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Piknova B, Park JW, Thomas SM, Tunau-Spencer KJ, Schechter AN. Nitrate and Nitrite Metabolism in Aging Rats: A Comparative Study. Nutrients 2023; 15:nu15112490. [PMID: 37299453 DOI: 10.3390/nu15112490] [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: 04/17/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Nitric oxide (NO) (co)regulates many physiological processes in the body. Its short-lived free radicals force synthesis in situ and on-demand, without storage possibility. Local oxygen availability determines the origin of NO-either by synthesis by nitric oxide synthases (NOS) or by the reduction of nitrate to nitrite to NO by nitrate/nitrite reductases. The existence of nitrate reservoirs, mainly in skeletal muscle, assures the local and systemic availability of NO. Aging is accompanied by changes in metabolic pathways, leading to a decrease in NO availability. We explored age-related changes in various rat organs and tissues. We found differences in nitrate and nitrite contents in tissues of old and young rats at baseline levels, with nitrate levels being generally higher and nitrite levels being generally lower in old rats. However, there were no differences in the levels of nitrate-transporting proteins and nitrate reductase between old and young rats, with the exception of in the eye. Increased dietary nitrate led to significantly higher nitrate enrichment in the majority of old rat organs compared to young rats, suggesting that the nitrate reduction pathway is not affected by aging. We hypothesize that age-related NO accessibility changes originate either from the NOS pathway or from changes in NO downstream signaling (sGC/PDE5). Both possibilities need further investigation.
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Affiliation(s)
- Barbora Piknova
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Ji Won Park
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Samantha M Thomas
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Khalid J Tunau-Spencer
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
| | - Alan N Schechter
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892, USA
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Wang L, Liu Y, Zhang X, Ye Y, Xiong X, Zhang S, Gu L, Jian Z, Wang H. Endoplasmic Reticulum Stress and the Unfolded Protein Response in Cerebral Ischemia/Reperfusion Injury. Front Cell Neurosci 2022; 16:864426. [PMID: 35602556 PMCID: PMC9114642 DOI: 10.3389/fncel.2022.864426] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/07/2022] [Indexed: 12/15/2022] Open
Abstract
Ischemic stroke is an acute cerebrovascular disease characterized by sudden interruption of blood flow in a certain part of the brain, leading to serious disability and death. At present, treatment methods for ischemic stroke are limited to thrombolysis or thrombus removal, but the treatment window is very narrow. However, recovery of cerebral blood circulation further causes cerebral ischemia/reperfusion injury (CIRI). The endoplasmic reticulum (ER) plays an important role in protein secretion, membrane protein folding, transportation, and maintenance of intracellular calcium homeostasis. Endoplasmic reticulum stress (ERS) plays a crucial role in cerebral ischemia pathophysiology. Mild ERS helps improve cell tolerance and restore cell homeostasis; however, excessive or long-term ERS causes apoptotic pathway activation. Specifically, the protein kinase R-like endoplasmic reticulum kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE1) pathways are significantly activated following initiation of the unfolded protein response (UPR). CIRI-induced apoptosis leads to nerve cell death, which ultimately aggravates neurological deficits in patients. Therefore, it is necessary and important to comprehensively explore the mechanism of ERS in CIRI to identify methods for preserving brain cells and neuronal function after ischemia.
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Affiliation(s)
- Lei Wang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yan Liu
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xu Zhang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yingze Ye
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xiaoxing Xiong
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Shudi Zhang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Lijuan Gu
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhihong Jian
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China
- Zhihong Jian,
| | - Hongfa Wang
- Rehabilitation Medicine Center, Department of Anesthesiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, China
- *Correspondence: Hongfa Wang,
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3
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Pearson R, Butler A. Glyceryl Trinitrate: History, Mystery, and Alcohol Intolerance. Molecules 2021; 26:6581. [PMID: 34770988 PMCID: PMC8587134 DOI: 10.3390/molecules26216581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 11/23/2022] Open
Abstract
Glyceryl trinitrate (GTN) is one of the earliest known treatments for angina with a fascinating history that bridges three centuries. However, despite its central role in the nitric oxide (NO) story as a NO-donating compound, establishing the precise mechanism of how GTN exerts its medicinal benefit has proven to be far more difficult. This review brings together the explosive and vasodilatory nature of this three-carbon molecule while providing an update on the likely in vivo pathways through which GTN, and the rest of the organic nitrate family, release NO, nitrite, or a combination of both, while also trying to explain nitrate tolerance. Over the last 20 years the alcohol detoxification enzyme, aldehyde dehydrogenase (ALDH), has undoubtedly emerged as the front runner to explaining GTN's bioactivation. This is best illustrated by reduced GTN efficacy in subjects carrying the single point mutation (Glu504Lys) in ALDH, which is also responsible for alcohol intolerance, as characterized by flushing. While these findings are significant for anyone following the GTN story, they appear particularly relevant for healthcare professionals, and especially so, if administering GTN to patients as an emergency treatment. In short, although the GTN puzzle has not been fully solved, clinical study data continue to cement the importance of ALDH, as uncovered in 2002, as a key GTN activator.
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Affiliation(s)
- Russell Pearson
- School of Pharmacy & Bioengineering, Keele University, Newcastle-under-Lyme ST5 5BG, Staffordshire, UK
| | - Anthony Butler
- School of Psychology & Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK;
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Liu Y, Croft KD, Hodgson JM, Mori T, Ward NC. Mechanisms of the protective effects of nitrate and nitrite in cardiovascular and metabolic diseases. Nitric Oxide 2020; 96:35-43. [PMID: 31954804 DOI: 10.1016/j.niox.2020.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/18/2019] [Accepted: 01/13/2020] [Indexed: 12/28/2022]
Abstract
Within the body, NO is produced by nitric oxide synthases via converting l-arginine to citrulline. Additionally, NO is also produced via the NOS-independent nitrate-nitrite-NO pathway. Unlike the classical pathway, the nitrate-nitrite-NO pathway is oxygen independent and viewed as a back-up function to ensure NO generation during ischaemia/hypoxia. Dietary nitrate and nitrite have emerged as substrates for endogenous NO generation and other bioactive nitrogen oxides with promising protective effects on cardiovascular and metabolic function. In brief, inorganic nitrate and nitrite can decrease blood pressure, protect against ischaemia-reperfusion injury, enhance endothelial function, inhibit platelet aggregation, modulate mitochondrial function and improve features of the metabolic syndrome. However, many questions regarding the specific mechanisms of these protective effects on cardiovascular and metabolic diseases remain unclear. In this review, we focus on nitrate/nitrite bioactivation, as well as the potential mechanisms for nitrate/nitrite-mediated effects on cardiovascular and metabolic diseases. Understanding how dietary nitrate and nitrite induce beneficial effect on cardiovascular and metabolic diseases could open up novel therapeutic opportunities in clinical practice.
