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Guo S, Li Z, Liu Y, Cheng Y, Jia D. Ferroptosis: a new target for hepatic ischemia-reperfusion injury? Free Radic Res 2024:1-21. [PMID: 39068663 DOI: 10.1080/10715762.2024.2386075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/30/2024]
Abstract
Ischemia-reperfusion injury (IRI) can seriously affect graft survival and prognosis and is an unavoidable event during liver transplantation. Ferroptosis is a novel iron-dependent form of cell death characterized by iron accumulation and overwhelming lipid peroxidation; it differs morphologically, genetically, and biochemically from other well-known cell death types (autophagy, necrosis, and apoptosis). Accumulating evidence has shown that ferroptosis is involved in the pathogenesis of hepatic IRI, and targeting ferroptosis may be a promising therapeutic approach. Here, we review the pathways and phenomena involved in ferroptosis, explore the associations and implications of ferroptosis and hepatic IRI, and discuss possible strategies for modulating ferroptosis to alleviate the hepatic IRI.
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Affiliation(s)
- Shanshan Guo
- Department of Nephropathy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zexin Li
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Yi Liu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Ying Cheng
- Department of Organ Transplantation, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Degong Jia
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Wang D, Tian Z, Zhang P, Zhen L, Meng Q, Sun B, Xu X, Jia T, Li S. The molecular mechanisms of cuproptosis and its relevance to cardiovascular disease. Biomed Pharmacother 2023; 163:114830. [PMID: 37150036 DOI: 10.1016/j.biopha.2023.114830] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 04/11/2023] [Accepted: 04/30/2023] [Indexed: 05/09/2023] Open
Abstract
Recently, cuproptosis has been demonstrated to be a new non-apototic cell death mode that is characterized by copper dependence and the regulation of mitochondrial respiration. Cuproptosis is distinct from known cell death modes such as apoptosis, necrosis, pyroptosis, or ferroptosis. Excessive copper induces cuproptosis by promoting protein toxic stress reactions via copper-dependent anomalous oligomerization of lipoylation proteins in the tricarboxylic acid (TCA) cycle and reducing iron-sulfur cluster protein levels. Ferredoxin1 (FDX1) promotes dihydrolipoyl transacetylase (DLAT) lipoacylation and abates iron-sulfur cluster proteins by reducing Cu2+ to Cu+, inducing cell death. Copper homeostasis depends on the copper transporter, and disturbances to this homeostasis cause cuproptosis. Recent evidence has shown that cuproptosis plays a significant role in the occurrence and development of many cardiovascular diseases, such as myocardial ischemia/reperfusion (I/R) injury, heart failure, atherosclerosis, and arrhythmias. Copper chelators, such as ammonium tetrathiomolybdate(VI) and DL-Penicillamine, may ease the above cardiovascular diseases by inhibiting the cuproptosis pathway. Oxidative phosphorylation inhibitors may inhibit cuproptosis by inhibiting protein stress response. In conclusion, cuproptosis plays an essential role in cardiovascular disease pathogenesis. Inhibition of cardiovascular cuproptosis is expected to become a potential treatment. Here, we will thoroughly review the molecular mechanisms involved in cuproptosis and its significance in cardiovascular disease.
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Affiliation(s)
- Di Wang
- Department of Anesthesiology, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Zhenyu Tian
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health. Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational. Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Peng Zhang
- Department of Urology, Zibo Hospital of Integrated Traditional Chinese and Western Medicine, Zibo, China
| | - Lv Zhen
- Department of Cardiology, Zibo First Hospital, Zibo, China
| | - Qingju Meng
- Department of Internal Medicine, Zoucheng Xiangcheng Town Health Center, Jining, China
| | - Benteng Sun
- Department of Primary and Secondary education, Qufu Mingde School, Jining, China
| | - Xingli Xu
- Ultrasound in Cardiac Electrophysiology and Biomechanics Key Laboratory of Sichuan Province, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Tong Jia
- Department of Geratology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong First Medical University, Jinan, China
| | - Shengqiang Li
- Department of Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong First Medical University, Jinan, China.
