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Batchu SN, Kaur H, Yerra VG, Advani SL, Kabir MG, Liu Y, Klein T, Advani A. Lung and Kidney ACE2 and TMPRSS2 in Renin-Angiotensin System Blocker-Treated Comorbid Diabetic Mice Mimicking Host Factors That Have Been Linked to Severe COVID-19. Diabetes 2021; 70:759-771. [PMID: 33310740 DOI: 10.2337/db20-0765] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/27/2020] [Indexed: 12/20/2022]
Abstract
The causes of the increased risk of severe coronavirus disease 2019 (COVID-19) in people with diabetes are unclear. It has been speculated that renin-angiotensin system (RAS) blockers may promote COVID-19 by increasing ACE2, which severe acute respiratory syndrome coronavirus 2 uses to enter host cells, along with the host protease TMPRSS2. Taking a reverse translational approach and by combining in situ hybridization, primary cell isolation, immunoblotting, quantitative RT-PCR, and liquid chromatography-tandem mass spectrometry, we studied lung and kidney ACE2 and TMPRSS2 in diabetic mice mimicking host factors linked to severe COVID-19. In healthy young mice, neither the ACE inhibitor ramipril nor the AT1 receptor blocker telmisartan affected lung or kidney ACE2 or TMPRSS2, except for a small increase in kidney ACE2 protein with ramipril. In contrast, mice with comorbid diabetes (aging, high-fat diet, and streptozotocin-induced diabetes) had heightened lung ACE2 and TMPRSS2 protein levels and increased lung ACE2 activity. None of these parameters were affected by RAS blockade. ACE2 was similarly upregulated in the kidneys of mice with comorbid diabetes compared with aged controls, whereas TMPRSS2 (primarily distal nephron) was highest in telmisartan-treated animals. Upregulation of lung ACE2 activity in comorbid diabetes may contribute to an increased risk of severe COVID-19. This upregulation is driven by comorbidity and not by RAS blockade.
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Affiliation(s)
- Sri Nagarjun Batchu
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Harmandeep Kaur
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Veera Ganesh Yerra
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Suzanne L Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - M Golam Kabir
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Youan Liu
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Thomas Klein
- Department of Cardiometabolic Diseases Research, Boehringer Ingelheim Pharma, Biberach, Germany
| | - Andrew Advani
- Keenan Research Centre for Biomedical Science and Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
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Abstract
Endothelial progenitor cells (EPCs) play a critical role in maintenance of the endothelial integrity and vascular homeostasis, as well as in neovascularization. Dysfunctional EPCs are believed to contribute to the endothelial dysfunction and are closely related to the development of various cardiovascular diseases, such as hypertension, hyperlipidemia, and stroke. However, the underlying mechanisms of EPC dysfunction are complicated and remain largely elusive. Recent studies have demonstrated that reactive oxygen species (ROS) are key factors that involve in modulation of stem and progenitor cell function under various physiologic and pathologic conditions. It has been shown that NADPH oxidase (NOX)-derived ROS are the major sources of ROS in cardiovascular system. Accumulating evidence suggests that NOX-mediated oxidative stress can modulate EPC bioactivities, such as mobilization, migration, and neovascularization, and that inhibition of NOX has been shown to improve EPC functions. This review summarized recent progress in the studies on the correlation between NOX-mediated EPC dysfunction and cardiovascular diseases.