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Affiliation(s)
- Yang Liu
- School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - Kevin D Croft
- School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - Jonathan M Hodgson
- School of Biomedical Sciences, University of Western Australia, Perth, Australia; School of Medical and Health Sciences, Edith Cowan University, Perth, Australia
| | - Trevor Mori
- Medical School, University of Western Australia, Perth, Australia
| | - Natalie C Ward
- Medical School, University of Western Australia, Perth, Australia; School of Public Health and Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
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Rosenbaek JB, Pedersen EB, Bech JN. The effect of sodium nitrite infusion on renal function, brachial and central blood pressure during enzyme inhibition by allopurinol, enalapril or acetazolamide in healthy subjects: a randomized, double-blinded, placebo-controlled, crossover study. BMC Nephrol 2018; 19:244. [PMID: 30241504 PMCID: PMC6150994 DOI: 10.1186/s12882-018-1035-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/03/2018] [Indexed: 12/25/2022] Open
Abstract
Background Sodium nitrite (NaNO2) causes vasodilation, presumably by enzymatic conversion to nitric oxide (NO). Several enzymes with nitrite reducing capabilities have been discovered in vitro, but their relative importance in vivo has not been investigated. We aimed to examine the effects of NaNO2 on blood pressure, fractional sodium excretion (FENa), free water clearance (CH2O) and GFR, after pre-inhibition of xanthine oxidase, carbonic anhydrase, and angiotensin-converting enzyme. The latter as an approach to upregulate endothelial NO synthase activity. Methods In a double-blinded, placebo-controlled, crossover study, 16 healthy subjects were treated, in a randomized order, with placebo, allopurinol 150 mg twice daily (TD), enalapril 5 mg TD, or acetazolamide 250 mg TD. After 4 days of treatment and standardized diet, the subjects were examined at our lab. During intravenous infusion of 240 μg NaNO2/kg/hour for 2 h, we measured changes in brachial and central blood pressure (BP), plasma cyclic guanosine monophosphate (P-cGMP), plasma and urine osmolality, GFR by 51Cr-EDTA clearance, FENa and urinary excretion rate of cGMP (U-cGMP) and nitrite and nitrate (U-NOx). Subjects were supine and orally water-loaded throughout the examination day. Results Irrespective of pretreatment, we observed an increase in FENa, heart rate, U-NOx, and a decrease in CH2O and brachial systolic BP during NaNO2 infusion. P-cGMP and U-cGMP did not change during infusion. We observed a consistent trend towards a reduction in central systolic BP, which was only significant after allopurinol. Conclusion This study showed a robust BP lowering, natriuretic and anti-aquaretic effect of intravenous NaNO2 regardless of preceding enzyme inhibition. None of the three enzyme inhibitors used convincingly modified the pharmacological effects of NaNO2. The steady cGMP indicates little or no conversion of nitrite to NO. Thus the effect of NaNO2 may not be mediated by NO generation. Trial registration EU Clinical Trials Register, 2013-003404-39. Registered December 3 2013.
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Affiliation(s)
- Jeppe B Rosenbaek
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Laegaardvej 12J, DK-7500, Holstebro, Denmark.
| | - Erling B Pedersen
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Laegaardvej 12J, DK-7500, Holstebro, Denmark
| | - Jesper N Bech
- University Clinic in Nephrology and Hypertension, Regional Hospital West Jutland and Aarhus University, Laegaardvej 12J, DK-7500, Holstebro, Denmark
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6
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Tropea T, Wareing M, Greenwood SL, Feelisch M, Sibley CP, Cottrell EC. Nitrite mediated vasorelaxation in human chorionic plate vessels is enhanced by hypoxia and dependent on the NO-sGC-cGMP pathway. Nitric Oxide 2018; 80:82-88. [PMID: 30179715 PMCID: PMC6199414 DOI: 10.1016/j.niox.2018.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/05/2018] [Accepted: 08/30/2018] [Indexed: 11/25/2022]
Abstract
Adequate perfusion of the placental vasculature is essential to meet the metabolic demands of fetal growth and development. Lacking neural control, local tissue metabolites, circulating and physical factors contribute significantly to blood flow regulation. Nitric oxide (NO) is a key regulator of fetoplacental vascular tone. Nitrite, previously considered an inert end-product of NO oxidation, has been shown to provide an important source of NO. Reduction of nitrite to NO may be particularly relevant in tissue when the oxygen-dependent NO synthase (NOS) activity is compromised, e.g. in hypoxia. The contribution of this pathway in the placenta is currently unknown. We hypothesised that nitrite vasodilates human placental blood vessels, with enhanced efficacy under hypoxia. Placentas were collected from uncomplicated pregnancies and the vasorelaxant effect of nitrite (10-6-5x10-3 M) was assessed using wire myography on isolated pre-constricted chorionic plate arteries (CPAs) and veins (CPVs) under normoxic (pO2 ∼5%) and hypoxic (pO2 ∼1%) conditions. The dependency on the NO-sGC-cGMP pathway and known nitrite reductase (NiR) activities was also investigated. Nitrite caused concentration-dependent vasorelaxation in both arteries and veins, and this effect was enhanced by hypoxia, significantly in CPVs (P < 0.01) and with a trend in CPAs (P = 0.054). Pre-incubation with NO scavengers (cPTIO and oxyhemoglobin) attenuated (P < 0.01 and P < 0.0001, respectively), and the sGC inhibitor ODQ completely abolished nitrite-mediated vasorelaxation, confirming the involvement of NO and sGC. Inhibition of potential NiR enzymes xanthine oxidoreductase, mitochondrial aldehyde dehydrogenase and mitochondrial bc1 complex did not attenuate vasorelaxation. This data suggests that nitrite may provide an important reservoir of NO bioactivity within the placenta to enhance blood flow when fetoplacental oxygenation is impaired, as occurring in pregnancy diseases such as pre-eclampsia and fetal growth restriction.
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Affiliation(s)
- Teresa Tropea
- Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, Maternal & Fetal Health Research Centre, University of Manchester, United Kingdom.
| | - Mark Wareing
- Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, Maternal & Fetal Health Research Centre, University of Manchester, United Kingdom
| | - Susan L Greenwood
- Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, Maternal & Fetal Health Research Centre, University of Manchester, United Kingdom
| | - Martin Feelisch
- Clinical and Experimental Sciences, Faculty of Medicine, Southampton General Hospital and Institute for Life Sciences, University of Southampton, United Kingdom
| | - Colin P Sibley
- Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, Maternal & Fetal Health Research Centre, University of Manchester, United Kingdom
| | - Elizabeth C Cottrell
- Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, Maternal & Fetal Health Research Centre, University of Manchester, United Kingdom
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7
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Carlström M, Lundberg JO, Weitzberg E. Mechanisms underlying blood pressure reduction by dietary inorganic nitrate. Acta Physiol (Oxf) 2018; 224:e13080. [PMID: 29694703 DOI: 10.1111/apha.13080] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/28/2018] [Accepted: 04/18/2018] [Indexed: 12/20/2022]
Abstract
Nitric oxide (NO) importantly contributes to cardiovascular homeostasis by regulating blood flow and maintaining endothelial integrity. Conversely, reduced NO bioavailability is a central feature during natural ageing and in many cardiovascular disorders, including hypertension. The inorganic anions nitrate and nitrite are endogenously formed after oxidation of NO synthase (NOS)-derived NO and are also present in our daily diet. Knowledge accumulated over the past two decades has demonstrated that these anions can be recycled back to NO and other bioactive nitrogen oxides via serial reductions that involve oral commensal bacteria and various enzymatic systems. Intake of inorganic nitrate, which is predominantly found in green leafy vegetables and beets, has a variety of favourable cardiovascular effects. As hypertension is a major risk factor of morbidity and mortality worldwide, much attention has been paid to the blood pressure reducing effect of inorganic nitrate. Here, we describe how dietary nitrate, via stimulation of the nitrate-nitrite-NO pathway, affects various organ systems and discuss underlying mechanisms that may contribute to the observed blood pressure-lowering effect.
