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Oliveira-Paula GH, I M Batista R, Stransky S, Tella SC, Ferreira GC, Portella RL, Pinheiro LC, Damacena-Angelis C, Riascos-Bernal DF, Sidoli S, Sibinga N, Tanus-Santos JE. Orally administered sodium nitrite prevents the increased α-1 adrenergic vasoconstriction induced by hypertension and promotes the S-nitrosylation of calcium/calmodulin-dependent protein kinase II. Biochem Pharmacol 2023; 212:115571. [PMID: 37127250 PMCID: PMC10198929 DOI: 10.1016/j.bcp.2023.115571] [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: 02/13/2023] [Revised: 04/18/2023] [Accepted: 04/24/2023] [Indexed: 05/03/2023]
Abstract
The unsatisfactory rates of adequate blood pressure control among patients receiving antihypertensive treatment calls for new therapeutic strategies to treat hypertension. Several studies have shown that oral sodium nitrite exerts significant antihypertensive effects, but the mechanisms underlying these effects remain unclear. While these mechanisms may involve nitrite-derived S-nitrosothiols, their implication in important alterations associated with hypertension, such as aberrant α1-adrenergic vasoconstriction, has not yet been investigated. Here, we examined the effects of oral nitrite treatment on vascular responses to the α1-adrenergic agonist phenylephrine in two-kidney, one clip (2K1C) hypertensive rats and investigated the potential underlying mechanisms. Our results show that treatment with oral sodium nitrite decreases blood pressure and prevents the increased α1-adrenergic vasoconstriction in 2K1C hypertensive rats. Interestingly, we found that these effects require vascular protein S-nitrosylation, and to investigate the specific S-nitrosylated proteins we performed an unbiased nitrosoproteomic analysis of vascular smooth muscle cells (VSMCs) treated with the nitrosylating compound S-nitrosoglutathione (GSNO). This analysis revealed that GSNO markedly increases the nitrosylation of calcium/calmodulin-dependent protein kinase II γ (CaMKIIγ), a multifunctional protein that mediates the α1-adrenergic receptor signaling. This result was associated with reduced α1-adrenergic receptor-mediated CaMKIIγ activity in VSMCs. We further tested the relevance of these findings in vivo and found that treatment with oral nitrite increases CaMKIIγ S-nitrosylation and blunts the increased CaMKIIγ activity induced by phenylephrine in rat aortas. Collectively, these results are consistent with the idea that oral sodium nitrite treatment increases vascular protein S-nitrosylation, including CaMKIIγ as a target, which may ultimately prevent the increased α1-adrenergic vasoconstriction induced by hypertension. These mechanisms may help to explain the antihypertensive effects of oral nitrite and hold potential implications in the therapy of hypertension and other cardiovascular diseases associated with abnormal α1-adrenergic vasoconstriction.
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Affiliation(s)
- Gustavo H Oliveira-Paula
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil; Department of Medicine (Cardiology Division), Department of Developmental and Molecular Biology, and Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, New York, NY, USA
| | - Rose I M Batista
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil; Department of Medicine (Cardiology Division), Department of Developmental and Molecular Biology, and Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, New York, NY, USA
| | - Stephanie Stransky
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY, USA
| | - Sandra C Tella
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Graziele C Ferreira
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Rafael L Portella
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil; Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Celio Damacena-Angelis
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Dario F Riascos-Bernal
- Department of Medicine (Cardiology Division), Department of Developmental and Molecular Biology, and Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, New York, NY, USA
| | - Simone Sidoli
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY, USA
| | - Nicholas Sibinga
- Department of Medicine (Cardiology Division), Department of Developmental and Molecular Biology, and Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, New York, NY, USA
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
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Aramide Modupe Dosunmu-Ogunbi A, Galley JC, Yuan S, Schmidt HM, Wood KC, Straub AC. Redox Switches Controlling Nitric Oxide Signaling in the Resistance Vasculature and Implications for Blood Pressure Regulation: Mid-Career Award for Research Excellence 2020. Hypertension 2021; 78:912-926. [PMID: 34420371 DOI: 10.1161/hypertensionaha.121.16493] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The arterial resistance vasculature modulates blood pressure and flow to match oxygen delivery to tissue metabolic demand. As such, resistance arteries and arterioles have evolved a series of highly orchestrated cell-cell communication mechanisms between endothelial cells and vascular smooth muscle cells to regulate vascular tone. In response to neurohormonal agonists, release of several intracellular molecules, including nitric oxide, evokes changes in vascular tone. We and others have uncovered novel redox switches in the walls of resistance arteries that govern nitric oxide compartmentalization and diffusion. In this review, we discuss our current understanding of redox switches controlling nitric oxide signaling in endothelial and vascular smooth muscle cells, focusing on new mechanistic insights, physiological and pathophysiological implications, and advances in therapeutic strategies for hypertension and other diseases.
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Affiliation(s)
- Atinuke Aramide Modupe Dosunmu-Ogunbi
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA
| | - Joseph C Galley
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA
| | - Shuai Yuan
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA
| | - Heidi M Schmidt
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA
| | - Katherine C Wood
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA
| | - Adam C Straub
- Heart, Lung, Blood and Vascular Medicine Institute (A.A.M.D.-O., J.C.G., S.Y., H.M.S., K.C.W., A.C.S.), University of Pittsburgh, PA.,Department of Pharmacology and Chemical Biology (A.A.M.D.-O., J.C.G., H.M.S., A.C.S), University of Pittsburgh, PA.,Center for Microvascular Research (A.C.S.), University of Pittsburgh, PA
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Nitrite and tempol combination promotes synergic effects and alleviates right ventricular wall stress during acute pulmonary thromboembolism. Nitric Oxide 2021; 115:23-29. [PMID: 34133975 DOI: 10.1016/j.niox.2021.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/29/2021] [Accepted: 06/11/2021] [Indexed: 11/22/2022]
Abstract
INTRODUCTION The mechanical obstruction and pulmonary vasoconstriction are major determinants of the sudden right ventricular (RV) afterload increases observed during acute pulmonary thromboembolism (APT). Vasodilators and antioxidants agents have been shown to mitigate pulmonary hypertension. We examined whether sodium nitrite and the antioxidant tempol combination could be advantageous in an APT sheep model. METHODS APT was induced in anesthetized sheep by autologous blood clots (250 mg/kg) into the right atrium. Thirty minutes after APT induction, the animals received a continuous infusion of tempol (1.0 mg/kg/min), increasing sodium nitrite infusion (5, 15, and 50 μmol/kg), or a simultaneous combination of both drugs. Saline was used as a control treatment. Hemodynamic measurements were carried out every 15 min. Also, whole blood nitrite and serum 8-isoprostanes levels were measured. RESULTS APT induced sustained pulmonary hypertension, increased dp/dtmax, and rate pressure product (RPP). Nitrite or tempol treatments attenuated these increases (P < 0.05). When both drugs were combined, we found a robust reduction in the RV RPP compared with the treatments alone (P < 0.05). The sole nitrite infusion increased blood nitrite concentrations by 35 ± 6 μM (P < 0.05), whereas the nitrite and tempol combination produced higher blood nitrite concentrations by approximately 54 ± 7 μM. Tempol or nitrite infusions, both alone or combined, blunted the increases in 8-isoprostane concentrations observed after APT. CONCLUSIONS Nitrite and tempol combination protects against APT-induced RV wall stress. The association of both drugs may offer an advantage to treat RV failure during severe APT.
