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Bargagli M, Anderegg MA, Fuster DG. Effects of thiazides and new findings on kidney stones and dysglycemic side effects. Acta Physiol (Oxf) 2024:e14155. [PMID: 38698738 DOI: 10.1111/apha.14155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/08/2024] [Accepted: 04/22/2024] [Indexed: 05/05/2024]
Abstract
Thiazide and thiazide-like diuretics (thiazides) belong to the most frequently prescribed drugs worldwide. By virtue of their natriuretic and vasodilating properties, thiazides effectively lower blood pressure and prevent adverse cardiovascular outcomes. In addition, through their unique characteristic of reducing urine calcium, thiazides are also widely employed for the prevention of kidney stone recurrence and reduction of bone fracture risk. Since their introduction into clinical medicine in the early 1960s, thiazides have been recognized for their association with metabolic side effects, particularly impaired glucose tolerance, and new-onset diabetes mellitus. Numerous hypotheses have been advanced to explain thiazide-induced glucose intolerance, yet underlying mechanisms remain poorly defined. Regrettably, the lack of understanding and unpredictability of these side effects has prompted numerous physicians to refrain from prescribing these effective, inexpensive, and widely accessible drugs. In this review, we outline the pharmacology and mechanism of action of thiazides, highlight recent advances in the understanding of thiazide-induced glucose intolerance, and provide an up-to-date discussion on the role of thiazides in kidney stone prevention.
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Affiliation(s)
- Matteo Bargagli
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Swiss National Centre of Competence in Research (NCCR) Kidney.CH, University of Zürich, Zürich, Switzerland
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Manuel A Anderegg
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Swiss National Centre of Competence in Research (NCCR) Kidney.CH, University of Zürich, Zürich, Switzerland
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Daniel G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Swiss National Centre of Competence in Research (NCCR) Kidney.CH, University of Zürich, Zürich, Switzerland
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
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2
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Anisman SD, Erickson SB, Fodor KM. Thiazide diuretics. BMJ 2024; 384:e075174. [PMID: 38316445 DOI: 10.1136/bmj-2023-075174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Affiliation(s)
| | - Stephen B Erickson
- Mayo Clinic, Division of Nephrology and Hypertension, Rochester, MN, USA
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3
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Sriperumbuduri S, Welling P, Ruzicka M, Hundemer GL, Hiremath S. Potassium and Hypertension: A State-of-the-Art Review. Am J Hypertens 2024; 37:91-100. [PMID: 37772757 DOI: 10.1093/ajh/hpad094] [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] [Received: 09/21/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 09/30/2023] Open
Abstract
Hypertension is the single most important and modifiable risk factor for cardiovascular morbidity and mortality worldwide. Non pharmacologic interventions, in particular dietary modifications have been established to decrease blood pressure (BP) and hypertension related adverse cardiovascular events. Among those dietary modifications, sodium intake restriction dominates guidelines from professional organizations and has garnered the greatest attention from the mainstream media. Despite guidelines and media exhortations, dietary sodium intake globally has not noticeably changed over recent decades. Meanwhile, increasing dietary potassium intake has remained on the sidelines, despite similar BP-lowering effects. New research reveals a potential mechanism of action, with the elucidation of its effect on natriuresis via the potassium switch effect. Additionally, potassium-substituted salt has been shown to not only reduce BP, but also reduce the risk for stroke and cardiovascular mortality. With these data, we argue that the focus on dietary modification should shift from a sodium-focused to a sodium- and potassium-focused approach with an emphasis on intervention strategies which can easily be implemented into clinical practice.
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Affiliation(s)
- Sriram Sriperumbuduri
- Division of Nephrology, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Paul Welling
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Marcel Ruzicka
- Division of Nephrology, Department of Medicine, University of Ottawa and the Ottawa Hospital Research Institute, Ottawa, Canada
| | - Gregory L Hundemer
- Division of Nephrology, Department of Medicine, University of Ottawa and the Ottawa Hospital Research Institute, Ottawa, Canada
| | - Swapnil Hiremath
- Division of Nephrology, Department of Medicine, University of Ottawa and the Ottawa Hospital Research Institute, Ottawa, Canada
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4
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Pham NYT, Owen JG, Singh N, Shaffi SK. The Use of Thiazide Diuretics for the Treatment of Hypertension in Patients With Advanced Chronic Kidney Disease. Cardiol Rev 2023; 31:99-107. [PMID: 34224450 DOI: 10.1097/crd.0000000000000404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The use of thiazide diuretics for the treatment of hypertension in patients with advance chronic kidney disease. Thiazides have been recommended as the first-line for the treatment of hypertension, yet their use has been discouraged in advanced chronic kidney disease (CKD), as they are suggested to be ineffective in advanced CKD. Recent data suggest that thiazide diuretics may be beneficial blood pressure control in addition to natriuresis in existing CKD. This review discusses the commercially available thiazides with a focus on thiazide pharmacology, most common adverse effects, clinical uses of thiazide diuretic, and the evidence for efficacy of thiazide use in advanced CKD.
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Affiliation(s)
- Ngoc-Yen T Pham
- From the University of New Mexico Hospitals, Albuquerque, NM
| | - Jonathan G Owen
- University of New Mexico Health Sciences Center, Albuquerque, NM
| | - Namita Singh
- University of New Mexico Health Sciences Center, Albuquerque, NM
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5
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Best Practices in Medical Management of Chronic Hypertension. PHYSICIAN ASSISTANT CLINICS 2022. [DOI: 10.1016/j.cpha.2022.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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6
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Use of Thiazides to Treat Hypertension and Advanced CKD. Curr Cardiol Rep 2022; 24:2131-2137. [PMID: 36301404 DOI: 10.1007/s11886-022-01817-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/17/2022] [Indexed: 01/11/2023]
Abstract
PURPOSE OF REVIEW Hypertension is often difficult to control in patients with CKD as manifested by suboptimal control rates in this population. Use of thiazides in CKD patients has been limited as these agents are thought to be ineffective in reducing blood pressure in people with advanced CKD. This review summarizes recent studies impacting indications and safety of use of thiazide in patients with CKD and discusses the mechanism of how thiazides reduce blood pressure. RECENT FINDINGS Chlorthalidone reduces blood pressure compared to placebo in patients with advanced CKD, challenging the belief that thiazide diuretics lose efficacy at lower levels of GFR. Recent clinical trial data indicate that thiazides are effective in patients with advanced kidney disease for blood pressure lowering. However, monitoring of electrolytes and kidney function is important to ensure patient safety when prescribing these agents in patients with CKD.
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7
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Minutolo R, De Nicola L, Mallamaci F, Zoccali C. Thiazide diuretics are back in CKD: the case of chlorthalidone. Clin Kidney J 2022; 16:41-51. [PMID: 36726437 PMCID: PMC9871852 DOI: 10.1093/ckj/sfac198] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Indexed: 02/04/2023] Open
Abstract
Sodium and volume excess is the fundamental risk factor underlying hypertension in chronic kidney disease (CKD) patients, who represent the prototypical population characterized by salt-sensitive hypertension. Low salt diets and diuretics constitute the centrepiece for blood pressure control in CKD. In patients with CKD stage 4, loop diuretics are generally preferred to thiazides. Furthermore, thiazide diuretics have long been held as being of limited efficacy in this population. In this review, by systematically appraising published randomized trials of thiazides in CKD, we show that this class of drugs may be useful even among people with advanced CKD. Thiazides cause a negative sodium balance and reduce body fluids by 1-2 l within the first 2-4 weeks and these effects go along with improvement in hypertension control. The recent CLICK trial has documented the antihypertensive efficacy of chlorthalidone, a long-acting thiazide-like diuretic, in stage 4 CKD patients with poorly controlled hypertension. Overall, chlorthalidone use could be considered in patients with treatment-resistant hypertension when spironolactone cannot be administered or must be withdrawn due to side effects. Hyponatremia, hypokalaemia, volume depletion and acute kidney injury are side effects that demand a vigilant attitude by physicians prescribing these drugs. Well-powered randomized trials assessing hard outcomes are still necessary to more confidently recommend the use of these drugs in advanced CKD.
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Affiliation(s)
| | - Luca De Nicola
- Division of Nephrology, Department of Scienze Mediche e Chirurgiche Avanzate, University of Campania “Luigi Vanvitelli”Naples, Italy
| | - Francesca Mallamaci
- Unità Operativa di Nefrologia, Dialisi e Trapianto Renale, Grande Ospedale Metropolitano di Reggio Calabria, Rome, Italy,Institute of Clinical Physiology-Reggio Calabria Unit, National Research Council of Italy, Rome, Italy
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Hofmann A, Hamann B, Klimova A, Müglich M, Wolk S, Busch A, Frank F, Sabarstinski P, Kapalla M, Nees JA, Brunssen C, Poitz DM, Morawietz H, Reeps C. Pharmacotherapies and Aortic Heme Oxygenase-1 Expression in Patients with Abdominal Aortic Aneurysm. Antioxidants (Basel) 2022; 11:antiox11091753. [PMID: 36139827 PMCID: PMC9495607 DOI: 10.3390/antiox11091753] [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: 08/03/2022] [Revised: 08/29/2022] [Accepted: 08/31/2022] [Indexed: 11/25/2022] Open
Abstract
Background: Treatment of cardiovascular risk factors slows the progression of small abdominal aortic aneurysms (AAA). Heme oxygenase-1 (HO-1) is a stress- and hemin-induced enzyme providing cytoprotection against oxidative stress when overexpressed. However, nothing is known about the effects of cardiometabolic standard therapies on HO-1 expression in aortic walls in patients with end-stage AAA. Methods: The effects of statins, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), calcium channel blockers (CCBs), beta-blockers, diuretics, acetylsalicylic acid (ASA), and therapeutic anticoagulation on HO-1 mRNA and protein expressions were analyzed in AAA patients using multivariate logistic regression analysis and comparison of monotherapy. Results: Analysis of monotherapy revealed that HO-1 mRNA and protein expressions were higher in patients on diuretics and lower in patients on statin therapy. Tests on combinations of antihypertensive medications demonstrated that ACE inhibitors and diuretics, ARBs and diuretics, and beta-blockers and diuretics were associated with increase in HO-1 mRNA expression. ASA and therapeutic anticoagulation were not linked to HO-1 expression. Conclusion: Diuretics showed the strongest association with HO-1 expression, persisting even in combination with other antihypertensive medications. Hence, changes in aortic HO-1 expression in response to different medical therapies and their effects on vessel wall degeneration should be analyzed in future studies.