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Affiliation(s)
- M. Carlström
- Department of Physiology and Pharmacology; Karolinska Institutet; Stockholm Sweden
| | - J. O. Lundberg
- Department of Physiology and Pharmacology; Karolinska Institutet; Stockholm Sweden
| | - E. Weitzberg
- Department of Physiology and Pharmacology; Karolinska Institutet; Stockholm Sweden
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8
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Buerk DG, Liu Y, Zaccheo KA, Barbee KA, Jaron D. Nitrite-Mediated Hypoxic Vasodilation Predicted from Mathematical Modeling and Quantified from in Vivo Studies in Rat Mesentery. Front Physiol 2017; 8:1053. [PMID: 29321744 PMCID: PMC5733546 DOI: 10.3389/fphys.2017.01053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 12/01/2017] [Indexed: 12/26/2022] Open
Abstract
Nitric oxide (NO) generated from nitrite through nitrite reductase activity in red blood cells has been proposed to play a major role in hypoxic vasodilation. However, we have previously predicted from mathematical modeling that much more NO can be derived from tissue nitrite reductase activity than from red blood cell nitrite reductase activity. Evidence in the literature suggests that tissue nitrite reductase activity is associated with xanthine oxidoreductase (XOR) and/or aldehyde oxidoreductase (AOR). We investigated the role of XOR and AOR in nitrite-mediated vasodilation from computer simulations and from in vivo exteriorized rat mesentery experiments. Vasodilation responses to nitrite in the superfusion medium bathing the mesentery equilibrated with 5% O2 (normoxia) or zero O2 (hypoxia) at either normal or acidic pH were quantified. Experiments were also conducted following intraperitoneal (IP) injection of nitrite before and after inhibiting XOR with allopurinol or inhibiting AOR with raloxifene. Computer simulations for NO and O2 transport using reaction parameters reported in the literature were also conducted to predict nitrite-dependent NO production from XOR and AOR activity as a function of nitrite concentration, PO2 and pH. Experimentally, the largest arteriolar responses were found with nitrite >10 mM in the superfusate, but no statistically significant differences were found with hypoxic and acidic conditions in the superfusate. Nitrite-mediated vasodilation with IP nitrite injections was reduced or abolished after inhibiting XOR with allopurinol (p < 0.001). Responses to IP nitrite before and after inhibiting AOR with raloxifene were not as consistent. Our mathematical model predicts that under certain conditions, XOR and AOR nitrite reductase activity in tissue can significantly elevate smooth muscle cell NO and can serve as a compensatory pathway when endothelial NO production is limited by hypoxic conditions. Our theoretical and experimental results provide further evidence for a role of tissue nitrite reductases to contribute additional NO to compensate for reduced NO production by endothelial nitric oxide synthase during hypoxia. Our mathematical model demonstrates that under extreme hypoxic conditions with acidic pH, endogenous nitrite levels alone can be sufficient for a functionally significant increase in NO bioavailability. However, these conditions are difficult to achieve experimentally.
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Affiliation(s)
- Donald G Buerk
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - Yien Liu
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - Kelly A Zaccheo
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - Kenneth A Barbee
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - Dov Jaron
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
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Deryagin OG, Gavrilova SA, Gainutdinov KL, Golubeva AV, Andrianov VV, Yafarova GG, Buravkov SV, Koshelev VB. Molecular Bases of Brain Preconditioning. Front Neurosci 2017; 11:427. [PMID: 28790886 PMCID: PMC5524930 DOI: 10.3389/fnins.2017.00427] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/11/2017] [Indexed: 12/20/2022] Open
Abstract
Preconditioning of the brain induces tolerance to the damaging effects of ischemia and prevents cell death in ischemic penumbra. The development of this phenomenon is mediated by mitochondrial adenosine triphosphate-sensitive potassium (KATP+) channels and nitric oxide signaling (NO). The aim of this study was to investigate the dynamics of molecular changes in mitochondria after ischemic preconditioning (IP) and the effect of pharmacological preconditioning (PhP) with the KATP+-channels opener diazoxide on NO levels after ischemic stroke in rats. Immunofluorescence-histochemistry and laser-confocal microscopy were applied to evaluate the cortical expression of electron transport chain enzymes, mitochondrial KATP+-channels, neuronal and inducible NO-synthases, as well as the dynamics of nitrosylation and nitration of proteins in rats during the early and delayed phases of IP. NO cerebral content was studied with electron paramagnetic resonance (EPR) spectroscopy using spin trapping. We found that 24 h after IP in rats, there is a two-fold decrease in expression of mitochondrial KATP+-channels (p = 0.012) in nervous tissue, a comparable increase in expression of cytochrome c oxidase (p = 0.008), and a decrease in intensity of protein S-nitrosylation and nitration (p = 0.0004 and p = 0.001, respectively). PhP led to a 56% reduction of free NO concentration 72 h after ischemic stroke simulation (p = 0.002). We attribute this result to the restructuring of tissue energy metabolism, namely the provision of increased catalytic sites to mitochondria and the increased elimination of NO, which prevents a decrease in cell sensitivity to oxygen during subsequent periods of severe ischemia.
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Affiliation(s)
- Oleg G Deryagin
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Svetlana A Gavrilova
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Khalil L Gainutdinov
- Laboratory of Neurorehabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal UniversityKazan, Russia.,Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of SciencesKazan, Russia
| | - Anna V Golubeva
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Vyatcheslav V Andrianov
- Laboratory of Neurorehabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal UniversityKazan, Russia.,Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of SciencesKazan, Russia
| | - Guzel G Yafarova
- Laboratory of Neurorehabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal UniversityKazan, Russia.,Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of SciencesKazan, Russia
| | - Sergey V Buravkov
- Research Laboratory of Cellular Structure and Tissue Imaging Analysis, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
| | - Vladimir B Koshelev
- Department of Physiology and General Pathology, Medical Faculty, Lomonosov Moscow State UniversityMoscow, Russia
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10
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Vaos G, Zavras N. Antioxidants in experimental ischemia-reperfusion injury of the testis: Where are we heading towards? World J Methodol 2017; 7:37-45. [PMID: 28706858 PMCID: PMC5489422 DOI: 10.5662/wjm.v7.i2.37] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 04/07/2017] [Accepted: 05/15/2017] [Indexed: 02/06/2023] Open
Abstract
Testicular torsion (TT) is a medical emergency that primary affects newborns and young adolescents. It causes testicular injury due to the torsion of the spermatic cord and its components, initially in the venous blood flow and finally in the arterial blood flow. Prompt diagnosis and early surgical management are necessary in managing this urgent situation. The process of the pathophysiological events in ischemia-reperfusion is multifactorial and deals with the perception of the oxidative stress responsible for the consequences of ischemia/reperfusion (I/R) stress following TT. Duration and severity of torsion also play a significant role in the oxidative stress. A detrimental result of the defense system of the testes takes place resulting finally in testicular atrophy and impaired function. Antioxidant factors have been experimentally studied in an effort to front this state. They have been classified as endogenous or exogenous antioxidants. Endogenous antioxidants comprise a structure of enzymic enzymatic and non-enzymic enzymatic particles presented within cytoplasm and numerous other subunits in the cells. Exogenous antioxidants include a variety of natural and pharmaceutical agents that may prevent or ameliorate the harmful effects of I/R injury. In this study we review those factors and their ability to enhance the oxidative status of the testis. A feature insight into where we are heading is attempted.
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11
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Restini CBA, Gonçalves L. Nitric Oxide and Related Aspects Underlying Angina. Open Cardiovasc Med J 2017; 11:33-46. [PMID: 28567132 PMCID: PMC5418930 DOI: 10.2174/1874192401711010033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/10/2017] [Accepted: 02/27/2017] [Indexed: 01/08/2023] Open
Abstract
Increased number of patients affected by metabolic syndrome (MS) has prompted the necessity of better understanding what is involved in such syndrome. Nevertheless, the establishment of promising therapies depends on the knowledge about the interaction of molecules within MS. In such context, Nitric Oxide (NO) emerges from a bulk of works relating its roles on aspects of MS, including cardiovascular diseases, their symptoms and comorbidities, which are thought to be triggered by similar sources. NO, nitric oxide synthase and enzymatic chains are keys for those disease and symptoms processes. NO has been separately described as part of hypertensive, ischemic and pain signaling. Although there are similar pathways likely shared for generating cardiovascular symptoms such angina, they are barely associated to NO in literature. The present review aims to clarify the patterns of NO alteration in metabolic syndrome directly concerned to cardiovascular symptoms, especially angina.