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Moretti CH, Schiffer TA, Montenegro MF, Larsen FJ, Tsarouhas V, Carlström M, Samakovlis C, Weitzberg E, Lundberg JO. Dietary nitrite extends lifespan and prevents age-related locomotor decline in the fruit fly. Free Radic Biol Med 2020; 160:860-870. [PMID: 32980539 DOI: 10.1016/j.freeradbiomed.2020.09.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/24/2020] [Accepted: 09/14/2020] [Indexed: 02/08/2023]
Abstract
Aging is associated with decreased nitric oxide (NO) bioavailability and signalling. Boosting of a dietary nitrate-nitrite-NO pathway e.g. by ingestion of leafy green vegetables, improves cardiometabolic function, mitochondrial efficiency and reduces oxidative stress in humans and rodents, making dietary nitrate and nitrite an appealing intervention to address age-related disorders. On the other hand, these anions have long been implicated in detrimental health effects of our diet, particularly in formation of carcinogenic nitrosamines. The aim of this study was to assess whether inorganic nitrite affects lifespan in Drosophila melanogaster and investigate possible mechanisms underlying any such effect. In a survival assay, female flies fed a nitrite supplemented diet showed lifespan extension by 9 and 15% with 0.1 and 1 μM nitrite respectively, with no impact of nitrite on reproductive output. Interestingly, nitrite could also protect female flies from age-dependent locomotor decline, indicating a protective effect on healthspan. NO generation from nitrite involved Drosophila commensal bacteria and was indicated by a fluorescent probe as well as direct measurements of NO gas formation with chemiluminescence. Nutrient sensing pathways such as TOR and sirtuins, have been strongly implicated in lifespan extension. In aged flies, nitrite supplementation significantly downregulated dTOR and upregulated dSir2 gene expression. Total triglycerides and glucose were decreased, a described downstream effect of both TOR and sirtuin pathways. In conclusion, we demonstrate that very low doses of dietary nitrite extend lifespan and favour healthspan in female flies. We propose modulation of nutrient sensing pathways as driving mechanisms for such effects.
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Affiliation(s)
- Chiara H Moretti
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, 171 77, Sweden.
| | - Tomas A Schiffer
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Marcelo F Montenegro
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Filip J Larsen
- The Swedish School of Sport and Health Sciences, Stockholm, 114 86, Sweden
| | - Vasilios Tsarouhas
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm, 106 91, Sweden
| | - Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Christos Samakovlis
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm, 106 91, Sweden
| | - Eddie Weitzberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Jon O Lundberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, 171 77, Sweden.
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Oral nitrite treatment increases S-nitrosylation of vascular protein kinase C and attenuates the responses to angiotensin II. Redox Biol 2020; 38:101769. [PMID: 33126056 PMCID: PMC7596338 DOI: 10.1016/j.redox.2020.101769] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/24/2020] [Accepted: 10/18/2020] [Indexed: 02/07/2023] Open
Abstract
Nitrate and nitrite supplement deficient endogenous nitric oxide (NO) formation. While these anions may generate NO, recent studies have shown that circulating nitrite levels do not necessarily correlate with the antihypertensive effect of oral nitrite administration and that formation of nitrosylated species (RXNO) in the stomach is critically involved in this effect. This study examined the possibility that RXNO formed in the stomach after oral nitrite administration promotes target protein nitrosylation in the vasculature, inhibits vasoconstriction and the hypertensive responses to angiotensin II. Our results show that oral nitrite treatment enhances circulating RXNO concentrations (measured by ozone-based chemiluminescence methods), increases aortic protein kinase C (PKC) nitrosylation (measured by resin-assisted capture SNO-RAC method), and reduces both angiotensin II-induced vasoconstriction (isolated aortic ring preparation) and hypertensive (in vivo invasive blood pressure measurements) effects implicating PKC nitrosylation as a key mechanism for the responses to oral nitrite. Treatment of rats with the nitrosylating compound S-nitrosoglutathione (GSNO) resulted in the same effects described for oral nitrite. Moreover, partial depletion of thiols with buthionine sulfoximine prevented PKC nitrosylation and the blood pressure effects of oral nitrite. Further confirming a role for PKC nitrosylation, preincubation of aortas with GSNO attenuated the responses to both angiotensin II and to a direct PKC activator, and this effect was attenuated by ascorbate (reverses GSNO-induced nitrosylation). GSNO-induced nitrosylation also inhibited the increases in Ca2+ mobilization in angiotensin II-stimulated HEK293T cells expressing angiotensin type 1 receptor. Together, these results are consistent with the idea that PKC nitrosylation in the vasculature may underlie oral nitrite treatment-induced reduction in the vascular and hypertensive responses to angiotensin II. Oral nitrite treatment exerts antihypertensive effects. The mechanisms explaining such effects are not entirely known. Oral nitrite treatment increases circulating concentrations of nitrosylating species. Vascular PKC nitrosylation attenuates the vascular responses to angiotensin II.
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6
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Guimaraes DA, Batista RIM, Tanus-Santos JE. Nitrate and nitrite-based therapy to attenuate cardiovascular remodelling in arterial hypertension. Basic Clin Pharmacol Toxicol 2020; 128:9-17. [PMID: 32772466 DOI: 10.1111/bcpt.13474] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/29/2020] [Accepted: 07/26/2020] [Indexed: 12/16/2022]
Abstract
Hypertension is a highly prevalent disease marked by vascular and cardiac maladaptive remodelling induced mainly by renin-angiotensin system activation followed by oxidative stress. Here, we briefly describe these damages and review the current evidence supporting a potential role for nitrate and nitrite as antihypertensive molecules that act via nitric oxide (NO) formation-dependent and NO formation-independent mechanisms and how nitrate/nitrite inhibits cardiovascular remodelling in hypertension. The renin-angiotensin system activation and oxidative stress converge to activate proteases involved in cardiovascular remodelling in hypertension. Besides these proteases, several investigations have demonstrated that reduced endogenous NO bioavailability is a central pathological event in hypertension. In this regard, nitrate/nitrite, long considered inert products of NO, is now known as physiological molecules able to reduce blood pressure in hypertensive patients and in different experimental models of hypertension. These effects are associated with the formation of NO and other NO-related molecules, which could induce S-nitrosylation of target proteins. However, it remains unclear whether S-nitrosylation is an essential mechanism for the anti-remodelling effects of nitrate/nitrite in hypertension. Moreover, nitrate/nitrite produces antioxidant effects associated with the inhibition of signalling pathways involved in cardiovascular remodelling. Together, these findings may help to establish nitrate and nitrite as effective therapies in hypertension-induced cardiovascular remodelling.
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Affiliation(s)
- Danielle A Guimaraes
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Rose I M Batista
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
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Kapil V, Khambata RS, Jones DA, Rathod K, Primus C, Massimo G, Fukuto JM, Ahluwalia A. The Noncanonical Pathway for In Vivo Nitric Oxide Generation: The Nitrate-Nitrite-Nitric Oxide Pathway. Pharmacol Rev 2020; 72:692-766. [DOI: 10.1124/pr.120.019240] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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8
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Gonzaga NA, do Vale GT, da Silva CB, Pinheiro LC, Leite LN, Carneiro FS, Tanus-Santos JE, Tirapelli CR. Treatment with nitrite prevents reactive oxygen species generation in the corpora cavernosa and restores intracavernosal pressure in hypertensive rats. Nitric Oxide 2020; 94:19-26. [DOI: 10.1016/j.niox.2019.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/23/2019] [Accepted: 10/08/2019] [Indexed: 12/29/2022]
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9
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Abstract
Nitrite, an anion produced from the oxidative breakdown of nitric oxide (NO), has traditionally been viewed as an inert molecule. However, this dogma has been challenged with the findings that nitrite can be readily reduced to NO under pathological conditions, hence representing a physiologically relevant storage reservoir of NO either in the blood or tissues. Nitrite administration has been demonstrated to improve myocardial function in subjects with heart failure and to lower the blood pressure in hypertensive subjects. Thus, extensive amount of work has since been carried out to investigate the therapeutic potential of nitrite in treating cardiovascular diseases, especially hypertension. Studies done on several animal models of hypertension have demonstrated the efficacy of nitrite in preventing and ameliorating the pathological changes associated with the disease. This brief review of the current findings aims to re-evaluate the use of nitrite for the treatment of hypertension and in particular to highlight its role in improving endothelial function.
