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Agarwal R, Sinha AD, Tu W. Mechanisms of Antihypertensive Effect of Chlorthalidone in Advanced Chronic Kidney Disease: A Causal Mediation Analysis. Clin J Am Soc Nephrol 2024; 19:1025-1032. [PMID: 38865199 PMCID: PMC11321739 DOI: 10.2215/cjn.0000000000000484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024]
Abstract
Key Points Chlorthalidone reduces the amount of fluid and the BP, but fluid volume reduction is not the cause of lowering of BP. It is not volume loss but the response to volume loss such as the synthesis of substances that lower BP is important. Background Chlorthalidone (CTD) in a chronic kidney disease randomized trial demonstrated a robust reduction in systolic BP in stage 4 CKD. In this study, we explore the mechanisms underlying the antihypertensive effect of CTD. Methods In this prespecified analysis, we analyzed the contributions of baseline levels of 24-hour urinary sodium and aldosterone and the changes from baseline to 4 weeks in the multiple mediators reflecting volume status in a causal mediation analysis framework. Baseline levels of these mediators served as covariates. No power calculation for this analysis was performed. Results Of the 160 patients randomized, 140 (87.5%) were included in this analysis. Compared with placebo, CTD within 4 weeks reduced weight −1.5% (95% confidence interval [CI], −2.2 to −0.7) and volume −1.4% (95% CI, −2.2 to −0.6), stimulated plasma renin 40.5% (95% CI, 25.4% to 57.4%) and serum aldosterone 40.2% (95% CI, 11.7% to 76%), and reduced plasma N -terminal pro-B-type natriuretic peptide levels −19.4% (95% CI, −33.8% to −1.9%). Mediation analysis revealed the following results: for weight change, the total effect on systolic BP was −10.8 mm Hg (95% CI, −16 to −5.7), of which weight change (indirect effect) accounted for −0.9 mm Hg (95% CI, −4.2 to 2.5) and BP change independent of weight (direct effect) accounted for −10 mm Hg (−15.7 to −4.2). Thus, the percent mediation was 8.1% (95% CI, −22.4 to 38.5). Baseline excretion of 24-hour sodium or aldosterone or any of the changes in the above mediators examined accounted for <2 mm Hg BP drop and were not significant for any of the mediators. Conclusions CTD improved BP control among patients with advanced CKD independent of baseline urinary sodium, aldosterone, weight loss, or changes in the renin-angiotensin system or N -terminal pro-B-type natriuretic peptide. Clinical Trial registry name and registration number: CTD in chronic kidney disease ClinicalTrials.gov number: NCT02841280 .
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Affiliation(s)
- Rajiv Agarwal
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| | - Arjun D. Sinha
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
| | - Wanzhu Tu
- Department of Biostatistics and Health Data Science, Richard M. Fairbanks School of Public Health, Indiana University Center for Aging Research, Indiana University School of Medicine, Regenstrief Institute, Indianapolis, Indiana
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2
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Lau ES, Roshandelpoor A, Zarbafian S, Wang D, Guseh JS, Allen N, Varadarajan V, Nayor M, Shah RV, Lima JAC, Shah SJ, Yu B, Alotaibi M, Cheng S, Jain M, Lewis GD, Ho JE. Eicosanoid and eicosanoid-related inflammatory mediators and exercise intolerance in heart failure with preserved ejection fraction. Nat Commun 2023; 14:7557. [PMID: 37985769 PMCID: PMC10662264 DOI: 10.1038/s41467-023-43363-3] [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: 12/14/2022] [Accepted: 11/08/2023] [Indexed: 11/22/2023] Open
Abstract
Systemic inflammation has been implicated in the pathobiology of heart failure with preserved ejection fraction (HFpEF). Here, we examine the association of upstream mediators of inflammation as ascertained by fatty-acid derived eicosanoid and eicosanoid-related metabolites with HFpEF status and exercise manifestations of HFpEF. Among 510 participants with chronic dyspnea and preserved LVEF who underwent invasive cardiopulmonary exercise testing, we find that 70 of 890 eicosanoid and related metabolites are associated with HFpEF status, including 17 named and 53 putative eicosanoids (FDR q-value < 0.1). Prostaglandin (15R-PGF2α, 11ß-dhk-PGF2α) and linoleic acid derivatives (12,13 EpOME) are associated with greater odds of HFpEF, while epoxides (8(9)-EpETE), docosanoids (13,14-DiHDPA), and oxylipins (12-OPDA) are associated with lower odds of HFpEF. Among 70 metabolites, 18 are associated with future development of heart failure in the community. Pro- and anti-inflammatory eicosanoid and related metabolites may contribute to the pathogenesis of HFpEF and serve as potential targets for intervention.
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Affiliation(s)
- Emily S Lau
- Division of Cardiology, Department of Medicine, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts, 02114, USA
- Cardiovascular Research Center, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA
| | - Athar Roshandelpoor
- CardioVascular Institute, Division of Cardiology, Department of Medicine, 330 Brookline Avenue, Beth Israel Deaconess Medical Center, Boston, MA, 02215, USA
| | - Shahrooz Zarbafian
- Division of Cardiology, Department of Medicine, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts, 02114, USA
- Google LLC, 1600 Amphitheatre Parkway, Mountain View, CA, 94043, USA
| | - Dongyu Wang
- CardioVascular Institute, Division of Cardiology, Department of Medicine, 330 Brookline Avenue, Beth Israel Deaconess Medical Center, Boston, MA, 02215, USA
- Department of Biostatistics, Boston University School of Public Health, 715 Albany Street, Boston, MA, 02118, USA
| | - James S Guseh
- Division of Cardiology, Department of Medicine, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts, 02114, USA
- Cardiovascular Research Center, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA
| | - Norrina Allen
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, 420 East Superior Street, Chicago, IL, 60611, USA
| | - Vinithra Varadarajan
- Division of Cardiology, Department of Medicine Johns Hopkins University School of Medicine, 733 North Broadway, Baltimore, MD, 21205, USA
| | - Matthew Nayor
- Cardiology Division, Boston University School of Medicine, 715 Albany Street, Boston, MA, 02118, USA
| | - Ravi V Shah
- Vanderbilt Clinical and Translational Research Center (VTRACC), Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN, 37232, USA
| | - Joao A C Lima
- Division of Cardiology, Department of Medicine Johns Hopkins University School of Medicine, 733 North Broadway, Baltimore, MD, 21205, USA
| | - Sanjiv J Shah
- Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, 420 East Superior Street, Chicago, IL, 60611, USA
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 420 East Superior Street, Chicago, IL, 60611, USA
| | - Bing Yu
- Department of Epidemiology, Human Genetics and Environmental Sciences, University of Texas Health School of Public Health, 1200 Pressler Street, Houston, TX, 77030, USA
| | - Mona Alotaibi
- Division of Pulmonary and Critical Care and Sleep Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Susan Cheng
- Department of Cardiology, Smidt Heart Institute, Cedars-Sinai Medical Center, 127 South San Vincente Pavilion, Los Angeles, CA, 90048, USA
| | - Mohit Jain
- Department of Medicine and Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Gregory D Lewis
- Division of Cardiology, Department of Medicine, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts, 02114, USA
- Cardiovascular Research Center, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA
| | - Jennifer E Ho
- Cardiovascular Research Center, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA.
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3
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Golosova D, Levchenko V, Kravtsova O, Palygin O, Staruschenko A. Acute and long-term effects of cannabinoids on hypertension and kidney injury. Sci Rep 2022; 12:6080. [PMID: 35413977 PMCID: PMC9005691 DOI: 10.1038/s41598-022-09902-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 03/28/2022] [Indexed: 11/30/2022] Open
Abstract
Cannabinoids and their endogenous and synthetic analogs impact blood pressure and contribute to the incidence of hypertension. It was previously reported that the endocannabinoid system plays an important role in developing hypertension; however, it was also shown that cannabinoids elicit profound hypotension associated with hemorrhagic, cardiogenic, and endotoxic shock. This study aimed to test acute and chronic effects of an endogenous ligand of cannabinoid receptor anandamide (AEA) on blood pressure and kidney injury in vivo in conscious Dahl salt-sensitive (SS) rats. We demonstrated that acute i.v. bolus administration of a low or a high doses (0.05 or 3 mg/kg) of AEA did not affect blood pressure for 2 h after the injection in Dahl SS rats fed a normal salt diet (0.4% NaCl). Neither low nor high doses of AEA had any beneficial effects on blood pressure or kidney function. Furthermore, hypertensive rats fed a HS diet (8% NaCl) and chronically treated with 3 mg/kg of AEA exhibited a significant increase in blood pressure accompanied by increased renal interstitial fibrosis and glomerular damage at the late stage of hypertension. Western blot analyses revealed increased expression of Smad3 protein levels in the kidney cortex in response to chronic treatment with a high AEA dose. Therefore, TGF-β1/Smad3 signaling pathway may play a crucial role in kidney injury in SS hypertension during chronic treatment with AEA. Collectively, these data indicate that prolonged stimulation of cannabinoid receptors may result in aggravation of hypertension and kidney damage.
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Affiliation(s)
- Daria Golosova
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Vladislav Levchenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, 560 Channelside Dr., Tampa, FL, 33602, USA
| | - Olha Kravtsova
- Department of Molecular Pharmacology and Physiology, University of South Florida, 560 Channelside Dr., Tampa, FL, 33602, USA
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.,Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA. .,Department of Molecular Pharmacology and Physiology, University of South Florida, 560 Channelside Dr., Tampa, FL, 33602, USA. .,Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, 33602, USA. .,Clement J. Zablocki VA Medical Center, Milwaukee, WI, 53295, USA.
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4
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Palmu J, Watrous JD, Mercader K, Havulinna AS, Lagerborg KA, Salosensaari A, Inouye M, Larson MG, Rong J, Vasan RS, Lahti L, Andres A, Cheng S, Jousilahti P, Salomaa V, Jain M, Niiranen TJ. Eicosanoid Inflammatory Mediators Are Robustly Associated With Blood Pressure in the General Population. J Am Heart Assoc 2020; 9:e017598. [PMID: 32975162 PMCID: PMC7792391 DOI: 10.1161/jaha.120.017598] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background Epidemiological and animal studies have associated systemic inflammation with blood pressure (BP). However, the mechanistic factors linking inflammation and BP remain unknown. Fatty acid-derived eicosanoids serve as mediators of inflammation and have been suggested to regulate renal vascular tone, peripheral resistance, renin-angiotensin system, and endothelial function. We hypothesize that specific proinflammatory and anti-inflammatory eicosanoids are linked with BP. Methods and Results We studied a population sample of 8099 FINRISK 2002 participants randomly drawn from the Finnish population register (53% women; mean age, 48±13 years) and, for external validation, a sample of 2859 FHS (Framingham Heart Study) Offspring study participants (55% women; mean age, 66±9 years). Using nontargeted liquid chromatography-mass spectrometry, we profiled 545 distinct high-quality eicosanoids and related oxylipin mediators in plasma. Adjusting for conventional hypertension risk factors, we observed 187 (34%) metabolites that were significantly associated with systolic BP (P<Bonferroni-corrected threshold of 0.05/545). We used forward selection linear regression modeling in FINRISK to define a general formula for individual eicosanoid risk score. Individuals of the top risk score quartile in FINRISK had a 9.0 (95% CI, 8.0-10.1) mm Hg higher systolic BP compared with individuals in the lowest quartile in fully adjusted models. Observed metabolite associations were consistent across FINRISK and FHS. Conclusions Plasma eicosanoids demonstrate strong associations with BP in the general population. As eicosanoid compounds affect numerous physiological processes that are central to BP regulation, they may offer new insights about the pathogenesis of hypertension, as well as serve as potential targets for therapeutic intervention.