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Affiliation(s)
- Carolina Baraldi Araujo Restini
- Biotechnology Dept. (Lab: Cardiorenal Pharmacology)/Medical School, University of Ribeirao Preto (UNAERP), Ribeirão Preto-SP, Brazil
| | - Leticia Gonçalves
- Biotechnology Dept. (Lab: Cardiorenal Pharmacology)/Medical School, University of Ribeirao Preto (UNAERP), Ribeirão Preto-SP, Brazil
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12
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Abstract
Ischemic disorders, such as myocardial infarction, stroke, and peripheral vascular disease, are the most common causes of debilitating disease and death in westernized cultures. The extent of tissue injury relates directly to the extent of blood flow reduction and to the length of the ischemic period, which influence the levels to which cellular ATP and intracellular pH are reduced. By impairing ATPase-dependent ion transport, ischemia causes intracellular and mitochondrial calcium levels to increase (calcium overload). Cell volume regulatory mechanisms are also disrupted by the lack of ATP, which can induce lysis of organelle and plasma membranes. Reperfusion, although required to salvage oxygen-starved tissues, produces paradoxical tissue responses that fuel the production of reactive oxygen species (oxygen paradox), sequestration of proinflammatory immunocytes in ischemic tissues, endoplasmic reticulum stress, and development of postischemic capillary no-reflow, which amplify tissue injury. These pathologic events culminate in opening of mitochondrial permeability transition pores as a common end-effector of ischemia/reperfusion (I/R)-induced cell lysis and death. Emerging concepts include the influence of the intestinal microbiome, fetal programming, epigenetic changes, and microparticles in the pathogenesis of I/R. The overall goal of this review is to describe these and other mechanisms that contribute to I/R injury. Because so many different deleterious events participate in I/R, it is clear that therapeutic approaches will be effective only when multiple pathologic processes are targeted. In addition, the translational significance of I/R research will be enhanced by much wider use of animal models that incorporate the complicating effects of risk factors for cardiovascular disease. © 2017 American Physiological Society. Compr Physiol 7:113-170, 2017.
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Affiliation(s)
- Theodore Kalogeris
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
| | - Christopher P. Baines
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
- Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine, Columbia, Missouri, USA
| | - Maike Krenz
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Ronald J. Korthuis
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
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Porpino SKP, Zollbrecht C, Peleli M, Montenegro MF, Brandão MCR, Athayde-Filho PF, França-Silva MS, Larsson E, Lundberg JO, Weitzberg E, Persson EG, Braga VA, Carlström M. Nitric oxide generation by the organic nitrate NDBP attenuates oxidative stress and angiotensin II-mediated hypertension. Br J Pharmacol 2016; 173:2290-302. [PMID: 27160064 DOI: 10.1111/bph.13511] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/11/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE NO deficiency and oxidative stress are crucially involved in the development or progression of cardiovascular disease, including hypertension and stroke. We have previously demonstrated that acute treatment with the newly discovered organic nitrate, 2-nitrate-1,3-dibuthoxypropan (NDBP), is associated with NO-like effects in the vasculature. This study aimed to further characterize the mechanism(s) and to elucidate the therapeutic potential in a model of hypertension and oxidative stress. EXPERIMENTAL APPROACH A combination of ex vivo, in vitro and in vivo approaches was used to assess the effects of NDBP on vascular reactivity, NO release, NADPH oxidase activity and in a model of hypertension. KEY RESULTS Ex vivo vascular studies demonstrated NDBP-mediated vasorelaxation in mesenteric resistance arteries, which was devoid of tolerance. In vitro studies using liver and kidney homogenates revealed dose-dependent and sustained NO generation by NDBP, which was attenuated by the xanthine oxidase inhibitor febuxostat. In addition, NDBP reduced NADPH oxidase activity in the liver and prevented angiotensin II-induced activation of NADPH oxidase in the kidney. In vivo studies showed that NDBP halted the progression of hypertension in mice with chronic angiotensin II infusion. This was associated with attenuated cardiac hypertrophy, and reduced NADPH oxidase-derived oxidative stress and fibrosis in the kidney and heart. CONCLUSION AND IMPLICATIONS The novel organic nitrate NDBP halts the progression of angiotensin II-mediated hypertension. Mechanistically, our findings suggest that NDBP treatment is associated with sustained NO release and attenuated activity of NADPH oxidase, which to some extent requires functional xanthine oxidase.
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Affiliation(s)
- Suênia K P Porpino
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden.,Biotechnology Center, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Christa Zollbrecht
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Peleli
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Maria C R Brandão
- Biotechnology Center, Federal University of Paraíba, João Pessoa, PB, Brazil
| | | | | | - Erik Larsson
- Dept. of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Jon O Lundberg
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Eddie Weitzberg
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Erik G Persson
- Dept. of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Valdir A Braga
- Biotechnology Center, Federal University of Paraíba, João Pessoa, PB, Brazil
| | - Mattias Carlström
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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14
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Matsumoto A. [Fundamental Properties of Aldehyde Dehydrogenase 2 (ALDH2) and the Importance of the ALDH2 Polymorphism]. Nihon Eiseigaku Zasshi 2016; 71:55-68. [PMID: 26832618 DOI: 10.1265/jjh.71.55] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Human aldehyde dehydrogenase 2 (ALDH2) is a 56 kDa mitochondrial protein that forms homodimers through hydrogen bonding interactions between the Glu487 and Arg475 residues of two ALDH2 proteins. Two ALDH2 homodimers can interact to form an ALDH2 tetramer. ALDH2 is widely distributed throughout the organs of the body. In addition to its dehydrogenase activity, ALDH2 also exhibits esterase and reductase activities, with the main substrates for these three activities being aldehydes, 4-nitrophenyl acetate and nitroglycerin, respectively. ALDH2 can be readily inhibited by a wide variety of endogenous and exogenous chemicals, but the induction or activation of this enzyme remains unlikely. The polymorphism of ALDH2 to the corresponding ALDH2*2 variant results in a severe deficiency in ALDH2 activity, and this particular polymorphism is prevalent among people of Mongoloid descent. It seems reasonable to expect that people with the ALDH2*2 variant would be more vulnerable to stress and diseases because ALDH2 defends the human body against toxic aldehydes. However, it has been suggested that people with the ALDH2*2 variant are protected by alternative stress-defending systems. The ALDH2*2 variant has been reported to be associated with many different kinds of diseases, although the mechanisms underlying these associations have not yet been elucidated. ALDH2 polymorphism has a significant impact on human health; further studies are therefore required to determine the practical implications of this polymorphism in the fields of preventive and clinical medicine.
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Affiliation(s)
- Akiko Matsumoto
- Department of Social Medicine, Saga University School of Medicine
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15
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Shu X, Keller TCS, Begandt D, Butcher JT, Biwer L, Keller AS, Columbus L, Isakson BE. Endothelial nitric oxide synthase in the microcirculation. Cell Mol Life Sci 2015; 72:4561-75. [PMID: 26390975 PMCID: PMC4628887 DOI: 10.1007/s00018-015-2021-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/21/2015] [Accepted: 08/11/2015] [Indexed: 02/07/2023]
Abstract
Endothelial nitric oxide synthase (eNOS, NOS3) is responsible for producing nitric oxide (NO)--a key molecule that can directly (or indirectly) act as a vasodilator and anti-inflammatory mediator. In this review, we examine the structural effects of regulation of the eNOS enzyme, including post-translational modifications and subcellular localization. After production, NO diffuses to surrounding cells with a variety of effects. We focus on the physiological role of NO and NO-derived molecules, including microvascular effects on vessel tone and immune response. Regulation of eNOS and NO action is complicated; we address endogenous and exogenous mechanisms of NO regulation with a discussion of pharmacological agents used in clinical and laboratory settings and a proposed role for eNOS in circulating red blood cells.
