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Stanko P, Repova K, Baka T, Krajcirovicova K, Aziriova S, Barta A, Zorad S, Adamcova M, Simko F. Sacubitril/Valsartan Alleviates Cardiac Remodeling and Dysfunction in L-NAME-Induced Hypertension and Hypertensive Heart Disease. Biomedicines 2024; 12:733. [PMID: 38672089 PMCID: PMC11047969 DOI: 10.3390/biomedicines12040733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/06/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
There is ample evidence on the benefit of angiotensin receptor-neprilysin inhibitors (ARNIs) in heart failure, yet data regarding the potential protective action of ARNIs in hypertensive heart disease are sparse. The aim of this study was to show whether an ARNI exerts a protective effect in a model of Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertension with a hypertensive heart and to compare this potential benefit with an angiotensin-converting enzyme inhibitor, captopril. Five groups of adult male Wistar rats were studied (14 per group) for four weeks: untreated controls; ARNI (68 mg/kg/day); L-NAME (40 mg/kg/day); L-NAME treated with ARNI; and L-NAME treated with captopril (100 mg/kg/day). L-NAME administration induced hypertension, accompanied by increased left ventricular (LV) weight and fibrotic rebuilding of the LV in terms of increased concentration and content of hydroxyproline in insoluble collagen and in total collagen and with a histological finding of fibrosis. These alterations were associated with a compromised systolic and diastolic LV function. Treatment with either an ARNI or captopril reduced systolic blood pressure (SBP), alleviated LV hypertrophy and fibrosis, and prevented the development of both systolic and diastolic LV dysfunction. Moreover, the serum levels of prolactin and prolactin receptor were reduced significantly by ARNI and slightly by captopril. In conclusion, in L-NAME-induced hypertension, the dual inhibition of neprilysin and AT1 receptors by ARNI reduced SBP and prevented the development of LV hypertrophy, fibrosis, and systolic and diastolic dysfunction. These data suggest that ARNI could provide protection against LV structural remodeling and functional disorders in hypertensive heart disease.
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Affiliation(s)
- Peter Stanko
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, 81108 Bratislava, Slovakia; (P.S.); (K.R.); (T.B.); (K.K.); (S.A.)
- Department of Pneumology, Phthisiology and Functional Diagnostics, Slovak Medical University and Bratislava University Hospital, 82606 Bratislava, Slovakia
| | - Kristina Repova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, 81108 Bratislava, Slovakia; (P.S.); (K.R.); (T.B.); (K.K.); (S.A.)
| | - Tomas Baka
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, 81108 Bratislava, Slovakia; (P.S.); (K.R.); (T.B.); (K.K.); (S.A.)
| | - Kristina Krajcirovicova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, 81108 Bratislava, Slovakia; (P.S.); (K.R.); (T.B.); (K.K.); (S.A.)
| | - Silvia Aziriova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, 81108 Bratislava, Slovakia; (P.S.); (K.R.); (T.B.); (K.K.); (S.A.)
| | - Andrej Barta
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, 81371 Bratislava, Slovakia;
| | - Stefan Zorad
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia;
| | - Michaela Adamcova
- Department of Physiology, Faculty of Medicine in Hradec Kralove, Charles University, 50003 Hradec Kralove, Czech Republic;
| | - Fedor Simko
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, 81108 Bratislava, Slovakia; (P.S.); (K.R.); (T.B.); (K.K.); (S.A.)
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia;
- 3rd Department of Internal Medicine, Faculty of Medicine, Comenius University, 83305 Bratislava, Slovakia
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Baka T, Simko F. Ivabradine reversed nondipping heart rate in rats with l-NAME-induced hypertension. Clin Exp Pharmacol Physiol 2019; 46:607-610. [PMID: 30790319 DOI: 10.1111/1440-1681.13075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 12/13/2022]
Abstract
We hypothesized that decreasing elevated night-time heart rate (HR) in hypertension by administering a bradycardic agent (ivabradine) at bedtime could bring cardiovascular benefit. Since rats are nocturnal animals, they exhibit circadian rhythms phase-shifted relative to humans. Sixty-six Wistar rats were divided into non-diseased controls and rats with l-NAME-induced hypertension to compare the haemodynamic effects of daytime-dosed and night-time-dosed ivabradine. l-NAME-induced hypertension inverted the physiological 5.6% night-to-day HR dip to an undesirable HR rise by 11.1%. Ivabradine dosed at daytime (the rat's resting phase) reverted a night-to-day HR rise to HR dip by 14.2%. These results suggest a cardiovascular benefit of ivabradine dosed at the human's resting phase (night-time) for hypertensive patients with nondipping HR.