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Affiliation(s)
- Anja Hofmann
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
- Correspondence: ; Tel.: +49-351-458-16607
| | - Bianca Hamann
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Anna Klimova
- National Center for Tumor Diseases, Partner Site Dresden, Institute for Medical Informatics and Biometry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, D-01307 Dresden, Germany
| | - Margarete Müglich
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Steffen Wolk
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Albert Busch
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Frieda Frank
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Pamela Sabarstinski
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Marvin Kapalla
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
| | - Josef Albin Nees
- Clinic for Internal Medicine, Asklepios-ASB Klinik Radeberg, D-01454 Radeberg, Germany
| | - Coy Brunssen
- Division of Vascular Endothelium and Microcirculation, Department of Medicine III, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, D-01307 Dresden, Germany
| | - David M. Poitz
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital and Faculty of Medicine, Technische Universität Dresden, D-01307 Dresden, Germany
| | - Henning Morawietz
- Division of Vascular Endothelium and Microcirculation, Department of Medicine III, University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, D-01307 Dresden, Germany
| | - Christian Reeps
- Division of Vascular and Endovascular Surgery, Department of Visceral, Thoracic and Vascular Surgery, University Hospital and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, D-01307 Dresden, Germany
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9
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Ernst ME, Fravel MA. Thiazide and the Thiazide-Like Diuretics: Review of Hydrochlorothiazide, Chlorthalidone, and Indapamide. Am J Hypertens 2022; 35:573-586. [PMID: 35404993 DOI: 10.1093/ajh/hpac048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 01/27/2023] Open
Abstract
The term thiazide is universally understood to refer to diuretics that exert their principal action in the distal tubule. The thiazide class is heterogenous and can be further subdivided into compounds containing the benzothiadiazine ring structure-the thiazide-type (e.g., hydrochlorothiazide)-and those lacking the benzothiadiazine ring-the thiazide-like (e.g., chlorthalidone and indapamide) drugs. Thiazide-like agents are longer acting and constitute the diuretics used in most of the cardiovascular outcome trials that established benefits of treatment with diuretics, but pragmatic aspects, such as lack of availability in convenient formulations, limit their use. Regardless of class heterogeneity, thiazides have retained importance in the management of hypertension for over 60 years. They are reliably effective as monotherapy in a majority of hypertensive patients, and augment the efficacy of other classes of antihypertensives when used in combination. Importantly, a thiazide-based treatment regimen lowers cardiovascular events, and their sturdy effect reinforces their place among the recommended first-line agents to treat hypertension in major domestic and international hypertension guidelines. There are few head-to-head comparisons within the class, but potential differences have been explored indirectly as well as in non-blood pressure mechanisms and potential pleiotropic properties. Until proven otherwise, the importance of these differences remains speculative, and clinicians should assume that cardiovascular events will be lowered similarly across agents when equivalent blood pressure reduction occurs. Thiazides remain underutilized, with only about one-third of hypertensive patients receiving them. For many patients, however, a thiazide is an indispensable component of their regimen to achieve adequate blood pressure control.
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Affiliation(s)
- Michael E Ernst
- Department of Pharmacy Practice and Science, College of Pharmacy, The University of Iowa, Iowa City, Iowa, USA.,Department of Family Medicine, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Michelle A Fravel
- Department of Pharmacy Practice and Science, College of Pharmacy, The University of Iowa, Iowa City, Iowa, USA
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10
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McNally RJ, Farukh B, Chowienczyk PJ, Faconti L. Effect of diuretics on plasma aldosterone and potassium in primary hypertension: A systematic review and meta-analysis. Br J Clin Pharmacol 2022; 88:1964-1977. [PMID: 34820874 DOI: 10.1111/bcp.15156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 11/01/2021] [Accepted: 11/13/2021] [Indexed: 12/18/2022] Open
Abstract
AIM By contrast with drugs inhibiting the renin-angiotensin-aldosterone system (RAAS), diuretics stimulate renin release by the kidneys. Although plasma aldosterone (PA) is thought to be mainly regulated by RAAS activity, serum potassium has been shown to be an important factor in animal models and humans. Here we perform a systematic review and meta-analysis of randomised controlled trials (RCT) in hypertension investigating the effects of diuretic therapy on PA and the correlation of change in PA with that of potassium and blood pressure (BP). METHODS Three databases were searched: MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). Titles were first screened by title and abstract for relevance before full-text articles were assessed for eligibility according to a predefined inclusion/exclusion criteria. RESULTS A total of 1139 articles were retrieved, of which 42 met the prespecified inclusion/exclusion criteria. The average standardised difference in mean PA was similar for all classes of diuretic: thiazide/thiazide-like 0.299 (95% confidence interval [CI] 0.150, 0.447), loop 0.927 (0.37, 1.49), MRA/potassium-sparing 0.265 (0.173, 0.357) and combination 0.466 (0.137, 0.796), Q = 6.33, P = .097. In subjects untreated with another antihypertensive, there was a significant relationship between change in PA and change in systolic BP but no relationship with the change in potassium. CONCLUSION In RCTs of diuretic therapy in hypertension, there is an increase in PA with all classes of diuretic and no significant between-class heterogeneity. Change in PA is not related with potassium but correlates with the change in BP in subjects untreated with another antihypertensive medication.
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Affiliation(s)
- Ryan J McNally
- Department of Clinical Pharmacology, King's College London British Heart Foundation Centre, London, UK
| | - Bushra Farukh
- Department of Clinical Pharmacology, King's College London British Heart Foundation Centre, London, UK
| | - Philip J Chowienczyk
- Department of Clinical Pharmacology, King's College London British Heart Foundation Centre, London, UK
| | - Luca Faconti
- Department of Clinical Pharmacology, King's College London British Heart Foundation Centre, London, UK
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11
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Mondaca-Ruff D, Araos P, Yañez CE, Novoa UF, Mora IG, Ocaranza MP, Jalil JE. Hydrochlorothiazide Reduces Cardiac Hypertrophy, Fibrosis and Rho-Kinase Activation in DOCA-Salt Induced Hypertension. J Cardiovasc Pharmacol Ther 2021; 26:724-735. [PMID: 34623176 DOI: 10.1177/10742484211053109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Thiazides are one of the most common antihypertensive drugs used for hypertension treatment and hydrochlorothiazide (HCTZ) is the most frequently used diuretic for hypertension treatment. The Rho/Rho-kinase (ROCK) path plays a key function in cardiovascular remodeling. We hypothesized that in preclinical hypertension HCTZ reduces myocardial ROCK activation and consequent myocardial remodeling. METHODS The preclinical model of deoxycorticosterone (DOCA)-salt hypertension was used (Sprague-Dawley male rats). After 3 weeks, in 3 different groups: HCTZ, the ROCK inhibitor fasudil or spironolactone was added (3 weeks). After 6 weeks myocardial hypertrophy and fibrosis, cardiac levels of profibrotic proteins, mRNA levels (RT PCR) of pro remodeling and pro oxidative molecules and ROCK activity were determined. RESULTS Blood pressure, myocardial hypertrophy and fibrosis were reduced significantly by HCTZ, fasudil and spironolactone. In the heart, increased levels of the pro-fibrotic proteins Col-I, Col-III and TGF-β1 and gene expression of pro-remodeling molecules TGF-β1, CTGF, MCP-1 and PAI-1 and the pro-oxidative molecules gp91phox and p22phox were significantly reduced by HCTZ, fasudil and spironolactone. ROCK activity in the myocardium was increased by 54% (P < 0.05) as related to the sham group and HCTZ, spironolactone and fasudil, reduced ROCK activation to control levels. CONCLUSIONS HCTZ reduced pathologic LVH by controlling blood pressure, hypertrophy and myocardial fibrosis and by decreasing myocardial ROCK activation, expression of pro remodeling, pro fibrotic and pro oxidative genes. In hypertension, the observed effects of HCTZ on the myocardium might explain preventive outcomes of thiazides in hypertension, specifically on LVH regression and incident heart failure.
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Affiliation(s)
- David Mondaca-Ruff
- Laboratory of Molecular Cardiology, Division of Cardiovascular Diseases, School of Medicine, 60709Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Patricio Araos
- Laboratory of Molecular Cardiology, Division of Cardiovascular Diseases, School of Medicine, 60709Pontificia Universidad Católica de Chile, Santiago, Chile.,Laboratorio de Fisiopatologia Renal, Instituto de Ciencias Biomédicas, 28041Universidad Autónoma de Chile, Santiago, Chile
| | - Cristián E Yañez
- Laboratory of Molecular Cardiology, Division of Cardiovascular Diseases, School of Medicine, 60709Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ulises F Novoa
- Department of Biomedical Sciences, 495640Facultad de Ciencias de la Salud, Universidad de Talca, Talca, Chile
| | - Italo G Mora
- Laboratory of Molecular Cardiology, Division of Cardiovascular Diseases, School of Medicine, 60709Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María Paz Ocaranza
- Laboratory of Molecular Cardiology, Division of Cardiovascular Diseases, School of Medicine, 60709Pontificia Universidad Católica de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), 60709Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Center for New Drugs for Hypertension (CENDHY), 60709Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jorge E Jalil
- Laboratory of Molecular Cardiology, Division of Cardiovascular Diseases, School of Medicine, 60709Pontificia Universidad Católica de Chile, Santiago, Chile.,Center for New Drugs for Hypertension (CENDHY), 60709Pontificia Universidad Católica de Chile, Santiago, Chile
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Abstract
Diuretics are listed in hypertension guidelines as one of three equally weighted first-line treatment options. In order to differentiate between antihypertensives, a lot of discussion has been directed at side effect profiles and as a result, has created a perhaps disproportionate fear of the metabolic effects that can be associated with diuretics. Data, however, show that the risk of a clinically meaningful change in laboratory parameters is very low, whereas the benefits of volume control and natriuresis are high and the reductions in morbidity and mortality are clinically significant. Moreover, as clinically significant differences in safety and efficacy profiles exist among diuretics, several international guidelines have started making a distinction between thiazides (hydrochlorothiazide) and thiazide-like (chlorthalidone, indapamide) diuretics; and some of them now recommend longer acting thiazide-like diuretics. In time, pending more data, chlorthalidone and indapamide may need to be subdivided further into separate classifications.