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Affiliation(s)
- Xiaohong Shu
- College of Pharmacy, Dalian Medical University, Dalian, 116044, China
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
| | - T C Stevenson Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, USA
| | - Daniela Begandt
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
| | - Joshua T Butcher
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
| | - Lauren Biwer
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, USA
| | - Alexander S Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, USA
| | - Linda Columbus
- Department of Chemistry, University of Virginia, Charlottesville, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, P.O. Box 801394, Charlottesville, VA, 22908, USA.
- Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, USA.
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16
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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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17
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Liu M, Zollbrecht C, Peleli M, Lundberg JO, Weitzberg E, Carlström M. Nitrite-mediated renal vasodilatation is increased during ischemic conditions via cGMP-independent signaling. Free Radic Biol Med 2015; 84:154-160. [PMID: 25841777 DOI: 10.1016/j.freeradbiomed.2015.03.025] [Citation(s) in RCA: 27] [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: 01/13/2015] [Revised: 03/17/2015] [Accepted: 03/23/2015] [Indexed: 11/16/2022]
Abstract
The kidney is vulnerable to hypoxia, and substantial efforts have been made to ameliorate renal ischemic injury secondary to pathological conditions. Stimulation of the nitrate-nitrite-nitric oxide pathway is associated with renal and cardiovascular protection in disease models, but less is known about the vascular effects during renal ischemia. This study was aimed at investigating the vascular effects of nitrite in the kidney during normoxic and ischemic conditions. Using a multiwire myograph system, we assessed nitrite-mediated relaxation (10(-9)-10(-4)mol/L) in isolated and preconstricted renal interlobar arteries from C57BL/6 mice under normal conditions (pO2 13kPa; pH 7.4) and with low oxygen tension and low pH to mimic ischemia (pO2 3kPa; pH 6.6). Xanthine oxidoreductase expression was analyzed by quantitative PCR, and production of reactive nitrogen species was measured by DAF-FM DA fluorescence. During normoxia significant vasodilatation (15±3%) was observed only at the highest concentration of nitrite, which was dependent on NO-sGC-cGMP signaling. The vasodilatory responses to nitrite were greatly sensitized and enhanced during hypoxia with low pH, demonstrating significant dilatation (11±1%) already in the physiological range (10(-8)mol/L), with a maximum response of 27±2% at 10(-4) mol/L. In contrast to normoxia, and to that observed with a classical NO donor (DEA NONOate), this sensitization was independent of sGC-cGMP signaling. Moreover, inhibition of various enzymatic systems reported to reduce nitrite in other vascular beds, i.e., aldehyde oxidase (raloxifene), aldehyde dehydrogenase (cyanamide), and NO synthase (L-NAME), had no effect on the nitrite response. However, inhibition of xanthine oxidoreductase (XOR; febuxostat or allopurinol) abolished the sensitized response to nitrite during hypoxia and acidosis. In conclusion, in contrast to normoxia, nitrite exerted potent vasorelaxation during ischemic conditions already at physiological concentrations. This effect was dependent on functional XOR but independent of classical downstream signaling by sGC-cGMP.
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Affiliation(s)
- Ming Liu
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Christa Zollbrecht
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Maria Peleli
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Jon O Lundberg
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Eddie Weitzberg
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden
| | - Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, S-17177 Stockholm, Sweden.
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18
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Arif S, Borgognone A, Lin ELS, O'Sullivan AG, Sharma V, Drury NE, Menon A, Nightingale P, Mascaro J, Bonser RS, Horowitz JD, Feelisch M, Frenneaux MP, Madhani M. Role of aldehyde dehydrogenase in hypoxic vasodilator effects of nitrite in rats and humans. Br J Pharmacol 2015; 172:3341-52. [PMID: 25754766 PMCID: PMC4500370 DOI: 10.1111/bph.13122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/09/2015] [Accepted: 02/27/2015] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Hypoxic conditions favour the reduction of nitrite to nitric oxide (NO) to elicit vasodilatation, but the mechanism(s) responsible for bioconversion remains ill defined. In the present study, we assess the role of aldehyde dehydrogenase 2 (ALDH2) in nitrite bioactivation under normoxia and hypoxia in the rat and human vasculature. EXPERIMENTAL APPROACH The role of ALDH2 in vascular responses to nitrite was studied using rat thoracic aorta and gluteal subcutaneous fat resistance vessels from patients with heart failure (HF; 16 patients) in vitro and by measurement of changes in forearm blood flow (FBF) during intra-arterial nitrite infusion (21 patients) in vivo. Specifically, we investigated the effects of (i) ALDH2 inhibition by cyanamide or propionaldehyde and the (ii) tolerance-independent inactivation of ALDH2 by glyceryl trinitrate (GTN) on the vasodilator activity of nitrite. In each setting, nitrite effects were measured via evaluation of the concentration-response relationship under normoxic and hypoxic conditions in the absence or presence of ALDH2 inhibitors. KEY RESULTS Both in rat aorta and human resistance vessels, dilatation to nitrite was diminished following ALDH2 inhibition, in particular under hypoxia. In humans there was a non-significant trend towards attenuation of nitrite-mediated increases in FBF. CONCLUSIONS AND IMPLICATIONS In human and rat vascular tissue in vitro, hypoxic nitrite-mediated vasodilatation involves ALDH2. In patients with HF in vivo, the role of this enzyme in nitrite bioactivation is at the most, modest, suggesting the involvement of other more important mechanisms.
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Affiliation(s)
- Sayqa Arif
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Alessandra Borgognone
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Erica Lai-Sze Lin
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Aine G O'Sullivan
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Vishal Sharma
- Department of Cardiology, Royal Liverpool University Hospital, Liverpool, UK
| | - Nigel E Drury
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Ashvini Menon
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Peter Nightingale
- Wellcome Trust Clinical Research Facility, Queen Elizabeth Hospital, Edgbaston, Birmingham, UK
| | - Jorge Mascaro
- Department of Cardiothoracic Surgery, Queen Elizabeth Hospital, University Hospitals Birmingham, Edgbaston, Birmingham, UK
| | - Robert S Bonser
- Department of Cardiothoracic Surgery, Queen Elizabeth Hospital, University Hospitals Birmingham, Edgbaston, Birmingham, UK
| | - John D Horowitz
- Basil Hetzel Institute, Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Martin Feelisch
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | | | - Melanie Madhani
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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19
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Apostoli GL, Solomon A, Smallwood MJ, Winyard PG, Emerson M. Role of inorganic nitrate and nitrite in driving nitric oxide-cGMP-mediated inhibition of platelet aggregation in vitro and in vivo. J Thromb Haemost 2014; 12:1880-9. [PMID: 25163536 DOI: 10.1111/jth.12711] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 08/20/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Nitric oxide (NO) is a critical negative regulator of platelets that is implicated in the pathology of thrombotic diseases. Platelets generate NO, but the presence and functional significance of NO synthase (NOS) in platelets is unclear. Inorganic nitrate/nitrite is increasingly being recognized as a source of bioactive NO, although its role in modulating platelets during health and vascular dysfunction is incompletely understood. METHODS We investigated the functional significance and upstream sources of NO-cGMP signaling events in platelets by using established methods for assessing in vitro and in vivo platelet aggregation, and assessed the bioconversion of inorganic nitrate to nitrite during deficiency of endothelial NOS (eNOS). RESULTS The phosphodiesterase 5 (PDE5) inhibitor sildenafil inhibited human platelet aggregation in vitro. This inhibitory effect was abolished by a guanylyl cyclase inhibitor and NO scavengers, but unaffected by NOS inhibition. Inorganic nitrite drove cGMP-mediated inhibition of human platelet aggregation in vitro and nitrate inhibited platelet function in eNOS(-/-) mice in vivo in a model of thromboembolic radiolabeled platelet aggregation associated with an enhanced plasma nitrite concentration as compared with wild-type mice. CONCLUSIONS Platelets generate transient, endogenous cGMP signals downstream of NO that are primarily independent of NOS and may be enhanced by inhibition of PDE5. Furthermore, nitrite can generate transient NO-cGMP signals in platelets. The absence of eNOS leads to enhanced plasma nitrite levels following nitrate administration in vivo, which negatively impacts on platelet function. Our data suggest that inorganic nitrate exerts an antiplatelet effect during eNOS deficiency, and, potentially, that dietary nitrate may reduce platelet hyperactivity during endothelial dysfunction.