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Affiliation(s)
- Joonatan Palmu
- Department of Internal Medicine University of Turku Finland.,Department of Public Health Solutions Finnish Institute for Health and Welfare Turku and Helsinki Finland
| | - Jeramie D Watrous
- Departments of Medicine and Pharmacology University of California, San Diego CA
| | - Kysha Mercader
- Departments of Medicine and Pharmacology University of California, San Diego CA
| | - Aki S Havulinna
- Department of Public Health Solutions Finnish Institute for Health and Welfare Turku and Helsinki Finland.,Institute for Molecular Medicine Finland and Helsinki Institute of Life Science Helsinki Finland
| | - Kim A Lagerborg
- Departments of Medicine and Pharmacology University of California, San Diego CA
| | - Aaro Salosensaari
- Department of Internal Medicine University of Turku Finland.,Department of Future Technologies University of Turku Finland
| | - Mike Inouye
- Department of Public Health and Primary Care University of Cambridge United Kingdom.,National Heart, Lung and Blood Institute's and Boston University's Framingham Heart Study Framingham MA
| | - Martin G Larson
- National Heart, Lung and Blood Institute's and Boston University's Framingham Heart Study Framingham MA.,Department of Biostatistics Boston University School of Public Health Boston MA
| | - Jian Rong
- National Heart, Lung and Blood Institute's and Boston University's Framingham Heart Study Framingham MA
| | - Ramachandran S Vasan
- National Heart, Lung and Blood Institute's and Boston University's Framingham Heart Study Framingham MA.,Sections of Preventive Medicine and Epidemiology, and Cardiovascular Medicine Department of Medicine Department of Epidemiology Boston University Schools of Medicine and Public Health Boston MA
| | - Leo Lahti
- Department of Future Technologies University of Turku Finland
| | - Allen Andres
- Departments of Medicine and Pharmacology University of California, San Diego CA
| | - Susan Cheng
- National Heart, Lung and Blood Institute's and Boston University's Framingham Heart Study Framingham MA.,Division of Cardiology Brigham and Women's Hospital Boston MA.,Smidt Heart InstituteCedars-Sinai Medical Center Los Angeles CA
| | - Pekka Jousilahti
- Department of Public Health Solutions Finnish Institute for Health and Welfare Turku and Helsinki Finland
| | - Veikko Salomaa
- Department of Public Health Solutions Finnish Institute for Health and Welfare Turku and Helsinki Finland
| | - Mohit Jain
- Departments of Medicine and Pharmacology University of California, San Diego CA
| | - Teemu J Niiranen
- Department of Internal Medicine University of Turku Finland.,Department of Public Health Solutions Finnish Institute for Health and Welfare Turku and Helsinki Finland.,Division of Medicine Turku University Hospital Turku Finland
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5
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Wasserman AH, Venkatesan M, Aguirre A. Bioactive Lipid Signaling in Cardiovascular Disease, Development, and Regeneration. Cells 2020; 9:E1391. [PMID: 32503253 PMCID: PMC7349721 DOI: 10.3390/cells9061391] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/23/2020] [Accepted: 06/01/2020] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular disease (CVD) remains a leading cause of death globally. Understanding and characterizing the biochemical context of the cardiovascular system in health and disease is a necessary preliminary step for developing novel therapeutic strategies aimed at restoring cardiovascular function. Bioactive lipids are a class of dietary-dependent, chemically heterogeneous lipids with potent biological signaling functions. They have been intensively studied for their roles in immunity, inflammation, and reproduction, among others. Recent advances in liquid chromatography-mass spectrometry techniques have revealed a staggering number of novel bioactive lipids, most of them unknown or very poorly characterized in a biological context. Some of these new bioactive lipids play important roles in cardiovascular biology, including development, inflammation, regeneration, stem cell differentiation, and regulation of cell proliferation. Identifying the lipid signaling pathways underlying these effects and uncovering their novel biological functions could pave the way for new therapeutic strategies aimed at CVD and cardiovascular regeneration.
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Affiliation(s)
- Aaron H. Wasserman
- Regenerative Biology and Cell Reprogramming Laboratory, Institute for Quantitative Health Science and Engineering (IQ), Michigan State University, East Lansing, MI 48824, USA; (A.H.W.); (M.V.)
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Manigandan Venkatesan
- Regenerative Biology and Cell Reprogramming Laboratory, Institute for Quantitative Health Science and Engineering (IQ), Michigan State University, East Lansing, MI 48824, USA; (A.H.W.); (M.V.)
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Aitor Aguirre
- Regenerative Biology and Cell Reprogramming Laboratory, Institute for Quantitative Health Science and Engineering (IQ), Michigan State University, East Lansing, MI 48824, USA; (A.H.W.); (M.V.)
- Department of Biomedical Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824, USA
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Liu B, Wu X, Zeng R, Yin Y, Guo T, Xu Y, Zhang Y, Leng J, Ge J, Yu G, Guo J, Zhou Y. Prostaglandin E 2 sequentially activates E-prostanoid receptor-3 and thromboxane prostanoid receptor to evoke contraction and increase in resistance of the mouse renal vasculature. FASEB J 2020; 34:2568-2578. [PMID: 31908041 DOI: 10.1096/fj.201901611r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 10/21/2019] [Accepted: 12/04/2019] [Indexed: 02/05/2023]
Abstract
Although recognized to have an in vivo vasodepressor effect blunted by the vasoconstrictor effect of E-prostanoid receptor-3 (EP3), prostaglandin E2 (PGE2 ) evokes contractions of many vascular beds that are sensitive to antagonizing the thromboxane prostanoid receptor (TP). This study aimed to determine the direct effect of PGE2 on renal arteries and/or the whole renal vasculature and how each of these two receptors is involved in the responses. Experiments were performed on isolated vessels and perfused kidneys of wild-type mice and/or mice with deficiency in TP (TP-/- ), EP3 (EP3-/- ), or both TP and EP3 (TP-/- /EP3-/- ). Here we show that PGE2 (0.001-30 μM) evoked not only contraction of main renal arteries, but also a decrease of flow in perfused kidneys. EP3-/- diminished the response to 0.001-0.3 μM PGE2 , while TP-/- reduced that to the prostanoid of higher concentrations. In TP-/- /EP3-/- vessels and perfused kidneys, PGE2 did not evoke contraction but instead resulted in vasodilator responses. These results demonstrate that PGE2 functions as an overall direct vasoconstrictor of the mouse renal vasculature with an effect reflecting the vasoconstrictor activities outweighing that of dilation. Also, our results suggest that EP3 dominates the vasoconstrictor effect of PGE2 of low concentrations (≤0.001-0.3 μM), but its effect is further added by that of TP, which has a higher efficacy, although activated by higher concentrations (from 0.01 μM) of the same prostanoid PGE2 .
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Affiliation(s)
- Bin Liu
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Xiangzhong Wu
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Ruhui Zeng
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
- Department of Gynaecology and Obstetrics, First Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Yehu Yin
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Tingting Guo
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Yineng Xu
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Yingzhan Zhang
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Jing Leng
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Jiahui Ge
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Gang Yu
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Jinwei Guo
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
| | - Yingbi Zhou
- Cardiovascular Research Center, Shantou University Medical College, Shantou, China
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Song CY, Khan NS, Liao FF, Wang B, Shin JS, Bonventre JV, Malik KU. Brain Cytosolic Phospholipase A2α Mediates Angiotensin II-Induced Hypertension and Reactive Oxygen Species Production in Male Mice. Am J Hypertens 2018; 31:622-629. [PMID: 29342227 PMCID: PMC5905655 DOI: 10.1093/ajh/hpy009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/09/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Recently, we reported that angiotensin II (Ang II)-induced hypertension is mediated by group IV cytosolic phospholipase A2α (cPLA2α) via production of prohypertensive eicosanoids. Since Ang II increases blood pressure (BP) via its action in the subfornical organ (SFO), it led us to investigate the expression and possible contribution of cPLA2α to oxidative stress and development of hypertension in this brain area. METHODS Adenovirus (Ad)-green fluorescence protein (GFP) cPLA2α short hairpin (sh) RNA (Ad-cPLA2α shRNA) and its control Ad-scrambled shRNA (Ad-Scr shRNA) or Ad-enhanced cyan fluorescence protein cPLA2α DNA (Ad-cPLA2α DNA) and its control Ad-GFP DNA were transduced into SFO of cPLA2α+/+ and cPLA2α−/− male mice, respectively. Ang II (700 ng/kg/min) was infused for 14 days in these mice, and BP was measured by tail-cuff and radio telemetry. cPLA2 activity, reactive oxygen species production, and endoplasmic reticulum stress were measured in the SFO. RESULTS Transduction of SFO with Ad-cPLA2α shRNA, but not Ad-Scr shRNA in cPLA2α+/+ mice, minimized expression of cPLA2α, Ang II-induced cPLA2α activity and oxidative stress in the SFO, BP, and cardiac and renal fibrosis. In contrast, Ad-cPLA2α DNA, but not its control Ad-GFP DNA in cPLA2α−/− mice, restored the expression of cPLA2α, and Ang II-induced increase in cPLA2 activity and oxidative stress in the SFO, BP, cardiac, and renal fibrosis. CONCLUSIONS These data suggest that cPLA2α in the SFO is crucial in mediating Ang II-induced hypertension and associated pathogenesis. Therefore, development of selective cPLA2α inhibitors could be useful in treating hypertension and its pathogenesis.
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Affiliation(s)
- Chi Young Song
- Department of Pharmacology, College of Medicine, University of Tennessee HSC, Memphis, Tennessee, USA
| | - Nayaab S Khan
- Department of Pharmacology, College of Medicine, University of Tennessee HSC, Memphis, Tennessee, USA
| | - Francesca-Fang Liao
- Department of Pharmacology, College of Medicine, University of Tennessee HSC, Memphis, Tennessee, USA
| | - Bin Wang
- Department of Pharmacology, College of Medicine, University of Tennessee HSC, Memphis, Tennessee, USA
| | - Ji Soo Shin
- Department of Pharmacology, College of Medicine, University of Tennessee HSC, Memphis, Tennessee, USA
| | - Joseph V Bonventre
- Renal Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kafait U Malik
- Department of Pharmacology, College of Medicine, University of Tennessee HSC, Memphis, Tennessee, USA
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8
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Bioactive lipids derived from arachidonic acid metabolism in different types of renal replacement therapy. Chem Phys Lipids 2017; 206:71-77. [PMID: 28533146 DOI: 10.1016/j.chemphyslip.2017.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Metabolism and plasma concentration of lipids and lipid-derived compounds play an important role in kidney physiology and pathological processes. The component of membrane phospholipids - arachidonic acid (AA) and its active derivatives - eicosanoids are involved in the development of hypertension, diabetes, inflammation and may contribute to progression of chronic kidney disease (CKD). The purpose of the study was to determine, whether the type of renal replacement therapy has an effect on eicosanoids metabolism. MATERIALS AND METHODS The study included 145 patients with CKD: on conservative treatment (n=68), on peritoneal dialysis (PD) (n=23) and undergoing chronic haemodialysis (HD) (n=54). The concentrations of TXB2, 20-HETE, 8-epi-PGF2α in platelet poor plasma (PPP) were determined using the ELISA method and 5-HETE, 12-HETE, 15-HETE were measured using the RP-HPLC. RESULTS The concentrations of TXB2 in HD group, both before (2.28±0.72ng/mL) and after (1.49±0.63ng/mL) haemodialysis treatment differed significantly from PD group (57.76±6.13ng/mL). Haemodialysis session led to the significant decrease in TXB2 plasma concentration (p=0.046). 20-HETE concentrations in HD group (113.55±107.54pg/mL and 199.54±142.98pg/mL before and after haemodialysis, respectively) were significantly higher than in CKD 3-5 group (8.96±12.66pg/mL) and PD group (47.78±34.07pg/mL). The highest concentration of 12-HETE was obtained in PD patients (3.58±3.99ng/mL) and differed significantly from HD group after haemodialysis (0.97±0.28ng/mL) and CKD3-5 group (1.06±0.52ng/mL). The concentrations of 5-HETE, 15-HETE and 8-epi-PGF2α-III did not differ significantly among examined groups. CONCLUSIONS The concentrations of active AA metabolites depend on the mode of renal replacement therapy and are associated with intensity of oxidative stress. They might be considered as potential indicators of kidney damage.