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Affiliation(s)
- Wei Chih Ling
- Department of Pre-clinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Kajang, Selangor; and
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Dharmani Devi Murugan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Segawa Y, Hashimoto H, Maruyama S, Shintani M, Ohno H, Nakai Y, Osera T, Kurihara N. Dietary capsaicin-mediated attenuation of hypertension in a rat model of renovascular hypertension. Clin Exp Hypertens 2019; 42:352-359. [PMID: 31518162 DOI: 10.1080/10641963.2019.1665676] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Background: Capsaicin, a pungent component of chili pepper, has been reported to decrease blood pressure (BP) and to cause vasorelaxation via nitric oxide (NO) production. However, it is still unclear how dietary capsaicin effects on renovascular hypertension. To examine this, we observed the effects of dietary capsaicin on BP in 2-kidney, 1-clip renovascular hypertension (2K1C) rats, and investigated the participation of NO in the mechanism.Methods: Rats with 2K1C or sham-operated rats (SHAM) were treated with 0.006% capsaicin diet (CAP) or control diet (CTL) for 6 weeks. Systolic BP (SBP) was measured by tail-cuff method once a week. In the end, mean arterial BP (MAP) was measured in the rats under anesthesia. These observations were performed also in the rats taking a NO synthase (NOS) inhibitor (LN). After rats were euthanized, thoracic aortas were collected and used for western blot analyses to evaluate the phosphorylated ratio of endothelial NOS (eNOS), protein kinase A (PKA) and B (Akt), in order to explore a mechanism of the effects on BP by dietary capsaicin.Results: SBP and MAP in 2K1C rats were significantly higher than in SHAM rats when fed CTL, but not when fed CAP. Those in 2K1C-CAP rats were significantly lower than in 2K1C-CTL rats. LN suppressed the effect of dietary capsaicin. The ratios of phosphorylated (p-) eNOS/eNOS and p-Akt/Akt, but not p-PKA/PKA, were significantly increased in rats fed CAP compared with rats fed CTL.Conclusion: Dietary capsaicin may alleviate 2K1C renovascular hypertension, probably via enhancing phosphorylation of Akt and eNOS.Abbreviations: 2K1C: 2-kidney, 1-clip hypertension model; Akt: protein kinase B; Ang II: angiotensin II; ANOVA: measures analysis of variance; BP: blood pressure; EC: endothelial cell; eNOS: endothelial nitric oxide synthase; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; L-NAME, LN: Nω-Nitro-L-arginine methyl ester hydrochloride; MA: mesenteric arteries; MAP: mean arterial blood pressure; NO: nitric oxide; PKA: protein kinase A; PVDF: polyvinylidene difluoride; SBP: Systolic blood pressure; SHR: spontaneously hypertensive rats; SN: sympathetic nervous; TRPV1: transient receptor potential vanilloid type 1; WKY: Wistar Kyoto rats.
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Affiliation(s)
- Yukiko Segawa
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan
| | - Hiroko Hashimoto
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan.,Nutrition, Osaka Seikei College, Osaka, Japan
| | - Saki Maruyama
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan
| | - Miki Shintani
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan
| | - Hitomi Ohno
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan
| | - Yuko Nakai
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan
| | - Tomoko Osera
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan.,Nutrition and Health Sciences, Toyo University, Gunma, Japan
| | - Nobutaka Kurihara
- Hygiene and Preventive Medicine, Kobe Women's University, Kobe, Japan
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Amaral JH, Rizzi ES, Alves-Lopes R, Pinheiro LC, Tostes RC, Tanus-Santos JE. Antioxidant and antihypertensive responses to oral nitrite involves activation of the Nrf2 pathway. Free Radic Biol Med 2019; 141:261-268. [PMID: 31251976 DOI: 10.1016/j.freeradbiomed.2019.06.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/14/2019] [Accepted: 06/24/2019] [Indexed: 12/27/2022]
Abstract
Impaired redox balance contributes to the cardiovascular alterations of hypertension and activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway may counteract these alterations. While nitrite recycles back to NO and exerts antioxidant and antihypertensive effects, the mechanisms involved in these responses are not fully understood. We hypothesized that nitrite treatment of two-kidney, one-clip (2K1C) hypertensive rats activates the Nrf2 pathway, promotes the transcription of antioxidant genes, and improves the vascular redox imbalance and dysfunction in this model. Two doses of oral nitrite were studied: 15 mg/kg and the sub-antihypertensive dose of 1 mg/kg. Nitrite 15 mg/kg (but not 1 mg/kg) decreased blood pressure and increased circulating plasma nitrite and nitrate. Both doses blunted hypertension-induced increases in mesenteric artery reactive oxygen species concentrations assessed by DHE technique and restored the impaired mesenteric artery responses to acetylcholine. While 2K1C hypertension decreased nuclear Nrf2 accumulation, both doses of nitrite increased nuclear Nrf2 accumulation and mRNA expression of Nrf2-regulated genes including superoxide dismutase-1 (SOD1), catalase (CAT), glutathione peroxidase (GPX), thioredoxin-1(TRDX-1) and -2 (TRDX-2). To further confirm nitrite-mediated antioxidant effects, we measured vascular SOD and GPX activity and we found that nitrite at 1 or 15 mg/kg increased the activity of both enzymes (P < 0.05). These results suggest that activation of the Nrf2 pathway promotes antioxidant effects of nitrite, which may improve the vascular dysfunction in hypertension, even when nitrite is given at a sub-antihypertensive dose. These findings may have many clinical implications, particularly in the therapy of hypertension and other cardiovascular diseases.
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Affiliation(s)
- Jefferson H Amaral
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Elen S Rizzi
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Rhéure Alves-Lopes
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Rita C Tostes
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil.
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12
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Oliveira-Paula GH, Pinheiro LC, Tanus-Santos JE. Mechanisms impairing blood pressure responses to nitrite and nitrate. Nitric Oxide 2019; 85:35-43. [PMID: 30716418 DOI: 10.1016/j.niox.2019.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/13/2018] [Accepted: 01/29/2019] [Indexed: 02/07/2023]
Abstract
Hypertension is a multifactorial disease associated with impaired nitric oxide (NO) production and bioavailability. In this respect, restoring NO activity by using nitrite and nitrate has been considered a potential therapeutic strategy to treat hypertension. This possibility is justified by the understanding that both nitrite and nitrate may be recycled back to NO and also promote the generation of other bioactive species. This process involves a complex biological circuit known as the enterosalivary cycle of nitrate, where this anion is actively taken up by the salivary glands and converted to nitrite by nitrate-reducing bacteria in the oral cavity. Nitrite is then ingested and reduced to NO and other nitroso species under the acid conditions of the stomach, whereas reminiscent nitrite that escapes gastric reduction is absorbed systemically and can be converted into NO by nitrite-reductases in tissues. While there is no doubt that nitrite and nitrate exert antihypertensive effects, several agents can impair the blood pressure responses to these anions by disrupting the enterosalivary cycle of nitrate. These agents include dietary and smoking-derived thiocyanate, antiseptic mouthwash, proton pump inhibitors, ascorbate at high concentrations, and xanthine oxidoreductase inhibitors. In this article, we provide an overview of the physiological aspects of nitrite and nitrate bioactivation and the therapeutic potential of these anions in hypertension. We also discuss mechanisms by which agents counteracting the antihypertensive responses to nitrite and nitrate mediate their effects. These critical aspects should be taken into consideration when suggesting nitrate or nitrite-based therapies to patients.