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Affiliation(s)
- G L Apostoli
- Platelet Biology Group, Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, UK
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20
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Bailey JC, Feelisch M, Horowitz JD, Frenneaux MP, Madhani M. Pharmacology and therapeutic role of inorganic nitrite and nitrate in vasodilatation. Pharmacol Ther 2014; 144:303-20. [PMID: 24992304 DOI: 10.1016/j.pharmthera.2014.06.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 06/25/2014] [Indexed: 02/07/2023]
Abstract
Nitrite has emerged as an important bioactive molecule that can be biotransformed to nitric oxide (NO) related metabolites in normoxia and reduced to NO under hypoxic and acidic conditions to exert vasodilatory effects and confer a variety of other benefits to the cardiovascular system. Abundant research is currently underway to understand the mechanisms involved and define the role of nitrite in health and disease. In this review we discuss the impact of nitrite and dietary nitrate on vascular function and the potential therapeutic role of nitrite in acute heart failure.
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Affiliation(s)
- J C Bailey
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, UK
| | - M Feelisch
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - J D Horowitz
- The Queen Elizabeth Hospital, Adelaide, Australia
| | - M P Frenneaux
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - M Madhani
- Centre for Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, UK.
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21
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Kim-Shapiro DB, Gladwin MT. Mechanisms of nitrite bioactivation. Nitric Oxide 2014; 38:58-68. [PMID: 24315961 PMCID: PMC3999231 DOI: 10.1016/j.niox.2013.11.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 11/19/2013] [Accepted: 11/21/2013] [Indexed: 12/18/2022]
Abstract
It is now accepted that the anion nitrite, once considered an inert oxidation product of nitric oxide (NO), contributes to hypoxic vasodilation, physiological blood pressure control, and redox signaling. As such, its application in therapeutics is being actively tested in pre-clinical models and in human phase I-II clinical trials. Major pathways for nitrite bioactivation involve its reduction to NO by members of the hemoglobin or molybdopterin family of proteins, or catalyzed dysproportionation. These conversions occur preferentially under hypoxic and acidic conditions. A number of enzymatic systems reduce nitrite to NO and their activity and importance are defined by oxygen tension, specific organ system and allosteric and redox effectors. In this work, we review different proposed mechanisms of nitrite bioactivation, focusing on analysis of kinetics and experimental evidence for the relevance of each mechanism under different conditions.
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Affiliation(s)
- Daniel B Kim-Shapiro
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109, United States; Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, United States.
| | - Mark T Gladwin
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, United States; Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15213, United States.
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22
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Omar SA, Artime E, Webb AJ. A comparison of organic and inorganic nitrates/nitrites. Nitric Oxide 2012; 26:229-40. [PMID: 22491087 DOI: 10.1016/j.niox.2012.03.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 02/15/2012] [Accepted: 03/22/2012] [Indexed: 11/19/2022]
Abstract
Although both organic and inorganic nitrates/nitrites mediate their principal effects via nitric oxide, there are many important differences. Inorganic nitrate and nitrite have simple ionic structures and are produced endogenously and are present in the diet, whereas their organic counterparts are far more complex, and, with the exception of ethyl nitrite, are all medicinally synthesised products. These chemical differences underlie the differences in pharmacokinetic properties allowing for different modalities of administration, particularly of organic nitrates, due to the differences in their bioavailability and metabolic profiles. Whilst the enterosalivary circulation is a key pathway for orally ingested inorganic nitrate, preventing an abrupt effect or toxic levels of nitrite and prolonging the effects, this is not used by organic nitrates. The pharmacodynamic differences are even greater; while organic nitrates have potent acute effects causing vasodilation, inorganic nitrite's effects are more subtle and dependent on certain conditions. However, in chronic use, organic nitrates are considerably limited by the development of tolerance and endothelial dysfunction, whereas inorganic nitrate/nitrite may compensate for diminished endothelial function, and tolerance has not been reported. Also, while inorganic nitrate/nitrite has important cytoprotective effects against ischaemia-reperfusion injury, continuous use of organic nitrates may increase injury. While there are concerns that inorganic nitrate/nitrite may induce carcinogenesis, direct evidence of this in humans is lacking. While organic nitrates may continue to dominate the therapeutic arena, this may well change with the increasing recognition of their limitations, and ongoing discovery of beneficial effects and specific advantages of inorganic nitrate/nitrite.
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Affiliation(s)
- Sami A Omar
- King's College London British Heart Foundation Centre, Cardiovascular Division, Department of Clinical Pharmacology, London, UK
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23
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Nossaman BD, Pankey EA, Badejo AR, Casey DB, Uppu S, Murthy SN, Kadowitz PJ. Analysis of responses to glyceryl trinitrate and sodium nitrite in the intact chest rat. Nitric Oxide 2012; 26:223-8. [PMID: 22465477 DOI: 10.1016/j.niox.2012.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 02/17/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
Abstract
Responses to glyceryl trinitrate/nitroglycerin (GTN), S-nitrosoglutathione (GSNO), and sodium nitrite were compared in the intact chest rat. The iv injections of GTN, sodium nitrite, and GSNO produced dose-dependent decreases in pulmonary and systemic arterial pressures. In as much as cardiac output was not reduced, the decreases in pulmonary and systemic arterial pressures indicate that GTN, sodium nitrite, and GSNO have significant vasodilator activity in the pulmonary and systemic vascular beds in the rat. Responses to GTN were attenuated by cyanamide, but not allopurinol, whereas responses to nitrite formed by the metabolism of GTN were attenuated by allopurinol and cyanamide. The results with allopurinol and cyanamide suggest that only mitochondrial aldehyde dehydrogenase is involved in the bioactivation of GTN, sodium nitrite, and GSNO, whereas both pathways are involved in the bioactivation of nitrite anion in the intact rat. The comparison of vasodilator activity indicates that GSNO and GTN are more than 1000-fold more potent than sodium nitrite in decreasing pulmonary and systemic arterial pressures in the rat. Following administration of 1H-[1,2,4]-oxadizaolo[4,3-]quinoxaline-1-one (ODQ), responses to GTN were significantly attenuated, indicating that responses are mediated by the activation of soluble guanylyl cyclase. These data suggest that the reduction of nitrite to nitric oxide formed from the metabolism of GTN, cannot account for the vasodilator activity of GTN in the intact rat and that another mechanism; perhaps the formation of an S-NO, may mediate the vasodilator response to GTN in this species.