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9
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Armstrong M, van Hoorebeke C, Horn T, Deschamps J, Freedman JC, Kalyanaraman C, Jacobson MP, Holman T. Human 15-LOX-1 active site mutations alter inhibitor binding and decrease potency. Bioorg Med Chem 2016; 24:5380-5387. [PMID: 27647374 DOI: 10.1016/j.bmc.2016.08.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 12/17/2022]
Abstract
Human 15-lipoxygenase-1 (h15-LOX-1 or h12/15-LOX) reacts with polyunsaturated fatty acids and produces bioactive lipid derivatives that are implicated in many important human diseases. One such disease is stroke, which is the fifth leading cause of death and the first leading cause of disability in America. The discovery of h15-LOX-1 inhibitors could potentially lead to novel therapeutics in the treatment of stroke, however, little is known about the inhibitor/active site interaction. This study utilizes site-directed mutagenesis, guided in part by molecular modeling, to gain a better structural understanding of inhibitor interactions within the active site. We have generated eight mutants (R402L, R404L, F414I, F414W, E356Q, Q547L, L407A, I417A) of h15-LOX-1 to determine whether these active site residues interact with two h15-LOX-1 inhibitors, ML351 and an ML094 derivative, compound 18. IC50 values and steady-state inhibition kinetics were determined for the eight mutants, with four of the mutants affecting inhibitor potency relative to wild type h15-LOX-1 (F414I, F414W, E356Q and L407A). The data indicate that ML351 and compound 18, bind in a similar manner in the active site to an aromatic pocket close to F414 but have subtle differences in their specific binding modes. This information establishes the binding mode for ML094 and ML351 and will be leveraged to develop next-generation inhibitors.
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Affiliation(s)
- Michelle Armstrong
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - Christopher van Hoorebeke
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - Thomas Horn
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - Joshua Deschamps
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - J Cody Freedman
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States
| | - Chakrapani Kalyanaraman
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, CA 94143, United States
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, CA 94143, United States
| | - Theodore Holman
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, United States.
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10
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Khan NS, Song CY, Thirunavukkarasu S, Fang XR, Bonventre JV, Malik KU. Cytosolic Phospholipase A2α Is Essential for Renal Dysfunction and End-Organ Damage Associated With Angiotensin II-Induced Hypertension. Am J Hypertens 2016; 29:258-65. [PMID: 26045535 DOI: 10.1093/ajh/hpv083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/13/2015] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The kidney plays an important role in regulating blood pressure (BP). cPLA2α in the kidney is activated by various agents including angiotensin II (Ang II) and selectively releases arachidonic acid (AA) from tissue lipids, generating pro- and antihypertensive eicosanoids. Since activation of cPLA2α is the rate-limiting step in AA release, this study was conducted to determine its contribution to renal dysfunction and end-organ damage associated with Ang II-induced hypertension. METHODS cPLA2α(+/+) and cPLA2α(-/-) mice were infused with Ang II (700 ng/ kg/min) or its vehicle for 13 days. Mice were placed in metabolic cages to monitor their food and water intake, and urine was collected and its volume was measured. Doppler imaging was performed to assess renal hemodynamics. On the 13th day of Ang II infusion, mice were sacrificed and their tissues and blood collected for further analysis. RESULTS Ang II increased renal vascular resistance, water intake, and urine output and Na(+) excretion, decreased urine osmolality, and produced proteinuria in cPLA2α(+/+) mice. Ang II also caused accumulation of F4/80(+) macrophages and CD3(+) T cells and renal fibrosis, and increased oxidative stress in the kidneys of cPLA2α(+/+) mice. All these effects of Ang II were minimized in cPLA2α(-/-) mice. CONCLUSION cPLA2α contributes to renal dysfunction, inflammation, and end-organ damage, most likely via the action of pro-hypertensive eicosanoids and increased oxidative stress associated with Ang II-induced hypertension. Thus, cPLA2α could serve as a potential therapeutic target for treating renal dysfunction and end-organ damage in hypertension.
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Affiliation(s)
- Nayaab S Khan
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Chi Young Song
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Shyamala Thirunavukkarasu
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Xiao R Fang
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Joseph V Bonventre
- Renal Division, Department of Medicine, Brigham and Women's Hospital Boston, Harvard Medical School, Harvard Institute of Medicine, Boston, Massachusetts, USA
| | - Kafait U Malik
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee, USA;
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11
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Ivanov I, Kuhn H, Heydeck D. Structural and functional biology of arachidonic acid 15-lipoxygenase-1 (ALOX15). Gene 2015; 573:1-32. [PMID: 26216303 PMCID: PMC6728142 DOI: 10.1016/j.gene.2015.07.073] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/26/2015] [Accepted: 07/21/2015] [Indexed: 12/14/2022]
Abstract
Lipoxygenases (LOX) form a family of lipid peroxidizing enzymes, which have been implicated in a number of physiological processes and in the pathogenesis of inflammatory, hyperproliferative and neurodegenerative diseases. They occur in two of the three domains of terrestrial life (bacteria, eucarya) and the human genome involves six functional LOX genes, which encode for six different LOX isoforms. One of these isoforms is ALOX15, which has first been described in rabbits in 1974 as enzyme capable of oxidizing membrane phospholipids during the maturational breakdown of mitochondria in immature red blood cells. During the following decades ALOX15 has extensively been characterized and its biological functions have been studied in a number of cellular in vitro systems as well as in various whole animal disease models. This review is aimed at summarizing the current knowledge on the protein-chemical, molecular biological and enzymatic properties of ALOX15 in various species (human, mouse, rabbit, rat) as well as its implication in cellular physiology and in the pathogenesis of various diseases.
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Affiliation(s)
- Igor Ivanov
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Hartmut Kuhn
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
| | - Dagmar Heydeck
- Institute of Biochemistry, Charité - University Medicine Berlin, Charitéplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
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12
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Khan NS, Song CY, Jennings BL, Estes AM, Fang XR, Bonventre JV, Malik KU. Cytosolic phospholipase A2α is critical for angiotensin II-induced hypertension and associated cardiovascular pathophysiology. Hypertension 2015; 65:784-92. [PMID: 25667212 DOI: 10.1161/hypertensionaha.114.04803] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Angiotensin II activates cytosolic phospholipase A(2)α (cPLA2α) and releases arachidonic acid from tissue phospholipids, which mediate or modulate ≥1 cardiovascular effects of angiotensin II and has been implicated in hypertension. Because arachidonic acid release is the rate limiting step in eicosanoid production, cPLA2α might play a central role in the development of angiotensin II-induced hypertension. To test this hypothesis, we investigated the effect of angiotensin II infusion for 13 days by micro-osmotic pumps on systolic blood pressure and associated pathogenesis in wild type (cPLA2α(+/+)) and cPLA2α(-/-) mice. Angiotensin II-induced increase in systolic blood pressure in cPLA2α(+/+) mice was abolished in cPLA2α(-/-) mice; increased systolic blood pressure was also abolished by the arachidonic acid metabolism inhibitor, 5,8,11,14-eicosatetraynoic acid in cPLA2α(+/+) mice. Angiotensin II in cPLA2α(+/+) mice increased cardiac cPLA2 activity and urinary eicosanoid excretion, decreased cardiac output, caused cardiovascular remodeling with endothelial dysfunction, and increased vascular reactivity in cPLA2α(+/+) mice; these changes were diminished in cPLA2α(-/-) mice. Angiotensin II also increased cardiac infiltration of F4/80(+) macrophages and CD3(+) T lymphocytes, cardiovascular oxidative stress, expression of endoplasmic reticulum stress markers p58(IPK), and CHOP in cPLA2α(+/+) but not cPLA2α(-/-) mice. Angiotensin II increased cardiac activity of ERK1/2 and cSrc in cPLA2α(+/+) but not cPLA2α(-/-) mice. These data suggest that angiotensin II-induced hypertension and associated cardiovascular pathophysiological changes are mediated by cPLA2α activation, most likely through the release of arachidonic acid and generation of eicosanoids with predominant prohypertensive effects and activation of ≥1 signaling molecules, including ERK1/2 and cSrc.
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Affiliation(s)
- Nayaab S Khan
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Chi Young Song
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Brett L Jennings
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Anne M Estes
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Xiao R Fang
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Joseph V Bonventre
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.)
| | - Kafait U Malik
- From the Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN (N.S.K., C.Y.S., B.L.J., A.M.E., X.R.F., K.U.M.); and Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institute of Medicine, Boston, MA (J.V.B.).
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13
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Kuhn H, Banthiya S, van Leyen K. Mammalian lipoxygenases and their biological relevance. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:308-30. [PMID: 25316652 DOI: 10.1016/j.bbalip.2014.10.002] [Citation(s) in RCA: 419] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/30/2014] [Accepted: 10/03/2014] [Indexed: 02/07/2023]
Abstract
Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated not only in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOXs oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in the regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".
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Affiliation(s)
- Hartmut Kuhn
- Institute of Biochemistry, University Medicine Berlin - Charite, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
| | - Swathi Banthiya
- Institute of Biochemistry, University Medicine Berlin - Charite, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Klaus van Leyen
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts Genrel Hospital and Harvard Medical School, Charlestown, MA, USA
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Abstract
In the mammalian kidney, prostaglandins (PGs) are important mediators of physiologic processes, including modulation of vascular tone and salt and water. PGs arise from enzymatic metabolism of free arachidonic acid (AA), which is cleaved from membrane phospholipids by phospholipase A2 activity. The cyclooxygenase (COX) enzyme system is a major pathway for metabolism of AA in the kidney. COX are the enzymes responsible for the initial conversion of AA to PGG2 and subsequently to PGH2, which serves as the precursor for subsequent metabolism by PG and thromboxane synthases. In addition to high levels of expression of the "constitutive" rate-limiting enzyme responsible for prostanoid production, COX-1, the "inducible" isoform of cyclooxygenase, COX-2, is also constitutively expressed in the kidney and is highly regulated in response to alterations in intravascular volume. PGs and thromboxane A2 exert their biological functions predominantly through activation of specific 7-transmembrane G-protein-coupled receptors. COX metabolites have been shown to exert important physiologic functions in maintenance of renal blood flow, mediation of renin release and regulation of sodium excretion. In addition to physiologic regulation of prostanoid production in the kidney, increases in prostanoid production are also seen in a variety of inflammatory renal injuries, and COX metabolites may serve as mediators of inflammatory injury in renal disease.
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Affiliation(s)
- Raymond C Harris
- George M. O'Brien Kidney and Urologic Diseases Center and Division of Nephrology, Vanderbilt University School of Medicine and Nashville Veterans Affairs Hospital, Nashville, Tennessee, USA.