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Affiliation(s)
- Tomas Baka
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic
| | - Fedor Simko
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic.,3rd Department of Internal Medicine, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic.,Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovak Republic
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Krajcirovicova K, Aziriova S, Baka T, Repova K, Adamcova M, Paulis L, Simko F. Ivabradine does not impair anxiety-like behavior and memory in both healthy and L-NAME-induced hypertensive rats. Physiol Res 2019; 67:S655-S664. [PMID: 30607972 DOI: 10.33549/physiolres.934048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cardiovascular pathologies are frequently associated with anxiety and other behavioral disturbances. Ivabradine, an inhibitor of the hyperpolarization-activated cyclic nucleotide-gated channels in the sinoatrial node, decreases heart rate and provides cardiovascular protection. Although ivabradine is increasingly used in cardiovascular medicine, the data on its behavioral effects are lacking. The aim of this work was to show ivabradine's potential effect on behavior in healthy and hypertensive rats. After a four-week treatment period, systolic blood pressure was increased in the N(G)-nitro-L-arginine methyl ester (L-NAME)-group and ivabradine significantly reduced it. Furthermore, it reduced the heart rate in both the control and L-NAME-group. In the control group, ivabradine enhanced the time spent in and transition to the open arms of the elevated plus maze test (EPM). In the L-NAME-group, ivabradine does not show a significant effect on the time spent in the EPM open arms and the number of transitions into them. Furthermore, ivabradine has no impact on cognitive function in both control and L-NAME groups. We conclude that ivabradine showed no undesirable effects on anxiety, locomotion or learning; in fact, some of these parameters were even improved. For the first time it has been shown that ivabradine is a safe cardiovascular drug regarding its effect on psycho-behavioral manifestations.
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Affiliation(s)
- K Krajcirovicova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic.
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Hmaid AAAA, Markelic M, Otasevic V, Masovic S, Jankovic A, Korac B, Korac A. Structural alterations in rat myocardium induced by chronic l-arginine and l-NAME supplementation. Saudi J Biol Sci 2018; 25:537-544. [PMID: 29686516 PMCID: PMC5910630 DOI: 10.1016/j.sjbs.2016.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 12/09/2015] [Accepted: 01/12/2016] [Indexed: 02/07/2023] Open
Abstract
Structural changes affecting cardiomyocyte function may contribute to the pathophysiological remodeling underlying cardiac function impairment. Recent reports have shown that endogenous nitric oxide (NO) plays an important role in this process. In order to examine the role of NO in cardiomyocyte remodeling, male rats were acclimated to room temperature (22 ± 1 °C) or cold (4 ± 1 °C) and treated with 2.25% l-arginine·HCl or 0.01% l-NAME (Nω-nitro-l-arginine methyl ester)·HCl for 45 days. Untreated groups served as controls. Right heart ventricles were routinely prepared for light microscopic examination. Stereological estimations of volume densities of cardiomyocytes, surrounding blood vessels and connective tissue, as well as the morphometric measurements of cardiomyocyte diameters were performed. Tissue sections were also analyzed for structural alterations. We observed that both l-arginine and l-NAME supplementation induced cardiomyocyte hypertrophy, regardless of ambient temperature. However, cardiomyocyte hypertrophy was associated with fibrosis and extra collagen deposition only in the l-NAME treated group. Taken together, our results suggest that NO has a modulatory role in right heart ventricle remodeling by coordinating hypertrophy of cardiomyocytes and fibrous tissue preventing cardiac fibrosis.