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Affiliation(s)
- Gustavo H Oliveira-Paula
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
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13
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Oliveira-Paula GH, Tanus-Santos JE. Nitrite-stimulated Gastric Formation of S-nitrosothiols As An Antihypertensive Therapeutic Strategy. Curr Drug Targets 2019; 20:431-443. [DOI: 10.2174/1389450119666180816120816] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/24/2018] [Accepted: 08/07/2018] [Indexed: 12/14/2022]
Abstract
Hypertension is usually associated with deficient nitric oxide (NO) bioavailability, and therefore stimulating NO activity is an important antihypertensive strategy. Recently, many studies have shown that both nitrite and nitrate anions are not simple products of NO metabolism and indeed may be reduced back to NO. While enzymes with nitrite-reductase activity capable of generating NO from nitrite may contribute to antihypertensive effects of nitrite, another mechanism involving the generation of NO-related species in the stomach from nitrite has been validated. Under the acidic conditions of the stomach, nitrite generates NO-related species that form S-nitrosothiols. Conversely, drugs that increase gastric pH may impair the gastric formation of S-nitrosothiols, which may mediate antihypertensive effects of oral nitrite or nitrate. Therefore, it is now becoming clear that promoting gastric formation of S-nitrosothiols may result in effective antihypertensive responses, and this mechanism opens a window of opportunity in the therapy of hypertension. In this review, we discuss the recent studies supporting the gastric generation of S-nitrosothiols as a potential antihypertensive mechanism of oral nitrite. We also highlight some drugs that increase S-nitrosothiols bioavailability, which may also improve the responses to nitrite/nitrate therapy. This new approach may result in increased nitrosation of critical pharmacological receptors and enzymes involved in the pathogenesis of hypertension, which tend to respond less to their activators resulting in lower blood pressure.
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Affiliation(s)
- Gustavo H. Oliveira-Paula
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Jose E. Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
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14
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Carlstrom M, Montenegro MF. Therapeutic value of stimulating the nitrate-nitrite-nitric oxide pathway to attenuate oxidative stress and restore nitric oxide bioavailability in cardiorenal disease. J Intern Med 2019; 285:2-18. [PMID: 30039620 DOI: 10.1111/joim.12818] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cardiovascular disorders including hypertension and associated renal disease are major health problems affecting more than 1.5 billion people worldwide. Apart from nonmodifiable factors such as ageing, family history and gender, both sedentary lifestyle and unhealthy dietary habits are considered as major risk factors. The disorders are interrelated suggesting common pathological pathways. Mechanistically, oxidative stress and compromised function of the nitric oxide synthase (NOS) system leading to endothelial dysfunction and reduction in nitric oxide (NO) bioavailability have been widely implicated and associated with development and progression of disease. New strategies that correct this redox imbalance and increase NO bioactivity may have major clinical implications. The inorganic anions, nitrate and nitrite, are endogenously formed by oxidization of NOS-derived NO, but there are also high amounts of nitrate in our daily diet. In this regard, accumulated evidence over the past two decades demonstrates that these anions can be recycled back to NO and other bioactive nitrogen oxides, thus offering an attractive alternative strategy for therapeutic exploitation. In this review, we describe how dietary stimulation of the nitrate-nitrite-NO pathway affects cardiovascular and renal functions in health and disease via modulation of oxidative stress and NO bioavailability. Clinical studies addressing potential effects on the renal system are still limited, but blood pressure-lowering effects of nitrate supplementation have been demonstrated in healthy and hypertensive subjects as well as in patients with chronic kidney disease. However, larger clinical studies are warranted to reveal whether chronic nitrate treatment can slow-down the progression of cardiorenal disease and associated complications.
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Affiliation(s)
- M Carlstrom
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - M F Montenegro
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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15
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Rizzi E, Amaral JH, Guimarães DA, Conde-Tella SO, Pinheiro LC, Gerlach RF, Castro MM, Tanus-Santos JE. Nitrite treatment downregulates vascular MMP-2 activity and inhibits vascular remodeling in hypertension independently of its antihypertensive effects. Free Radic Biol Med 2019; 130:234-243. [PMID: 30399409 DOI: 10.1016/j.freeradbiomed.2018.11.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/30/2018] [Accepted: 11/02/2018] [Indexed: 12/12/2022]
Abstract
Hypertension is associated with cardiovascular remodeling. Given that impaired redox state activates matrix metalloproteinase (MMP)- 2 and promotes vascular remodeling, we hypothesized that nitrite treatment at a non-antihypertensive dose exerts antioxidant effects and attenuates both MMP-2 activation and vascular remodeling of hypertension. We examined the effects of oral sodium nitrite at antihypertensive (15 mg/kg) or non-antihypertensive (1 mg/kg) daily dose in hypertensive rats (two kidney, one clip; 2K1C model). Sham-operated and 2K1C hypertensive rats received vehicle or nitrite by gavage for four weeks. Systolic blood pressure decreased only in hypertensive rats treated with nitrite 15 mg/Kg/day. Both low and high nitrite doses decreased 2K1C-induced vascular remodeling assessed by measuring aortic cross-sectional area, media/lumen ratio, and number of vascular smooth muscle cells/aortic length. Both low and high nitrite doses decreased 2K1C-induced vascular oxidative stress assessed in situ with the fluorescent dye DHE and with the lucigenin chemiluminescence assay. Vascular MMP-2 expression and activity were assessed by gel zymography, Western blot, and in situ zymography increased with hypertension. While MMP-2 levels did not change in response to both doses of nitrite, both doses completely prevented hypertension-induced increases in vascular MMP activity. Moreover, incubation of aortas from hypertensive rats with nitrite at 1-20 μmol/L reduced gelatinolytic activity by 20-30%. This effect was fully inhibited by the xanthine oxidase (XOR) inhibitor febuxostat, suggesting XOR-mediated generation of nitric oxide (NO) from nitrite as a mechanism explaining the responses to nitrite. In vitro incubation of aortic extracts with nitrite 20 μmol/L did not affect MMP-2 activity. These results show that nitrite reverses the vascular structural alterations of hypertension, independently of anti-hypertensive effects. This response is mediated, at least in part, by XOR and is attributable to antioxidant effects of nitrite blunting vascular MMP-2 activation. Our findings suggest nitrite therapy to reverse structural alterations of hypertension.
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Affiliation(s)
- Elen Rizzi
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil; Biotechnology Unit, Ribeirao Preto University, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Jefferson H Amaral
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Danielle A Guimarães
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Sandra O Conde-Tella
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Raquel F Gerlach
- Department of Morphology, Estomatology and Physiology, Dental School of Ribeirao Preto, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Michele M Castro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, Ribeirao Preto, SP 14049-900, Brazil.
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16
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Guimaraes DA, Dos Passos MA, Rizzi E, Pinheiro LC, Amaral JH, Gerlach RF, Castro MM, Tanus-Santos JE. Nitrite exerts antioxidant effects, inhibits the mTOR pathway and reverses hypertension-induced cardiac hypertrophy. Free Radic Biol Med 2018. [PMID: 29530793 DOI: 10.1016/j.freeradbiomed.2018.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cardiac hypertrophy is a common consequence of chronic hypertension and leads to heart failure and premature death. The anion nitrite is now considered as a bioactive molecule able to exert beneficial cardiovascular effects. Previous results showed that nitrite attenuates hypertension-induced increases in reactive oxygen species (ROS) production in the vasculature. Whether antioxidant effects induced by nitrite block critical signaling pathways involved in cardiac hypertrophy induced by hypertension has not been determined yet. The Akt/mTOR signaling pathway is responsible to activate protein synthesis during cardiac remodeling and is activated by increased ROS production, which is commonly found in hypertension. Here, we investigated the effects of nitrite treatment on cardiac remodeling and activation of this hypertrophic signaling pathway in 2 kidney-1 clip (2K1C) hypertension. Sham and 2K1C rats were treated with oral nitrite at 1 or 15 mg/kg for four weeks. Nitrite treatment (15 mg/kg) reduced systolic blood pressure and decreased ROS production in the heart tissue from hypertensive rats. This nitrite dose also blunted hypertension-induced activation of mTOR pathway and cardiac hypertrophy. While the lower nitrite dose (1 mg/kg) did not affect blood pressure, it exerted antioxidant effects and tended to attenuate mTOR pathway activation and cardiac hypertrophy induced by hypertension. Our findings provide strong evidence that nitrite treatment decreases cardiac remodeling induced by hypertension as a result of its antioxidant effects and downregulation of mTOR signaling pathway. This study may help to establish nitrite as an effective therapy in hypertension-induced cardiac hypertrophic remodeling.