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13
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Bovée DM, Visser WJ, Middel I, De Mik-van Egmond A, Greupink R, Masereeuw R, Russel FGM, Danser AHJ, Zietse R, Hoorn EJ. A Randomized Trial of Distal Diuretics versus Dietary Sodium Restriction for Hypertension in Chronic Kidney Disease. J Am Soc Nephrol 2020; 31:650-662. [PMID: 31996411 DOI: 10.1681/asn.2019090905] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/11/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Distal diuretics are considered less effective than loop diuretics in CKD. However, data to support this perception are limited. METHODS To investigate whether distal diuretics are noninferior to dietary sodium restriction in reducing BP in patients with CKD stage G3 or G4 and hypertension, we conducted a 6-week, randomized, open-label crossover trial comparing amiloride/hydrochlorothiazide (5 mg/50 mg daily) with dietary sodium restriction (60 mmol per day). Antihypertension medication was discontinued for a 2-week period before randomization. We analyzed effects on BP, kidney function, and fluid balance and related this to renal clearance of diuretics. RESULTS A total of 26 patients (with a mean eGFR of 39 ml/min per 1.73 m2) completed both treatments. Dietary sodium restriction reduced sodium excretion from 160 to 64 mmol per day. Diuretics produced a greater reduction in 24-hour systolic BP (SBP; from 138 to 124 mm Hg) compared with sodium restriction (from 134 to 129 mm Hg), as well as a significantly greater effect on extracellular water, eGFR, plasma renin, and aldosterone. Both interventions resulted in a similar decrease in body weight and NT-proBNP. Neither approaches decreased albuminuria significantly, whereas diuretics did significantly reduce urinary angiotensinogen and β2-microglobulin excretion. Although lower eGFR and higher plasma indoxyl sulfate correlated with lower diuretic clearance, the diuretic effects on body weight and BP at lower eGFR were maintained. During diuretic treatment, higher PGE2 excretion correlated with lower free water clearance, and four patients developed mild hyponatremia. CONCLUSIONS Distal diuretics are noninferior to dietary sodium restriction in reducing BP and extracellular volume in CKD. Diuretic sensitivity in CKD is maintained despite lower diuretic clearance. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER DD-study: Diet or Diuretics for Salt-sensitivity in Chronic Kidney Disease (DD), NCT02875886.
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Affiliation(s)
| | | | - Igor Middel
- Division of Pharmacology, Department of Pharmaceutical Sciences, University Utrecht, Utrecht, The Netherlands; and
| | | | - Rick Greupink
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rosalinde Masereeuw
- Division of Pharmacology, Department of Pharmaceutical Sciences, University Utrecht, Utrecht, The Netherlands; and
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - A H Jan Danser
- Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
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14
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Genetic factors associated with elevation of uric acid after treatment with thiazide-like diuretic in patients with essential hypertension. Hypertens Res 2019; 43:220-226. [DOI: 10.1038/s41440-019-0356-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 10/11/2019] [Accepted: 10/12/2019] [Indexed: 11/08/2022]
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Rapoport RM, Soleimani M. Mechanism of Thiazide Diuretic Arterial Pressure Reduction: The Search Continues. Front Pharmacol 2019; 10:815. [PMID: 31543812 PMCID: PMC6730501 DOI: 10.3389/fphar.2019.00815] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/24/2019] [Indexed: 12/21/2022] Open
Abstract
Thiazide diuretic (TZD)-mediated chronic reduction of arterial pressure is thought to occur through decreased total peripheral vascular resistance. Further, the decreased peripheral vascular resistance is accomplished through TZD activation of an extrarenal target, resulting in inhibition of vascular constriction. However, despite greater than five decades of investigation, little progress has been made into the identification of the TZD extrarenal target. Proposed mechanisms range from direct inhibition of constrictor and activation of relaxant signaling pathways in the vascular smooth muscle to indirect inhibition through decreased neurogenic and hormonal regulatory pathways. Surprisingly, particularly in view of this lack of progress, comprehensive reviews of the subject are absent. Moreover, even though it is well recognized that 1) several types of hypertension are insensitive to TZD reduction of arterial pressure and, further, TZD fail to reduce arterial pressure in normotensive subjects and animals, and 2) different mechanisms underlie acute and chronic TZD, findings derived from these models and parameters remain largely undifferentiated. This review 1) comprehensively describes findings associated with TZD reduction of arterial pressure; 2) differentiates between observations in TZD-sensitive and TZD-insensitive hypertension, normotensive subjects/animals, and acute and chronic effects of TZD; 3) critically evaluates proposed TZD extrarenal targets; 4) proposes guiding parameters for relevant investigations into extrarenal TZD target identification; and 5) proposes a working model for TZD chronic reduction of arterial pressure through vascular dilation.
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Affiliation(s)
- Robert M Rapoport
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Manoocher Soleimani
- Research Service, Veterans Affairs Medical Center, Cincinnati, OH, United States.,Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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16
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Schlickmann F, Boeing T, Mariano LNB, da Silva RDCMVDAF, da Silva LM, de Andrade SF, de Souza P, Cechinel-Filho V. Gallic acid, a phenolic compound isolated from Mimosa bimucronata (DC.) Kuntze leaves, induces diuresis and saluresis in rats. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2018; 391:649-655. [PMID: 29663016 DOI: 10.1007/s00210-018-1502-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/06/2018] [Indexed: 11/28/2022]
Abstract
Although present in the leaves of Mimosa bimucronata (DC.) and many other medicinal plants commonly used to augment urinary volume excretion, the effects of gallic acid as a diuretic agent remain to be studied. Wistar rats were orally treated with vehicle, hydrochlorothiazide, or gallic acid. The effects of gallic acid in the presence of hydrochlorothiazide, furosemide, amiloride, L-NAME, atropine, and indomethacin were also investigated. Diuretic index, pH, conductivity, and electrolyte excretion were evaluated at the end of the experiment (after 8 or 24 h). Gallic acid induced diuretic and saluretic (Na+ and Cl-) effects, without interfering with K+ excretion, when orally given to female and male rats at a dose of 3 mg/kg. These effects were associated with increased creatinine and conductivity values while pH was unaffected by any of the treatments. Plasma Na+, K+, and Cl- levels were not affected by any of the acute treatments. The combination with hydrochlorothiazide or furosemide was unable to intensify the effects of gallic acid when compared with the response obtained with each drug alone. On the other hand, the treatment with amiloride plus gallic acid amplified both diuresis and saluresis, besides to a marked potassium-sparing effect. Its diuretic action was significantly prevented in the presence of indomethacin, a cyclooxygenase inhibitor, but not with the pretreatments with L-NAME or atropine. Although several biological activities have already been described for gallic acid, this is the first study demonstrating its potential as a diuretic agent.
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Affiliation(s)
- Fabile Schlickmann
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil
| | - Thaise Boeing
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil
| | - Luisa Nathália Bolda Mariano
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil
| | | | - Luisa Mota da Silva
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil
| | - Sérgio Faloni de Andrade
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil
| | - Priscila de Souza
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil.
| | - Valdir Cechinel-Filho
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC, 88302-901, Brazil
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17
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Activation of human smooth muscle BK channels by hydrochlorothiazide requires cell integrity and the presence of BK β 1 subunit. Acta Pharmacol Sin 2018; 39:371-381. [PMID: 29188803 DOI: 10.1038/aps.2017.133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/28/2017] [Indexed: 12/13/2022] Open
Abstract
Thiazide-like diuretics are the most commonly used drugs to treat arterial hypertension, with their efficacy being linked to their chronic vasodilatory effect. Previous studies suggest that activation of the large conductance voltage- and Ca2+-dependent K+ (BK) channel (Slo 1, MaxiK channel) is responsible for the thiazide-induced vasodilatory effect. But the direct electrophysiological evidence supporting this claim is lacking. BK channels can be associated with one small accessory β-subunit (β1-β4) that confers specific biophysical and pharmacological characteristics to the current phenotype. The β1-subunit is primarily expressed in smooth muscle cells (SMCs). In this study we investigated the effect of hydrochlorothiazide (HCTZ) on BK channel activity in native SMCs from human umbilical artery (HUASMCs) and HEK293T cells expressing the BK channel (with and without the β1-subunit). Bath application of HCTZ (10 μmol/L) significantly augmented the BK current in HUASMCs when recorded using the whole-cell configurations, but it did not affect the unitary conductance and open probability of the BK channel in HUASMCs evaluated in the inside-out configuration, suggesting an indirect mechanism requiring cell integrity. In HEK293T cells expressing BK channels, HCTZ-augmented BK channel activity was only observed when the β1-subunit was co-expressed, being concentration-dependent with an EC50 of 28.4 μmol/L, whereas membrane potential did not influence the concentration relationship. Moreover, HCTZ did not affect the BK channel current in HEK293T cells evaluated in the inside-out configuration, but significantly increases the open probability in the cell-attached configuration. Our data demonstrate that a β1-subunit-dependent mechanism that requires SMC integrity leads to HCTZ-induced BK channel activation.
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18
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Shahin MH, Gong Y, Frye RF, Rotroff DM, Beitelshees AL, Baillie RA, Chapman AB, Gums JG, Turner ST, Boerwinkle E, Motsinger-Reif A, Fiehn O, Cooper-DeHoff RM, Han X, Kaddurah-Daouk R, Johnson JA. Sphingolipid Metabolic Pathway Impacts Thiazide Diuretics Blood Pressure Response: Insights From Genomics, Metabolomics, and Lipidomics. J Am Heart Assoc 2017; 7:e006656. [PMID: 29288159 PMCID: PMC5778957 DOI: 10.1161/jaha.117.006656] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 11/01/2017] [Indexed: 01/04/2023]
Abstract
BACKGROUND Although hydrochlorothiazide (HCTZ) is a well-established first-line antihypertensive in the United States, <50% of HCTZ treated patients achieve blood pressure (BP) control. Thus, identifying biomarkers that could predict the BP response to HCTZ is critically important. In this study, we utilized metabolomics, genomics, and lipidomics to identify novel pathways and biomarkers associated with HCTZ BP response. METHODS AND RESULTS First, we conducted a pathway analysis for 13 metabolites we recently identified to be significantly associated with HCTZ BP response. From this analysis, we found the sphingolipid metabolic pathway as the most significant pathway (P=5.8E-05). Testing 78 variants, within 14 genes involved in the sphingolipid metabolic canonical pathway, with the BP response to HCTZ identified variant rs6078905, within the SPTLC3 gene, as a novel biomarker significantly associated with the BP response to HCTZ in whites (n=228). We found that rs6078905 C-allele carriers had a better BP response to HCTZ versus noncarriers (∆SBP/∆DBP: -11.4/-6.9 versus -6.8/-3.5 mm Hg; ∆SBP P=6.7E-04; ∆DBP P=4.8E-04). Additionally, in blacks (n=148), we found genetic signals in the SPTLC3 genomic region significantly associated with the BP response to HCTZ (P<0.05). Last, we observed that rs6078905 significantly affects the baseline level of 4 sphingomyelins (N24:2, N24:3, N16:1, and N22:1; false discovery rate <0.05), from which N24:2 sphingomyelin has a significant correlation with both HCTZ DBP-response (r=-0.42; P=7E-03) and SBP-response (r=-0.36; P=2E-02). CONCLUSIONS This study provides insight into potential pharmacometabolomic and genetic mechanisms underlying HCTZ BP response and suggests that SPTLC3 is a potential determinant of the BP response to HCTZ. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00246519.