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15
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Elbasan Z, Gür M, Sahin DY, Tanboğa IH, Cayli M. Mean platelet volume and abnormal left ventricle geometric patterns in patients with untreated essential hypertension. Platelets 2012; 24:521-7. [PMID: 23216609 DOI: 10.3109/09537104.2012.738839] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abnormal left ventricle (LV) geometric patterns are associated with a greater risk of hypertensive vascular complications. The mean platelet volume (MPV) reflects the platelet activity, and is associated with overall vascular mortality. Although association between MPV and LV hypertrophy in hypertensive patients has been investigated, relation between abnormal LV geometric patterns and MPV was not studied so far. The aim of this study is to investigate the relationship between MPV and abnormal LV geometric patterns in hypertensive patients. Measurements were obtained from 223 patients with untreated essential hypertension (Mean age = 52.1 ± 5.2 years). Four different geometric patterns (NG; normal geometry, CR; concentric remodelling, EH; eccentric hypertrophy, CH; concentric hypertrophy) were determined according to the LV mass index (LVMI) and relative wall thickness (RWth). MPV, high sensitive C-reactive protein (hsCRP) and other biochemical markers were measured in all patients. The highest MPV values were determined in CH group compared with NG, CR and EH groups (p < 0.05, for all). MPV values were similar among the NG, CR and EH groups (p > 0.05, for all). MPV was associated with age, glucose, hsCRP, RWth, LVMI and LV geometry in bivariate analysis (p < 0.05, for all). Age (β = 0.110, p = 0.033), LVMI (β = 0.471, p < 0.001) and hsCRP (β = 0.525, p < 0.001) were independent predictors of high MPV in multiple linear regression analysis. The highest MPV values were observed in the CH group. This result may be associated with increased inflammation and LV hypertrophy in this geometric pattern.
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Affiliation(s)
- Zafer Elbasan
- Department of Cardiology, Adana Numune Education and Research Hospital , Adana , Turkey
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16
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Sparks MA, Makhanova NA, Griffiths RC, Snouwaert JN, Koller BH, Coffman TM. Thromboxane receptors in smooth muscle promote hypertension, vascular remodeling, and sudden death. Hypertension 2012; 61:166-73. [PMID: 23150508 DOI: 10.1161/hypertensionaha.112.193250] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The prostanoid thromboxane A2 has been implicated to contribute to the pathogenesis of many cardiovascular diseases, including hypertension. To study the role of vascular thromboxane-prostanoid (TP) receptors in blood pressure regulation, we generated mice with cell-specific deletion of TP receptors in smooth muscle using Cre/Loxp technology. We crossed the KISM22α-Cre transgenic mouse line expressing Cre recombinase in smooth muscle cells with a mouse line bearing a conditional allele of the Tbxa2r gene (Tp(flox)). In KISM22α-Cre(+)Tp(flox/flox) (TP-SMKO) mice, TP receptors were efficiently deleted from vascular smooth muscle cells. In TP-SMKOs, acute vasoconstrictor responses to the TP agonist U46619 were attenuated to a similar extent in both the peripheral and renal circulations. Yet, acute vascular responses to angiotensin II were unaffected at baseline and after chronic angiotensin II administration. Infusion of high-dose U46619 caused circulatory collapse and death in a majority of control mice but had negligible hemodynamic effects in TP-SMKOs, which were completely protected from U46619-induced sudden death. Baseline blood pressures were normal in TP-SMKOs. However, the absence of TP receptors in vascular smooth muscle cells was associated with significant attenuation of angiotensin II-induced hypertension and diminished vascular remodeling. This was also associated with reduced urinary thromboxane production after chronic angiotensin II. Thus, TP receptors in vascular smooth muscle cells play a major role in mediating the actions of thromboxane A(2) in TP agonist-induced shock, hypertension, and vascular remodeling of the aorta.
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Affiliation(s)
- Matthew A Sparks
- Division of Nephrology and Department of Medicine, Duke University, Durham, NC 27710, USA
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17
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Jennings BL, Estes AM, Anderson LJ, Fang XR, Yaghini FA, Fan Z, Gonzalez FJ, Campbell WB, Malik KU. Cytochrome P450 1B1 gene disruption minimizes deoxycorticosterone acetate-salt-induced hypertension and associated cardiac dysfunction and renal damage in mice. Hypertension 2012; 60:1510-6. [PMID: 23108654 DOI: 10.1161/hypertensionaha.112.202606] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Previously, we showed that the cytochrome P450 1B1 inhibitor 2,3',4,5'-tetramethoxystilbene reversed deoxycorticosterone acetate (DOCA)-salt-induced hypertension and minimized endothelial and renal dysfunction in the rat. This study was conducted to test the hypothesis that cytochrome P450 1B1 contributes to cardiac dysfunction, and renal damage and inflammation associated with DOCA-salt-induced hypertension, via increased production of reactive oxygen species and modulation of neurohumoral factors and signaling molecules. DOCA-salt increased systolic blood pressure, cardiac and renal cytochrome P450 1B1 activity, and plasma levels of catecholamines, vasopressin, and endothelin-1 in wild-type (Cyp1b1(+/+)) mice that were minimized in Cyp1b1(-/-) mice. Cardiac function, assessed by echocardiography, showed that DOCA-salt increased the thickness of the left ventricular posterior and anterior walls during diastole, the left ventricular internal diameter, and end-diastolic and end-systolic volume in Cyp1b1(+/+) but not in Cyp1b1(-/-) mice; stroke volume was not altered in either genotype. DOCA-salt increased renal vascular resistance and caused vascular hypertrophy and renal fibrosis, increased renal infiltration of macrophages and T lymphocytes, caused proteinuria, increased cardiac and renal nicotinamide adenine dinucleotide phosphate-oxidase activity, caused production of reactive oxygen species, and increased activities of extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, and cellular-Src; these were all reduced in DOCA-salt-treated Cyp1b1(-/-) mice. Renal and cardiac levels of eicosanoids were not altered in either genotype of mice. These data suggest that, in DOCA-salt hypertension in mice, cytochrome P450 1B1 plays a pivotal role in cardiovascular dysfunction, renal damage, and inflammation, and increased levels of catecholamines, vasopressin, and endothelin-1, consequent to generation of reactive oxygen species and activation of extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, and cellular-Src independent of eicosanoids.
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Affiliation(s)
- Brett L Jennings
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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18
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Mulligan CM, Sparagna GC, Le CH, De Mooy AB, Routh MA, Holmes MG, Hickson-Bick DL, Zarini S, Murphy RC, Xu FY, Hatch GM, McCune SA, Moore RL, Chicco AJ. Dietary linoleate preserves cardiolipin and attenuates mitochondrial dysfunction in the failing rat heart. Cardiovasc Res 2012; 94:460-8. [PMID: 22411972 DOI: 10.1093/cvr/cvs118] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS Cardiolipin (CL) is a tetra-acyl phospholipid that provides structural and functional support to several proteins in the inner mitochondrial membrane. The majority of CL in the healthy mammalian heart contains four linoleic acid acyl chains (L(4)CL). A selective loss of L(4)CL is associated with mitochondrial dysfunction and heart failure in humans and animal models. We examined whether supplementing the diet with linoleic acid would preserve cardiac L(4)CL and attenuate mitochondrial dysfunction and contractile failure in rats with hypertensive heart failure. METHODS AND RESULTS Male spontaneously hypertensive heart failure rats (21 months of age) were administered diets supplemented with high-linoleate safflower oil (HLSO) or lard (10% w/w; 28% kilocalorie fat) or without supplemental fat (control) for 4 weeks. HLSO preserved L(4)CL and total CL to 90% of non-failing levels (vs. 61-75% in control and lard groups), and attenuated 17-22% decreases in state 3 mitochondrial respiration observed in the control and lard groups (P < 0.05). Left ventricular fractional shortening was significantly higher in HLSO vs. control (33 ± 2 vs. 29 ± 2%, P < 0.05), while plasma insulin levels were lower (5.4 ± 1.1 vs. 9.1 ± 2.3 ng/mL; P < 0.05), with no significant effect of lard supplementation. HLSO also increased serum concentrations of several eicosanoid species compared with control and lard diets, but had no effect on plasma glucose or blood pressure. CONCLUSION Moderate consumption of HLSO preserves CL and mitochondrial function in the failing heart and may be a useful adjuvant therapy for this condition.
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Affiliation(s)
- Christopher M Mulligan
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO 80523-1582, USA
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19
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17-Octadecynoic acid improves contractile response to angiotensin II by releasing vasocontrictor prostaglandins. Prostaglandins Other Lipid Mediat 2012; 97:36-42. [DOI: 10.1016/j.prostaglandins.2011.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 07/26/2011] [Accepted: 07/28/2011] [Indexed: 11/19/2022]
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Contribution of cytochrome P450 1B1 to hypertension and associated pathophysiology: a novel target for antihypertensive agents. Prostaglandins Other Lipid Mediat 2011; 98:69-74. [PMID: 22210049 DOI: 10.1016/j.prostaglandins.2011.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/18/2011] [Accepted: 12/12/2011] [Indexed: 12/24/2022]
Abstract
The aim of this review is to discuss the contribution of cytochrome P450 (CYP) 1B1 in vascular smooth muscle cell growth, hypertension, and associated pathophysiology. CYP1B1 is expressed in cardiovascular and renal tissues, and mediates angiotensin II (Ang II)-induced activation of NADPH oxidase and generation of reactive oxygen species (ROS), and vascular smooth muscle cell migration, proliferation, and hypertrophy. Moreover, CYP1B1 contributes to the development and/or maintenance of hypertension produced by Ang II-, deoxycorticosterone (DOCA)-salt-, and N(ω)-nitro-L-arginine methyl ester-induced hypertension and in spontaneously hypertensive rats. The pathophysiological changes, including cardiovascular hypertrophy, increased vascular reactivity, endothelial and renal dysfunction, injury and inflammation associated with Ang II- and/or DOCA-salt induced hypertension in rats, and Ang II-induced hypertension in mice are minimized by inhibition of CYP1B1 activity with 2,4,3',5'-tetramethoxystilbene or by Cyp1b1 gene disruption in mice. These pathophysiological changes appear to be mediated by increased production of ROS via CYP1B1-dependent NADPH oxidase activity and extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, and c-Src.
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Quehenberger O, Yamashita T, Armando AM, Dennis EA, Palinski W. Effect of gestational hypercholesterolemia and maternal immunization on offspring plasma eicosanoids. Am J Obstet Gynecol 2011; 205:156.e15-25. [PMID: 21621186 DOI: 10.1016/j.ajog.2011.03.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 02/09/2011] [Accepted: 03/17/2011] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Maternal immunization with oxidized low-density lipoprotein prior to pregnancy prevents pathogenic in utero programming by gestational hypercholesterolemia, but it is unknown whether gestational hypercholesterolemia and maternal immunization affect similar pathways. STUDY DESIGN A lipidomic approach was used for unbiased plasma eicosanoid profiling in adult offspring of immunized and nonimmunized normocholesterolemic or hypercholesterolemic rabbit mothers. RESULTS Gestational hypercholesterolemia was associated with increased levels of some eicosanoids formed by the cyclooxygenase and 12-lipoxygenase pathways only (including thromboxane B2, prostaglandin [PG] F2α, PGE2, and PGD2). Immunization of hypercholesterolemic or normocholesterolemic mothers reduced 9 of 14 eicosanoids of the cyclooxygenase pathway, 21 of 23 eicosanoids of the 5- and 12-lipoxygenase pathways (eg, 5-hydroxyeicosatetraenoic acid, hepoxilin B3, 12-hydroxyeicosatetraenoic acid), 8 of 19 eicosanoids of the cytochrome P-450 pathway, and all metabolites of the nonenzymatic pathway. CONCLUSION Maternal immunization not only counteracts in utero programming by gestational hypercholesterolemia but reduces a broad range of eicosanoid modulators of immunity and inflammation in offspring.