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Affiliation(s)
- Amal Abdussalam Ali A. Hmaid
- Chair of Cell and Tissue Biology, Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
| | - Milica Markelic
- Chair of Cell and Tissue Biology, Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
| | - Vesna Otasevic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Sava Masovic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Aleksandra Jankovic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Bato Korac
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”, University of Belgrade, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Aleksandra Korac
- Chair of Cell and Tissue Biology, Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
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Simko F, Baka T, Krajcirovicova K, Repova K, Aziriova S, Zorad S, Poglitsch M, Adamcova M, Reiter RJ, Paulis L. Effect of Melatonin on the Renin-Angiotensin-Aldosterone System in l-NAME-Induced Hypertension. Molecules 2018; 23:molecules23020265. [PMID: 29382124 PMCID: PMC6017142 DOI: 10.3390/molecules23020265] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 01/15/2018] [Accepted: 01/25/2018] [Indexed: 12/24/2022] Open
Abstract
The renin-angiotensin-aldosterone system (RAAS) is a dominant player in several cardiovascular pathologies. This study investigated whether alterations induced by l-NAME, (NLG)-nitro-l-arginine methyl ester, a nitric oxide synthase inhibitor, and the protective effect of melatonin are associated with changes in the RAAS. Four groups of 3-month-old male Wistar rats (n = 10) were treated as follows for four weeks: untreated controls, rats treated with melatonin (10 mg/kg/day), rats treated with l-NAME (40 mg/kg/day), and rats treated with l-NAME + melatonin. l-NAME administration led to hypertension and left ventricular (LV) fibrosis in terms of enhancement of soluble, insoluble and total collagen concentration and content. Melatonin reduced systolic blood pressure enhancement and lowered the concentration and content of insoluble and total collagen in the LV. The serum concentration of angiotensin (Ang) 1–8 (Ang II) and its downstream metabolites were reduced in the l-NAME group and remained unaltered by melatonin. The serum aldosterone level and its ratio to Ang II (AA2-ratio) were increased in the l-NAME group without being modified by melatonin. We conclude that l-NAME-hypertension is associated with reduced level of Ang II and its downstream metabolites and increased aldosterone concentration and AA2-ratio. Melatonin exerts its protective effect in l-NAME-induced hypertension without affecting RAAS.
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Affiliation(s)
- Fedor Simko
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Sasinkova 4, 81108 Bratislava, Slovakia.
- 3rd Department of Internal Medicine, Faculty of Medicine, Comenius University, 83305 Bratislava, Slovakia.
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia.
| | - Tomas Baka
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Sasinkova 4, 81108 Bratislava, Slovakia.
| | - Kristina Krajcirovicova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Sasinkova 4, 81108 Bratislava, Slovakia.
| | - Kristina Repova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Sasinkova 4, 81108 Bratislava, Slovakia.
| | - Silvia Aziriova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Sasinkova 4, 81108 Bratislava, Slovakia.
| | - Stefan Zorad
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia.
| | | | - Michaela Adamcova
- Department of Physiology, School of Medicine, Charles University, 50003 Hradec Kralove, Czech Republic.
| | - Russel J Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA.
| | - Ludovit Paulis
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Sasinkova 4, 81108 Bratislava, Slovakia.
- Institute of Normal and Pathological Physiology, Center for Experimental Medicine, Slovak Academy of Sciences, 81371 Bratislava, Slovakia.
