Antioxidant pyruvate inhibits cardiac formation of reactive oxygen species through changes in redox state

2000 ◽  
Vol 279 (5) ◽  
pp. H2431-H2438 ◽  
Author(s):  
Eberhard Bassenge ◽  
Olaf Sommer ◽  
Michael Schwemmer ◽  
Rolf Bünger
Keyword(s):  
Reactive Oxygen Species ◽  
Xanthine Oxidase ◽  
Nadh Oxidase ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Oxidase Inhibitor ◽  
Oxygen Species ◽  
Xanthine Oxidase Inhibitor ◽  
Ros Formation ◽  
Myocardial Ischemia Reperfusion

Myocardial ischemia-reperfusion is associated with bursts of reactive oxygen species (ROS) such as superoxide radicals (O2 −·). Membrane-associated NADH oxidase (NADHox) activity is a hypothetical source of O2 −·, implying the NADH concentration-to-NAD+ concentration ratio ([NADH]/[NAD+]) as a determinant of ROS. To test this hypothesis, cardiac NADHox and ROS formation were measured as influenced by pyruvate or l-lactate. Pre- and postischemic Langendorff guinea pig hearts were perfused at different pyruvate/l-lactate concentrations to alter cytosolic [NADH]/[NAD+]. NADHox and ROS were measured with the use of lucigenin chemiluminescence and electron spin resonance, respectively. In myocardial homogenates, pyruvate (0.05, 0.5 mM) and the NADHox blocker hydralazine markedly inhibited NADHox (16 ± 2%, 58 ± 9%). In postischemic hearts, pyruvate (0.1–5.0 mM) dose dependently inhibited ROS up to 80%. However,l-lactate (1.0–15.0 mM) stimulated both basal and postischemic ROS severalfold. Furthermore,l-lactate-induced basal ROS was dose dependently inhibited by pyruvate (0.1–5.0 mM) and not the xanthine oxidase inhibitor oxypurinol. Pyruvate did not inhibit ROS from xanthine oxidase. The data suggest a substantial influence of cytosolic NADH on cardiac O2 −· formation that can be inhibited by submillimolar pyruvate. Thus cytotoxicities due to cardiac ischemia-reperfusion ROS may be alleviated by redox reactants such as pyruvate.

scholarly journals Molecular Characterization of Reactive Oxygen Species in Myocardial Ischemia-Reperfusion Injury

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tingyang Zhou ◽  
Chia-Chen Chuang ◽  
Li Zuo
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Ischemia ◽  
Energy Demand ◽  
Heart Diseases ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
High Energy ◽  
Protective Mechanism ◽  
Oxygen Species ◽  
Myocardial Ischemia Reperfusion

Myocardial ischemia-reperfusion (I/R) injury is experienced by individuals suffering from cardiovascular diseases such as coronary heart diseases and subsequently undergoing reperfusion treatments in order to manage the conditions. The occlusion of blood flow to the tissue, termed ischemia, can be especially detrimental to the heart due to its high energy demand. Several cellular alterations have been observed upon the onset of ischemia. The danger created by cardiac ischemia is somewhat paradoxical in that a return of blood to the tissue can result in further damage. Reactive oxygen species (ROS) have been studied intensively to reveal their role in myocardial I/R injury. Under normal conditions, ROS function as a mediator in many cell signaling pathways. However, stressful environments significantly induce the generation of ROS which causes the level to exceed body’s antioxidant defense system. Such altered redox homeostasis is implicated in myocardial I/R injury. Despite the detrimental effects from ROS, low levels of ROS have been shown to exert a protective effect in the ischemic preconditioning. In this review, we will summarize the detrimental role of ROS in myocardial I/R injury, the protective mechanism induced by ROS, and potential treatments for ROS-related myocardial injury.

Intracellular generation of reactive oxygen species in endothelial cells exposed to anoxia-reoxygenation

1997 ◽  
Vol 272 (5) ◽  
pp. L897-L902 ◽  
Author(s):  
J. J. Zulueta ◽  
R. Sawhney ◽  
F. S. Yu ◽  
C. C. Cote ◽  
P. M. Hassoun
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Intracellular Ros ◽  
Ros Formation ◽  
Oxide Synthase

