing nitric oxide, a key regulator of vascular tone. The balance between hypoxia-inducible factor-1α and hypoxia-inducible factor-2α activity in keratinocytes controls skin perfusion, systemic thermoregulation, and systemic BP by nitric oxide-dependent mechanisms. Furthermore, the skin accumulates Na which generates a barrier to promote immunological host defense. Immune cells control skin Na metabolism and the clearance of Na via the lymphatic system. Reduced lymphatic clearance increases BP. SUMMARY Apart from the well-known role of the brain, blood vessels, and the kidney, the skin is important for systemic BP control in humans and in experimental animals.
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20
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An alternative hypothesis to the widely held view that renal excretion of sodium accounts for resistance to salt-induced hypertension. Kidney Int 2016; 90:965-973. [PMID: 27546606 DOI: 10.1016/j.kint.2016.05.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 12/24/2022]
Abstract
It is widely held that in response to high salt diets, normal individuals are acutely and chronically resistant to salt-induced hypertension because they rapidly excrete salt and retain little of it so that their blood volume, and therefore blood pressure, does not increase. Conversely, it is also widely held that salt-sensitive individuals develop salt-induced hypertension because of an impaired renal capacity to excrete salt that causes greater salt retention and blood volume expansion than that which occurs in normal salt-resistant individuals. Here we review results of both acute and chronic salt-loading studies that have compared salt-induced changes in sodium retention and blood volume between normal subjects (salt-resistant normotensive control subjects) and salt-sensitive subjects. The results of properly controlled studies strongly support an alternative view: during acute or chronic increases in salt intake, normal salt-resistant subjects undergo substantial salt retention and do not excrete salt more rapidly, retain less sodium, or undergo lesser blood volume expansion than do salt-sensitive subjects. These observations: (i) directly conflict with the widely held view that renal excretion of sodium accounts for resistance to salt-induced hypertension, and (ii) have implications for contemporary understanding of how various genetic, immunologic, and other factors determine acute and chronic blood pressure responses to high salt diets.
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21
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Morris RC, Schmidlin O, Sebastian A, Tanaka M, Kurtz TW. Vasodysfunction That Involves Renal Vasodysfunction, Not Abnormally Increased Renal Retention of Sodium, Accounts for the Initiation of Salt-Induced Hypertension. Circulation 2016; 133:881-93. [PMID: 26927006 DOI: 10.1161/circulationaha.115.017923] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- R Curtis Morris
- From the Departments of Medicine (R.C.M., O.S., A.S., M.T.) and Laboratory Medicine (T.W.K.), University of California, San Francisco.
| | - Olga Schmidlin
- From the Departments of Medicine (R.C.M., O.S., A.S., M.T.) and Laboratory Medicine (T.W.K.), University of California, San Francisco
| | - Anthony Sebastian
- From the Departments of Medicine (R.C.M., O.S., A.S., M.T.) and Laboratory Medicine (T.W.K.), University of California, San Francisco
| | - Masae Tanaka
- From the Departments of Medicine (R.C.M., O.S., A.S., M.T.) and Laboratory Medicine (T.W.K.), University of California, San Francisco
| | - Theodore W Kurtz
- From the Departments of Medicine (R.C.M., O.S., A.S., M.T.) and Laboratory Medicine (T.W.K.), University of California, San Francisco.
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22
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Titanium Implant Impairment and Surrounding Muscle Cell Death Following High-Salt Diet: An In Vivo Study. PLoS One 2016; 11:e0146873. [PMID: 26761710 PMCID: PMC4711999 DOI: 10.1371/journal.pone.0146873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/25/2015] [Indexed: 12/04/2022] Open
Abstract
Aim of the study High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation) program similar to that currently used in human care following arthroplasty. Results After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation. Conclusion Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.