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Affiliation(s)
- Mohamed H Shahin
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL
| | - Yan Gong
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL
| | - Reginald F Frye
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL
| | - Daniel M Rotroff
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC
| | | | | | | | - John G Gums
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL
| | | | - Eric Boerwinkle
- Human Genetics Center and Institute for Molecular Medicine, University of Texas Health Science Center, Houston, TX
| | | | - Oliver Fiehn
- Genome Center, University of California at Davis, CA
- Biochemistry Department, King Abdulaziz University, Jeddah, Saudi-Arabia
| | - Rhonda M Cooper-DeHoff
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL
| | - Xianlin Han
- Sanford-Burnham Medical Research Institute, Orlando, FL
| | - Rima Kaddurah-Daouk
- Department of Psychiatry and Behavioural Sciences and Department of Medicine, Duke University, Durham, NC
| | - Julie A Johnson
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics, University of Florida, Gainesville, FL
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19
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Alshahrani S, Rapoport RM, Zahedi K, Jiang M, Nieman M, Barone S, Meredith AL, Lorenz JN, Rubinstein J, Soleimani M. The non-diuretic hypotensive effects of thiazides are enhanced during volume depletion states. PLoS One 2017; 12:e0181376. [PMID: 28719636 PMCID: PMC5515454 DOI: 10.1371/journal.pone.0181376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/29/2017] [Indexed: 12/25/2022] Open
Abstract
Thiazide derivatives including Hydrochlorothiazide (HCTZ) represent the most common treatment of mild to moderate hypertension. Thiazides initially enhance diuresis via inhibition of the kidney Na+-Cl- Cotransporter (NCC). However, chronic volume depletion and diuresis are minimal while lowered blood pressure (BP) is maintained on thiazides. Thus, a vasodilator action of thiazides is proposed, likely via Ca2+-activated K+ (BK) channels in vascular smooth muscles. This study ascertains the role of volume depletion induced by salt restriction or salt wasting in NCC KO mice on the non-diuretic hypotensive action of HCTZ. HCTZ (20mg/kg s.c.) lowered BP in 1) NCC KO on a salt restricted diet but not with normal diet; 2) in volume depleted but not in volume resuscitated pendrin/NCC dKO mice; the BP reduction occurs without any enhancement in salt excretion or reduction in cardiac output. HCTZ still lowered BP following treatment of NCC KO on salt restricted diet with paxilline (8 mg/kg, i.p.), a BK channel blocker, and in BK KO and BK/NCC dKO mice on salt restricted diet. In aortic rings from NCC KO mice on normal and low salt diet, HCTZ did not alter and minimally decreased maximal phenylephrine contraction, respectively, while contractile sensitivity remained unchanged. These results demonstrate 1) the non-diuretic hypotensive effects of thiazides are augmented with volume depletion and 2) that the BP reduction is likely the result of HCTZ inhibition of vasoconstriction through a pathway dependent on factors present in vivo, is unrelated to BK channel activation, and involves processes associated with intravascular volume depletion.
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Affiliation(s)
- Saeed Alshahrani
- Department of Pharmacology and Cell Biophysics, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
| | - Robert M. Rapoport
- Department of Pharmacology and Cell Biophysics, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
| | - Kamyar Zahedi
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States of America
- Division of Nephrology, Department of Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, United States of America
| | - Min Jiang
- Division of Cardiology, Department of Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
| | - Michelle Nieman
- Department of Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
| | - Sharon Barone
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States of America
- Division of Nephrology, Department of Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, United States of America
| | - Andrea L. Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - John N. Lorenz
- Department of Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
| | - Jack Rubinstein
- Division of Cardiology, Department of Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
| | - Manoocher Soleimani
- Department of Pharmacology and Cell Biophysics, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
- Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, OH, United States of America
- Division of Nephrology, Department of Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, United States of America
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, United States of America
- * E-mail:
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20
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Digne-Malcolm H, Frise MC, Dorrington KL. How Do Antihypertensive Drugs Work? Insights from Studies of the Renal Regulation of Arterial Blood Pressure. Front Physiol 2016; 7:320. [PMID: 27524972 PMCID: PMC4965470 DOI: 10.3389/fphys.2016.00320] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/13/2016] [Indexed: 11/13/2022] Open
Abstract
Though antihypertensive drugs have been in use for many decades, the mechanisms by which they act chronically to reduce blood pressure remain unclear. Over long periods, mean arterial blood pressure must match the perfusion pressure necessary for the kidney to achieve its role in eliminating the daily intake of salt and water. It follows that the kidney is the most likely target for the action of most effective antihypertensive agents used chronically in clinical practice today. Here we review the long-term renal actions of antihypertensive agents in human studies and find three different mechanisms of action for the drugs investigated. (i) Selective vasodilatation of the renal afferent arteriole (prazosin, indoramin, clonidine, moxonidine, α-methyldopa, some Ca(++)-channel blockers, angiotensin-receptor blockers, atenolol, metoprolol, bisoprolol, labetolol, hydrochlorothiazide, and furosemide). (ii) Inhibition of tubular solute reabsorption (propranolol, nadolol, oxprenolol, and indapamide). (iii) A combination of these first two mechanisms (amlodipine, nifedipine and ACE-inhibitors). These findings provide insights into the actions of antihypertensive drugs, and challenge misconceptions about the mechanisms underlying the therapeutic efficacy of many of the agents.
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Affiliation(s)
| | - Matthew C. Frise
- Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
| | - Keith L. Dorrington
- Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
- Nuffield Department of Anaesthetics, John Radcliffe HospitalOxford, UK
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21
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Hughes AD. How do thiazide and thiazide-like diuretics lower blood pressure? J Renin Angiotensin Aldosterone Syst 2016; 5:155-60. [PMID: 15803433 DOI: 10.3317/jraas.2004.034] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Thiazide diuretics are widely used for the treatment of hypertension, but the mechanism by which these drugs lower blood pressure in the long term remains unknown. This article reviews current knowledge about the hypotensive actions of thiazides and thiazide-like diuretics and discusses possible mechanisms of action.
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Affiliation(s)
- Alun D Hughes
- Clinical Pharmacology, Faculty of Medicine, Imperial College London, London W21NY, UK.
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22
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Fujii N, Louie JC, McNeely BD, Zhang SY, Tran MA, Kenny GP. K+ channel mechanisms underlying cholinergic cutaneous vasodilation and sweating in young humans: roles of KCa, KATP, and KV channels? Am J Physiol Regul Integr Comp Physiol 2016; 311:R600-6. [PMID: 27440718 DOI: 10.1152/ajpregu.00249.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/14/2016] [Indexed: 11/22/2022]
Abstract
Acetylcholine released from cholinergic nerves is involved in heat loss responses of cutaneous vasodilation and sweating. K(+) channels are thought to play a role in regulating cholinergic cutaneous vasodilation and sweating, though which K(+) channels are involved in their regulation remains unclear. We evaluated the hypotheses that 1) Ca(2+)-activated K(+) (KCa), ATP-sensitive K(+) (KATP), and voltage-gated K(+) (KV) channels all contribute to cholinergic cutaneous vasodilation; and 2) KV channels, but not KCa and KATP channels, contribute to cholinergic sweating. In 13 young adults (24 ± 5 years), cutaneous vascular conductance (CVC) and sweat rate were evaluated at intradermal microdialysis sites that were continuously perfused with: 1) lactated Ringer (Control), 2) 50 mM tetraethylammonium (KCa channel blocker), 3) 5 mM glybenclamide (KATP channel blocker), and 4) 10 mM 4-aminopyridine (KV channel blocker). At all sites, cholinergic cutaneous vasodilation and sweating were induced by coadministration of methacholine (0.0125, 0.25, 5, 100, and 2,000 mM, each for 25 min). The methacholine-induced increase in CVC was lower with the KCa channel blocker relative to Control at 0.0125 (1 ± 1 vs. 9 ± 6%max) and 5 (2 ± 5 vs. 17 ± 14%max) mM methacholine, whereas it was lower in the presence of KATP (69 ± 7%max) and KV (57 ± 14%max) channel blocker compared with Control (79 ± 6%max) at 100 mM methacholine. Furthermore, methacholine-induced sweating was lower at the KV channel blocker site (0.42 ± 0.17 mg·min(-1)·cm(-2)) compared with Control (0.58 ± 0.15 mg·min(-1)·cm(-2)) at 2,000 mM methacholine. In conclusion, we show that KCa, KATP, and KV channels play a role in cholinergic cutaneous vasodilation, whereas only KV channels contribute to cholinergic sweating in normothermic resting humans.
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Affiliation(s)
- Naoto Fujii
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Jeffrey C Louie
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Brendan D McNeely
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Sarah Yan Zhang
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - My-An Tran
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
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23
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Affiliation(s)
- John E Hall
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson.
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24
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Fujii N, Meade RD, Minson CT, Brunt VE, Boulay P, Sigal RJ, Kenny GP. Cutaneous blood flow during intradermal NO administration in young and older adults: roles for calcium-activated potassium channels and cyclooxygenase? Am J Physiol Regul Integr Comp Physiol 2016; 310:R1081-7. [PMID: 27053645 DOI: 10.1152/ajpregu.00041.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/30/2016] [Indexed: 01/22/2023]
Abstract
Nitric oxide (NO) increases cutaneous blood flow; however, the underpinning mechanism(s) remains to be elucidated. We hypothesized that the cutaneous blood flow response during intradermal administration of sodium nitroprusside (SNP, a NO donor) is regulated by calcium-activated potassium (KCa) channels and cyclooxygenase (COX) in young adults. We also hypothesized that these contributions are diminished in older adults given that aging can downregulate KCa channels and reduce COX-derived vasodilator prostanoids. In 10 young (23 ± 5 yr) and 10 older (54 ± 4 yr) adults, cutaneous vascular conductance (CVC) was measured at four forearm skin sites infused with 1) Ringer (Control), 2) 50 mM tetraethylammonium (TEA), a nonspecific KCa channel blocker, 3) 10 mM ketorolac, a nonspecific COX inhibitor, or 4) 50 mM TEA + 10 mM ketorolac via intradermal microdialysis. All skin sites were coinfused with incremental doses of SNP (0.005, 0.05, 0.5, 5, and 50 mM each for 25 min). During SNP administration, CVC was similar at the ketorolac site (0.005-50 mM, all P > 0.05) relative to Control, but lower at the TEA and TEA + ketorolac sites (0.005-0.05 mM, all P < 0.05) in young adults. In older adults, ketorolac increased CVC relative to Control during 0.005-0.05 mM SNP administration (all P < 0.05), but this increase was not observed when TEA was coadministered (all P > 0.05). Furthermore, TEA alone did not modulate CVC during any concentration of SNP administration in older adults (all P > 0.05). We show that during low-dose NO administration (e.g., 0.005-0.05 mM), KCa channels contribute to cutaneous blood flow regulation in young adults; however, in older adults, COX inhibition increases cutaneous blood flow through a KCa channel-dependent mechanism.