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Affiliation(s)
- Danielle A Guimaraes
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Madla A Dos Passos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Elen Rizzi
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil; Department of Biotechnology, University of Ribeirao Preto, UNAERP, Ribeirao Preto, SP, Brazil
| | - Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Jefferson H Amaral
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Raquel F Gerlach
- Department of Morphology, Estomatology and Physiology, Dental School of Ribeirao Preto, University of Sao Paulo, Av. Bandeirantes 3900 14049-900, Ribeirao Preto, SP, Brazil
| | - Michele M Castro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
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17
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Martins-Oliveira A, Guimaraes DA, Ceron CS, Rizzi E, Oliveira DM, Tirapelli CR, Casarini DE, Fernandes FB, Pinheiro LC, Tanus-Santos JE. Direct renin inhibition is not enough to prevent reactive oxygen species generation and vascular dysfunction in renovascular hypertension. Eur J Pharmacol 2018; 821:97-104. [DOI: 10.1016/j.ejphar.2018.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/08/2017] [Accepted: 01/08/2018] [Indexed: 02/07/2023]
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18
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Acute oral dose of sodium nitrite induces redox imbalance, DNA damage, metabolic and histological changes in rat intestine. PLoS One 2017; 12:e0175196. [PMID: 28384248 PMCID: PMC5383256 DOI: 10.1371/journal.pone.0175196] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/22/2017] [Indexed: 12/16/2022] Open
Abstract
Industrialization and unchecked use of nitrate/nitrite salts for various purposes has increased human exposure to high levels of sodium nitrite (NaNO2) which can act as a pro-oxidant and pro-carcinogen. Oral exposure makes the gastrointestinal tract particularly susceptible to nitrite toxicity. In this work, the effect of administration of a single acute oral dose of NaNO2 on rat intestine was studied. Animals were randomly divided into four groups and given single doses of 20, 40, 60 and 75 mg NaNO2/kg body weight. Untreated animals served as the control group. An NaNO2 dose-dependent decline in the activities of brush border membrane enzymes, increase in lipid peroxidation, protein oxidation, hydrogen peroxide levels and decreased thiol content was observed in all treated groups. The activities of various metabolic and antioxidant defense enzymes were also altered. NaNO2 induced a dose-dependent increase in DNA damage and DNA-protein crosslinking. Histopathological studies showed marked morphological damage in intestinal cells. The intestinal damage might be due to nitrite-induced oxidative stress, direct action of nitrite anion or chemical modification by reaction intermediates.
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Pinheiro LC, Tanus-Santos JE, Castro MM. The potential of stimulating nitric oxide formation in the treatment of hypertension. Expert Opin Ther Targets 2017; 21:543-556. [PMID: 28338370 DOI: 10.1080/14728222.2017.1310840] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Hypertension is a leading cause of morbidity and mortality worldwide. A major pathophysiological factor contributing to hypertension is reduced nitric oxide (NO) bioavailability. Strategies to address this pathophysiological mechanism could offer significant advantages. Areas covered: In this review we aimed at examining a variety of drugs (statins, beta-adrenergic receptor blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, angiotensin II type-1 receptor blockers) used to treat hypertension and other cardiovascular diseases, particularly with respect to their potential of increasing NO bioavailability and activity in the cardiovascular system. There is now evidence supporting the notion that many cardiovascular drugs activate NO signaling or enhance NO bioavailability as a contributing mechanism to their beneficial cardiovascular effects. Moreover, other drugs may attenuate NO inactivation by superoxide and other reactive oxygen species by exerting antioxidant effects. More recently, the NO oxidation products nitrite and nitrate have been acknowledged as sources of NO after recycling back to NO. Activation of the nitrate-nitrite-NO pathway is an alternate pathway that may generate NO from both anions and exert antihypertensive effects. Expert opinion: In this review, we provide an overview of the possible mechanisms by which these drugs enhance NO bioavailability and help in the therapy of hypertension.
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Affiliation(s)
- Lucas C Pinheiro
- a Department of Pharmacology, Ribeirao Preto Medical School , University of Sao Paulo , Ribeirao Preto , Brazil
| | - Jose E Tanus-Santos
- a Department of Pharmacology, Ribeirao Preto Medical School , University of Sao Paulo , Ribeirao Preto , Brazil
| | - Michele M Castro
- a Department of Pharmacology, Ribeirao Preto Medical School , University of Sao Paulo , Ribeirao Preto , Brazil
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20
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Pinheiro LC, Ferreira GC, Amaral JH, Portella RL, Tella SDOC, Passos MA, Tanus-Santos JE. Oral nitrite circumvents antiseptic mouthwash-induced disruption of enterosalivary circuit of nitrate and promotes nitrosation and blood pressure lowering effect. Free Radic Biol Med 2016; 101:226-235. [PMID: 27769921 DOI: 10.1016/j.freeradbiomed.2016.10.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/15/2016] [Accepted: 10/17/2016] [Indexed: 02/04/2023]
Abstract
The nitric oxide (NO•) metabolites nitrite and nitrate exert antihypertensive effects by mechanisms that involve gastric formation of S-nitrosothiols. However, while the use of antiseptic mouthwash (AM) is known to attenuate the responses to nitrate by disrupting its enterosalivary cycle, there is little information about whether AM attenuates the effects of orally administered nitrite. We hypothesized that the antihypertensive effects of orally administered nitrite would not be prevented by AM because, in contrast to oral nitrate, oral nitrite could promote S-nitrosothiols formation in the stomach without intereference by AM. Chronic effects of oral nitrite or nitrate were studied in two-kidney, one-clip (2K1C) hypertensive rats (and normotensive controls) treated with AM (or vehicle) once/day. We found that orally administered nitrite exerts antihypertensive effects that were not affected by AM. This finding contrasts with lack of antihypertensive responses to oral nitrate in 2K1C hypertensive rats treated with AM. Nitrite and nitrate treatments increased plasma nitrites, nitrates, and S-nitrosothiols concentrations. However, while treatment with AM attenuated the increases in plasma nitrite concentrations after both nitrite and nitrate treatments, AM attenuated the increases in S-nitrosothiols in nitrate-treated rats, but not in nitrite-treated rats. Moreover, AM attenuated vascular S-nitrosylation (detected by the SNO-RAC method) after nitrate, but not after nitrite treatment. Significant correlations were found between the hypotensive responses and S-nitrosothiols, and vascular S-nitrosylation levels. These results show for the first time that oral nitrite exerts antihypertensive effects notwithstanding the fact that antiseptic mouthwash disrupts the enterosalivary circulation of nitrate. Our results support a major role for S-nitrosothiols formation resulting in vascular S-nitrosylation as a key mechanism for the antihypertensive effects of both oral nitrite and nitrate.
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Affiliation(s)
- Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil
| | - Graziele C Ferreira
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil
| | - Jefferson H Amaral
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil
| | - Rafael L Portella
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil
| | - Sandra de O C Tella
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil
| | - Madla A Passos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil.
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21
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Mechanisms involved in cardiovascular protection associated with a vegetarian diet. Clin Chim Acta 2016; 462:40. [DOI: 10.1016/j.cca.2016.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 08/29/2016] [Indexed: 11/24/2022]
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22
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Rocha BS, Nunes C, Laranjinha J. Tuning constitutive and pathological inflammation in the gut via the interaction of dietary nitrate and polyphenols with host microbiome. Int J Biochem Cell Biol 2016; 81:393-402. [PMID: 27989963 DOI: 10.1016/j.biocel.2016.10.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/22/2016] [Accepted: 10/26/2016] [Indexed: 02/08/2023]
Abstract
Chronic inflammation is currently recognized as a critical process in modern-era epidemics such as diabetes, obesity and neurodegeneration. However, little attention is paid to the constitutive inflammatory pathways that operate in the gut and that are mandatory for local welfare and the prevention of such multi-organic diseases. Hence, the digestive system, while posing as a barrier between the external environment and the host, is crucial for the balance between constitutive and pathological inflammatory events. Gut microbiome, a recently discovered organ, is now known to govern the interaction between exogenous agents and the host with ensued impact on local and systemic homeostasis. Whereas gut microbiota may be modulated by a myriad of factors, diet constitutes one of its major determinants. Thus, dietary compounds that influence microbial flora may thereby impact on inflammatory pathways. One such example is the redox environment in the gut lumen which is highly dependent on the local generation of nitric oxide along the nitrate-nitrite-nitric oxide pathway and that is further enhanced by simultaneous consumption of polyphenols. In this paper, different pathways encompassing the interaction of dietary nitrate and polyphenols with gut microbiota will be presented and discussed in connection with local and systemic inflammatory events. Furthermore, it will be discussed how these interactive cycles (nitrate-polyphenols-microbiome) may pose as novel strategies to tackle inflammatory diseases.