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Shi F, Zhang P, Mao Y, Wang C, Zheng M, Zhao Z. The nitroxide Tempo inhibits hydroxyl radical production from the Fenton-like reaction of iron(II)-citrate with hydrogen peroxide. Biochem Biophys Res Commun 2016; 483:159-164. [PMID: 28042034 DOI: 10.1016/j.bbrc.2016.12.174] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 12/26/2016] [Indexed: 12/23/2022]
Abstract
In vivo physiological ligand citrate can bind iron(II) ions to form the iron(II)-citrate complex. Inhibition of hydroxyl radical (OH) production from the Fenton-like reaction of iron(II)-citrate with H2O2 is biologically important, as this reaction may account for one of the mechanisms of the labile iron pool in vivo to induce oxidative stress and pathological conditions. Nitroxides have promising potentials as therapeutic antioxidants. However, there are controversial findings indicating that they not only act as antioxidants but also as pro-oxidants when engaged in Fenton reactions. Although the underlying mechanisms are proposed to be the inhibition or enhancement of the OH production by nitroxides, the proposed elucidations are only based on assessing biological damages and not demonstrated directly by measuring the OH production in the presence of nitroxides. In this study, therefore, we employed EPR and fluorescence spectroscopies to show direct evidence that nitroxide 2,2,6,6-tetramethyl-piperidine-1-oxyl (Tempo) inhibited OH production from the Fenton-like reaction of iron(II)-citrate with H2O2 by up to 90%. We also demonstrated spectrophotometrically, for the first time, that this inhibition was due to oxidation of the iron(II)-citrate by Tempo with a stoichiometry of Tempo:Iron(III)-citrate = 1.1:1.0. A scheme was proposed to illustrate the roles of nitroxides engaged in Fenton/Fenton-like reactions.
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Affiliation(s)
- Fengqiang Shi
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Peifeng Zhang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Yujia Mao
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Can Wang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Meiqing Zheng
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China
| | - Zhongwei Zhao
- Department of Chemical Biology, School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China.
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Vinokur V, Berenshtein E, Bulvik B, Grinberg L, Eliashar R, Chevion M. The bitter fate of the sweet heart: impairment of iron homeostasis in diabetic heart leads to failure in myocardial protection by preconditioning. PLoS One 2013; 8:e62948. [PMID: 23690966 PMCID: PMC3655153 DOI: 10.1371/journal.pone.0062948] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 03/26/2013] [Indexed: 11/25/2022] Open
Abstract
Cardiovascular dysfunction is a major complication of diabetes. Examining mechanistic aspects underlying the incapacity of the diabetic heart to respond to ischemic preconditioning (IPC), we could show that the alterations in iron homeostasis can explain this phenomenon. Correlating the hemodynamic parameters with levels of ferritin, the main iron storage and detoxifying protein, without and with inhibitors of protein degradation, substantiated this explanation. Diabetic hearts were less sensitive to ischemia-reperfusion stress, as indicated by functional parameters and histology. Mechanistically, since ferritin has been shown to provide cellular protection against insults, including ischemia-reperfusion stress and as the basal ferritin level in diabetic heart was 2-fold higher than in controls, these are in accord with the greater resistance of the diabetic heart to ischemia-reperfusion. Additionally, during ischemia-reperfusion, preceded by IPC, a rapid and extensive loss in ferritin levels, during the prolonged ischemia, in diabetic heart but not in non-diabetic controls, provide additional substantiation to the explanation for loss of respond to IPC. Current research is shedding light on the mechanism behind ferritin degradation as well, suggesting a novel explanation for diabetes-induced loss of cardioprotection.
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Affiliation(s)
- Vladimir Vinokur
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Otolaryngology, Hadassah-University Hospital, Jerusalem, Israel
| | - Eduard Berenshtein
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Baruch Bulvik
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Leonid Grinberg
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ron Eliashar
- Department of Otolaryngology, Hadassah-University Hospital, Jerusalem, Israel
| | - Mordechai Chevion
- Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
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The heart-protective mechanism of nitronyl nitroxide radicals on murine viral myocarditis induced by CVB3. Biochimie 2012; 94:1951-9. [PMID: 22634370 DOI: 10.1016/j.biochi.2012.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Accepted: 05/15/2012] [Indexed: 12/15/2022]
Abstract
Our previous researches showed that nitronyl nitroxyl derivatives, NNP and NNVP were good anti-oxidants and provided radioprotective effects in C6 cells. The objective of the present study is to investigate the possible antiviral effects and underlying pharmacological of the two nitronyl nitroxide radicals against CVB3 in vitro and in vivo. The results showed that NNP and NNVP were some of the most potent compounds in terms of their antiviral effects by protecting myocardial cells against oxidative damage of free radicals. Treatment with NNP or NNVP could decrease the intracellular ROS level in vitro. They could lead to a significant decrease in activities of biochemical markers AST, CK and LDH in infected murine serum and could increase SOD and CAT activities and decreased MDA activities compared with infected control in vivo. NNP and NNVP could reduce NO production in infected mice by reacting with NO to produce the imino nitroxides which was confirmed by ESR spectrometry. In addition, NNP and NNVP could both decrease the mRNA expression of proinflammatory cytokines, TNF-α, IL-2 and IL-6. In conclusion, nitronyl nitroxide radicals NNP and NNVP were shown to have antiviral activities against CVB3 and they may represent potential therapeutic agents for viral myocarditis.