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Devarajan S, Yahiro E, Uehara Y, Habe S, Nishiyama A, Miura SI, Saku K, Urata H. Depressor effect of chymase inhibitor in mice with high salt-induced moderate hypertension. Am J Physiol Heart Circ Physiol 2015; 309:H1987-96. [PMID: 26432844 DOI: 10.1152/ajpheart.00721.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 10/02/2015] [Indexed: 12/24/2022]
Abstract
The aim of the present study was to determine whether long-term high salt intake in the drinking water induces hypertension in wild-type (WT) mice and whether a chymase inhibitor or other antihypertensive drugs could reverse the increase of blood pressure. Eight-week-old male WT mice were supplied with drinking water containing 2% salt for 12 wk (high-salt group) or high-salt drinking water plus an oral chymase inhibitor (TPC-806) at four different doses (25, 50, 75, or 100 mg/kg), captopril (75 mg/kg), losartan (100 mg/kg), hydrochlorothiazide (3 mg/kg), eplerenone (200 mg/kg), or amlodipine (6 mg/kg). Control groups were given normal water with or without the chymase inhibitor. Blood pressure and heart rate gradually showed a significant increase in the high-salt group, whereas a dose-dependent depressor effect of the chymase inhibitor was observed. There was also partial improvement of hypertension in the losartan- and eplerenone-treated groups but not in the captopril-, hydrochlorothiazide-, and amlodipine-treated groups. A high salt load significantly increased chymase-dependent ANG II-forming activity in the alimentary tract. In addition, the relative contribution of chymase to ANG II formation, but not actual average activity, showed a significant increase in skin and skeletal muscle, whereas angiotensin-converting enzyme-dependent ANG II-forming activity and its relative contribution were reduced by high salt intake. Plasma and urinary renin-angiotensin system components were significantly increased in the high-salt group but were significantly suppressed in the chymase inhibitor-treated group. In conclusion, 2% salt water drinking for 12 wk caused moderate hypertension and activated the renin-angiotensin system in WT mice. A chymase inhibitor suppressed both the elevation of blood pressure and heart rate, indicating a definite involvement of chymase in salt-sensitive hypertension.
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Affiliation(s)
- Sankar Devarajan
- Department of Cardiovascular Diseases, Fukuoka University Chikushi Hospital, Fukuoka, Japan
| | - Eiji Yahiro
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Yoshinari Uehara
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Shigehisa Habe
- Department of Parasitology, Fukuoka University School of Medicine, Fukuoka, Japan; and
| | - Akira Nishiyama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shin-ichiro Miura
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Keijiro Saku
- Department of Cardiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Hidenori Urata
- Department of Cardiovascular Diseases, Fukuoka University Chikushi Hospital, Fukuoka, Japan;
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24
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Dahlmann A, Dörfelt K, Eicher F, Linz P, Kopp C, Mössinger I, Horn S, Büschges-Seraphin B, Wabel P, Hammon M, Cavallaro A, Eckardt KU, Kotanko P, Levin NW, Johannes B, Uder M, Luft FC, Müller DN, Titze JM. Magnetic resonance-determined sodium removal from tissue stores in hemodialysis patients. Kidney Int 2015; 87:434-41. [PMID: 25100048 PMCID: PMC4932096 DOI: 10.1038/ki.2014.269] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 01/31/2023]
Abstract
We have previously reported that sodium is stored in skin and muscle. The amounts stored in hemodialysis (HD) patients are unknown. We determined whether (23)Na magnetic resonance imaging (sodium-MRI) allows assessment of tissue sodium and its removal in 24 HD patients and 27 age-matched healthy controls. We also studied 20 HD patients before and shortly after HD with a batch dialysis system with direct measurement of sodium in dialysate and ultrafiltrate. Age was associated with higher tissue sodium content in controls. This increase was paralleled by an age-dependent decrease of circulating levels of vascular endothelial growth factor-C (VEGF-C). Older (>60 years) HD patients showed increased sodium and water in skin and muscle and lower VEGF-C levels compared with age-matched controls. After HD, patients with low VEGF-C levels had significantly higher skin sodium content compared with patients with high VEGF-C levels (low VEGF-C: 2.3 ng/ml and skin sodium: 24.3 mmol/l; high VEGF-C: 4.1 ng/ml and skin sodium: 18.2 mmol/l). Thus, sodium-MRI quantitatively detects sodium stored in skin and muscle in humans and allows studying sodium storage reduction in ESRD patients. Age and VEGF-C-related local tissue-specific clearance mechanisms may determine the efficacy of tissue sodium removal with HD. Prospective trials on the relationship between tissue sodium content and hard end points could provide new insights into sodium homeostasis, and clarify whether increased sodium storage is a cardiovascular risk factor.