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Affiliation(s)
- Naoto Fujii
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada
| | | | - Vienna E Brunt
- Department of Human Physiology, The University of Oregon, Eugene, Oregon
| | - Pierre Boulay
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, Canada; and
| | - Ronald J Sigal
- Departments of Medicine, Cardiac Sciences and Community Health Sciences, Faculties of Medicine and Kinesiology, University of Calgary, Calgary, Canada
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada;
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25
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Gagliano-Jucá T, Napolitano M, Del Grossi Ferraz Carvalho F, Campos R, Mónica FZ, Claudino MA, Antunes E, Lopes AG, De Nucci G. Hydrochlorothiazide Potentiates Contractile Activity of Mouse Cavernosal Smooth Muscle. Sex Med 2016; 4:e113-23. [PMID: 27006319 PMCID: PMC5005312 DOI: 10.1016/j.esxm.2016.02.003] [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: 11/24/2015] [Revised: 02/04/2016] [Accepted: 02/21/2016] [Indexed: 11/24/2022] Open
Abstract
Introduction Hydrochlorothiazide has a negative influence on penile erection but little is known about the mechanism(s) involved. Aims To characterize the effects of this diuretic on mouse corpus cavernosum (CC) smooth muscle in vitro and ex vivo. Methods CC strips of C57BL/6 mice (12–16 weeks old) were mounted in organ baths containing Krebs-Henseleit solution and tissue reactivity was evaluated. Expression of genes encoding diuretic targets and enzymes involved in penile erection were evaluated by polymerase chain reaction. Main Outcome Measures Stimulation-response curves to phenylephrine (10 nmol/L–100 μmol/L) or to electrical field stimulation (1–32 Hz) were constructed, with or without hydrochlorothiazide. Strips of CC from mice after long-term hydrochlorothiazide treatment (6 mg/kg/day for 4 weeks) with or without amiloride (0.6 mg/kg/day for 4 weeks) in vivo also were studied. Nitric oxide and Rho-kinase pathways were evaluated. Results Hydrochlorothiazide (100 μmol/L) increased the maximum response to phenylephrine by 64% in vitro. This effect was unaffected by the addition of indomethacin (5 μmol/L) but was abolished by N(ω)-nitro-L-arginine methyl ester (100 μmol/L). Hydrochlorothiazide (100 μmol/L) potentiated electrical field stimulation-induced contraction in vitro, but not ex vivo. Long-term treatment with hydrochlorothiazide increased the maximum response to phenylephrine by 60% and resulted in a plasma concentration of 500 ± 180 nmol/L. Amiloride (100μmol/L) caused rightward shifts in concentration-response curves to phenylephrine in vitro. Long-term treatment with hydrochlorothiazide plus amiloride did not significantly increase the maximum response to phenylephrine (+13%). Reverse transcriptase polymerase chain reaction did not detect the NaCl cotransporter in mouse CC. Hydrochlorothiazide did not change Rho-kinase activity, whereas amiloride decreased it in vitro and ex vivo (approximately 18% and 24% respectively). A 40% decrease in Rock1 expression also was observed after long-term treatment with hydrochlorothiazide plus amiloride. Conclusion Hydrochlorothiazide potentiates contraction of smooth muscle from mouse CC. These findings could explain why diuretics such as hydrochlorothiazide are associated with erectile dysfunction.
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Affiliation(s)
- Thiago Gagliano-Jucá
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Mauro Napolitano
- Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo (USP), Sao Paulo, SP, Brazil.
| | | | - Rafael Campos
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Fabíola Zakia Mónica
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Mário Angelo Claudino
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Edson Antunes
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Anibal Gil Lopes
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Gilberto De Nucci
- Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo (USP), Sao Paulo, SP, Brazil; Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
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Abstract
Antihypertensive agents are commonly prescribed by physicians to prevent the long-term mortality from chronic hypertension. They are also given to improve survival in a number of conditions (eg, heart failure, coronary artery disease), independent of the effect on blood pressure. Several classes of antihypertensives are available with unique pharmacologic characteristics and adverse effects. Not all agents in the same class have identical effects, and careful selection of drugs based on the comorbid conditions is recommended.
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Abstract
PURPOSE OF REVIEW Chronic kidney disease is common, associated with increased cardiovascular risk, and frequently complicated by hypertension, requiring multiple agents for control. Thiazides are naturally attractive for use in this population; unfortunately, they are classically thought to be ineffective in advanced chronic kidney disease based on both theoretical considerations and the earliest studies of these agents. This report reviews the studies of thiazide use in chronic kidney disease since the 1970s, including five randomized controlled trials, all of which report at least some degree of efficacy. RECENT FINDINGS Two recent studies add further evidence for the utility and efficacy of thiazides in chronic kidney disease. Of these two, one used gold standard ambulatory blood pressure monitoring in patients with poorly controlled hypertension and advanced chronic kidney disease and found chlorthalidone reduces blood pressure. The second is the largest study to date of thiazides in chronic kidney disease; adding a fixed low-dose chlorthalidone as the first diuretic to the antihypertensive regimen improved blood pressure. SUMMARY These numerous small but positive studies reinforce the need for a randomized trial to demonstrate safety and efficacy of thiazides in advanced chronic kidney disease.
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Is there a preferred diuretic class for patients with renal impairment and hypertension? ACTA ACUST UNITED AC 2016; 10:282-4. [PMID: 26979914 DOI: 10.1016/j.jash.2016.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 02/13/2016] [Indexed: 11/20/2022]
Abstract
It is widely believed that "high-ceiling" loop diuretics are required in patients with renal impairment and that "low-ceiling" thiazides are not sufficiently potent to cause meaningful natriuresis and diuresis. If this statement is true, at what level of renal function do thiazides lose their punch? Another related issue is the enlightened use of diuretic combinations. Use of diuretics in chronic kidney disease and hypertension has been addressed in the many guidelines, but further insight is provided in this installment of the "Controversies" series by two well-known authorities, William Elliott, M.D. Ph.D. and Rajiv Agarwal, M.D.
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Därr R, Bursztyn M, Pamporaki C, Peitzsch M, Siegert G, Bornstein SR, Eisenhofer G. Dipping in Ambulatory Blood Pressure Monitoring Correlates With Overnight Urinary Excretion of Catecholamines and Sodium. J Clin Hypertens (Greenwich) 2016; 18:921-6. [DOI: 10.1111/jch.12791] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/05/2015] [Accepted: 12/10/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Roland Därr
- Department of Medicine III; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
| | - Michael Bursztyn
- Department of Medicine; Hypertension Unit; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Christina Pamporaki
- Department of Medicine III; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
| | - Mirko Peitzsch
- Institute of Clinical Chemistry and Laboratory Medicine; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
| | - Gabriele Siegert
- Institute of Clinical Chemistry and Laboratory Medicine; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
| | - Stefan R. Bornstein
- Department of Medicine III; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
| | - Graeme Eisenhofer
- Department of Medicine III; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
- Institute of Clinical Chemistry and Laboratory Medicine; University Hospital Carl Gustav Carus at the Technische Universität Dresden; Dresden Germany
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Shahin MH, Johnson JA. Mechanisms and pharmacogenetic signals underlying thiazide diuretics blood pressure response. Curr Opin Pharmacol 2016; 27:31-7. [PMID: 26874237 DOI: 10.1016/j.coph.2016.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 01/12/2016] [Indexed: 01/13/2023]
Abstract
Thiazide (TZD) diuretics are among the most commonly prescribed antihypertensives globally; however their chronic blood pressure (BP) lowering mechanism remains unclear. Herein we discuss the current evidence regarding specific mechanisms regulating the antihypertensive effects of TZDs, suggesting that TZDs act via multiple complex and interacting mechanisms, including natriuresis with short term use and direct vasodilatory effects chronically. Additionally, we review pharmacogenomics signals that have been associated with TZDs BP-response in several cohorts (i.e. NEDD4L, PRKCA, EDNRA-GNAS, and YEATS4) and discuss how these genes might be related to TZD BP-response mechanism. Understanding the association between these genes and TZD BP mechanism might facilitate the development of new drugs and therapeutic approaches based on a deeper understanding of the determinants of BP-response.
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Affiliation(s)
- Mohamed H Shahin
- Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics, College of Pharmacy, University of Florida, Gainesville, FL, USA
| | - Julie A Johnson
- Department of Pharmacotherapy and Translational Research, Center for Pharmacogenomics, College of Pharmacy, University of Florida, Gainesville, FL, USA.
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Abstract
Widely prevalent in the general population, chronic kidney disease (CKD) is frequently complicated with hypertension. Control of hypertension in this high-risk population is a major modifiable cardiovascular and renal risk factor but often requires multiple medications. Although thiazides are an attractive agent, guidelines have previously recommended against thiazide use in stage 4 CKD. We review the updated guidelines on thiazide use in advanced CKD, the antihypertensive mechanism of thiazides, and the clinical studies of thiazides in CKD. Older uncontrolled studies have shown that metolazone reduces blood pressure in CKD, but more recently small randomized controlled trials of hydrochlorothiazide in CKD have shown significant improvement in mean arterial pressure of 15 mmHg. Two recent uncontrolled studies of chlorthalidone including one that used ambulatory blood pressure monitoring found significant improvements in blood pressure. These findings all suggest that thiazides may be efficacious even in advanced CKD; however, electrolyte abnormalities were common in the studies reviewed so close monitoring is necessary during use. Adequately powered randomized trials are now needed before the routine use of thiazide diuretics in advanced CKD can be recommended.