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González J, Valls N, Brito R, Rodrigo R. Essential hypertension and oxidative stress: New insights. World J Cardiol 2014; 6:353-366. [PMID: 24976907 PMCID: PMC4072825 DOI: 10.4330/wjc.v6.i6.353] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 03/01/2014] [Accepted: 05/08/2014] [Indexed: 02/06/2023] Open
Abstract
Essential hypertension is a highly prevalent pathological condition that is considered as one of the most relevant cardiovascular risk factors and is an important cause of morbidity and mortality around the world. Despite the fact that mechanisms underlying hypertension are not yet fully elucidated, a large amount of evidence shows that oxidative stress plays a central role in its pathophysiology. Oxidative stress can be defined as an imbalance between oxidant agents, such as superoxide anion, and antioxidant molecules, and leads to a decrease in nitric oxide bioavailability, which is the main factor responsible for maintaining the vascular tone. Several vasoconstrictor peptides, such as angiotensin II, endothelin-1 and urotensin II, act through their receptors to stimulate the production of reactive oxygen species, by activating enzymes like NADPH oxidase and xanthine oxidase. The knowledge of the mechanism described above has allowed generating new therapeutic strategies against hypertension based on the use of antioxidants agents, including vitamin C and E, N-Acetylcysteine, polyphenols and selenium, among others. These substances have different therapeutic targets, but all represent antioxidant reinforcement. Several clinical trials using antioxidants have been made. The aim of the present review is to provide new insights about the key role of oxidative stress in the pathophysiology of essential hypertension and new clinical attempts to demonstrate the usefulness of antioxidant therapy in the treatment of hypertension.
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Hlavačková L, Vranková S, Janega P, Pecháňová O, Babál P. The effect of indapamide on development of myocardial hypertrophy and fibrosis in L-NAME-induced hypertension in rat. Physiol Res 2011; 60:845-52. [PMID: 21995907 DOI: 10.33549/physiolres.932201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The aim of this study was to analyze the effect of indapamide and its combination with ACE inhibitor (captopril) and antioxidant (Provinols™) on both myocardial hypertrophy and fibrosis. Wistar rats were treated with L-NAME (40 mg/kg/day, L); L-NAME plus indapamide (1 mg/kg/day), or captopril (10 mg/kg/day), or Provinols™ (40 mg/kg/day), or combination of indapamide with captopril, and indapamide with Provinols™ for 7 weeks. Blood pressure (BP), LV hypertrophy and fibrosis were determined. The content of collagens type I and III was evaluated morphometrically after picrosirius red staining. L-NAME treatment led to increased BP, LV hypertrophy, total fibrosis and relative content of collagens without the change in collagen type I/III ratio. Indapamide and captopril decreased BP, LV hypertrophy and the collagen ratio without affecting total fibrosis, while Provinols™ reduced BP, the collagen ratio and fibrosis without affecting LV hypertrophy. The combinations decreased all the parameters. Decrease of LV hypertrophy was achieved by drugs with the best reducing effect on BP, fibrosis reduction was reached by the antioxidant treatment with only partial effect on BP. Thus, the combination of antihypertensive and antioxidant treatment may represent a powerful tool in preventing myocardial remodeling induced by hypertension.
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Affiliation(s)
- L Hlavačková
- Department of Pathology, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic
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Rodrigo R, González J, Paoletto F. The role of oxidative stress in the pathophysiology of hypertension. Hypertens Res 2011; 34:431-40. [PMID: 21228777 DOI: 10.1038/hr.2010.264] [Citation(s) in RCA: 254] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hypertension is considered to be the most important risk factor in the development of cardiovascular disease. An increasing body of evidence suggests that oxidative stress, which results in an excessive generation of reactive oxygen species (ROS), has a key role in the pathogenesis of hypertension. The modulation of the vasomotor system involves ROS as mediators of vasoconstriction induced by angiotensin II, endothelin-1 and urotensin-II, among others. The bioavailability of nitric oxide (NO), which is a major vasodilator, is highly dependent on the redox status. Under physiological conditions, low concentrations of intracellular ROS have an important role in the normal redox signaling maintaining vascular function and integrity. However, under pathophysiological conditions, increased levels of ROS contribute to vascular dysfunction and remodeling through oxidative damage. In human hypertension, an increase in the production of superoxide anions and hydrogen peroxide, a decrease in NO synthesis and a reduction in antioxidant bioavailability have been observed. In turn, antioxidants are reducing agents that can neutralize these oxidative and otherwise damaging biomolecules. The use of antioxidant vitamins, such as vitamins C and E, has gained considerable interest as protecting agents against vascular endothelial damage. Available data support the role of these vitamins as effective antioxidants that can counteract ROS effects. This review discusses the mechanisms involved in ROS generation, the role of oxidative stress in the pathogenesis of vascular damage in hypertension, and the possible therapeutic strategies that could prevent or treat this disorder.