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Affiliation(s)
- Oswald Quehenberger
- Department of Medicine of the University of California-San Diego, La Jolla, CA, USA
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Lin R, Wang X, Zhou W, Fu W, Wang Y, Huang W, Jin L. Association of Polymorphisms in the Solute Carrier Organic Anion Transporter Family Member 1B1 Gene with Essential Hypertension in the Uyghur Population. Ann Hum Genet 2010; 75:305-11. [DOI: 10.1111/j.1469-1809.2010.00622.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Sahan-Firat S, Jennings BL, Yaghini FA, Song CY, Estes AM, Fang XR, Farjana N, Khan AI, Malik KU. 2,3',4,5'-Tetramethoxystilbene prevents deoxycorticosterone-salt-induced hypertension: contribution of cytochrome P-450 1B1. Am J Physiol Heart Circ Physiol 2010; 299:H1891-901. [PMID: 20852048 DOI: 10.1152/ajpheart.00655.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Reactive oxygen species (ROS) contribute to various models of hypertension, including deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Recently, we have shown that ROS, generated by cytochrome P-450 1B1 (CYP1B1) from arachidonic acid, mediate vascular smooth muscle cell growth caused by angiotensin II. This study was conducted to determine the contribution of CYP1B1 to hypertension and associated pathophysiological changes produced by DOCA (30 mg/kg) given subcutaneously per week with 1% NaCl + 0.1% KCl in drinking water to uninephrectomized rats for 6 wk. DOCA-salt treatment increased systolic blood pressure (SBP). Injections of the selective inhibitor of CYP1B1, 2,3',4,5'-tetramethoxystilbene (TMS; 300 μg/kg ip every 3rd day) initiated at the 4th week of DOCA-salt treatment normalized SBP and decreased CYP1B1 activity but not its expression in the aorta, heart, and kidney. TMS also inhibited cardiovascular and kidney hypertrophy, prevented the increase in vascular reactivity and endothelial dysfunction, and minimized the increase in urinary protein and K(+) output and the decrease in urine osmolality, Na(+) output, and creatinine clearance associated with DOCA-salt treatment. These pathophysiological changes caused by DOCA-salt treatment and associated increase in vascular superoxide production, NADPH oxidase activity, and expression of NOX-1, and ERK1/2 and p38 MAPK activities in the aorta, heart, and kidney were inhibited by TMS. These data suggest that CYP1B1 contributes to DOCA-salt-induced hypertension and associated pathophysiological changes, most likely as a result of increased ROS production and ERK1/2 and p38 MAPK activity, and could serve as a novel target for the development of agents like TMS to treat hypertension.
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Affiliation(s)
- Seyhan Sahan-Firat
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Jennings BL, Sahan-Firat S, Estes AM, Das K, Farjana N, Fang XR, Gonzalez FJ, Malik KU. Cytochrome P450 1B1 contributes to angiotensin II-induced hypertension and associated pathophysiology. Hypertension 2010; 56:667-74. [PMID: 20805442 DOI: 10.1161/hypertensionaha.110.154518] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hypertension is the leading cause of cardiovascular diseases, and angiotensin II is one of the major components of the mechanisms that contribute to the development of hypertension. However, the precise mechanisms for the development of hypertension are unknown. Our recent study showing that angiotensin II-induced vascular smooth muscle cell growth depends on cytochrome P450 1B1 led us to investigate its contribution to hypertension caused by this peptide. Angiotensin II was infused via miniosmotic pump into rats (150 ng/kg per minute) or mice (1000 μg/kg per day) for 13 days resulting in increased blood pressure, increased cardiac and vascular hypertrophy, increased vascular reactivity to vasoconstrictor agents, increased vascular reactive oxygen species production, and endothelial dysfunction in both species. The increase in blood pressure and associated pathophysiological changes were minimized by the cytochrome P450 1B1 inhibitor 2,3',4,5'-tetramethoxystilbene in both species and was markedly reduced in Cyp1b1(-/-) mice. These data suggest that cytochrome P450 1B1 contributes to angiotensin II-induced hypertension and associated pathophysiological changes. Moreover, 2,3',4,5'-tetramethoxystilbene, which prevents both cytochrome P450 1B1-dependent and -independent components of angiotensin II-induced hypertension and inhibits associated pathophysiological changes could be clinically useful in the treatment of hypertension and associated cardiovascular and inflammatory diseases.
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Affiliation(s)
- Brett L Jennings
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tenn 38163, USA
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25
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Yaghini FA, Song CY, Lavrentyev EN, Ghafoor HUB, Fang XR, Estes AM, Campbell WB, Malik KU. Angiotensin II-induced vascular smooth muscle cell migration and growth are mediated by cytochrome P450 1B1-dependent superoxide generation. Hypertension 2010; 55:1461-7. [PMID: 20439821 DOI: 10.1161/hypertensionaha.110.150029] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cytochrome P450 1B1, expressed in vascular smooth muscle cells, can metabolize arachidonic acid in vitro into several products including 12- and 20-hydroxyeicosatetraenoic acids that stimulate vascular smooth muscle cell growth. This study was conducted to determine whether cytochrome P450 1B1 contributes to angiotensin II-induced rat aortic smooth muscle cell migration, proliferation, and protein synthesis. Angiotensin II stimulated migration of these cells, measured by the wound healing approach, by 1.78-fold; and DNA synthesis, measured by [(3)H]thymidine incorporation, by 1.44-fold after 24 hours; and protein synthesis, measured by [(3)H]leucine incorporation, by 1.40-fold after 48 hours. Treatment of vascular smooth muscle cells with the cytochrome P450 1B1 inhibitor 2,4,3',5'-tetramethoxystilbene or transduction of these cells with adenovirus cytochrome P450 1B1 small hairpin RNA but not its scrambled control reduced the activity of this enzyme and abolished angiotensin II- and arachidonic acid-induced cell migration, as well as [(3)H]thymidine and [(3)H]leucine incorporation. Metabolism of arachidonic acid to 5-, 12-, 15-, and 20-hydoxyeicosatetraenoic acids in these cells was not altered, but angiotensin II- and arachidonic acid-induced reactive oxygen species production and extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase activity were inhibited by 2,4,3',5'-tetramethoxystilbene and cytochrome P450 1B1 small hairpin RNA (shRNA) and by Tempol, which inactivates reactive oxygen species. Tempol did not alter cytochrome P450 1B1 activity. These data suggest that angiotensin II-induced vascular smooth muscle cell migration and growth are mediated by reactive oxygen species generated from arachidonic acid by cytochrome P450 1B1 and activation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase.
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Affiliation(s)
- Fariborz A Yaghini
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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26
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Crowley SD, Song YS, Lin EE, Griffiths R, Kim HS, Ruiz P. Lymphocyte responses exacerbate angiotensin II-dependent hypertension. Am J Physiol Regul Integr Comp Physiol 2010; 298:R1089-97. [PMID: 20147609 DOI: 10.1152/ajpregu.00373.2009] [Citation(s) in RCA: 186] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Activation of the immune system by ANG II contributes to the pathogenesis of hypertension, and pharmacological suppression of lymphocyte responses can ameliorate hypertensive end-organ damage. Therefore, to examine the mechanisms through which lymphocytes mediate blood pressure elevation, we studied ANG II-dependent hypertension in scid mice lacking lymphocyte responses and wild-type controls. Scid mice had a blunted hypertensive response to chronic ANG II infusion and accordingly developed less cardiac hypertrophy. Moreover, lymphocyte deficiency led to significant reductions in heart and kidney injury following 4 wk of angiotensin. The muted hypertensive response in the scid mice was associated with increased sodium excretion, urine volumes, and weight loss beginning on day 5 of angiotensin infusion. To explore the mechanisms underlying alterations in blood pressure and renal sodium handling, we measured gene expression for vasoactive mediators in the kidney after 4 wk of ANG II administration. Scid mice and controls had similar renal expression for interferon-gamma, interleukin-1beta, and interleukin-6. By contrast, lymphocyte deficiency (i.e., scid mice) during ANG II infusion led to upregulation of tumor necrosis factor-alpha, endothelial nitric oxide synthase (eNOS), and cyclooxygenase-2 (COX-2) in the kidney. In turn, this enhanced eNOS and COX-2 expression in the scid kidneys was associated with exaggerated renal generation of nitric oxide, prostaglandin E(2), and prostacyclin, all of which promote natriuresis. Thus, the absence of lymphocyte activity protects from hypertension by allowing blood pressure-induced sodium excretion, possibly via stimulation of eNOS- and COX-2-dependent pathways.
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Affiliation(s)
- Steven D Crowley
- Department of Medicine, Duke University Medical Center, Durham, NC, USA.
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Araujo M, Welch WJ. Tubuloglomerular feedback is decreased in COX-1 knockout mice after chronic angiotensin II infusion. Am J Physiol Renal Physiol 2010; 298:F1059-63. [PMID: 20107114 DOI: 10.1152/ajprenal.00547.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prostaglandins (PGs), produced by two isoforms of cyclooxygenase (COX), COX-1 and COX-2, are important modulators of renal hemodynamics. COX-1 and COX-2 are expressed in the kidney often at distinct sites. Thromboxane (TxA(2)), PGE(2), and prostacyclin (PGI(2)) are the major PGs in the renal cortex of mice. Acute infusion of the vasoconstrictor ANG II increases COX-2-dependent PGE(2) and PGI(2). COX-2 is primarily expressed in the macula densa (MD), where several PG synthases are also expressed. We previously showed that MD COX-2 products modulate tubuloglomerular feedback (TGF) in the rat. Genetic deletion of COX-1 enhances COX-2 production of PGs, decreases renal and urinary PGs, and attenuates ANG II-induced hypertension. The present study tested the effects of chronic ANG II infusion on TGF in COX-1 knockout (KO) mice. Basal TGF was similar in COX-1 KO and wild-type (WT) mice. Chronic ANG II infusion increased TGF in WT mice (WT: 9.3 +/- 0.7 vs. WT + ANG II: 12.2 +/- 1.6 mmHg, P < 0.02). However, chronic ANG II decreased TGF in COX-1 KO mice (KO: 11.4 +/- 1.1 vs. KO + ANG II: 8.3 +/- 0.6 mmHg, P < 0.01). Pretreatment with the COX-2 inhibitor SC-58,236 in COX-1 KO mice prevented the ANG II-associated reduction in TGF (11.4 +/- 1.0 vs. 11.5 +/- 0.28 mmHg, not significant). Excretion of 6-keto-PGF(2alpha), the metabolite of PGI(2), was increased by ANG II infusion, whereas excretion of TxB(2), the stable metabolite of TxA(2), was not changed. ANG II infusion increased mean arterial pressure similarly in both WT and KO mice (WT: 93 +/- 2 vs. KO: 92 +/- 3 mmHg), but not in KO mice pretreated with SC-58,236 (85 +/- 2 mmHg). This study shows that COX-1-generated PGs partially mediate ANG II increases in TGF and that COX-2 PGs offset that effect.