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Affiliation(s)
- Bárbara S Rocha
- Faculty of Pharmacy and Center for Neurosciences and Cell Biology, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
| | - Carla Nunes
- Faculty of Pharmacy and Center for Neurosciences and Cell Biology, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal
| | - João Laranjinha
- Faculty of Pharmacy and Center for Neurosciences and Cell Biology, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal.
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23
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Gonçalves-Rizzi VH, Possomato-Vieira JS, Sales Graça TU, Nascimento RA, Dias-Junior CA. Sodium nitrite attenuates hypertension-in-pregnancy and blunts increases in soluble fms-like tyrosine kinase-1 and in vascular endothelial growth factor. Nitric Oxide 2016; 57:71-78. [DOI: 10.1016/j.niox.2016.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 05/05/2016] [Accepted: 05/11/2016] [Indexed: 01/09/2023]
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24
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Sodium nitrite attenuates MMP-9 production by endothelial cells and may explain similar effects of atorvastatin. Naunyn Schmiedebergs Arch Pharmacol 2015; 389:223-31. [PMID: 26614570 DOI: 10.1007/s00210-015-1192-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/11/2015] [Indexed: 12/27/2022]
Abstract
Imbalanced matrix metalloproteinase (MMP) activity promotes cardiovascular alterations that are attenuated by statins. These drugs exert pleiotropic effects independent of cholesterol concentrations, including upregulation of nitric oxide (NO) formation and MMP downregulation. However, statins also increase tissue concentrations of nitrites, which activate new signaling pathways independent of NO. We examined whether atorvastatin attenuates MMP-9 production by human umbilical vein endothelial cells (HUVEC) stimulated with phorbol 12-myristate 13-acetate (PMA) by mechanisms possibly involving increased nitrite, and whether this effect results of NO formation. We also examined whether such an effect is improved by sildenafil, an inhibitor of phosphodiesterase-5 which potentiates NO-induced increases in cyclic GMP. MMP activity and nitrite concentrations were measured by gelatin zymography and ozone-based reductive chemiluminescence, respectively, in the conditioned medium of HUVECs incubated for 24 h with these drugs. Phospho-NFκB p65 concentrations were measured in cell lysate to assess NFκB activation. Atorvastatin attenuated PMA-induced MMP-9 gelatinolytic activity by mechanisms not involving NO, although it increased nitrite concentrations, whereas sildenafil had no effects. Combining both drugs showed no improved responses compared to atorvastatin alone. While sodium nitrite attenuated MMP-9 production by HUVECs, adding hemoglobin (NO scavenger) did not affect the responses to nitrite. Neither atorvastatin nor nitrite inhibited PMA-induced increases in phospho-NFκB p65 concentrations. These findings show that sodium nitrite attenuates MMP-9 production by endothelial cells and may explain similar effects exerted by atorvastatin. With both drugs, the inhibitory effects on MMP-9 production are not dependent on NO formation or on inhibition of NFκB activation. Our findings may help to elucidate important new nitrite-mediated mechanisms by which statins affect imbalanced MMP activity in a variety of cardiovascular disease.
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25
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Pinheiro LC, Amaral JH, Ferreira GC, Portella RL, Ceron CS, Montenegro MF, Toledo JC, Tanus-Santos JE. Gastric S-nitrosothiol formation drives the antihypertensive effects of oral sodium nitrite and nitrate in a rat model of renovascular hypertension. Free Radic Biol Med 2015; 87:252-62. [PMID: 26159506 DOI: 10.1016/j.freeradbiomed.2015.06.038] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 06/11/2015] [Accepted: 06/26/2015] [Indexed: 01/01/2023]
Abstract
Many effects of nitrite and nitrate are attributed to increased circulating concentrations of nitrite, ultimately converted into nitric oxide (NO(•)) in the circulation or in tissues by mechanisms associated with nitrite reductase activity. However, nitrite generates NO(•) , nitrous anhydride, and other nitrosating species at low pH, and these reactions promote S-nitrosothiol formation when nitrites are in the stomach. We hypothesized that the antihypertensive effects of orally administered nitrite or nitrate involve the formation of S-nitrosothiols, and that those effects depend on gastric pH. The chronic effects of oral nitrite or nitrate were studied in two-kidney, one-clip (2K1C) hypertensive rats treated with omeprazole (or vehicle). Oral nitrite lowered blood pressure and increased plasma S-nitrosothiol concentrations independently of circulating nitrite levels. Increasing gastric pH with omeprazole did not affect the increases in plasma nitrite and nitrate levels found after treatment with nitrite. However, treatment with omeprazole severely attenuated the increases in plasma S-nitrosothiol concentrations and completely blunted the antihypertensive effects of nitrite. Confirming these findings, very similar results were found with oral nitrate. To further confirm the role of gastric S-nitrosothiol formation, we studied the effects of oral nitrite in hypertensive rats treated with the glutathione synthase inhibitor buthionine sulfoximine (BSO) to induce partial thiol depletion. BSO treatment attenuated the increases in S-nitrosothiol concentrations and antihypertensive effects of oral nitrite. These data show that gastric S-nitrosothiol formation drives the antihypertensive effects of oral nitrite or nitrate and has major implications, particularly to patients taking proton pump inhibitors.
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Affiliation(s)
- Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Jefferson H Amaral
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Graziele C Ferreira
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Rafael L Portella
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Carla S Ceron
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Marcelo F Montenegro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil
| | - Jose Carlos Toledo
- Department of Chemistry, Faculty of Philosophy and Sciences of Ribeirao Preto, University of Sao Paulo, 14040-901, Ribeirao Preto, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil.
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Boonla O, Kukongviriyapan U, Pakdeechote P, Kukongviriyapan V, Pannangpetch P, Thawornchinsombut S. Peptides-Derived from Thai Rice Bran Improves Endothelial Function in 2K-1C Renovascular Hypertensive Rats. Nutrients 2015; 7:5783-99. [PMID: 26184305 PMCID: PMC4517029 DOI: 10.3390/nu7075252] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/06/2015] [Accepted: 07/08/2015] [Indexed: 11/16/2022] Open
Abstract
In recent years, a number of studies have investigated complementary medical approaches to the treatment of hypertension using dietary supplements. Rice bran protein hydrolysates extracted from rice is a rich source of bioactive peptides. The present study aimed to investigate the vasorelaxation and antihypertensive effects of peptides-derived from rice bran protein hydrolysates (RBP) in a rat model of two kidney-one clip (2K-1C) renovascular hypertension. 2K-1C hypertension was induced in male Sprague-Dawley rats by placing a silver clip around the left renal artery, whereas sham-operated rats were served as controls. 2K-1C and sham-operated rats were intragastrically administered with RBP (50 mg·kg−1 or 100 mg·kg−1) or distilled water continuously for six weeks. We observed that RBP augmented endothelium-dependent vasorelaxation in all animals. Administration of RBP to 2K-1C rats significantly reduced blood pressure and decreased peripheral vascular resistance compared to the sham operated controls (p < 0.05). Restoration of normal endothelial function and blood pressure was associated with reduced plasma angiotensin converting enzyme (ACE), decreased superoxide formation, reduced plasma malondialdehyde and increased plasma nitrate/nitrite (p < 0.05). Up-regulation of eNOS protein and down-regulation of p47phox protein were found in 2K-1C hypertensive rats-treated with RBP. Our results suggest that RBP possesses antihypertensive properties which are mainly due to the inhibition of ACE, and its vasodilatory and antioxidant activity.