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Affiliation(s)
- Ramón Rodrigo
- Renal Pathophysiology Laboratory, Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile.
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Carotid distension and distensibility impairment in individuals affected by familial combined hyperlipidemia. Atherosclerosis 2010; 212:177-80. [DOI: 10.1016/j.atherosclerosis.2010.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 04/16/2010] [Accepted: 05/02/2010] [Indexed: 11/16/2022]
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Ruiz-Hurtado G, Delgado C. Nitric oxide pathway in hypertrophied heart: new therapeutic uses of nitric oxide donors. J Hypertens 2010; 28 Suppl 1:S56-61. [PMID: 20823718 DOI: 10.1097/01.hjh.0000388496.66330.b8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Left ventricular hypertrophy (LVH) is regarded as a complication common to a number of cardiovascular diseases, including hypertension, myocardial infarction and ischaemia associated with coronary artery disease. Initially LVH is a compensatory mechanism, but in the long term cardiac hypertrophy predisposes individuals to heart failure, myocardial infarction and sudden death. Alteration of the nitric oxide (NO) pathway is believed to play an important role in the haemodynamically overloaded heart and pathological cardiac remodelling. Although re-establishment of the physiological NO pathway could be considered an important therapeutic target, the use of conventional nitrates is limited in the clinical setting by the development of tissue resistance and tolerance and by the shortage of large-scale clinical trials unequivocally confirming the beneficial impact of NO donors on cardiovascular morbidity and mortality. The aim of this review is to present current therapeutic options for dealing with changes in the L-arginine-NO pathway. The most promising therapeutic approach is represented by a new neutral sugar organic nitrate, LA-419, the thiol group of which seems to protect NO from degradation, thereby increasing its bioavailability. In a model of aortic stenosis-induced pressure overload, LA-419 has been found to restore the complete NO signalling cascade and reduce left ventricular remodelling, but without restoring the original pressure gradient, indicating a possible direct antiproliferative effect. Future studies are needed to confirm this therapeutic benefit in other animal models of hypertension and in the clinical setting.
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Affiliation(s)
- Gema Ruiz-Hurtado
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain
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Marques MJ, Barbin ICC, Taniguti APT, Oggian DS, Ferretti R, Santo Neto H. Myocardial fibrosis is unaltered by long-term administration of L-arginine in dystrophin deficient mdx mice: a histomorphometric analysis. ACTA BIOLOGICA HUNGARICA 2010; 61:168-74. [PMID: 20519171 DOI: 10.1556/abiol.61.2010.2.5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cardiac failure secondary to myocardial fibrosis (MF) significantly contributes to death in Duchenne muscular dystrophy (DMD), a fatal form of muscle disease. In aging, the mdx mice, an animal model of DMD, MF is similar to that observed in humans. Nitric oxide-based therapy has been proposed to retard MF in DMD and a candidate is L-arginine (L-arg). In this study we evaluated the effects of long-term therapy with L-arg in the MF of mdx mice. mdx mice (6 months old) were treated with L-arg in drinking water. Control mdx mice received water only. After 15 months of treatment, hearts were stained with Masson's trichrome for analysis of MF and with hematoxilyn and eosin for analysis of inflammation and cardiomyocyte damage. We observed that MF was not affected (29.5 +/- 2.5% of MF area for control vs 31.4 +/- 2% for L-arginine-treated animals; P > 0.05). The density of inflammatory cells was reduced (169 +/- 12 cells/mm 2 in control vs 102 +/- 9 cells/mm 2 in L-arg-treated; P < 0.05). The present study shows that long-term administration of L-arg is not effective in retarding MF in mdx dystrophinopathy.