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Affiliation(s)
- Magali Araujo
- Division of Nephrology and Hypertension, Department of Medicine, Georgetown University, 4000 Reservoir Road, Washington, DC 20057, USA
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Dołegowska B, Błogowski W, Kedzierska K, Safranow K, Jakubowska K, Olszewska M, Rać M, Chlubek D, Ciechanowski K. Platelets arachidonic acid metabolism in patients with essential hypertension. Platelets 2009; 20:242-9. [PMID: 19440924 DOI: 10.1080/09537100902849836] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Arachidonic acid's (AA) metabolites, eicosanoids, exert a tremendous influence on circulatory and vascular homeostasis, and in humans are generated by many organs and cell types. In this study we wanted to verify whether platelets AA metabolism play a significant role in pathogenesis of essential hypertension (EH). Participants were divided into the study (EH) and the control group. Plasma and urine concentrations of isoprostanes (8-iPF(2alpha)-III) and thromboxane B(2) (TxB(2)) were determined using the ELISA method. The levels of 5- and 12-hydroxyeicosatetraenoic (HETE) acids, generated by platelets, were analysed using RP-HPLC. In a suspension of not stimulated and AA-stimulated platelets TxB(2) level was statistically lower in the study than in the control group (p < 0.0001 and 0.001 respectively). The concentration of 12-HETE was significantly elevated in EH patients compared to the control group; however, only in the non-stimulated conditions (p < 0.05). Plasma and urine F2-isoprostanes levels were significantly higher in hypertensive individuals than in the control group (p < 0.00002 and p < 0.01 respectively). Moreover, EH patients excreted more TxB(2) in urine than normotensive individuals (p < 0.05). Our results highlight the mutual connections between the platelets AA metabolism and indicate its possible role in the pathogenesis of arterial hypertension. Moreover, we hypothesize that platelets AA metabolism may exert a pro-atherosclerotic effect. Finally, we suggest the use of (5-HETE+12-HETE)/TxB(2) parameter in further studies.
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Affiliation(s)
- Barbara Dołegowska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Szczecin, Poland
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29
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Chawengsub Y, Gauthier KM, Campbell WB. Role of arachidonic acid lipoxygenase metabolites in the regulation of vascular tone. Am J Physiol Heart Circ Physiol 2009; 297:H495-507. [PMID: 19525377 DOI: 10.1152/ajpheart.00349.2009] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stimulation of vascular endothelial cells with agonists such as acetylcholine (ACh) or bradykinin or with shear stress activates phospholipases and releases arachidonic acid (AA). AA is metabolized by cyclooxygenases, cytochrome P-450s, and lipoxygenases (LOs) to vasoactive products. In some arteries, a substantial component of the vasodilator response is dependent on LO metabolites of AA. Nitric oxide (NO)- and prostaglandin (PG)-independent vasodilatory responses to ACh and AA are reduced by inhibitors of LO and by antisense oligonucleotides specifically against 15-LO-1. Vasoactive 15-LO metabolites derived from the vascular endothelium include 15-hydroxy-11,12-epoxyeicosatrienoic acid (15-H-11,12-HEETA) that is hydrolyzed by soluble epoxide hydrolase to 11,12,15-trihydroxyeicosatrienoic acid (11,12,15-THETA). HEETA and THETA are endothelium-derived hyperpolarizing factors that induce vascular relaxations by activation of smooth muscle apamin-sensitive, calcium-activated, small-conductance K(+) channels causing hyperpolarization. In other arteries, the 12-LO metabolite 12-hydroxyeicosatetraenoic acid is synthesized by the vascular endothelium and relaxes smooth muscle by large-conductance, calcium-activated K(+) channel activation. Thus formation of vasodilator eicosanoids derived from LO pathways contributes to the regulation of vascular tone, local blood flow, and blood pressure.
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Affiliation(s)
- Yuttana Chawengsub
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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30
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Wang X, Villar VAM, Armando I, Eisner GM, Felder RA, Jose PA. Dopamine, kidney, and hypertension: studies in dopamine receptor knockout mice. Pediatr Nephrol 2008; 23:2131-46. [PMID: 18615257 PMCID: PMC3724362 DOI: 10.1007/s00467-008-0901-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 04/18/2008] [Accepted: 05/07/2008] [Indexed: 02/06/2023]
Abstract
Dopamine is important in the pathogenesis of hypertension because of abnormalities in receptor-mediated regulation of renal sodium transport. Dopamine receptors are classified into D(1)-like (D(1), D(5)) and D(2)-like (D(2), D(3), D(4)) subtypes, all of which are expressed in the kidney. Mice deficient in specific dopamine receptors have been generated to provide holistic assessment on the varying physiological roles of each receptor subtype. This review examines recent studies on these mutant mouse models and evaluates the impact of individual dopamine receptor subtypes on blood pressure regulation.
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Affiliation(s)
- Xiaoyan Wang
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | | | - Ines Armando
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - Gilbert M. Eisner
- Department of Medicine, Georgetown University Medical Center, Washington, DC, USA
| | - Robin A. Felder
- Department of Pathology, University of Virginia Health Sciences Center, Charlottesville, VA, USA
| | - Pedro A. Jose
- Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
- Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, DC, USA
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Francois H, Makhanova N, Ruiz P, Ellison J, Mao L, Rockman HA, Coffman TM. A role for the thromboxane receptor in L-NAME hypertension. Am J Physiol Renal Physiol 2008; 295:F1096-102. [PMID: 18684890 DOI: 10.1152/ajprenal.00369.2007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Actions of the lipid mediator thromboxane (Tx) A2 acting through the TP receptor contribute to the pathogenesis of cardiovascular disease. To further explore the role of TxA2 in hypertension, we examined the consequences of deficiency of the TP receptor on the course of hypertension associated with endothelial dysfunction and salt sensitivity. To this end, the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) was administered to TP-deficient (Tp-/-) and wild-type (Tp+/+) control mice in drinking water for 21 wk along with a high-salt (HS; 6% NaCl) diet. Administration of L-NAME increased urinary excretion of TxB2 to a similar extent in both Tp+/+ and Tp-/- animals. L-NAME also caused significant and sustained elevations in blood pressure that reached a maximum between weeks 3 and 6. However, the severity of hypertension was attenuated in the Tp-/- mice throughout the study period (P<0.001). At the end of the study, the wild-type mice developed significant cardiac hypertrophy (23.6+/-2% increase in heart-to-body weight ratio). The severity of cardiac hypertrophy was attenuated in the TP-deficient group (11.1+/-2.6%; P<0.05). In contrast, kidney hypertrophy was exaggerated in the Tp-/- mice compared with controls (37.1+/-5.4 vs. 12.3+/-2.3%; P<0.01). Moreover, the severity of glomerulosclerosis, tubule vacuolization, and interstitial chronic inflammation was also enhanced in the Tp-/- group (P<0.01). Thus, in L-NAME hypertension, TP receptors contribute to elevated blood pressure and cardiac hypertrophy. In this model, TP receptors also provided unexpected protection against kidney injury.
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Affiliation(s)
- Helene Francois
- Department of Medicine, Duke University Medical Center, Rm. 2018 MSRB II, 106 Research Drive, Durham, NC 27710, USA
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Zeng C, Armando I, Luo Y, Eisner GM, Felder RA, Jose PA. Dysregulation of dopamine-dependent mechanisms as a determinant of hypertension: studies in dopamine receptor knockout mice. Am J Physiol Heart Circ Physiol 2008; 294:H551-69. [PMID: 18083900 PMCID: PMC4029502 DOI: 10.1152/ajpheart.01036.2007] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and by interacting with vasoactive hormones/humoral factors, such as aldosterone, angiotensin, catecholamines, endothelin, oxytocin, prolactin pro-opiomelancortin, reactive oxygen species, renin, and vasopressin. Dopamine receptors are classified into D(1)-like (D(1) and D(5)) and D(2)-like (D(2), D(3), and D(4)) subtypes based on their structure and pharmacology. In recent years, mice deficient in one or more of the five dopamine receptor subtypes have been generated, leading to a better understanding of the physiological role of each of the dopamine receptor subtypes. This review summarizes the results from studies of various dopamine receptor mutant mice on the role of individual dopamine receptor subtypes and their interactions with other G protein-coupled receptors in the regulation of blood pressure.
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MESH Headings
- Animals
- Blood Pressure/genetics
- Blood Pressure/physiology
- Dopamine/physiology
- Hypertension/genetics
- Hypertension/physiopathology
- Mice
- Mice, Knockout
- Receptors, Dopamine/genetics
- Receptors, Dopamine/physiology
- Receptors, Dopamine D1/genetics
- Receptors, Dopamine D1/physiology
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/physiology
- Receptors, Dopamine D3/genetics
- Receptors, Dopamine D3/physiology
- Receptors, Dopamine D4/genetics
- Receptors, Dopamine D4/physiology
- Receptors, Dopamine D5/genetics
- Receptors, Dopamine D5/physiology
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Affiliation(s)
- Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing City 400042, People's Republic of China.
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Mitchell KD, Botros FT, Navar LG. Intrarenal renin-angiotensin system and counteracting protective mechanisms in angiotensin II-dependent hypertension. ACTA ACUST UNITED AC 2007; 94:31-48. [PMID: 17444274 DOI: 10.1556/aphysiol.94.2007.1-2.5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It is now well accepted that alterations in kidney function, due either to primary renal disease or to inappropriate hormonal influences on the kidney, are a cardinal characteristic in all forms of hypertension, and lead to a reduced ability of the kidneys to excrete sodium and the consequent development of elevated arterial pressures. However, it is also apparent that many extrarenal factors are important contributors to altered kidney function and hypertension. Central to many hypertensinogenic processes is the inappropriate activation of the renin-angiotensin system (RAS) and its downstream consequences by various pathophysiologic mechanisms. There may also be derangements in arachidonic acid metabolites, endothelium derived factors such as nitric oxide and carbon monoxide, and various paracrine and neural systems that normally interact with or provide a counteracting balance to the actions of the RAS. Thus, when the capacity of the kidneys to maintain sodium balance and extracellular fluid volume within appropriate ranges is compromised, increases in arterial pressure become necessary to re-establish normal balance.
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Affiliation(s)
- K D Mitchell
- Department of Physiology, Tulane Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, 1430 Tulane Ave, SL 39, New Orleans, Louisiana, LA 70112, USA.
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Zeng C, Sanada H, Watanabe H, Eisner GM, Felder RA, Jose PA. Functional genomics of the dopaminergic system in hypertension. Physiol Genomics 2005; 19:233-46. [PMID: 15548830 DOI: 10.1152/physiolgenomics.00127.2004] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Abnormalities in dopamine production and receptor function have been described in human essential hypertension and rodent models of genetic hypertension. Under normal conditions, D(1)-like receptors (D(1) and D(5)) inhibit sodium transport in the kidney and intestine. However, in the Dahl salt-sensitive and spontaneously hypertensive rats (SHRs) and in humans with essential hypertension, the D(1)-like receptor-mediated inhibition of epithelial sodium transport is impaired because of an uncoupling of the D(1)-like receptor from its G protein/effector complex. The uncoupling is receptor specific, organ selective, nephron-segment specific, precedes the onset of hypertension, and cosegregates with the hypertensive phenotype. The defective transduction of the renal dopaminergic signal is caused by activating variants of G protein-coupled receptor kinase type 4 (GRK4: R65L, A142V, A486V). The GRK4 locus is linked to and GRK4 gene variants are associated with human essential hypertension, especially in salt-sensitive hypertensive subjects. Indeed, the presence of three or more GRK4 variants impairs the natriuretic response to dopaminergic stimulation in humans. In genetically hypertensive rats, renal inhibition of GRK4 expression ameliorates the hypertension. In mice, overexpression of GRK4 variants causes hypertension either with or without salt sensitivity according to the variant. GRK4 gene variants, by preventing the natriuretic function of the dopaminergic system and by allowing the antinatriuretic factors (e.g., angiotensin II type 1 receptor) to predominate, may be responsible for salt sensitivity. Subclasses of hypertension may occur because of additional perturbations caused by variants of other genes, the quantitative interaction of which may vary depending upon the genetic background.