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Rodiño-Janeiro BK, Paradela-Dobarro B, Castiñeiras-Landeira MI, Raposeiras-Roubín S, González-Juanatey JR, Álvarez E. Current status of NADPH oxidase research in cardiovascular pharmacology. Vasc Health Risk Manag 2013; 9:401-28. [PMID: 23983473 PMCID: PMC3750863 DOI: 10.2147/vhrm.s33053] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The implications of reactive oxygen species in cardiovascular disease have been known for some decades. Rationally, therapeutic antioxidant strategies combating oxidative stress have been developed, but the results of clinical trials have not been as good as expected. Therefore, to move forward in the design of new therapeutic strategies for cardiovascular disease based on prevention of production of reactive oxygen species, steps must be taken on two fronts, ie, comprehension of reduction-oxidation signaling pathways and the pathophysiologic roles of reactive oxygen species, and development of new, less toxic, and more selective nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors, to clarify both the role of each NADPH oxidase isoform and their utility in clinical practice. In this review, we analyze the value of NADPH oxidase as a therapeutic target for cardiovascular disease and the old and new pharmacologic agents or strategies to prevent NADPH oxidase activity. Some inhibitors and different direct or indirect approaches are available. Regarding direct NADPH oxidase inhibition, the specificity of NADPH oxidase is the focus of current investigations, whereas the chemical structure-activity relationship studies of known inhibitors have provided pharmacophore models with which to search for new molecules. From a general point of view, small-molecule inhibitors are preferred because of their hydrosolubility and oral bioavailability. However, other possibilities are not closed, with peptide inhibitors or monoclonal antibodies against NADPH oxidase isoforms continuing to be under investigation as well as the ongoing search for naturally occurring compounds. Likewise, some different approaches include inhibition of assembly of the NADPH oxidase complex, subcellular translocation, post-transductional modifications, calcium entry/release, electron transfer, and genetic expression. High-throughput screens for any of these activities could provide new inhibitors. All this knowledge and the research presently underway will likely result in development of new drugs for inhibition of NADPH oxidase and application of therapeutic approaches based on their action, for the treatment of cardiovascular disease in the next few years.
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Affiliation(s)
- Bruno K Rodiño-Janeiro
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- European Molecular Biology Laboratory, Grenoble, France
| | | | | | - Sergio Raposeiras-Roubín
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- Cardiology Department, University Clinic Hospital of Santiago de Compostela,
Santiago de Compostela, Spain
| | - José R González-Juanatey
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- Cardiology Department, University Clinic Hospital of Santiago de Compostela,
Santiago de Compostela, Spain
- Medicine Department, University of Santiago de Compostela, Santiago de Compostela,
Spain
| | - Ezequiel Álvarez
- Health Research Institute of Santiago de Compostela, Santiago de Compostela,
Spain
- Medicine Department, University of Santiago de Compostela, Santiago de Compostela,
Spain
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da Silva AS, Dias LD, Borges JF, Markoski MM, de Souza MS, Irigoyen MC, Machado UF, Schaan BD. Renal GLUT1 reduction depends on angiotensin-converting enzyme inhibition in diabetic hypertensive rats. Life Sci 2013; 92:1174-9. [DOI: 10.1016/j.lfs.2013.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 04/15/2013] [Accepted: 05/01/2013] [Indexed: 10/26/2022]
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Safari F, Bayat G, Shekarforoush S, Hekmatimoghaddam S, Anvari Z, Moghadam MF, Hajizadeh S. Expressional profile of cardiac uncoupling protein-2 following myocardial ischemia reperfusion in losartan- and ramiprilat-treated rats. J Renin Angiotensin Aldosterone Syst 2013; 15:209-17. [PMID: 23372044 DOI: 10.1177/1470320312474050] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND AIMS The aim of this study was to investigate the early changes of cardiac uncoupling protein-2 (UCP2) expression following myocardial ischemia reperfusion in rats chronically treated with ramiprilat and losartan. METHODS Male Wistar rats were assigned into seven groups (six in each): intact (control); sham-operated; nontreated rats subjected to ischemia and reperfusion (IR); ramiprilat-treated rats with (Ram+IR) and without ischemia (Ram); losartan treated with (Los+IR) and without ischemia (Los). Quantitative evaluation of UCP2 mRNA was carried out using real-time reverse transcription-polymerase chain reaction (RT-PCR). Mitochondria were isolated, and protein expression was quantified by Western blotting. RESULTS In IR group: UCP2 protein but not mRNA level was increased in the ischemic area of the left ventricle (LV) (172% ± 26.7, p < 0.001 vs. LV of control). Following acute myocardial IR, UCP2 protein levels was increased in the ischemic area of the LV but not in RV, suggesting the local effect of ischemia on UCP2 expression. IR-induced overexpression of UCP2 was suppressed by ramiprilat and losartan. CONCLUSION These findings suggest that losartan and ramiprilat can suppress UCP2 expression following myocardial IR, and by this mechanism may protect the myocardium against IR injury.