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Affiliation(s)
- Maria Julia Marques
- Universidade Estadual de Campinas (UNICAMP) Departamento de Anatomia, Instituto de Biologia Celular, Fisiologia e Biofisica CP 6109 13083-970 Campinas, SP Brazil
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Paulis L, Pechanova O, Zicha J, Barta A, Gardlik R, Celec P, Kunes J, Simko F. Melatonin interactions with blood pressure and vascular function during L-NAME-induced hypertension. J Pineal Res 2010; 48:102-8. [PMID: 20041987 DOI: 10.1111/j.1600-079x.2009.00732.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The mechanisms responsible for the antihypertensive effect of melatonin are not completely understood. To elucidate the possible role of the nitric oxide (NO) pathway in the hemodynamic actions of melatonin, the effects of this indolamine on vascular function during hypertension induced by the NO-synthase (NOS) inhibitor, N(omega)-nitro-L-arginine-methyl ester (L-NAME) were investigated. Four groups of male adult Wistar rats were employed: control, L-NAME (40 mg/kg), melatonin (10 mg/kg) and L-NAME + melatonin for 5 wks. Systolic and diastolic blood pressure were measured invasively in the carotid artery. Conjugated dienes concentration (an oxidative load marker), NOS RNA expression and its activity and RNA expression of cyclooxygenase-(COX)-1 and COX-2 were determined in the aorta. Acetylcholine-induced responses and their NO-mediated component were evaluated in femoral and mesenteric artery. Moreover, endothelium-derived constricting factor (EDCF)-dependent vasoconstriction and inner diameter were determined in the femoral artery. Chronic L-NAME treatment induced hypertension, elevated the oxidative load and inhibited NOS activity. Moreover, impaired NO-dependent relaxation, augmented EDCF-constriction, increased COX-2 expression and reduced arterial inner diameter were observed. Melatonin added to L-NAME treatment completely prevented elevation of the oxidative load in the aorta. However, melatonin was not able to prevent NOS activity decline, elevation of COX-2 expression or the impairment of vascular responses (except moderate improvement in relaxation of small mesenteric arteries) and it exerted only slight antihypertensive effect. In conclusion, in addition to the reduction of the oxidative load, the restoration of the NO pathway seems to play an important role in the antihypertensive effect of melatonin.
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Affiliation(s)
- Ludovit Paulis
- Center for Cardiovascular Research, Charite-Universitatsmedizin, Berlin, Germany.
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Brooks WW, Conrad CH, Robinson KG, Colucci WS, Bing OHL. L-arginine fails to prevent ventricular remodeling and heart failure in the spontaneously hypertensive rat. Am J Hypertens 2009; 22:228-34. [PMID: 19057517 DOI: 10.1038/ajh.2008.334] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The effects of long-term oral administration of L-arginine, a substrate for nitric oxide (NO) production, on left ventricular (LV) remodeling, myocardial function and the prevention of heart failure (HF) was compared to the angiotensin-converting enzyme (ACE) inhibitor captopril in a rat model of hypertensive HF (aged spontaneously hypertensive rat (SHR)). METHODS SHRs and age-matched normotensive Wistar-Kyoto (WKY) rats were assigned to either no treatment, treatment with L-arginine (7.5 g/l in drinking water) or captopril (1 g/l in drinking water) beginning at 14 months of age, a time when SHRs exhibit stable compensated hypertrophy with no hemodynamic impairment; animals were studied at 23 months of age or at the time of HF. RESULTS In untreated SHR, relative to WKY, there was significant LV hypertrophy, myocardial fibrosis, and isolated LV muscle performance and response to isoproterenol (ISO) were depressed; and, 7 of 10 SHRs developed HF. Captopril administration to six SHRs attenuated hypertrophy and prevented impaired inotropic responsiveness to ISO, contractile dysfunction, fibrosis, increased passive stiffness, and HF. In contrast, L-arginine administration to SHR increased LV hypertrophy and myocardial fibrosis while cardiac performance was depressed; and 7 of 9 SHRs developed HF. In WKY, L-arginine treatment but not captopril resulted in increased LV weight and the contractile response to ISO was blunted. Neither L-arginine nor captopril treatment of WKY changed fibrosis and HF did not occur. CONCLUSION These data demonstrate that in contrast to captopril, long-term treatment with L-arginine exacerbates age-related cardiac hypertrophy, fibrosis, and did not prevent contractile dysfunction or the development of HF in aging SHR.