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Affiliation(s)
- Chunyu Zeng
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, People's Republic of China
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Jerez S, Peral de Bruno M, Coviello A. Nitric oxide modulates angiotensin II-induced endothelial vasoconstrictor prostanoid release. Eur J Pharmacol 2005; 520:127-34. [PMID: 16139266 DOI: 10.1016/j.ejphar.2005.07.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Accepted: 07/13/2005] [Indexed: 10/25/2022]
Abstract
UNLABELLED This study investigated the modulation of angiotensin II-induced endothelial prostanoid release in rabbit aortic rings. Two cumulative dose response curves with 90-min washing interval were performed. Incubation with L-N(G)-nitroarginine methyl ester (L-NAME) 10(-4) M increased angiotensin II maximal contractile response (E(max)). This effect was reversed by indomethacin 10(-5) M, diphenyliodinum 10(-5) M, Tempol 10(-5) M or ascorbic acid 10(-4) M in both cumulative dose response curves and by SQ 29548 10(-6) M in the second cumulative dose response curve. When segments were treated with tetraethylamonium 10(-3) M but not with glibenclamide 10(-5) M during the washing period, L-NAME recovered its ability to enhance the E(max) in arteries incubated with SQ 29548. CONCLUSIONS nitric oxide modulates angiotensin II-induced endothelial release of cyclooxygenase-dependent eicosanoids, one of which acts through thromboxane A(2)/prostaglandin H(2) receptors and would decrease K(Ca) channel activity. An increase in free radical production may account for the enhancement of such prostanoid release. Furthermore, it was found that in the present conditions, the release of the hyperpolarizing factor would improve in order to maintain the vascular tone.
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Affiliation(s)
- Susana Jerez
- Departamento de Bioingeniería, Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET, Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Tucumán, Argentina.
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37
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Tchana-Sato V, Dogné JM, Lambermont B, Ghuysen A, Magis D, Morimont P, Hanson J, D'Orio V, Limet R, Kolh P. Effects of BM-573, a thromboxane A2 modulator on systemic hemodynamics perturbations induced by U-46619 in the pig. Prostaglandins Other Lipid Mediat 2005; 78:82-95. [PMID: 16303607 DOI: 10.1016/j.prostaglandins.2005.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Revised: 02/01/2005] [Accepted: 04/18/2005] [Indexed: 10/25/2022]
Abstract
The aim of our study was to evaluate the effects of thromboxane A2 (TXA2) agonist, U-46619, on systemic circulatory parameters in the pigs before and after administration of a novel TXA2 receptor antagonist and synthase inhibitor (BM-573). Twelve anesthetized pigs were randomly assigned in two groups: in Ago group (n=6), the animals received six consecutive injections of U-46619 at 30 min interval, while in Anta group (n=6) they received an increasing dosage regimen of BM-573 10 min before each U-46619 injection. The effects of each dose of BM-573 on ex vivo platelet aggregation induced by arachidonic acid, collagen or ADP were also evaluated. Vascular properties such as characteristic impedance, peripheral resistance, compliance, arterial elastance were estimated using a windkessel model. Intravenous injections of 0.500 mg/ml of BM-573 and higher doses resulted in a complete inhibition of platelet aggregation induced by arachidonic acid. In the same conditions, BM-573 completely blocked the increase of arterial elastance, and stabilized both mean aortic blood pressure and mean systemic blood flow. In conclusion, BM-573 could therefore be a promising therapeutic approach in pathophysiological states where TXA2 plays a main role in the increase of vascular resistance like in pathologies such as systemic hypertension.
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Affiliation(s)
- Vincent Tchana-Sato
- Hemodynamic Research Center (HemoLiège), University of Liège, Liège 4000, Belgium.
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Cediel E, de Las Heras N, Sanz-Rosa D, Velasco O, Cachofeiro V, Lahera V. AT-1 receptor antagonism modifies the mediation of endothelin-1, thromboxane A2, and catecholamines in the renal constrictor response to angiotensin II. Kidney Int 2005:S3-9. [PMID: 15613065 DOI: 10.1111/j.1523-1755.2005.09302.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The present study investigated the consequences of partial AT(1) receptor blockade on the participation of catecholamines, thromboxane A(2) (TXA(2)), and endothelin-1 (ET-1) in the renal vasoconstriction induced by angiotensin II (Ang II). METHODS For this purpose, the increase in renal perfusion pressure (RPP) produced by Ang II was studied in isolated kidneys from untreated or irbesartan-treated Wistar Kyoto and spontaneously hypertensive rats (SHR), in absence or presence of the alfa-1 receptor antagonist, prazosin, the TXA(2) receptor antagonist, ifetroban, or the ET(A)/ET(B) receptor antagonist, PD145065. RESULTS Systolic arterial pressure (SAP) was higher (P < 0.05) in SHR than in WKY. Increases in RPP produced by Ang II were comparable in kidneys from both untreated groups. Treatment with irbesartan reduced SAP and RPP in both strains in a comparable extent. Presence of prazosin, ifetroban, or PD145065 in perfusion media reduced (P < 0.05) Ang II maximal response in all groups. Maximal inhibition of Ang II-induced vasoconstriction produced by the 3 antagonists was comparable in untreated WKY, but that of ifetroban and PD145065 was lower (P < 0.05) than that of prazosin in untreated SHR. Maximal inhibition of Ang II-induced vasoconstriction produced by the 3 antagonists was comparable in WKY treated with irbesartan, and not different to that observed in untreated WKY. Maximal inhibitory effect of the 3 antagonists was higher (P < 0.05) in treated than in untreated SHR. CONCLUSION The study further supports the importance of catecholamines, TXA(2), and ET-1 as mediators of the renal vasoconstriction induced by Ang II in both normotensive and hypertensive rats. Hypertensive conditions appeared to reduce the participation of TXA(2) and ET-1 in Ang II-induced vasoconstriction when compared with normotensive conditions. Chronic partial blockade of AT(1) receptors did not affect the participation of catecholamines, TXA(2), and ET-1 in normotensive rats, but increased the participation of the 3 mediators in SHR. This suggests that when AT(1) receptors are partially blocked, other vasoconstrictor factors could exert part of the renal vasoconstrictor effects of Ang II.
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Affiliation(s)
- Eva Cediel
- Departamento Científico, BMS España SA, Madrid, Spain
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Silvestre JS, Lévy BI. Hormones and the neovascularization process: role of angiotensin II. EXS 2004:77-93. [PMID: 15617472 DOI: 10.1007/3-7643-7311-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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40
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Stanke-Labesque F, Hardy G, Caron F, Cracowski JL, Bessard G. Inhibition of leukotriene synthesis with MK-886 prevents a rise in blood pressure and reduces noradrenaline-evoked contraction in L-NAME-treated rats. Br J Pharmacol 2003; 140:186-94. [PMID: 12967948 PMCID: PMC1574003 DOI: 10.1038/sj.bjp.0705405] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
(1) Long-term treatment of rats with Nomega-nitro-l-arginine methyl ester (l-NAME) induces hypertension associated with inflammatory and vascular changes. Leukotrienes are proinflammatory vasoactive products that are suspected to be involved in the pathogenesis of hypertension. We investigated, in rats chronically treated with l-NAME, the involvement of leukotrienes in the in vivo regulation of blood pressure and the in vitro contraction elicited by noradrenaline in isolated aorta. (2) Rats were randomly assigned to four groups and orally treated for 3 weeks with l-NAME (1 mg ml-1), l-NAME (1 mg ml-1) plus the leukotriene biosynthesis inhibitor MK-886 (0.1 mg ml-1), MK-886 (0.1 mg ml-1) alone or vehicle (Methocel, 0.1%). All the drugs were added to the drinking fluid. (3) The mean arterial blood pressure (MABP) increased significantly in l-NAME-treated rats (173.3+/-9.4 mmHg (n=25)) vs Methocel-treated rats (110.7+/-4.8 mmHg (n=11), P<0.001). Chronic treatment with MK-886 prevented this rise in MABP. (4) Aortic rings with or without endothelium were suspended in organ baths for recording isometric changes in response to noradrenaline. Pretreatment with either MK-886 (10 microm), the CysLT1 receptor antagonist MK571 (1 microm) or the dual CysLT1/CysLT2 receptor antagonist BAY-u9773 (0.1 microm) reduced (P<0.05) noradrenaline-induced contractions in intact aortic rings from l-NAME-treated rats only. (5) Noradrenaline (0.3 microm) induced a two-fold increase in cysteinyl leukotriene (CysLT) release (measured by enzyme immunoassay) in intact aortic rings from l-NAME-treated rats only. (6) These data suggested (1) a role for the 5-lipoxygenase pathway in the regulation of blood pressure in l-NAME-treated rats and (2) the involvement of endothelial CysLTs in noradrenaline-induced contraction in aorta from l-NAME-treated rats.
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Liu P, Misurski DA, Gopalakrishnan V. Cysteinyl leukotriene-dependent [Ca2+]i responses to angiotensin II in cardiomyocytes. Am J Physiol Heart Circ Physiol 2003; 284:H1269-76. [PMID: 12531730 DOI: 10.1152/ajpheart.00303.2002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With the use of fura 2 measurements in multiple and single cells, we examined whether cysteinyl leukotrienes (CysLT) mediate angiotensin II (ANG II)-evoked increases in cytosolic free Ca(2+) concentration ([Ca(2+)](i)) in neonatal rat cardiomyocytes. ANG II-evoked CysLT release peaked at 1 min. The angiotensin type 1 (AT(1)) antagonist losartan, but not the AT(2) antagonist PD-123319, attenuated the elevations in [Ca(2+)](i) and CysLT levels evoked by ANG II. Vasopressin and endothelin-1 increased [Ca(2+)](i) but not CysLT levels. The 5-lipoxygenase (5-LO) inhibitor AA-861 and the CysLT(1)-selective antagonist MK-571 reduced the maximal [Ca(2+)](i) responses to ANG II but not to vasopressin and endothelin-1. While MK-571 reduced the responses to leukotriene D(4) (LTD(4)), the dual CysLT antagonist BAY-u9773 completely blocked the [Ca(2+)](i) elevation to both LTD(4) and LTC(4). These data confirm that ANG II-evoked increases, but not vasopressin- and endothelin-1-evoked increases, in [Ca(2+)](i) involve generation of the 5-lipoxygenase metabolite CysLT. The inositol (1,4,5)-trisphosphate [Ins(1,4,5)P(3)] antagonist 2-aminoethoxydiphenyl borate attenuated the [Ca(2+)](i) responses to ANG II and LTD(4). Thus AT(1) receptor activation by ANG II is linked to CysLT-mediated Ca(2+) release from Ins(1,4,5)P(3)-sensitive intracellular stores to augment direct ANG II-evoked Ca(2+) mobilization in rat cardiomyocytes.
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Affiliation(s)
- Pinggang Liu
- Department of Pharmacology and the Cardiovascular Risk Factor Reduction Unit, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E5
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He FJ, MacGregor GA. Salt, blood pressure and the renin-angiotensin system. J Renin Angiotensin Aldosterone Syst 2003; 4:11-6. [PMID: 12692748 DOI: 10.3317/jraas.2003.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Much evidence from epidemiological, migration, intervention, animal and genetic studies suggests that salt intake plays an important role in regulating blood pressure (BP). At the same time, many clinical trials have shown that reducing salt intake lowers BP. However, the magnitude of the fall in BP for a given reduction in salt intake varies with age, ethnic group and BP levels. This difference has been suggested to be related to the responsiveness of the renin-angiotensin system (RAS). However, the sympathetic nervous system, the kallikrein-kinin system, the nitric oxide system, and many eicosanoids may also play a role. In this article, we address the important role of the RAS in determining the fall in BP with salt reduction.