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Affiliation(s)
- Fatemeh Safari
- Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Department of Physiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Department of Physiology, Tarbiat Modares University, Tehran, Iran
| | - Gholamreza Bayat
- Department of Physiology, Tarbiat Modares University, Tehran, Iran Department of Physiology and Pharmacology, Faculty of Medical Sciences, Alborz University of Medical Sciences, Karaj, Iran
| | | | - Seyedhossein Hekmatimoghaddam
- Department of Laboratory Sciences, School of Paramedicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Zahra Anvari
- Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | | | - Sohrab Hajizadeh
- Department of Physiology, Tarbiat Modares University, Tehran, Iran Institute for Cognitive Science Studies (ICSS), Tehran, Iran
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Huynh K, Kiriazis H, Du XJ, Love JE, Jandeleit-Dahm KA, Forbes JM, McMullen JR, Ritchie RH. Coenzyme Q10 attenuates diastolic dysfunction, cardiomyocyte hypertrophy and cardiac fibrosis in the db/db mouse model of type 2 diabetes. Diabetologia 2012; 55:1544-53. [PMID: 22374176 DOI: 10.1007/s00125-012-2495-3] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 01/16/2012] [Indexed: 01/02/2023]
Abstract
AIMS/HYPOTHESIS An increase in the production of reactive oxygen species is commonly thought to contribute to the development of diabetic cardiomyopathy. This study aimed to assess whether administration of the antioxidant coenzyme Q(10) would protect the diabetic heart against dysfunction and remodelling, using the db/db mouse model of type 2 diabetes. Furthermore, we aimed to compare the efficacy of coenzyme Q(10) to that of the ACE inhibitor ramipril. METHODS Six-week-old non-diabetic db/+ mice and diabetic db/db mice received either normal drinking water or water supplemented with coenzyme Q(10) for 10 weeks. Endpoint cardiac function was assessed by echocardiography and catheterisation. Ventricular tissue was collected for histology, gene expression and protein analysis. RESULTS Untreated db/db diabetic mice exhibited hyperglycaemia, accompanied by diastolic dysfunction and adverse structural remodelling, including cardiomyocyte hypertrophy, myocardial fibrosis and increased apoptosis. Systemic lipid peroxidation and myocardial superoxide generation were also elevated in db/db mice. Coenzyme Q(10) and ramipril treatment reduced superoxide generation, ameliorated diastolic dysfunction and reduced cardiomyocyte hypertrophy and fibrosis in db/db mice. Phosphorylation of Akt, although depressed in untreated db/db mice, was restored with coenzyme Q(10) administration. We postulate that preservation of cardioprotective Akt signalling may be a mechanism by which coenzyme Q(10)-treated db/db mice are protected from pathological cardiac hypertrophy. CONCLUSIONS/INTERPRETATION These data demonstrate that coenzyme Q(10) attenuates oxidative stress and left ventricular diastolic dysfunction and remodelling in the diabetic heart. Addition of coenzyme Q(10) to the current therapy used in diabetic patients with diastolic dysfunction warrants further investigation.