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Affiliation(s)
- Orachorn Boonla
- Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
| | - Upa Kukongviriyapan
- Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
| | - Poungrat Pakdeechote
- Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
| | - Veerapol Kukongviriyapan
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
| | | | - Supawan Thawornchinsombut
- Department of Food Technology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand.
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Consistent antioxidant and antihypertensive effects of oral sodium nitrite in DOCA-salt hypertension. Redox Biol 2015; 5:340-346. [PMID: 26119848 PMCID: PMC4491646 DOI: 10.1016/j.redox.2015.06.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 06/15/2015] [Accepted: 06/17/2015] [Indexed: 02/01/2023] Open
Abstract
Hypertension is a common disease that includes oxidative stress as a major feature, and oxidative stress impairs physiological nitric oxide (NO) activity promoting cardiovascular pathophysiological mechanisms. While inorganic nitrite and nitrate are now recognized as relevant sources of NO after their bioactivation by enzymatic and non-enzymatic pathways, thus lowering blood pressure, mounting evidence suggests that sodium nitrite also exerts antioxidant effects. Here we show for the first time that sodium nitrite exerts consistent systemic and vascular antioxidant and antihypertensive effects in the deoxycorticosterone-salt (DOCA-salt) hypertension model. This is particularly important because increased oxidative stress plays a major role in the DOCA-salt hypertension model, which is less dependent on activation of the renin-angiotensin system than other hypertension models. Indeed, antihypertensive effects of oral nitrite were associated with increased plasma nitrite and nitrate concentrations, and completely blunted hypertension-induced increases in plasma 8-isoprostane and lipid peroxide levels, in vascular reactive oxygen species, in vascular NADPH oxidase activity, and in vascular xanthine oxidoreductase activity. Together, these findings provide evidence that the oral administration of sodium nitrite consistently decreases the blood pressure in association with major antioxidant effects in experimental hypertension. Nitrite is known to recycle back to NO under specific conditions. Antihypertensive effects have been shown for sodium nitrite in some animal models. The DOCA-salt hypertension model includes oxidative stress as a major pathogenetic mechanism. This study shows antihypertensive effects of nitrite in the DOCA-salt hypertension model. Reduction in arterial blood pressure was associated with important antioxidant effects of sodium nitrite.
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Guimaraes DA, Tanus-Santos JE. Combining drugs to optimize the therapy of hypertension: experimental evidence derived from animal models. Hypertens Res 2015; 38:457-8. [DOI: 10.1038/hr.2015.52] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Meschiari CA, Zuardi LR, Gomes VA, Costa de Almeida GR, Novaes AB, Gerlach RF, Marcaccini AM. Salivary, blood and plasma nitrite concentrations in periodontal patients and healthy individuals before and after periodontal treatment. Clin Chim Acta 2015; 444:293-6. [PMID: 25748039 DOI: 10.1016/j.cca.2015.02.045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 02/13/2015] [Accepted: 02/18/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND To date, no study has employed ozone-based reductive chemiluminescence to compare nitrite concentration in the saliva of periodontal disease (PD) and healthy individuals or in the various blood compartments of the same individuals before and after periodontal treatment. We evaluated nitrite concentrations in whole, submandibular, and parotid saliva, as well as in whole blood, erythrocytes, and plasma of healthy volunteers and patients with chronic periodontitis. METHODS Data obtained for the PD and control groups were compared before and 3 months after periodontal therapy. RESULTS At baseline, stimulated whole saliva nitrite concentration was lower in PD patients (mean=57.3 ± 9.8 μmol/L) as compared with healthy individuals (92.5 ± 13.6 μmol/L, P<0.05). PD and periodontal treatment did not affect submandibular or parotid saliva nitrite concentrations. PD patients presented higher baseline whole blood nitrite concentration (238.4 ± 45.7 μmol/L) as compared with values recorded 3 months after therapy (141.3 ± 20.1 nmol/L, P<0.05). PD patients' erythrocytes exhibited higher baseline nitrite concentration (573.1 ± 97.8 nmol/L) as compared with three months after therapy (298.7 ± 52.1 nmol/L, P<0.05). Again, PD and PD treatment did not impact plasma nitrite concentration. CONCLUSIONS PD patients had lower nitrite concentration in whole saliva, and this situation remained unchanged after periodontal treatment. Nevertheless, erythrocytes and whole blood nitrite levels diminished after periodontal treatment.
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Affiliation(s)
- Cesar A Meschiari
- Department of Pharmacology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
| | - Leonardo R Zuardi
- Department of Morphology and Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Valeria A Gomes
- Department of Gynecology and Obstetrics, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Glauce R Costa de Almeida
- Department of Morphology and Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Arthur B Novaes
- Department of Oral Maxillofacial Surgery & Traumatology and Periodontology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Raquel F Gerlach
- Department of Morphology and Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Andrea M Marcaccini
- School of Dentistry, University of Ribeirão Preto (UNAERP), Ribeirão Preto, SP, Brazil
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The antihypertensive effects of sodium nitrite are not associated with circulating angiotensin converting enzyme inhibition. Nitric Oxide 2014; 40:52-9. [PMID: 24878382 DOI: 10.1016/j.niox.2014.05.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/04/2014] [Accepted: 05/20/2014] [Indexed: 01/15/2023]
Abstract
Nitrite-derived nitric oxide (NO) formation exerts antihypertensive effects. Because NO inhibits angiotensin converting enzyme (ACE) activity, we carried a comprehensive series of experiments in rats to test the hypothesis that sodium nitrite exerts antihypertensive effects by inhibiting ACE. We examined whether sodium nitrite (15 mg/kg; or vehicle; by gavage): (I) attenuates the pressor responses to angiotensin I at doses of 0.03, 0.1, 0.3, 1, 3, and 10 μg/kg intravenously; (II) attenuates the acute hypertension induced by L-NAME (100 mg/kg; or vehicle; by gavage); (III) attenuates the chronic hypertension induced by L-NAME (1 g/L in drinking water; or vehicle) administered for 6 weeks; (IV) attenuates the hypertension in the 2 kidney-1 clip (2K1C) chronic hypertension model. Blood samples were collected at the end of each study and plasma angiotensin converting enzyme (ACE) activity was measured with a fluorimetric assay using Hippuryl-His-Leu as substrate. ACE inhibitors were used as positive controls. Plasma nitrite concentrations were measured by ozone-based reductive chemiluminescence. The in vitro effects of sodium nitrite (0, 1, 3, 10, 30, 100 μmol/L) on plasma ACE activity were also determined. We found that sodium nitrite did not affect the pressor responses to angiotensin I. Moreover, while sodium nitrite exerted significant antihypertensive effects in acute and chronic hypertension models, no significant effects on plasma ACE activity were found. In vitro experiments showed no effects of sodium nitrite on plasma ACE activity. This is the first study to demonstrate that the acute and chronic antihypertensive effects of sodium nitrite are not associated with significant inhibition of circulating ACE activity.
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Vascular xanthine oxidoreductase contributes to the antihypertensive effects of sodium nitrite in l-NAME hypertension. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:591-8. [DOI: 10.1007/s00210-014-0970-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 02/24/2014] [Indexed: 12/17/2022]
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Sindler AL, Devan AE, Fleenor BS, Seals DR. Inorganic nitrite supplementation for healthy arterial aging. J Appl Physiol (1985) 2014; 116:463-77. [PMID: 24408999 PMCID: PMC3949212 DOI: 10.1152/japplphysiol.01100.2013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/03/2014] [Indexed: 12/12/2022] Open
Abstract
Aging is the major risk factor for cardiovascular diseases (CVD). This is attributable primarily to adverse changes in arteries, notably, increases in large elastic artery stiffness and endothelial dysfunction mediated by inadequate concentrations of the vascular-protective molecule, nitric oxide (NO), and higher levels of oxidative stress and inflammation. Inorganic nitrite is a promising precursor molecule for augmenting circulating and tissue NO bioavailability because it requires only a one-step reduction to NO. Nitrite also acts as an independent signaling molecule, exerting many of the effects previously attributed to NO. Results of recent studies indicate that nitrite may be effective in the treatment of vascular aging. In old mice, short-term oral sodium nitrite supplementation reduces aortic pulse wave velocity, the gold-standard measure of large elastic artery stiffness, and ameliorates endothelial dysfunction, as indicated by normalization of NO-mediated endothelium-dependent dilation. These improvements in age-related vascular dysfunction with nitrite are mediated by reductions in oxidative stress and inflammation, and may be linked to increases in mitochondrial biogenesis and health. Increasing nitrite levels via dietary intake of nitrate appears to have similarly beneficial effects in many of the same physiological and clinical settings. Several clinical trials are being performed to determine the broad therapeutic potential of increasing nitrite bioavailability on human health and disease, including studies related to vascular aging. In summary, inorganic nitrite, as well as dietary nitrate supplementation, represents a promising therapy for treatment of arterial aging and prevention of age-associated CVD in humans.