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43
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Cediel E, Vázquez-Cruz B, Navarro-Cid J, de las Heras N, Sanz-Rosa D, Cachofeiro V, Lahera V. Role of endothelin-1 and thromboxane A2 in renal vasoconstriction induced by angiotensin II in diabetes and hypertension. KIDNEY INTERNATIONAL. SUPPLEMENT 2002:S2-7. [PMID: 12410847 DOI: 10.1046/j.1523-1755.62.s82.2.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Interactions among angiotensin II (Ang II), endothelin-1 (ET-1) and thromboxane A2 (TXA2) may play an important role in the regulation of renal function. The present study investigated the participation of TXA2 and ET-1 in the increase in renal vascular resistances (RVR) induced by Ang II, as well as the consequences of diabetes, hypertension, and the combination of both on this response. METHODS Isolated kidneys from male normoglycemic or streptozotocin-induced diabetic Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were used. The increase in perfusion pressure (PP) produced by Ang II was studied in the absence or presence of the TXA2 receptor antagonist, ifetroban, or the ETA/ETB receptor antagonist, PD145065. RESULTS Systolic arterial pressure (SAP) was higher in SHR than in WKY, but diabetic rats (D) from each strain showed lower SAP values than their respective non-diabetic rats. Basal renal PP was higher in WKY and SHR than in WKY-D and SHR-D. Increases in renal PP produced by Ang II were comparable in the kidneys from all groups. Either ifetroban or PD145065 reduced the maximal Ang II response in all animals. The maximal inhibitory effect of ifetroban was higher (P<0.05) in WKY than in the other groups. However, the maximal inhibitory effect of PD145065 was lower in SHR than in the other groups. CONCLUSION This study supports a role for ET-1 and TXA2 as mediators of the increase in renal vascular resistance produced by Ang II. These results indicate that the participation of ET-1 in the renal vasoconstriction produced by Ang II was reduced under hypertensive conditions, and that of TXA2 was reduced by both diabetes and hypertension.
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MESH Headings
- Angiotensin II/metabolism
- Animals
- Blood Pressure
- Bridged Bicyclo Compounds, Heterocyclic/pharmacology
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Dose-Response Relationship, Drug
- Endothelin Receptor Antagonists
- Endothelin-1/metabolism
- Hypertension/complications
- Hypertension/metabolism
- Hypertension/physiopathology
- Kidney/blood supply
- Male
- Oligopeptides/pharmacology
- Oxazoles/pharmacology
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Receptors, Endothelin/metabolism
- Receptors, Thromboxane A2, Prostaglandin H2/antagonists & inhibitors
- Receptors, Thromboxane A2, Prostaglandin H2/metabolism
- Renal Circulation/drug effects
- Thromboxane A2/metabolism
- Vascular Resistance
- Vasoconstriction/drug effects
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Affiliation(s)
- Eva Cediel
- Department of Pharmacology FES-Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, México
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Abstract
Angiotensin II (Ang II) is a multifunctional hormone that influences the function of cardiovascular cells through a complex series of intracellular signaling events initiated by the interaction of Ang II with AT1 and AT2 receptors. AT1 receptor activation leads to cell growth, vascular contraction, inflammatory responses and salt and water retention, whereas AT2 receptors induce apoptosis, vasodilation and natriuresis. These effects are mediated via complex, interacting signaling pathways involving stimulation of PLC and Ca2+ mobilization; activation of PLD, PLA2, PKC, MAP kinases and NAD(P)H oxidase, and stimulation of gene transcription. In addition, Ang II activates many intracellular tyrosine kinases that play a role in growth signaling and inflammation, such as Src, Pyk2, p130Cas, FAK and JAK/STAT. These events may be direct or indirect via transactivation of tyrosine kinase receptors, including PDGFR, EGFR and IGFR. Ang II induces a multitude of actions in various tissues, and the signaling events following occupancy and activation of Ang receptors are tightly controlled and extremely complex. Alterations of these highly regulated signaling pathways may be pivotal in structural and functional abnormalities that underlie pathological processes in cardiovascular diseases such as cardiac hypertrophy, hypertension and atherosclerosis.
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Affiliation(s)
- R M Touyz
- Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, University of Montreal, Quebec, Canada.
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Affiliation(s)
- G A FitzGerald
- Center for Experimental Therapeutics, School of Medicine, 153 Johnson Pavillion, 3620 Hamilton Walk, University of Pennsylvania, Philadelphia, PA 19104-6084, USA
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Qi Z, Hao CM, Langenbach RI, Breyer RM, Redha R, Morrow JD, Breyer MD. Opposite effects of cyclooxygenase-1 and -2 activity on the pressor response to angiotensin II. J Clin Invest 2002. [DOI: 10.1172/jci0214752] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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47
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Qi Z, Hao CM, Langenbach RI, Breyer RM, Redha R, Morrow JD, Breyer MD. Opposite effects of cyclooxygenase-1 and -2 activity on the pressor response to angiotensin II. J Clin Invest 2002; 110:61-9. [PMID: 12093889 PMCID: PMC151026 DOI: 10.1172/jci14752] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Therapeutic use of cyclooxygenase-inhibiting (COX-inhibiting) nonsteroidal antiinflammatory drugs (NSAIDs) is often complicated by renal side effects including hypertension and edema. The present studies were undertaken to elucidate the roles of COX1 and COX2 in regulating blood pressure and renal function. COX2 inhibitors or gene knockout dramatically augment the pressor effect of angiotensin II (Ang II). Unexpectedly, after a brief increase, the pressor effect of Ang II was abolished by COX1 deficiency (either inhibitor or knockout). Ang II infusion also reduced medullary blood flow in COX2-deficient but not in control or COX1-deficient animals, suggesting synthesis of COX2-dependent vasodilators in the renal medulla. Consistent with this, Ang II failed to stimulate renal medullary prostaglandin E(2) and prostaglandin I(2) production in COX2-deficient animals. Ang II infusion normally promotes natriuresis and diuresis, but COX2 deficiency blocked this effect. Thus, COX1 and COX2 exert opposite effects on systemic blood pressure and renal function. COX2 inhibitors reduce renal medullary blood flow, decrease urine flow, and enhance the pressor effect of Ang II. In contrast, the pressor effect of Ang II is blunted by COX1 inhibition. These results suggest that, rather than having similar cardiovascular effects, the activities of COX1 and COX2 are functionally antagonistic.
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Affiliation(s)
- Zhonghua Qi
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
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Stanke-Labesque F, Hardy G, Vergnaud S, Devillier P, Peoc'h M, Randon J, Bricca G, Caron F, Cracowski JL, Bessard G. Involvement of cysteinyl leukotrienes in angiotensin II-induced contraction in isolated aortas from transgenic (mRen-2)27 rats. J Hypertens 2002; 20:263-72. [PMID: 11821711 DOI: 10.1097/00004872-200202000-00016] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We have previously reported that 5-lipoxygenase-derived products, and particularly the cysteinyl leukotrienes (CysLTs), were involved in angiotensin II (Ang II)-induced contractions in isolated aortas from spontaneously hypertensive rats. DESIGN The aim of this study was to assess the role of CysLTs in the vascular response to Ang II in an Ang II-dependent model of hypertension, the (mRen-2)27 transgenic rats (TGs). METHODS Intact aortic rings from TG and normotensive Sprague-Dawley rats (SDs) were suspended in organ chambers for isometric tension development in response to Ang II. In addition, the release of CysLTs in response to Ang II (0.3 micromol/l) was measured by enzyme immunoassay. RESULTS In isolated aortas from TG rats, pretreatment with the 5-lipoxygenase inhibitor (AA861, 10 micromol/l) or the CysLT1 receptor antagonist (MK571, 1 micromol/l) significantly (P < 0.05) reduced Ang II-induced contractions by 52 and 42%, respectively. In addition, Ang II induced a 2.6-fold increase in CysLT release (pg/mg dry weight tissue: 58.3 +/- 17.9 (Ang II, n = 7) versus 22.5 +/- 5.9 (basal, n = 7) P < 0.05), which was inhibited by the AT1 receptor antagonist losartan (1 micromol/l). In contrast, in aortas from SD rats, pretreatment with AA861 or MK571 did not alter Ang II-induced contraction and CysLT production remained unchanged after exposure to Ang II. CONCLUSION These data suggest that CysLTs are involved in the contractile responses to Ang II in isolated aortas from TG but not from SD rats.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Animals, Genetically Modified/physiology
- Aorta/drug effects
- Aorta/physiology
- Arachidonate 5-Lipoxygenase/immunology
- Benzoquinones/pharmacology
- Blood Pressure/physiology
- Blotting, Western
- Body Weight/physiology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/enzymology
- Endothelium, Vascular/immunology
- Leukotriene Antagonists
- Lipoxygenase Inhibitors/pharmacology
- Membrane Proteins
- Models, Animal
- Models, Cardiovascular
- Muscle Contraction/drug effects
- Muscle Contraction/physiology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/immunology
- Muscle, Smooth, Vascular/physiology
- Rats
- Rats, Inbred SHR/genetics
- Rats, Sprague-Dawley/genetics
- Receptors, Leukotriene/biosynthesis
- Vascular Patency/drug effects
- Vascular Patency/physiology
- Vasoconstrictor Agents/pharmacology
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Athirakul K, Kim HS, Audoly LP, Smithies O, Coffman TM. Deficiency of COX-1 causes natriuresis and enhanced sensitivity to ACE inhibition. Kidney Int 2001; 60:2324-9. [PMID: 11737606 DOI: 10.1046/j.1523-1755.2001.00072.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Prostanoid products of the cyclo-oxygenase (COX) pathway of arachidonic acid metabolism modulate blood pressure (BP) and sodium homeostasis. Conventional non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit both COX isoforms (COX-1 and -2), cause sodium retention, exacerbate hypertension, and interfere with the efficacy of certain anti-hypertensive agents such as angiotensin-converting enzyme (ACE) inhibitors. While a new class of NSAIDs that specifically inhibit COX-2 is now widely used, the relative contribution of the individual COX isoforms to these untoward effects is not clear. METHODS To address this question, we studied mice with targeted disruption of the COX-1 (Ptgs1) gene. Blood pressure, renin mRNA expression, and aldosterone were measured while dietary sodium was varied. To study interactions with the renin-angiotensin system, ACE inhibitors were administered and mice with combined deficiency of COX-1 and the angiotensin II subtype 1A (AT1A) receptor were generated. RESULTS On a regular diet, BP in COX-1-/- mice was near normal. However, during low salt feeding, BP values were reduced in COX-1-/- compared to +/+ animals, and this reduction in BP was associated with abnormal natriuresis despite appropriate stimulation of renin and aldosterone. Compared to COX-1+/+ mice, the actions of ACE inhibition were markedly accentuated in COX-1-/- mice. Sodium sensitivity and BP lowering also were enhanced in mice with combined deficiency of COX-1 and AT1A receptor. CONCLUSIONS The absence of COX-1 is associated with sodium loss and enhanced sensitivity to ACE inhibition, suggesting that COX-1 inhibition does not cause hypertension and abnormal sodium handling associated with NSAID use.
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Affiliation(s)
- K Athirakul
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina, USA
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