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Affiliation(s)
- K Huynh
- Baker IDI Heart and Diabetes Institute, PO Box 6492, St Kilda Road Central, Melbourne, Victoria 8008, Australia
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Mao M, Sudhahar V, Ansenberger-Fricano K, Fernandes DC, Tanaka LY, Fukai T, Laurindo FR, Mason RP, Vasquez-Vivar J, Minshall RD, Stadler K, Bonini MG. Nitroglycerin drives endothelial nitric oxide synthase activation via the phosphatidylinositol 3-kinase/protein kinase B pathway. Free Radic Biol Med 2012; 52:427-35. [PMID: 22037515 PMCID: PMC3432314 DOI: 10.1016/j.freeradbiomed.2011.09.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Revised: 09/12/2011] [Accepted: 09/17/2011] [Indexed: 02/07/2023]
Abstract
Nitroglycerin (GTN) has been clinically used to treat angina pectoris and acute heart episodes for over 100 years. The effects of GTN have long been recognized and active research has contributed to the unraveling of numerous metabolic routes capable of converting GTN to the potent vasoactive messenger nitric oxide. Recently, the mechanism by which minute doses of GTN elicit robust pharmacological responses was revisited and eNOS activation was implicated as an important route mediating vasodilation induced by low GTN doses (1-50nM). Here, we demonstrate that at such concentrations the pharmacologic effects of nitroglycerin are largely dependent on the phosphatidylinositol 3-kinase, Akt/PKB, and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) signal transduction axis. Furthermore, we demonstrate that nitroglycerin-dependent accumulation of 3,4,5-InsP(3), probably because of inhibition of PTEN, is important for eNOS activation, conferring a mechanistic basis for GTN pharmacological action at pharmacologically relevant doses.
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Affiliation(s)
- Mao Mao
- Section of Cardiology and Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Varadarajan Sudhahar
- Section of Cardiology and Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Kristine Ansenberger-Fricano
- Section of Cardiology and Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Denise C. Fernandes
- Vascular Biology Laboratory, Heart Institute (InCor), University of Sao Paulo School of Medicine, Sao Paulo, Brazil
| | - Leonardo Y. Tanaka
- Vascular Biology Laboratory, Heart Institute (InCor), University of Sao Paulo School of Medicine, Sao Paulo, Brazil
| | - Tohru Fukai
- Section of Cardiology and Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Francisco R.M. Laurindo
- Vascular Biology Laboratory, Heart Institute (InCor), University of Sao Paulo School of Medicine, Sao Paulo, Brazil
| | - Ronald P. Mason
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | - Richard D. Minshall
- Departments of Pharmacology and Anesthesiology, University of Illinois at Chicago, IL, 60612 USA
| | - Krisztian Stadler
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Marcelo G. Bonini
- Section of Cardiology and Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- Corresponding author at: Section of Cardiology and Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA. (M.G. Bonini)
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Organic nitrates and nitrate resistance in diabetes: the role of vascular dysfunction and oxidative stress with emphasis on antioxidant properties of pentaerithrityl tetranitrate. EXPERIMENTAL DIABETES RESEARCH 2010; 2010:213176. [PMID: 21234399 PMCID: PMC3014692 DOI: 10.1155/2010/213176] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 11/01/2010] [Indexed: 12/20/2022]
Abstract
Organic nitrates represent a class of drugs which are clinically used for treatment of ischemic symptoms of angina as well as for congestive heart failure based on the idea to overcome the impaired NO bioavailability by “NO” replacement therapy. The present paper is focused on parallels between diabetes mellitus and nitrate tolerance, and aims to discuss the mechanisms underlying nitrate resistance in the setting of diabetes. Since oxidative stress was identified as an important factor in the development of tolerance to organic nitrates, but also represents a hallmark of diabetic complications, this may represent a common principle for both disorders where therapeutic intervention should start. This paper examines the evidence supporting the hypothesis that pentaerithrityl tetranitrate may represent a nitrate for treatment of ischemia in diabetic patients. This evidence is based on the considerations of parallels between diabetes mellitus and nitrate tolerance as well as on preliminary data from experimental diabetes studies.