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Li WG, Zhang XY, Wu YJ, Gao MT, Zheng RL. The relationship between structure and antioxidative activity of piperidine nitroxides. J Pharm Pharmacol 2010; 58:941-9. [PMID: 16805954 DOI: 10.1211/jpp.58.7.0009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
We have investigated the relationship between structure and antioxidative activity of piperidine nitroxides which were substituted by different groups at the 4-position. All of the tested piperidine nitroxides inhibited malondialdehyde (MDA) generation caused either spontaneously or by a hydroxyl free radical generation system (Fe2+-ascorbic acid) in homogenates of liver, heart and kidney of rats, and antagonized H2O2-induced haemolysis from rat erythrocytes in a concentration-dependent manner. The same rank was followed: Bis-(4-amino-2,2,6,6-tetramethyl piperidinooxyl) (4-BIS-Tempo) and 4-azido-2,2,6,6-tetramethyl piperidinooxyl (4-N3-Tempo) >4-isothiocyanate-2,2,6,6-tetramethyl piperidinooxyl (4-ISO-Tempo), 4-2′,4′-dinitrophenyl-hydrazone-2,2,6,6-tetramethyl piperidinooxyl (4-D-Tempo), 4-sulfonate-2,2,6,6-tetramethyl piperidinooxyl (4-S-Tempo) and 4-amino-2,2,6,6-tetramethyl piperidinooxyl (4-NH2-Tempo) > 4-acetate ester-2,2,6,6-tetramethyl piperidinooxyl (4-A-Tempo) and 4-benzoate-2,2,6,6-tetra-methyl piperidinooxyl (4-B-Tempo). With the exception of 4-A-Tempo and 4-D-Tempo, the tested piperidine nitroxides inhibited superoxide anion (O2.-) release from neutrophils stimulated by zymosan. The concentration required for inhibiting O2.- release was higher than that of inhibiting MDA formation and haemolysis. However, 4-amino-2,2,6,6-tetramethyl piperidine (4-NH2-TempH) and other 4-position substitutes, such as NaN3 and isothiocyanate, had no effects on MDA formation, haemolysis or O2.- release. The results indicated that nitroxides have a wide range of scavenging reactive oxygen species (ROS) actions. The nitroxide moiety was the essential group while the 4-position substitutes could influence the activity of nitroxides on scavenging ROS.
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Affiliation(s)
- Wen-Guang Li
- School of Life Sciences, Lanzhou University, Lanzhou, Gansu 730 000, PR China
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Arieli D, Nahmany G, Casap N, Ad-El D, Samuni Y. The effect of a nitroxide antioxidant on ischemia-reperfusion injury in the ratin vivohind limb model. Free Radic Res 2009; 42:114-23. [DOI: 10.1080/10715760701834545] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wilcox CS, Pearlman A. Chemistry and antihypertensive effects of tempol and other nitroxides. Pharmacol Rev 2009; 60:418-69. [PMID: 19112152 DOI: 10.1124/pr.108.000240] [Citation(s) in RCA: 288] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nitroxides can undergo one- or two-electron reduction reactions to hydroxylamines or oxammonium cations, respectively, which themselves are interconvertible, thereby providing redox metabolic actions. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) is the most extensively studied nitroxide. It is a cell membrane-permeable amphilite that dismutates superoxide catalytically, facilitates hydrogen peroxide metabolism by catalase-like actions, and limits formation of toxic hydroxyl radicals produced by Fenton reactions. It is broadly effective in detoxifying these reactive oxygen species in cell and animal studies. When administered intravenously to hypertensive rodent models, tempol caused rapid and reversible dose-dependent reductions in blood pressure in 22 of 26 studies. This was accompanied by vasodilation, increased nitric oxide activity, reduced sympathetic nervous system activity at central and peripheral sites, and enhanced potassium channel conductance in blood vessels and neurons. When administered orally or by infusion over days or weeks to hypertensive rodent models, it reduced blood pressure in 59 of 68 studies. This was accompanied by correction of salt sensitivity and endothelial dysfunction and reduced agonist-evoked oxidative stress and contractility of blood vessels, reduced renal vascular resistance, and increased renal tissue oxygen tension. Thus, tempol is broadly effective in reducing blood pressure, whether given by acute intravenous injection or by prolonged administration, in a wide range of rodent models of hypertension.