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Paulis L, Matuskova J, Adamcova M, Pelouch V, Simko J, Krajcirovicova K, Potacova A, Hulin I, Janega P, Pechanova O, Simko F. Regression of left ventricular hypertrophy and aortic remodelling in NO-deficient hypertensive rats: effect of L-arginine and spironolactone. Acta Physiol (Oxf) 2008; 194:45-55. [PMID: 18419778 DOI: 10.1111/j.1748-1716.2008.01862.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AIM We investigated, whether the substrate for nitric oxide (NO) formation -L-arginine - and the aldosterone receptor antagonist - spironolactone - are able to reverse alterations of the left ventricle (LV) and aorta in N(omega)-nitro-L-arginine methyl ester (L-NAME)-induced hypertension. METHODS Six groups of male adult Wistar rats were investigated: controls after 4 and 7 weeks of experiment, rats treated with L-NAME for 4 weeks and three recovery groups: spontaneous-reversion (4 weeks L-NAME + 3 weeks placebo), spironolactone-induced reversion (4 weeks L-NAME + 3 weeks spironolactone) and L-arginine-induced reversion (4 weeks L-NAME+ 3 weeks L-arginine). Blood pressure was measured by tail-cuff plethysmography. Relative weight of the LV, myocardial fibrosis (based upon histomorphometry and hydroxyproline determination) and conjugated dienes in the LV and aortic cross-sectional area, inner diameter and wall thickness were determined. NO-synthase activity was investigated in the LV and aorta. RESULTS L-NAME administration induced hypertension, left ventricular hypertrophy (LVH), LV fibrosis, aortic thickening and diminution of NO-synthase activity in the LV and aorta. Reduction in blood pressure and regression of LVH were observed in all recovery groups, yet reduction in LV fibrosis and aortic thickening were not. NO-synthase activity was restored only in the L-arginine and spironolactone group. CONCLUSION In our study, the reversion of hypertension and LVH was not dependent on the restoration of NO-synthase activity. Moreover, LV fibrosis and aortic remodelling seem to be more resistant to conditions resulting in regression of LVH. Preserved level of fibrosis in the initial period of LVH regression might result in loss of structural homogeneity and possible functional alterations of the LV.
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Affiliation(s)
- L Paulis
- Institute of Pathophysiology, School of Medicine, Comenius University, Bratislava, Slovak Republic.
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Paulis L, Simko F. LA419, a novel nitric oxide donor, prevents cardiac remodeling via the endothelial nitric oxide synthase pathway: NO donors as a means of antiremodeling. Hypertension 2007; 50:1009-11. [PMID: 17984370 DOI: 10.1161/hypertensionaha.107.100032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Left ventricular hypertrophy (LVH), despite its adaptive nature, is associated with an increased risk of cardiovascular morbidity and mortality. Achievement of LVH regression is thus considered a principal therapeutic aim. However, regression of LVH induced by various therapeutic means may exhibit differing patterns, with variable biological implications. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) have been shown to induce prevention or regression of LVH in different models of pathological myocardial growth. In addition to reduction of LV mass, statins were shown to reduce myocardial fibrosis, increase capillary density network and attenuate electrical instability of the hypertrophied heart. Most importantly, statins improved systolic and diastolic LV function and even decreased mortality. The inhibition of hypertrophic growth was only partly achieved by reduction of haemodynamic overload. Direct mechanisms, such as inhibition of neurohumoral activation in the myocardial tissue, attenuated production of growth factors and markers of inflammation and reduction of oxidative stress also seem to participate. The protective effect of statins was associated with the inhibition of expression and activation of small guanosintriphosphate-binding proteins such as Ras and Rho, which control the intensity of oxidative stress, the production and availability of nitric oxide, and the expression of genes involved in myocardial growth. In addition to reduction of LV mass, statins may also improve the prognosis of LVH independently of their lipid-lowering effect.
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Affiliation(s)
- F Simko
- School of Medicine, Komensky University, Bratislava, Slovak Republic.
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