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Affiliation(s)
- Anke Dahlmann
- 1] Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany [2] Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Kathrin Dörfelt
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Florian Eicher
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Peter Linz
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Christoph Kopp
- 1] Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany [2] Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Irina Mössinger
- Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Stephan Horn
- Kuratorium für Heimdialyse und Nierentransplantation e.V., Erlangen, Germany
| | | | - Peter Wabel
- Fresenius Medical Care, Bad Homburg, Germany
| | - Matthias Hammon
- Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Alexander Cavallaro
- Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Kai-Uwe Eckardt
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | | | | | - Bernd Johannes
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Michael Uder
- Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Friedrich C Luft
- 1] Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine (MDC), Berlin, Germany [2] Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Dominik N Müller
- Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Jens M Titze
- 1] Junior Research Group 2, Interdisciplinary Centre for Clinical Research, Nikolaus-Fiebiger-Centre for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany [2] Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Helle F, Dahl TD, Chatziantoniou C. A low-cost, scalable technique to study distal coronary arteriole function. Acta Physiol (Oxf) 2014; 211:260-7. [PMID: 24698112 DOI: 10.1111/apha.12293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- F. Helle
- Renal Research Group; Department of Clinical Medicine; University of Bergen; Bergen Norway
| | - T. D. Dahl
- Renal Research Group; Department of Clinical Medicine; University of Bergen; Bergen Norway
- Department of Biomedicine; University of Bergen; Bergen Norway
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Affiliation(s)
- S. Reuter
- Klinik für Innere Medizin III; AG Experimentelle Nephrologie; Universitätsklinikum Jena; Jena Germany
| | - A. Patzak
- Institut für Vegetative Physiologie; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - R. Mrowka
- Klinik für Innere Medizin III; AG Experimentelle Nephrologie; Universitätsklinikum Jena; Jena Germany
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Abstract
PURPOSE OF REVIEW The equilibration theory of extracellular body fluids is tightly linked to sodium (Na) metabolism. It is accepted that with changes in salt intake, renal sodium elimination will prevent any change in interstitial Na content and concentration. This review summarizes recent anomalous findings regarding salt and water homeostasis that are inconsistent with current assumptions. RECENT FINDINGS Recent findings from chemical analysis studies of laboratory animals, as well as noninvasive quantitative Na MRI (Na-MRI) studies in patients, have shown that remarkable amounts of Na are stored in muscle and in skin without commensurate water retention. Furthermore, an ultra-long Na balance study in humans suggests the presence of endogenous clocks that generate weekly and monthly infradian rhythmicity of Na storage independent of salt intake. Animal experiments suggest that fluids in the skin interstitium are hypertonic compared with plasma, and that interstitial osmotic stress induces local extrarenal immune cell and lymph-capillary driven mechanisms for electrolyte clearance and maintenance of the internal environment. SUMMARY Recent quantitative evidence challenges current ideas on salt and water homeostasis, and suggests that Na homeostasis cannot be maintained without additional previously unappreciated extrarenal regulatory mechanisms.
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Affiliation(s)
- Jens Titze
- Interdisciplinary Center for Clinical Research and Department of Nephrology and Hypertension, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Wiig H, Schröder A, Neuhofer W, Jantsch J, Kopp C, Karlsen TV, Boschmann M, Goss J, Bry M, Rakova N, Dahlmann A, Brenner S, Tenstad O, Nurmi H, Mervaala E, Wagner H, Beck FX, Müller DN, Kerjaschki D, Luft FC, Harrison DG, Alitalo K, Titze J. Immune cells control skin lymphatic electrolyte homeostasis and blood pressure. J Clin Invest 2013; 123:2803-15. [PMID: 23722907 DOI: 10.1172/jci60113] [Citation(s) in RCA: 309] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 04/05/2013] [Indexed: 11/17/2022] Open
Abstract
The skin interstitium sequesters excess Na+ and Cl- in salt-sensitive hypertension. Mononuclear phagocyte system (MPS) cells are recruited to the skin, sense the hypertonic electrolyte accumulation in skin, and activate the tonicity-responsive enhancer-binding protein (TONEBP, also known as NFAT5) to initiate expression and secretion of VEGFC, which enhances electrolyte clearance via cutaneous lymph vessels and increases eNOS expression in blood vessels. It is unclear whether this local MPS response to osmotic stress is important to systemic blood pressure control. Herein, we show that deletion of TonEBP in mouse MPS cells prevents the VEGFC response to a high-salt diet (HSD) and increases blood pressure. Additionally, an antibody that blocks the lymph-endothelial VEGFC receptor, VEGFR3, selectively inhibited MPS-driven increases in cutaneous lymphatic capillary density, led to skin Cl- accumulation, and induced salt-sensitive hypertension. Mice overexpressing soluble VEGFR3 in epidermal keratinocytes exhibited hypoplastic cutaneous lymph capillaries and increased Na+, Cl-, and water retention in skin and salt-sensitive hypertension. Further, we found that HSD elevated skin osmolality above plasma levels. These results suggest that the skin contains a hypertonic interstitial fluid compartment in which MPS cells exert homeostatic and blood pressure-regulatory control by local organization of interstitial electrolyte clearance via TONEBP and VEGFC/VEGFR3-mediated modification of cutaneous lymphatic capillary function.
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Affiliation(s)
- Helge Wiig
- Department of Biomedicine, University of Bergen, Bergen, Norway
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