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Daiber A, Münzel T, Gori T. Organic nitrates and nitrate tolerance--state of the art and future developments. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2010; 60:177-227. [PMID: 21081219 DOI: 10.1016/b978-0-12-385061-4.00007-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The hemodynamic and antiischemic effects of nitroglycerin (GTN) are lost upon chronic administration due to the rapid development of nitrate tolerance. The mechanism of this phenomenon has puzzled several generations of scientists, but recent findings have led to novel hypotheses. The formation of reactive oxygen and nitrogen species in the mitochondria and the subsequent inhibition of the nitrate-bioactivating enzyme mitochondrial aldehyde dehydrogenase (ALDH-2) appear to play a central role, at least for GTN, that is, bioactivated by ALDH-2. Importantly, these findings provide the opportunity to reconcile the two "traditional" hypotheses of nitrate tolerance, that is, the one postulating a decreased bioactivation and the concurrent one suggesting a role of oxidative stress. Furthermore, recent animal and human experimental studies suggest that the organic nitrates are not a homogeneous group but demonstrate a broad diversity with regard to induction of vascular dysfunction, oxidative stress, and other side effects. In the past, attempts to avoid nitrate-induced side effects have focused on administration schedules that would allow a "nitrate-free interval"; in the future, the role of co-therapies with antioxidant compounds and of activation of endogeneous protective pathways such as the heme oxygenase 1 (HO-1) will need to be explored. However, the development of new nitrates, for example, tolerance-free aminoalkyl nitrates or combination of nitrate groups with established cardiovascular drugs like ACE inhibitors or AT(1)-receptor blockers (hybrid molecules) may be of great clinical interest.
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Affiliation(s)
- Andreas Daiber
- II. Medizinische Klinik, Labor für Molekulare Kardiologie und Abteilung für Kardiologie und Angiologie, Universitätsmedizin der Johannes-Gutenberg-Universität, Mainz, Germany
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Reply to Daiber
et al.
: “Doubt about an essential role for constitutive nitric oxide synthase in nitroglycerin-mediated vasodilation”. Proc Natl Acad Sci U S A 2008. [DOI: 10.1073/pnas.0809563105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Constitutive nitric oxide synthase activation is a significant route for nitroglycerin-mediated vasodilation. Proc Natl Acad Sci U S A 2008; 105:8569-74. [PMID: 18562300 DOI: 10.1073/pnas.0708615105] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The physiological effects of nitroglycerin as a potent vasodilator have long been documented. However, the molecular mechanisms by which nitroglycerin exerts its biological functions are still a matter of intense debate. Enzymatic pathways converting nitroglycerin to vasoactive compounds have been identified, but none of them seems to fully account for the reported clinical observations. Here, we demonstrate that nitroglycerin triggers constitutive nitric oxide synthase (NOS) activation, which is a major source of NO responsible for low-dose (1-10 nM) nitroglycerin-induced vasorelaxation. Our studies in cell cultures, isolated vessels, and whole animals identified endothelial NOS activation as a fundamental requirement for nitroglycerin action at pharmacologically relevant concentrations in WT animals.