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Affiliation(s)
- Bobby D Nossaman
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112-2699, USA
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24
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Pankey EA, Badejo AM, Casey DB, Lasker GF, Riehl RA, Murthy SN, Nossaman BD, Kadowitz PJ. Effect of chronic sodium nitrite therapy on monocrotaline-induced pulmonary hypertension. Nitric Oxide 2012; 27:1-8. [PMID: 22426035 DOI: 10.1016/j.niox.2012.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 02/25/2012] [Accepted: 02/27/2012] [Indexed: 11/28/2022]
Abstract
Pulmonary hypertension (PH) is a rare disorder that without treatment is progressive and often fatal within 3 years. The treatment of PH involves the use of a diverse group of drugs and lung transplantation. Although nitrite was once thought to be an inactive metabolite of endothelial-derived nitric oxide (NO), there is increasing evidence that nitrite may be useful in the treatment of PH, but the mechanism by which nitrite exerts its beneficial effect remains uncertain. The purpose of this study was to investigate the effect of chronic sodium nitrite treatment in a PH model in the rat. Following induction of PH with a single injection of monocrotaline, 60 mg; daily ip injections of sodium nitrite (3mg/kg) starting on day 14 and continuing for 21 days, resulted in a significantly lower pulmonary arterial pressure on day 35 when compared to values in untreated animals with monocrotaline-induced PH. In monocrotaline-treated rats, daily treatment with ip nitrite injections for 21 days decreased right ventricular mass and pathologic changes in small pulmonary arteries. Nitrite therapy did not change systemic arterial pressure or cardiac output when values were measured on day 35. The decreases in pulmonary arterial pressure in response to iv injections of sodium nitroprusside, sodium nitrite, and BAY 41-8543 were not different in rats with monocrotaline-induced pulmonary hypertension and rats with chronic nitrite therapy when compared to responses in animals in which pulmonary arterial pressure was increased with U46619. These findings are consistent with the hypothesis that the mechanisms that convert nitrite to vasoactive NO, activate soluble guanylyl cyclase and mediate the vasodilator response to NO or an NO derivative are not impaired. The present data are consistent with the results of a previous study in monocrotaline-induced PH in which systemic arterial pressure and cardiac output were not evaluated and are consistent with the hypothesis that nitrite is effective in the treatment of monocrotaline-induced PH in the rodent.
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Affiliation(s)
- Edward A Pankey
- Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112-2699, USA
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25
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Stefano GB, Kream RM. Reciprocal regulation of cellular nitric oxide formation by nitric oxide synthase and nitrite reductases. Med Sci Monit 2012; 17:RA221-6. [PMID: 21959625 PMCID: PMC3539480 DOI: 10.12659/msm.881972] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Our mini-review focuses on dual regulation of cellular nitric oxide (NO) signaling pathways by traditionally characterized enzymatic formation from L-arginine via the actions of NO synthases (NOS) and by enzymatic reduction of available cellular nitrite pools by a diverse class of cytosolic and mitochondrial nitrite reductases. Nitrite is a major metabolic product of NO and is found in all cell and tissue types that utilize NO signaling processes. Xanthine oxidoreductase (XOR) has been previously characterized as a housekeeping enzyme responsible for cellular uric acid formation via enzymatic conversion of hypoxanthine and xanthine. It has become apparent that XOR possesses multi-functional enzymatic activities outside the realm of xanthine metabolism and a small but significant literature also established a compelling functional association between administered sodium nitrite, XOR activation, and pharmacologically characterized NO transductive effects in positive cardiovascular function enhanced pulmonary perfusion, and protection against ischemia/reperfusion injury and hypoxic damage and oxidative stress. Similar positive vascular and cellular effects were observed to be functionally associated with mitochondrial aldehyde dehydrogenase and cytochrome c/cytochrome c oxidase. The profound implications of a reciprocal regulatory mechanism responsible for cytosolic and mitochondrial NO production are discussed below.
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Affiliation(s)
- George B Stefano
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, NY 11568-0210, USA.
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26
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Kalogeris T, Baines CP, Krenz M, Korthuis RJ. Cell biology of ischemia/reperfusion injury. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 298:229-317. [PMID: 22878108 PMCID: PMC3904795 DOI: 10.1016/b978-0-12-394309-5.00006-7] [Citation(s) in RCA: 1405] [Impact Index Per Article: 117.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Disorders characterized by ischemia/reperfusion (I/R), such as myocardial infarction, stroke, and peripheral vascular disease, continue to be among the most frequent causes of debilitating disease and death. Tissue injury and/or death occur as a result of the initial ischemic insult, which is determined primarily by the magnitude and duration of the interruption in the blood supply, and then subsequent damage induced by reperfusion. During prolonged ischemia, ATP levels and intracellular pH decrease as a result of anaerobic metabolism and lactate accumulation. As a consequence, ATPase-dependent ion transport mechanisms become dysfunctional, contributing to increased intracellular and mitochondrial calcium levels (calcium overload), cell swelling and rupture, and cell death by necrotic, necroptotic, apoptotic, and autophagic mechanisms. Although oxygen levels are restored upon reperfusion, a surge in the generation of reactive oxygen species occurs and proinflammatory neutrophils infiltrate ischemic tissues to exacerbate ischemic injury. The pathologic events induced by I/R orchestrate the opening of the mitochondrial permeability transition pore, which appears to represent a common end-effector of the pathologic events initiated by I/R. The aim of this treatise is to provide a comprehensive review of the mechanisms underlying the development of I/R injury, from which it should be apparent that a combination of molecular and cellular approaches targeting multiple pathologic processes to limit the extent of I/R injury must be adopted to enhance resistance to cell death and increase regenerative capacity in order to effect long-lasting repair of ischemic tissues.
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Affiliation(s)
- Theodore Kalogeris
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, USA
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27
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Sakata S, Yoshihara T, Arima H, Shiraishi F, Oniki H, Takahashi-Yanaga F, Matsumura K, Sasaguri T. Differential effects of organic nitrates on arterial diameter among healthy Japanese participants with different mitochondrial aldehyde dehydrogenase 2 genotypes: randomised crossover trial. BMJ Open 2011; 1:e000133. [PMID: 22021773 PMCID: PMC3191425 DOI: 10.1136/bmjopen-2011-000133] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES To determine whether polymorphisms at codon 487 (*1, GAA=Glu; *2, AAA=Lys) of mitochondrial aldehyde dehydrogenase 2 (ALDH2) influence nitroglycerine (glyceryl trinitrate (GTN))-induced vasodilation, and whether GTN or isosorbide dinitrate (ISDN) is a more effective antianginal agent in each ALDH2 genotype. DESIGN A randomised, open-label, crossover trial with 117 healthy Japanese (20-39 years) whose genotypes were determined (*1/*1, n=47; *1/*2, n=48; *2/*2, n=22) was performed at Kyushu University Hospital, Fukuoka, Japan. Participants were randomly assigned to treatment: sublingual spray of GTN (0.3 mg) or ISDN (1.25 mg). After ≥ 1 week, measurements were repeated using the other drug. The main outcome measures were the maximal rate of increase in the brachial artery diameter determined by ultrasonography, the time required to attain maximal dilation (T(max)) and the time required to attain 90% maximal dilation (T(0.9)). RESULTS The maximal artery diameter increase in response to GTN or ISDN did not differ among genotypes. However, GTN T(max) was significantly longer for *2/*2 (299.7 s, 269.0-330.4) than *1/*1 (254.7 s, 238.6-273.4; p=0.0190). GTN T(0.9) was significantly longer in the *1/*2 (206.1 s, 191.7-219.3) and *2/*2 (231.4 s, 211.8-251.0) genotypes than *1/*1 (174.9 s, 161.5-188.3; p=0.0068, p<0.0001, respectively). In contrast, the time-course of ISDN-induced vasodilation did not differ among genotypes. GTN T(max) and T(0.9) among *1 allele carriers (*1/*1 and *1/*2) were significantly shorter than those of ISDN, whereas the time course of GTN and ISDN vasodilation did not differ among participants carrying *2/*2. CONCLUSIONS The amplitude of GTN-induced vasodilation was not influenced by the ALDH2 genotype, but the response was significantly delayed in *2 allele carriers, especially *2/*2. GTN dilated the artery more quickly than ISDN in *1/*1 and *1/*2, but not in *2/*2. Trial registration number UMIN000001492 (UMIN-CTR database).