Reactive oxygen species (ROS) play an important role in the pathogenesis of ischemia-reperfusion injury. Extracellular H2O2 generation from bovine pulmonary artery endothelial cells (EC) is known to increase in response to anoxia-reoxygenation (A-R). To determine potential sources of intracellular ROS formation in EC in response to A-R, a fluorometric assay based on the oxidation of 2',7'-dichlorofluorescin was used. Intracellular ROS production declined 40% during 6 h of anoxia (P < 0.05). After A-R, the rates of intracellular ROS formation increased to 148 +/- 9% (P < 0.001) that of normoxic EC (100 +/- 3%). In EC exposed to A-R, allopurinol and NG-methyl-L-arginine (L-NMMA), inhibitors of xanthine oxidase (XO) and nitric oxide synthase (NOS), respectively, reduced intracellular ROS formation by 25 +/- 1% (P < 0.001) and 36 +/- 4% (P < 0.01). Furthermore, at low doses (i.e., 20 microM), deferoxamine and diethylenetriaminepentaacetic acid (DTPA) significantly inhibited intracellular ROS formation. However, at 100 microM, only deferoxamine caused further reduction in DCF fluorescence. In summary, EC respond to A-R by generating increased amounts of XO- and NOS-derived intracellular ROS. The inhibition, to a similar extent, caused by allopurinol and L-NMMA, as well as the effect of deferoxamine and DTPA suggest that the ROS detected is peroxynitrite. Based on these findings and previous work, we conclude that EC generate ROS in response to A-R from at least two different sources: a plasma membrane-bound NADPH oxidase-like enzyme that releases H2O2 extracellularly and XO, which generates intracellular O2-, which in turn may react with nitric oxide to form peroxynitrite.

scholarly journals Mitochondrial uncoupling does not decrease reactive oxygen species production after ischemia-reperfusion

2014 ◽  
Vol 307 (7) ◽  
pp. H996-H1004 ◽  
Author(s):  
Ricardo Quarrie ◽  
Daniel S. Lee ◽  
Levy Reyes ◽  
Warren Erdahl ◽  
Douglas R. Pfeiffer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Dysfunction ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Sprague Dawley ◽  
Mitochondrial Uncoupling ◽  
Mitochondrial Ros ◽  
Ros Formation

Cardiac ischemia-reperfusion (IR) leads to myocardial dysfunction by increasing production of reactive oxygen species (ROS). Mitochondrial H+ leak decreases ROS formation; it has been postulated that increasing H+ leak may be a mechanism of decreasing ROS production after IR. Ischemic preconditioning (IPC) decreases ROS formation after IR, but the mechanism is unknown. We hypothesize that pharmacologically increasing mitochondrial H+ leak would decrease ROS production after IR. We further hypothesize that IPC would be associated with an increase in the rate of H+ leak. Isolated male Sprague-Dawley rat hearts were subjected to either control or IPC. Mitochondria were isolated at end equilibration, end ischemia, and end reperfusion. Mitochondrial membrane potential (mΔΨ) was measured using a tetraphenylphosphonium electrode. Mitochondrial uncoupling was achieved by adding increasing concentrations of FCCP. Mitochondrial ROS production was measured by fluorometry using Amplex-Red. Pyridine dinucleotide levels were measured using HPLC. Before IR, increasing H+ leak decreased mitochondrial ROS production. After IR, ROS production was not affected by increasing H+ leak. H+ leak increased at end ischemia in control mitochondria. IPC mitochondria showed no change in the rate of H+ leak throughout IR. NADPH levels decreased after IR in both IPC and control mitochondria while NADH increased. Pharmacologically, increasing H+ leak is not a method of decreasing ROS production after IR. Replenishing the NADPH pool may be a means of scavenging the excess ROS thereby attenuating oxidative damage after IR.

scholarly journals SIRT1/SIRT3 Modulates Redox Homeostasis during Ischemia/Reperfusion in the Aging Heart

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 858
Author(s):  
Jingwen Zhang ◽  
Di Ren ◽  
Julia Fedorova ◽  
Zhibin He ◽  
Ji Li
Keyword(s):  
Reactive Oxygen Species ◽  
Ischemia Reperfusion ◽  
Redox Homeostasis ◽  
Reactive Oxygen ◽  
Primary Source ◽  
Cardiac Metabolism ◽  
Oxygen Species ◽  
Age Related ◽  
Ros Formation ◽  
Related Proteins

Ischemia/reperfusion (I/R) injury is the central cause of global death in cardiovascular diseases, which is characterized by disorders such as angina, stroke, and peripheral vascular disease, finally causing severe debilitating diseases and death. The increased rates of morbidity and mortality caused by I/R are parallel with aging. Aging-associated cardiac physiological structural and functional deterioration were found to contribute to abnormal reactive oxygen species (ROS) production during I/R stress. Disturbed redox homeostasis could further trigger the related signaling pathways that lead to cardiac irreversible damages with mitochondria dysfunction and cell death. It is notable that sirtuin proteins are impaired in aged hearts and are critical to maintaining redox homeostasis via regulating substrate metabolism and inflammation and thus preserving cardiac function under stress. This review discussed the cellular and functional alterations upon I/R especially in aging hearts. We propose that mitochondria are the primary source of reactive oxygen species (ROS) that contribute to I/R injury in aged hearts. Then, we highlight the cardiomyocyte protection of the age-related proteins Sirtuin1 (SIRT1) and Sirtuin1 (SIRT3) in response to I/R injury, and we discuss their modulation of cardiac metabolism and the inflammatory reaction that is involved in ROS formation.

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