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Wölkart G, Pang X, Stessel H, Kirchengast M, Brunner F. Chronic endothelin-A receptor antagonism is as protective as angiotensin converting enzyme inhibition against cardiac dysfunction in diabetic rats. Br J Pharmacol 2007; 151:1187-97. [PMID: 17572700 PMCID: PMC2189828 DOI: 10.1038/sj.bjp.0707325] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 04/23/2007] [Accepted: 05/02/2007] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Diabetes mellitus is associated with a specific cardiomyopathy. We compared the cardioprotective effects of an endothelin-A receptor blocker (ET(A)-RB) with those of an angiotensin-converting enzyme inhibitor (ACE-I) in rats with streptozotocin (STZ)-induced diabetes. EXPERIMENTAL APPROACH Diabetic rats were left untreated or received either the ET(A)-RB atrasentan or the ACE-I ramipril (each 3 mg kg(-1) per day) orally for 8 weeks. Isolated isovolumic heart function was studied during normoxia and in response to ischaemia-reperfusion. Cardiac fibrosis, tissue oxidative stress and tissue nitric oxide synthase (NOS) activity were determined. KEY RESULTS Basal left ventricular systolic contractility was lower in diabetic compared to nondiabetic hearts and ET(A)-RB or ACE-I treatment significantly antagonised the decline. Following 15 min of no-flow ischaemia, reperfusion systolic function was depressed and left-ventricular end-diastolic pressure (LVEDP) was elevated in diabetic hearts. ET(A)-RB or ACE-I treatment significantly improved recovery of reperfusion systolic and diastolic function, without differences between groups. Hydroxyproline (an index of tissue fibrosis) and malondialdehyde (a measure of tissue oxidative stress) were elevated at the end of reperfusion in diabetic, compared to nondiabetic hearts. Either treatment reduced hydroxyproline and malondialdehyde to control level. Constitutive NOS activity was similar in nondiabetic and diabetic hearts and unaffected by ET(A)-RB or ACE-I treatment. CONCLUSIONS AND IMPLICATIONS These results suggest that in experimental type 1 diabetes ET(A)-RB is as effective as an ACE-I in ameliorating myocardial functions during normoxia and ischaemia-reperfusion. Combining the two treatments neither afforded additive effects, nor diminished any protection effect seen with either drug.
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Affiliation(s)
- G Wölkart
- Department of Pharmacology and Toxicology, University of Graz Graz, Austria
| | - X Pang
- Department of Pharmacology and Toxicology, University of Graz Graz, Austria
| | - H Stessel
- Department of Pharmacology and Toxicology, University of Graz Graz, Austria
| | - M Kirchengast
- PRA International Mannheim, Germany
- Faculty of Clinical Medicine, Department of Pharmacology and Toxicology, Mannheim Ruprecht-Karls-University Heidelberg Mannheim, Germany
| | - F Brunner
- Department of Pharmacology and Toxicology, University of Graz Graz, Austria
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Thum T, Fraccarollo D, Thum S, Schultheiss M, Daiber A, Wenzel P, Munzel T, Ertl G, Bauersachs J. Differential effects of organic nitrates on endothelial progenitor cells are determined by oxidative stress. Arterioscler Thromb Vasc Biol 2007; 27:748-54. [PMID: 17255540 DOI: 10.1161/01.atv.0000258787.18982.73] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Reduced levels and impaired function of endothelial progenitor cells (EPCs) foster development and progression of atherosclerotic lesions. Endothelial nitric oxide synthase (eNOS)-derived NO regulates EPC mobilization and function. Organic nitrates release NO, and therefore may favorably affect EPC biology. METHODS AND RESULTS We compared the effects of 2 different nitrates on circulating EPC numbers and function. Treatment of rats with pentaerythritol-trinitrate (PETriN) or isosorbide dinitrate (ISDN) increased circulating EPC levels. EPC from ISDN- but not PETriN-treated animals displayed impaired migratory capacity and increased reactive oxygen species formation in EPCs. In vitro treatment with ISDN reduced migration and incorporation of human EPCs into vascular structures on matrigel, whereas PETriN improved EPC function. ISDN, but not PETriN, increased NADPH oxidase-mediated oxidative stress in cultured human EPCs. Addition of polyethylene-glycolated superoxide dismutase or diphenyliodonium normalized both ISDN-induced superoxide anion production and impaired migratory capacity of EPCs. CONCLUSIONS Long-acting nitrates increase levels of circulating EPCs, but differ in their effects on EPC function dependent on the induction of intracellular oxidative stress. Organic nitrates that improve EPC function may confer long-term cardiovascular protection based on their beneficial effects on EPC biology.
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Affiliation(s)
- Thomas Thum
- Department of Cardiology, University of Würzburg, University Hospital, Würzburg, Germany.
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