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Arias SCA, Souza RA, Malheiros DMAC, Fanelli C, Fujihara CK, Zatz R. An association of losartan-hydrochlorothiazide, but not losartan-furosemide, completely arrests progressive injury in the remnant kidney. Am J Physiol Renal Physiol 2016; 310:F135-43. [DOI: 10.1152/ajprenal.00388.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/03/2015] [Indexed: 11/22/2022] Open
Abstract
We have previously shown that an association of losartan and hydrochlorothiazide, initiated 1 mo after 5/6 nephrectomy (Nx), reversed hypertension and albuminuria and promoted lasting renoprotection. In this new study, we investigated whether equal or even better protection could be obtained by combining losartan and furosemide. Nx was performed in 58 Munich-Wistar rats. One month later, tail-cuff pressure and albuminuria were markedly elevated. At this time, Nx rats were distributed among the following four groups: untreated Nx rats, Nx rats that received losartan, Nx rats that received losartan + hydrochlorothiazide, and Nx rats that received losartan + furosemide. Seven months later, Nx rats exhibited high mortality, severe hypertension, albuminuria, glomerulosclerosis, and interstitial fibrosis. Losartan treatment limited mortality and attenuated the renal and hemodynamic abnormalities associated with Nx. As previously shown, the losartan + hydrochlorothiazide association normalized tail-cuff pressure and albumin, prevented renal injury, and reduced mortality to zero. The losartan + furosemide treatment failed to reduce tail-cuff pressure or albumin to normal and prevented renal injury less efficiently than the losartan and hydrochlorothiazide regimen. The reasons for the differing efficacies of the losartan + furosemide and losartan + hydrochlorothiazide schemes are unclear and may include beneficial nondiuretic actions of thiazides, such as vasorelaxation and antiproliferative activity. These results refute the established concept that thiazides and thiazide-like diuretics are ineffective at advanced chronic kidney disease stages. Rather, they suggest that, in view of their renoprotective action, these compounds may even be preferable to loop diuretics in the management of hypertension in advanced chronic kidney disease.
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Affiliation(s)
- Simone Costa Alarcon Arias
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Renata Alves Souza
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | | - Camilla Fanelli
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Clarice Kazue Fujihara
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Roberto Zatz
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
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Huang CC, Leu HB, Huang PH, Lin LY, Wu TC, Lin SJ, Chen JW. Hypertension subtypes modify metabolic response to thiazide diuretics. Eur J Clin Invest 2016; 46:80-91. [PMID: 26584406 DOI: 10.1111/eci.12571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 11/12/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND Blood pressure (BP) and metabolic response to thiazide diuretics might be varied in patients with different hypertension subtypes and ethnicities. This study aimed to investigate the response of BP and metabolic profiles to short-term thiazide treatment in an Asian cohort with different hypertension subtypes. DESIGN Serial ethnic Chinese nondiabetic subjects with hypertension were evaluated. After diet instruction and lifestyle modification for 2 weeks, patients who still had elevated systolic BP (SBP≥140 mmHg) and/or diastolic BP (DBP≥90 mmHg) were given 50 mg of hydrochlorothiazide daily for 2 weeks. The responses of BP and metabolic profiles were evaluated before and after treatment according to the patient's baseline BP subtype - isolated systolic hypertension (ISH), systo-diastolic hypertension (SDH) and isolated diastolic hypertension (IDH). RESULTS Hydrochlorothiazide treatment significantly reduced the BP in all 92 patients (62 males, aged 45·7 ± 9·6 years), irrespective of their baseline BP subtypes. In patients with SDH (n = 39) or IDH (n = 40), hydrochlorothiazide treatment significantly increased serum adiponectin (P = 0·001 and 0·007, respectively) and reduced asymmetric dimethylarginine levels (P < 0·001, in both groups). Serum cholesterol (P = 0·027) and fasting blood sugar levels (P = 0·044) were significantly improved only in the IDH patients. Furthermore, IDH was independently associated with changes in fasting blood sugar (β = -11·178, P = 0·022) and cholesterol (β = -22·654, P = 0·027). CONCLUSIONS The characteristics of the Asian hypertensive patients with diastolic hypertension can present a favourable metabolic response to the short-term hydrochlorothiazide treatment. The potential positive effect on cardiovascular risk should be validated in long-term studies in this diastolic type of hypertension.
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Affiliation(s)
- Chin-Chou Huang
- Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan.,Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medicine, National Yang-Ming University, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Hsin-Bang Leu
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medicine, National Yang-Ming University, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Healthcare and Management Center, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Po-Hsun Huang
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medicine, National Yang-Ming University, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Liang-Yu Lin
- Department of Medicine, National Yang-Ming University, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.,Division of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Tao-Cheng Wu
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medicine, National Yang-Ming University, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Shing-Jong Lin
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.,Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jaw-Wen Chen
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.,Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.,Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
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34
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Hamrahian SM, Falkner B. Hypertension in Chronic Kidney Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 956:307-325. [PMID: 27873228 DOI: 10.1007/5584_2016_84] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hypertension, a global public health problem, is currently the leading factor in the global burden of disease. It is the major modifiable risk factor for heart disease, stroke and kidney failure. Chronic kidney disease (CKD) is both a common cause of hypertension and CKD is also a complication of uncontrolled hypertension. The interaction between hypertension and CKD is complex and increases the risk of adverse cardiovascular and cerebrovascular outcomes. This is particularly significant in the setting of resistant hypertension commonly seen in patient with CKD. The pathophysiology of CKD associated hypertension is multi-factorial with different mechanisms contributing to hypertension. These pathogenic mechanisms include sodium dysregulation, increased sympathetic nervous system and alterations in renin angiotensin aldosterone system activity. Standardized blood pressure (BP) measurement is essential in establishing the diagnosis and management of hypertension in CKD. Use of ambulatory blood pressure monitoring provides an additional assessment of diurnal variation in BP commonly seen in CKD patients. The optimal BP target in the treatment of hypertension in general and CKD population remains a matter of debate and controversial despite recent guidelines and clinical trial data. Medical therapy of patients with CKD associated hypertension can be difficult and challenging. Additional evaluation by a hypertension specialist may be required in the setting of treatment resistant hypertension by excluding pseudo-resistance and treatable secondary causes. Treatment with a combination of antihypertensive drugs, including appropriate diuretic choice, based on estimated glomerular filtration rate, is a key component of hypertension management in CKD patients. In addition to drug treatment non-pharmacological approaches including life style modification, most important of which is dietary salt restriction, should be included in the management of hypertension in CKD patients.
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Affiliation(s)
- Seyed Mehrdad Hamrahian
- Division of Nephrology, Department of Medicine, Sidney Kimmel School of Medicine, Thomas Jefferson University, 833 Chestnut Street, Suite 700, Philadelphia, PA, 19107, USA.
| | - Bonita Falkner
- Division of Nephrology, Department of Medicine, Sidney Kimmel School of Medicine, Thomas Jefferson University, 833 Chestnut Street, Suite 700, Philadelphia, PA, 19107, USA
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35
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Brunt VE, Fujii N, Minson CT. Endothelial-derived hyperpolarization contributes to acetylcholine-mediated vasodilation in human skin in a dose-dependent manner. J Appl Physiol (1985) 2015; 119:1015-22. [PMID: 26384409 DOI: 10.1152/japplphysiol.00201.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 09/16/2015] [Indexed: 11/22/2022] Open
Abstract
Cutaneous acetylcholine (ACh)-mediated dilation is commonly used to assess microvascular function, but the mechanisms of dilation are poorly understood. Depending on dose and method of administration, nitric oxide (NO) and prostanoids are involved to varying extents and the roles of endothelial-derived hyperpolarizing factors (EDHFs) are unclear. In the present study, five incremental doses of ACh (0.01-100 mM) were delivered either as a 1-min bolus (protocol 1, n = 12) or as a ≥20-min continuous infusion (protocol 2, n = 10) via microdialysis fibers infused with 1) lactated Ringer, 2) tetraethylammonium (TEA) [a calcium-activated potassium channel (KCa) and EDHF inhibitor], 3) L-NNA+ketorolac [NO synthase (NOS) and cyclooxygenase (COX) inhibitors], and 4) TEA+L-NNA+Ketorolac. The hyperemic response was characterized as peak and area under the curve (AUC) cutaneous vascular conductance (CVC) for bolus infusions or plateau CVC for continuous infusions, and reported as %maximal CVC. In protocol 1, TEA, alone and combined with NOS+COX inhibition, attenuated peak CVC (100 mM Ringer 59 ± 6% vs. TEA 43 ± 5%, P < 0.05; L-NNA+ketorolac 35 ± 4% vs. TEA+L-NNA+ketorolac 25 ± 4%, P < 0.05) and AUC (Ringer 25,414 ± 3,528 vs. TEA 21,403 ± 3,416%·s, P < 0.05; L-NNA+ketorolac 25,628 ± 3,828%(.)s vs. TEA+L-NNA+ketorolac 20,772 ± 3,711%·s, P < 0.05), although these effects were only significant at the highest dose of ACh. At lower doses, TEA lengthened the total time of the hyperemic response (10 mM Ringer 609 ± 78 s vs. TEA 860 ± 67 s, P < 0.05). In protocol 2, TEA alone did not affect plateau CVC, but attenuated plateau in combination with NOS+COX inhibition (100 mM 50.4 ± 6.6% vs. 30.9 ± 6.3%, P < 0.05). Therefore, EDHFs contribute to cutaneous ACh-mediated dilation, but their relative contribution is altered by the dose and infusion procedure.
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Affiliation(s)
- Vienna E Brunt
- Department of Human Physiology, University of Oregon, Eugene, Oregon; and
| | - Naoto Fujii
- Department of Human Physiology, University of Oregon, Eugene, Oregon; and Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Ontario, Canada
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36
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Swenson ER. New insights into carbonic anhydrase inhibition, vasodilation, and treatment of hypertensive-related diseases. Curr Hypertens Rep 2015; 16:467. [PMID: 25079851 DOI: 10.1007/s11906-014-0467-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Carbonic anhydrase (CA) and its inhibitors are relevant to many physiological processes and diseases. The enzyme is differentially expressed throughout the body, in concentration and subcellular location, and as 13 catalytically active isoforms. Blood vessels contain small amounts of CA, but the enzyme's role in vascular physiology and blood pressure regulation is uncertain. However, considerable recent evidence points to vasodilation by CA inhibitors. CA inhibition in vascular smooth muscle, endothelium, heart, blood cells, and nervous system could all contribute. It is equally plausible that other targets besides CA for all known CA inhibitors may account for their vascular effects. I will review this knowledge and important remaining gaps relating to treatment of hypertensive-related diseases with potent sulfonamide inhibitors, such as acetazolamide; but also the possibility that CA inhibition by thiazides and loop diuretics, although generally weaker, may have antihypertensive effects beyond their inhibition of renal sodium transporters.