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Affiliation(s)
- Satoko Sakata
- Department of Medicine and Clinical Science, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tatsuya Yoshihara
- Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hisatomi Arima
- George Institute for Global Health, The University of Sydney, Sydney, Australia
| | - Fumie Shiraishi
- Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hideyuki Oniki
- Department of Medicine and Clinical Science, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Fumi Takahashi-Yanaga
- Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kiyoshi Matsumura
- Department of Medicine and Clinical Science, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toshiyuki Sasaguri
- Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
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28
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Abstract
The organic nitrite, amyl of nitrite, was initially used as a therapeutic agent in the treatment of angina pectoris, but was replaced over a decade later by the organic nitrate, nitroglycerin (NTG), due to the ease of administration and longer duration of action. The administration of organic nitrate esters, such as NTG, continues to be used in the treatment of angina pectoris and heart failure since the birth of modern pharmacology. Their clinical effectiveness is due to vasodilator activity in large veins and arteries through an as yet unidentified method of delivering nitric oxide (NO), or a NO-like compound. The major drawback is the development of tolerance with NTG, and the duration and route of administration with amyl of nitrite. Although the nitrites are no longer used in the treatment of hypertension or ischemic heart disease, the nitrite anion has recently been discovered to possess novel pharmacologic actions, such as modulating hypoxic vasodilation, and providing cytoprotection in ischemia-reperfusion injury. Although the actions of these 2 similar chemical classes (nitrites and organic nitrates) have often been considered to be alike, we still do not understand their mechanism of action. Finally, the nitrite anion, either from sodium nitrite or an intermediate NTG form, may act as a storage form for NO and provide support for investigating the use of these agents in the treatment of ischemic cardiovascular states. We review what is presently known about the use of nitrates and nitrites including the historical, current, and potential uses of these agents, and their mechanisms of action.
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29
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Gilchrist M, Shore AC, Benjamin N. Inorganic nitrate and nitrite and control of blood pressure. Cardiovasc Res 2010; 89:492-8. [PMID: 20884639 DOI: 10.1093/cvr/cvq309] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Continual nitric oxide (NO) synthesis is important in the regulation of vascular tone and thus blood pressure. Whereas classically NO is provided by the enzymatic oxidation of l-arginine via endothelial NO synthase, it is now clear that NO can also be generated in mammals from the reduction of nitrite and nitrate. Thus inorganic nitrate derived either from NO oxidation or from dietary sources may be an important storage form of reactive nitrogen oxides which can be reduced back to nitrite and NO when physiologically required or in pathological conditions. The very short half-life of NO and the ready availability of stored nitrite and nitrate make for a very sensitive and responsive blood pressure control system. This review will examine processes by which these storage forms are produced and how augmentation of dietary nitrate intake may have a beneficial effect on blood pressure and other vascular function in humans.
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Affiliation(s)
- Mark Gilchrist
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Science, Peninsula College of Medicine and Dentistry, University of Exeter, Barrack Road, Exeter EX2 5AX, UK.
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30
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Lasker GF, Matt CJ, Badejo, Jr. AM, Casey DB, Dhaliwal JS, Murthy SN, Kadowitz PJ. Intracavernosal administration of sodium nitrite as an erectile pharmacotherapy. Can J Physiol Pharmacol 2010; 88:770-6. [DOI: 10.1139/y10-032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
It has been reported that sodium nitrite (NaNO2) can act as a storage form of nitric oxide (NO) that can have beneficial pharmacologic actions. The present study was undertaken to investigate the effects of NaNO2 on erectile function in the rat. The intracavernosal (i.c.) injection of NaNO2 produced dose-related increases in i.c. pressure and decreases in systemic arterial pressure. NaNO2 was 1000-fold less potent than sodium nitroprusside in increasing i.c. pressure. Increases in i.c. pressure in response to NaNO2 were attenuated by the nitric oxide synthase (NOS) inhibitor N-nitro-l-arginine methyl ester (l-NAME). The increases in i.c. pressure in response to NaNO2 were not altered by the xanthine oxidoreductase inhibitor allopurinol. The decreases in systemic arterial pressure in response to i.c. injections of NaNO2 were attenuated by allopurinol and were either unchanged or increased by l-NAME. These data suggest that NaNO2 is converted to vasoactive NO in the corpora cavernosum and systemic vascular bed of the rat by different mechanisms. The present data suggest that the conversion of NaNO2 to vasoactive NO is mediated by NOS in the corpora cavernosum and by xanthine oxidoreductase in the systemic vascular bed of the rat. These data show NaNO2 can serve as a NO donor that increases erectile activity in the rat.
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Affiliation(s)
- George F. Lasker
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
| | - Christopher J. Matt
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
| | - Adeleke M. Badejo, Jr.
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
| | - David B. Casey
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
| | - Jasdeep S. Dhaliwal
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
| | - Subramanyam N. Murthy
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
| | - Philip J. Kadowitz
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, SL83, New Orleans, LA 70112-2699, USA
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31
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Badejo AM, Hodnette C, Dhaliwal JS, Casey DB, Pankey E, Murthy SN, Nossaman BD, Hyman AL, Kadowitz PJ. Mitochondrial aldehyde dehydrogenase mediates vasodilator responses of glyceryl trinitrate and sodium nitrite in the pulmonary vascular bed of the rat. Am J Physiol Heart Circ Physiol 2010; 299:H819-26. [PMID: 20543077 DOI: 10.1152/ajpheart.00959.2009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been reported that mitochondrial aldehyde dehydrogenase (ALDH2) catalyzes the formation of glyceryl dinitrate and inorganic nitrite from glyceryl trinitrate (GTN), leading to an increase in cGMP and vasodilation in the coronary and systemic vascular beds. However, the role of nitric oxide (NO) formed from nitrite in mediating the response to GTN in the pulmonary vascular bed is uncertain. The purpose of the present study was to determine if nitrite plays a role in mediating vasodilator responses to GTN. In this study, intravenous injections of GTN and sodium nitrite decreased pulmonary and systemic arterial pressures and increased cardiac output. The decreases in pulmonary arterial pressure under baseline and elevated tone conditions and decreases in systemic arterial pressure in response to GTN and sodium nitrite were attenuated by cyanamide, an ALDH2 inhibitor, whereas responses to the NO donor, sodium nitroprusside (SNP), were not altered. The decreases in pulmonary and systemic arterial pressure in response to GTN and SNP were not altered by allopurinol, an inhibitor of xanthine oxidoreductase, whereas responses to sodium nitrite were attenuated. GTN was approximately 1,000-fold more potent than sodium nitrite in decreasing pulmonary and systemic arterial pressures. These results suggest that ALDH2 plays an important role in the bioactivation of GTN and nitrite in the pulmonary and systemic vascular beds and that the reduction of nitrite to vasoactive NO does not play an important role in mediating vasodilator responses to GTN in the intact chest rat.
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Affiliation(s)
- Adeleke M Badejo
- Department of Pharmacology, Tulane University School of Medicine, New Orleans 70112-2699, USA
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