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Affiliation(s)
- Amy L Sindler
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado
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Guimarães DA, Rizzi E, Ceron CS, Pinheiro LC, Gerlach RF, Tanus-Santos JE. Atorvastatin and sildenafil lower blood pressure and improve endothelial dysfunction, but only atorvastatin increases vascular stores of nitric oxide in hypertension. Redox Biol 2013; 1:578-85. [PMID: 24363994 PMCID: PMC3863772 DOI: 10.1016/j.redox.2013.11.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 12/19/2022] Open
Abstract
Nitric oxide (NO)-derived metabolites including the anion nitrite can recycle back to NO and thus complement NO formation independent of NO synthases. While nitrite is as a major vascular storage pool and source of NO, little is known about drugs that increase tissue nitrite concentrations. This study examined the effects of atorvastatin or sildenafil, or the combination, on vascular nitrite concentrations and on endothelial dysfunction in the 2 kidney-1 clip (2K1C) hypertension model. Sham-operated or 2K1C hypertensive rats were treated with vehicle, atorvastatin (50 mg/Kg), sildenafil (45 mg/Kg), or both for 8 weeks. Systolic blood pressure (SBP) was monitored weekly. Nitrite concentrations were assessed in the aortas and in plasma samples by ozone-based reductive chemiluminescence assay. Aortic rings were isolated to assess endothelium-dependent and independent relaxation. Aortic NADPH activity and ROS production were evaluated by luminescence and dihydroethidium, respectively, and plasma TBARS levels were measured. Aortic nitrotyrosine staining was evaluated to assess peroxynitrite formation. Atorvastatin and sildenafil, alone or combined, significantly lowered SBP by approximately 40 mmHg. Atorvastatin significantly increased vascular nitrite levels by 70% in hypertensive rats, whereas sildenafil had no effects. Both drugs significantly improved the vascular function, and decreased vascular NADPH activity, ROS, and nitrotyrosine levels. Lower plasma TBARS concentrations were found with both treatments. The combination of drugs showed no improved responses compared to each drug alone. These findings show evidence that atorvastatin, but not sildenafil, increases vascular NO stores, although both drugs exert antioxidant effects, improve endothelial function, and lower blood pressure in 2K1C hypertension. Nitrite recycles back to NO and complements NO formation independent of NO synthases. Little is known about drugs that increase tissue nitrite concentrations. Atorvastatin or sildenafil lowered blood pressure in renovascular hypertension. Both drugs exerted antioxidant effects and improved endothelial dysfunction. Only atorvastatin increased vascular nitrite levels by 70% in hypertensive rats.
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Affiliation(s)
- Danielle A Guimarães
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirao Preto 14049-900, SP, Brazil
| | - Elen Rizzi
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirao Preto 14049-900, SP, Brazil
| | - Carla S Ceron
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirao Preto 14049-900, SP, Brazil
| | - Lucas C Pinheiro
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirao Preto 14049-900, SP, Brazil
| | - Raquel F Gerlach
- Department of Morphology, Physiology, and Basic Pathology, University of Sao Paulo, s/n Av. Café, Ribeirao Preto 14040-904, SP, Brazil
| | - Jose E Tanus-Santos
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Av. Bandeirantes 3900, Ribeirao Preto 14049-900, SP, Brazil
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Bryan NS. Pharmacological therapies, lifestyle choices and nitric oxide deficiency: A perfect storm. Pharmacol Res 2012; 66:448-56. [DOI: 10.1016/j.phrs.2012.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 08/28/2012] [Accepted: 09/15/2012] [Indexed: 01/05/2023]
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Miranda JA, Belo VA, Souza-Costa DC, Lanna CMM, Tanus-Santos JE. eNOS polymorphism associated with metabolic syndrome in children and adolescents. Mol Cell Biochem 2012; 372:155-60. [PMID: 22983816 DOI: 10.1007/s11010-012-1456-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/05/2012] [Indexed: 01/16/2023]
Abstract
We investigated whether genetic polymorphisms in the endothelial nitric oxide (eNOS) gene (T(786)C in the promoter region, Glu298Asp in exon 7, and 4b/4a in intron 4) or eNOS haplotypes are associated with metabolic syndrome (MetS) in obese children and adolescents. We studied 242 subjects: 108 healthy (controls), 64 normotensive obese, and 70 obese children and adolescents with MetS. Genotypes were determined by Taqman(®) allele discrimination assay and real-time polymerase chain reaction (PCR), and PCR followed by fragment separation by electrophoresis. We compared the distribution of eNOS genotypes, alleles, and haplotypes in the three groups of subjects. The CC genotype for the T(786)C polymorphism was more common in the MetS group than in the control group (OR = 3.27; CI 1.81-9.07; P < 0.05). However, we found no significant differences in the distribution of eNOS haplotypes (P > 0.00625; P for significance after correction for multiple comparisons). Our findings suggest that while eNOS haplotypes are not relevant, the CC genotype for the T(786)C polymorphism is associated with MetS in obese children and adolescents. Further studies examining interactions of eNOS haplotypes with environmental factors and other genetic markers are warranted.
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Affiliation(s)
- Josiane A Miranda
- Department of Pharmacology, State University of Campinas, Campinas, SP 13081-970, Brazil
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Pinheiro LC, Montenegro MF, Amaral JH, Ferreira GC, Oliveira AM, Tanus-Santos JE. Increase in gastric pH reduces hypotensive effect of oral sodium nitrite in rats. Free Radic Biol Med 2012; 53:701-9. [PMID: 22721923 DOI: 10.1016/j.freeradbiomed.2012.06.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/23/2012] [Accepted: 06/02/2012] [Indexed: 01/07/2023]
Abstract
The new pathway nitrate-nitrite-nitric oxide (NO) has emerged as a physiological alternative to the classical enzymatic pathway for NO formation from l-arginine. Nitrate is converted to nitrite by commensal bacteria in the oral cavity and the nitrite formed is then swallowed and reduced to NO under the acidic conditions of the stomach. In this study, we tested the hypothesis that increases in gastric pH caused by omeprazole could decrease the hypotensive effect of oral sodium nitrite. We assessed the effects of omeprazole treatment on the acute hypotensive effects produced by sodium nitrite in normotensive and L-NAME-hypertensive free-moving rats. In addition, we assessed the changes in gastric pH and plasma levels of nitrite, NO(x) (nitrate+nitrite), and S-nitrosothiols caused by treatments. We found that the increases in gastric pH induced by omeprazole significantly reduced the hypotensive effects of sodium nitrite in both normotensive and L-NAME-hypertensive rats. This effect of omeprazole was associated with no significant differences in plasma nitrite, NO(x), or S-nitrosothiol levels. Our results suggest that part of the hypotensive effects of oral sodium nitrite may be due to its conversion to NO in the acidified environment of the stomach. The increase in gastric pH induced by treatment with omeprazole blunts part of the beneficial cardiovascular effects of dietary nitrate and nitrite.
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Affiliation(s)
- Lucas C Pinheiro
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, 13081-970 Campinas, SP, Brazil
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