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Affiliation(s)
- Erik R Swenson
- Department of Veterans Affairs, Pulmonary and Critical Care Medicine, VA Puget Sound Health Care System, University of Washington, 1660 South Columbian Way, Seattle, WA, USA,
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37
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Sinnakirouchenan R, Kotchen TA. Role of Sodium Restriction and Diuretic Therapy for “Resistant” Hypertension in Chronic Kidney Disease. Semin Nephrol 2014; 34:514-9. [DOI: 10.1016/j.semnephrol.2014.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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38
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Choi PJ, Brunt VE, Fujii N, Minson CT. New approach to measure cutaneous microvascular function: an improved test of NO-mediated vasodilation by thermal hyperemia. J Appl Physiol (1985) 2014; 117:277-83. [PMID: 24903917 DOI: 10.1152/japplphysiol.01397.2013] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cutaneous hyperemia in response to rapid skin local heating to 42°C has been used extensively to assess microvascular function. However, the response is dependent on both nitric oxide (NO) and endothelial-derived hyperpolarizing factors (EDHFs), and increases cutaneous vascular conductance (CVC) to ∼90-95% maximum in healthy subjects, preventing the study of potential means to improve cutaneous function. We sought to identify an improved protocol for isolating NO-dependent dilation. We compared nine heating protocols (combinations of three target temperatures: 36°C, 39°C, and 42°C, and three rates of heating: 0.1°C/s, 0.1°C/10 s, 0.1°C/min) in order to select two protocols to study in more depth (protocol 1; N = 6). Then, CVC was measured at four microdialysis sites receiving: 1) lactated Ringer solution (Control), 2) 50-mM tetraethylammonium (TEA) to inhibit EDHFs, 3) 20-mM nitro-L-arginine methyl ester (L-NAME) to inhibit NO synthase, and 4) TEA+L-NAME, in response to local heating either to 39°C at 0.1°C/s (protocol 2; N = 10) or 42°C at 0.1°C/min (protocol 3; N = 8). Rapid heating to 39°C increased CVC to 43.1 ± 5.2%CVCmax (Control), which was attenuated by L-NAME (11.4 ± 2.8%CVCmax; P < 0.001) such that 82.8 ± 4.2% of the plateau was attributable to NO. During gradual heating, 81.5 ± 3.3% of vasodilation was attributable to NO at 40°C, but at 42°C only 32.7 ± 7.8% of vasodilation was attributable to NO. TEA+L-NAME attenuated CVC beyond L-NAME at temperatures >40°C (43.4 ± 4.5%CVCmax at 42°C, P < 0.001 vs. L-NAME), suggesting a role of EDHFs at higher temperatures. Our findings suggest local heating to 39°C offers an improved approach for isolating NO-dependent dilation and/or assessing perturbations that may improve microvascular function.
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Affiliation(s)
- Patricia J Choi
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Vienna E Brunt
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Naoto Fujii
- Department of Human Physiology, University of Oregon, Eugene, Oregon
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39
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Tamargo J, Segura J, Ruilope LM. Diuretics in the treatment of hypertension. Part 1: thiazide and thiazide-like diuretics. Expert Opin Pharmacother 2014; 15:527-47. [DOI: 10.1517/14656566.2014.879118] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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40
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Moes AD, van der Lubbe N, Zietse R, Loffing J, Hoorn EJ. The sodium chloride cotransporter SLC12A3: new roles in sodium, potassium, and blood pressure regulation. Pflugers Arch 2013; 466:107-18. [PMID: 24310820 DOI: 10.1007/s00424-013-1407-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 12/14/2022]
Abstract
SLC12A3 encodes the thiazide-sensitive sodium chloride cotransporter (NCC), which is primarily expressed in the kidney, but also in intestine and bone. In the kidney, NCC is located in the apical plasma membrane of epithelial cells in the distal convoluted tubule. Although NCC reabsorbs only 5 to 10% of filtered sodium, it is important for the fine-tuning of renal sodium excretion in response to various hormonal and non-hormonal stimuli. Several new roles for NCC in the regulation of sodium, potassium, and blood pressure have been unraveled recently. For example, the recent discoveries that NCC is activated by angiotensin II but inhibited by dietary potassium shed light on how the kidney handles sodium during hypovolemia (high angiotensin II) and hyperkalemia. The additive effect of angiotensin II and aldosterone maximizes sodium reabsorption during hypovolemia, whereas the inhibitory effect of potassium on NCC increases delivery of sodium to the potassium-secreting portion of the nephron. In addition, great steps have been made in unraveling the molecular machinery that controls NCC. This complex network consists of kinases and ubiquitinases, including WNKs, SGK1, SPAK, Nedd4-2, Cullin-3, and Kelch-like 3. The pathophysiological significance of this network is illustrated by the fact that modification of each individual protein in the network changes NCC activity and results in salt-dependent hypotension or hypertension. This review aims to summarize these new insights in an integrated manner while identifying unanswered questions.
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Affiliation(s)
- Arthur D Moes
- Department of Internal Medicine, Erasmus Medical Center, PO Box 2040, Room H-438, 3000 CA, Rotterdam, The Netherlands
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41
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Brunt VE, Fujii N, Minson CT. No independent, but an interactive, role of calcium-activated potassium channels in human cutaneous active vasodilation. J Appl Physiol (1985) 2013; 115:1290-6. [PMID: 23970531 DOI: 10.1152/japplphysiol.00358.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In human cutaneous microvasculature, endothelium-derived hyperpolarizing factors (EDHFs) account for a large portion of vasodilation associated with local stimuli. Thus we sought to determine the role of EDHFs in active vasodilation (AVD) to passive heating in two protocols. Whole body heating was achieved using water-perfused suits (core temperature increase of 0.8-1.0°C), and skin blood flow was measured using laser-Doppler flowmetry. In the first protocol, four sites were perfused continuously via microdialysis with: 1) control; 2) tetraethylammonium (TEA) to block calcium-activated potassium (KCa) channels, and thus the actions of EDHFs; 3) N-nitro-l-arginine methyl ester (l-NAME) to inhibit nitric oxide synthase (NOS); and 4) TEA + l-NAME (n = 8). Data are presented as percent maximal cutaneous vascular conductance (CVC). TEA had no effect on AVD (CVC during heated plateau: control 57.4 ± 4.9% vs. TEA 63.2 ± 5.2%, P = 0.27), indicating EDHFs are not obligatory. l-NAME attenuated plateau CVC to 33.7 ± 5.4% (P < 0.01 vs. control); while TEA + l-NAME augmented plateau CVC compared with l-NAME alone (49.7 ± 5.3%, P = 0.02). From these data, it appears combined blockade of EDHFs and NOS necessitates dilation through other means, possibly through inward rectifier (KIR) and/or ATP-sensitive (KATP) potassium channels. To test this second hypothesis, we measured AVD at the following sites (n = 8): 1) control, 2) l-NAME, 3) l-NAME + TEA, and 4) l-NAME + TEA + barium chloride (BaCl2; KIR and KATP blocker). The addition of BaCl2 to l-NAME + TEA reduced plateau CVC to 32.7 ± 6.6% (P = 0.02 vs. l-NAME + TEA), which did not differ from the l-NAME site. These data combined demonstrate a complex interplay between vasodilatory pathways, with cross-talk between NO, KCa channels, and KIR and/or KATP channels.
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Affiliation(s)
- Vienna E Brunt
- Department of Human Physiology, University of Oregon, Eugene, Oregon
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Karadsheh F, Weir MR. Thiazide and thiazide-like diuretics: an opportunity to reduce blood pressure in patients with advanced kidney disease. Curr Hypertens Rep 2013; 14:416-20. [PMID: 22886538 DOI: 10.1007/s11906-012-0293-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Thiazide and thiazide-like diuretics have been widely used as blood pressure-lowering agents for more than 5 decades. However, their use in patients with advanced chronic kidney disease has been limited and often discouraged. The exact mechanism of how thiazide and thiazide-like diuretics lower blood pressures is still in question. Emerging evidence suggests that thiazides and thiazide-like diuretics are effective as blood pressure-lowering drugs in patients with advanced chronic kidney disease. Review of the literature suggests that physicians should not discard thiazide and thiazide-like diuretics as options for blood pressure management in patients with chronic advanced kidney disease.
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Affiliation(s)
- Feras Karadsheh
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Chan CY, Peterson EJ, Ng TMH. Thiazide Diuretics as Chronic Antihypertensive Therapy in Patients with Severe Renal Disease—Is There a Role in the Absence of Diuresis? Ann Pharmacother 2012; 46:1554-8. [DOI: 10.1345/aph.1r212] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE: To determine whether thiazides have a chronic antihypertensive effect, in the absence of diuresis, in patients with severe renal disease (creatinine clearance <30 mL/min) or in those receiving dialysis. DATA SOURCES: A search was performed in PubMed, CENTRAL, and International Pharmaceutical Abstracts, using MeSH terms and/or key words. MeSH terms included kidney failure, chronic and exploded terms hydrochlorothiazide, renal dialysis, and thiazides. Key words included thiazide*, hydrochlorothiazide, chlorothiazide, chlorthalidone, indapamide, metolazone, methyclothiazide, bendroflumethiazide, hemodialysis, dialysis, kidney failure, renal failure, renal insufficiency, hypertension, vasodilation, vascular, and diuretics. STUDY SELECTION AND DATA EXTRACTION: All relevant English-language publications were evaluated. Studies evaluating the efficacy of thiazides in renal insufficiency or dialysis were limited to those that included blood pressure measurements. Studies were included only if treatment duration was at least 4 weeks to evaluate chronic antihypertensive effects. DATA SYNTHESIS: Thiazide diuretics are associated with a chronic reduction in peripheral vascular resistance secondary to a purported vasodilatory effect. However, few clinical studies have evaluated the chronic antihypertensive efficacy of thiazide and thiazide-like diuretics in patients with severe renal disease or those on dialysis. Agents studied include hydrochlorothiazide, chlorothiazide, indapamide, and metolazone, with results varying by drug and patient population. Hydrochlorothiazide 25–200 mg daily, chlorothiazide 500 mg twice daily, and indapamide 2.5 mg daily provided long-term blood pressure reduction in patients with severe renal disease who were not on dialysis. In studies involving patients on dialysis, hydrochlorothiazide 50 mg daily and metolazone 5 mg daily did not affect blood pressure; however, 1 study suggested that indapamide 2.5 mg daily may confer an antihypertensive effect. All studies were small (≤12 subjects) and had methodological limitations. CONCLUSIONS: Thiazide diuretics may decrease peripheral vascular resistance independent of natriuresis. However, because current clinical data are inconclusive as to the efficacy of these agents at chronically lowering blood pressure in patients with severe renal disease or in those on dialysis, thiazide diuretics cannot be routinely recommended for this indication.
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Affiliation(s)
- Cynthia Y Chan
- Cynthia Y Chan PharmD, at time of writing, PGY1 Resident in Pharmacy Practice, School of Pharmacy, University of Southern California, Los Angeles, CA
| | - Evan J Peterson
- Evan J Peterson PharmD, at time of writing, PGY2 Resident in Cardiology, School of Pharmacy, University of Southern California
| | - Tien MH Ng
- Tien MH Ng PharmD FCCP BCPS (AQ-C), Associate Professor of Clinical Pharmacy, School of Pharmacy, University of Southern California
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Brunt VE, Minson CT. KCa channels and epoxyeicosatrienoic acids: major contributors to thermal hyperaemia in human skin. J Physiol 2012; 590:3523-34. [PMID: 22674719 DOI: 10.1113/jphysiol.2012.236398] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
While it is accepted that NO is responsible for ∼60% of the plateau in cutaneous thermal hyperaemia, a large portion of the response remains unknown. We sought to determine whether the remaining ∼40% could be attributed to EDHF-mediated activation of KCa channels, and whether the epoxyeicosatrienoic acids (EETs), derived via cytochrome P450, were the predominant EDHF active in the response. Four microdialysis fibres were placed in the forearm skin of 20 subjects. In Protocol 1 (n = 10): (1) Control, (2) N(G)-nitro-l-arginine methyl ester (l-NAME), (3) a KCa channel inhibitor, tetraethylammonium (TEA), and (4) TEA + l-NAME. In Protocol 2 (n = 10): (1) Control, (2) l-NAME, (3) a cytochrome P450 inhibitor, sulfaphenazole, and (4) sulfaphenazole + l-NAME. Local heating to 42°C was performed and skin blood flow was measured with laser Doppler flowmetry. Data are presented as the percentage of maximal cutaneous vascular conductance (CVC). All drug sites attenuated plateau CVC from the control site (86 ± 1%) to 79 ± 3% with sulfaphenazole (P = 0.02 from control), 71 ± 3% with TEA (P = 0.01 from control), and further to 38 ± 2% with l-NAME (P < 0.001 from control, P < 0.001 from TEA). Plateau was largely attenuated with sulfaphenazole + l-NAME (24 ± 2%; P = 0.002 from l-NAME), and nearly abolished with l-NAME + TEA (13 ± 2%; P = 0.001 from sulfaphenazole + l-NAME), which was not different from baseline (P = 0.14). Furthermore, the initial peak was just 17 ± 2% with TEA + l-NAME (P < 0.001 from l-NAME). These data suggest EDHFs are responsible for a large portion of initial peak and the remaining 40% of the plateau phase, as administration of TEA in combination with l-NAME abolished the majority of hyperaemia. These data also suggest EETs contribute to about half of the EDHF response.
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Affiliation(s)
- Vienna E Brunt
- Department of Human Physiology, University of Oregon, Eugene, OR 97403-1240, USA
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Simple RP-HPLC method for determination of triple drug combination of valsartan, amlodipine and hydrochlorothiazide in human plasma. ACTA PHARMACEUTICA 2012; 62:45-58. [PMID: 22472448 DOI: 10.2478/v10007-012-0004-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A simple RP-HPLC method for the quantification of valsartan (VAL), amlodipine (AML) and hydrochlorothiazide (HCT) in human plasma was developed and validated. VAL, AML and HCT were resolved using a Gemini C18 column and mobile phase gradient starting from 20 % acetonitrile and 80 % 10 mmol L(-1) ammonium formate (V/V, pH 3.5 ± 0.2, by formic acid) to 70 % acetonitrile and 30 % 10 mmol L(-1) ammonium formate, over 20 minutes, with a flow rate of 1 mL min(-1). The samples were purified by protein precipitation and extraction. Telmisartan was used as internal standard. The method was validated according to USFDA and EMEA guidelines with good reproducibility and linear responses R = 0.9985 (VAL), 0.9964 (AML), and 0.9971 (HCT). RSDs of intra- and inter-day precision ranged 2.2-8.1 and 4.6-11.7 %, respectively, for all three drugs. Mean extraction recoveries of three QCs for the triple drug combination were 76.5 (VAL), 72.0 (AML) and 73.0 (HCT) % for human plasma. Although the LC-MS/MS method is more sensitive than HPLC, HPLC is still suitable for preliminary pharmacokinetic study. The experiments performed demostrated that simultaneous determination of all components of the triple drug combination in human plasma can be done by this method. Proposed method can be also used for guidance to the LC-MS/MS method.
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Ozkor MA, Quyyumi AA. Endothelium-derived hyperpolarizing factor and vascular function. Cardiol Res Pract 2011; 2011:156146. [PMID: 21876822 PMCID: PMC3157651 DOI: 10.4061/2011/156146] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/27/2011] [Accepted: 05/27/2011] [Indexed: 01/20/2023] Open
Abstract
Endothelial function refers to a multitude of physiological processes that maintain healthy homeostasis of the vascular wall. Exposure of the endothelium to cardiac risk factors results in endothelial dysfunction and is associated with an alteration in the balance of vasoactive substances produced by endothelial cells. These include a reduction in nitric oxide (NO), an increase in generation of potential vasoconstrictor substances and a potential compensatory increase in other mediators of vasodilation. The latter has been surmised from data demonstrating persistent endothelium-dependent vasodilatation despite complete inhibition of NO and prostaglandins. This remaining non-NO, non-prostaglandin mediated endothelium-dependent vasodilator response has been attributed to endothelium-derived hyperpolarizing factor/s (EDHF). Endothelial hyperpolarization is likely due to several factors that appear to be site and species specific. Experimental studies suggest that the contribution of the EDHFs increase as the vessel size decreases, with a predominance of EDHF activity in the resistance vessels, and a compensatory up-regulation of hyperpolarization in states characterized by reduced NO availability. Since endothelial dysfunction is a precursor for atherosclerosis development and its magnitude is a reflection of future risk, then the mechanisms underlying endothelial dysfunction need to be fully understood, so that adequate therapeutic interventions can be designed.
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Affiliation(s)
- Muhiddin A Ozkor
- The Heart Hospital, University College London, London WIG 8PH, UK
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Huang CC, Chung CM, Hung SI, Leu HB, Wu TC, Huang PH, Lin SJ, Pan WH, Chen JW. Genetic variation in renin predicts the effects of thiazide diuretics. Eur J Clin Invest 2011; 41:828-35. [PMID: 21261619 DOI: 10.1111/j.1365-2362.2011.02472.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND While genetic variants of renin-angiotensin-aldosterone system (RAAS) may modify the blood pressure (BP) response to thiazide diuretics, there was no evidence of genetic variations in renin (REN) playing a role. This study aimed to address the potential effects of genetic variations of RAAS on the response to initial treatment of hydrochlorothiazide (HCTZ). MATERIALS AND METHODS We enrolled nondiabetic hypertensive patients with a systolic blood pressure (SBP) ≥140 or a diastolic blood pressure (DBP) ≥90mmHg, who were either previously untreated or unsatisfactorily treated. After lifestyle modification and diet instruction for 2weeks, 90 patients with persistently elevated BP were given HCTZ 50 mg every morning for 2 weeks. Single nucleotide polymorphism markers were selected from genes involving in RAAS, including rs7079 and rs699 of angiotensinogen, rs4293 and rs4353 of angiotensin-converting enzyme and rs1464816 and rs11240688 of REN. RESULTS The patients were divided into three groups according to the SBP response after HCTZ. The upper 1/3 responders had older age (P=0·035), higher SBP (P=0·039), higher pulse pressure (P=0·006) and lower plasma REN activity (PRA) (P=0·020) when compared with the lower 1/3 responders. Renin rs11240688 CC polymorphism (β=9·931, corrected P=0·012), Log PRA (β=7·451, P=0·004) and baseline SBP (β=0·299, P=0·006) were the independent predictors for the BP lowering response. CONCLUSIONS In addition to PRA, renin rs11240688 CC polymorphism may also independently predict the effect of HCTZ.
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Affiliation(s)
- Chin-Chou Huang
- Department of Medical Research and Education Division of Cardiology, Department of Medicine, Taipei, Taiwan
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Yamada Y, Tsuboi K, Hattori T, Murase T, Ohtake M, Furukawa M, Ueyama J, Nishiyama A, Murohara T, Nagata K. Mechanism underlying the efficacy of combination therapy with losartan and hydrochlorothiazide in rats with salt-sensitive hypertension. Hypertens Res 2011; 34:809-16. [PMID: 21471973 DOI: 10.1038/hr.2011.34] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Although thiazide diuretics are commonly used to supplement angiotensin receptor blockers for treatment of hypertension, the mechanism underlying the therapeutic effects of this drug combination remains unclear. We investigated the antihypertensive and cardioprotective effects of combination therapy with losartan (LOS) and hydrochlorothiazide (HCTZ), in comparison with those of either drug alone, in Dahl salt-sensitive hypertensive rats. Rats fed a high-salt diet from 6 weeks of age were treated with LOS, HCTZ, both drugs (COMB) and vehicle from 6 to 11 weeks. The salt-induced increase in systolic blood pressure was attenuated moderately by LOS and to a greater extent by HCTZ and COMB. Left ventricular (LV) hypertrophy and fibrosis, diastolic dysfunction, as well as angiotensin-converting enzyme and angiotensin II type 1A (AT(1A)) receptor gene expression were attenuated similarly by LOS and HCTZ and more so by COMB. LOS downregulated expression of the AT(1A) receptor gene, without affecting that of the AT(2) receptor gene, in the aorta. In contrast, neither HCTZ nor COMB affected aortic expression of the AT(1A) receptor gene, but both markedly upregulated that of the AT(2) receptor gene. The salt-induced decrease in the plasma concentration of nitric oxide metabolites was attenuated substantially by LOS and abolished by both HCTZ and COMB. In conclusion, the combination of LOS and HCTZ attenuated hypertension, as well as LV remodeling and diastolic dysfunction, more effectively than did LOS or HCTZ alone in rats with salt-sensitive hypertension. Modulation of the cardiac and vascular renin-angiotensin system may have contributed to these beneficial effects of the drug combination.
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Affiliation(s)
- Yuichiro Yamada
- Department of Medical Technology, Nagoya University School of Health Sciences, Nagoya, Japan
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Duarte JD, Cooper-DeHoff RM. Mechanisms for blood pressure lowering and metabolic effects of thiazide and thiazide-like diuretics. Expert Rev Cardiovasc Ther 2010; 8:793-802. [PMID: 20528637 DOI: 10.1586/erc.10.27] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Thiazide and thiazide-like diuretics are among the most commonly used antihypertensives and have been available for over 50 years. However, the mechanism by which these drugs chronically lower blood pressure is poorly understood. Possible mechanisms include direct endothelial- or vascular smooth muscle-mediated vasodilation and indirect compensation to acute decreases in cardiac output. In addition, thiazides are associated with adverse metabolic effects, particularly hyperglycemia, and the mechanistic underpinnings of these effects are also poorly understood. Thiazide-induced hypokalemia, as well as other theories to explain these metabolic disturbances, including increased visceral adiposity, hyperuricemia, decreased glucose metabolism and pancreatic beta-cell hyperpolarization, may play a role. Understanding genetic variants with differential responses to thiazides could reveal new mechanistic candidates for future research to provide a more complete understanding of the blood pressure and metabolic response to thiazide diuretics.
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Affiliation(s)
- Julio D Duarte
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, 1600 SW Archer Road, Gainesville, FL 32610-0486, USA
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