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Affiliation(s)
- Christopher S Wilcox
- Division of Nephrology and Hypertension, Kidney and Vascular Disorder Center, Georgetown University, Washington, DC 20007, USA.
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Yang Z, Linden J, Berr SS, Kron IL, Beller GA, French BA. Timing of adenosine 2A receptor stimulation relative to reperfusion has differential effects on infarct size and cardiac function as assessed in mice by MRI. Am J Physiol Heart Circ Physiol 2008; 295:H2328-35. [PMID: 18849340 DOI: 10.1152/ajpheart.00091.2008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The activation of adenosine 2A receptors before reperfusion following coronary artery occlusion reduces infarct size and improves ejection fraction (EF). In this study, we examined the effects of delaying treatment with the adenosine 2A receptor agonist ATL146e (ATL) until 1 h postreperfusion. The infarct size and EF were serially assessed by gadolinium-diethylenetriaminepentaacetic acid-enhanced MRI in C57BL/6 mice at 1 and 24 h postreperfusion. The infarct size was also assessed by 2,3,5-triphenyltetrazolium chloride staining at 24 h. Mice were treated with ATL (10 microg/kg ip) either 2 min before reperfusion (early ATL) or 1 h postreperfusion (late ATL) following the 45-min coronary occlusion. The two methods used to assess infarct size at 24 h postreperfusion (MRI and 2,3,5-triphenyltetrazolium chloride) showed an excellent correlation (R=0.96). The risk region, determined at 24 h postreperfusion, was comparable between the control and ATL-treated groups. The infarct size by MRI at 1 versus 24 h postreperfusion was 25+/-1 vs. 26+/-1% of left ventricular mass (means+/-SE) in control mice, 16+/-2 versus 17+/-2% in early-ATL mice, and 24+/-2 versus 25+/-2% in late-ATL mice (intragroup, P=not significant; and intergroup, early ATL vs. control or late ATL, P<0.05). EF was reduced in control mice but was largely preserved between 1 and 24 h in both early-ATL and late-ATL mice (P<0.05). In conclusion, after coronary occlusion in mice, the extent of myocellular death due to ischemia-reperfusion injury is 95% complete within 1 h of reperfusion. The infarct size was significantly reduced by ATL when given just before reperfusion, but not 1 h postreperfusion. Either treatment window helped preserve the EF between 1 and 24 h postreperfusion.
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Affiliation(s)
- Zequan Yang
- Department of Surgery, University of Virginia, MR5 Bldg. Rm. 1219, Box 800759, 415 Lane Rd., Charlottesville, VA 22903, USA
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Bi W, Cai J, Xue P, Zhang Y, Liu S, Gao X, Li M, Wang Z, Baudy-Floc’h M, Green SA, Bi L. Protective effect of nitronyl nitroxide–amino acid conjugates on liver ischemia–reperfusion induced injury in rats. Bioorg Med Chem Lett 2008; 18:1788-94. [PMID: 18328700 DOI: 10.1016/j.bmcl.2008.02.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 02/08/2008] [Accepted: 02/13/2008] [Indexed: 01/23/2023]
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Goldstein S, Samuni A, Hideg K, Merenyi G. Structure−Activity Relationship of Cyclic Nitroxides as SOD Mimics and Scavengers of Nitrogen Dioxide and Carbonate Radicals. J Phys Chem A 2006; 110:3679-85. [PMID: 16526651 DOI: 10.1021/jp056869r] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Synthetic nitroxide antioxidants attenuate oxidative damage in various experimental models. Their protective effect reportedly depends on ring size and ring substituents and is greater for nitroxides having lower oxidation potential. The present study focuses on the kinetics and mechanisms of the reactions of piperidine, pyrrolidine and oxazolidine nitroxides with HO2*/O2*-, *NO2 and CO3*- radicals, which are key intermediates in many inflammatory and degenerative diseases. It is demonstrated that nitroxides are the most efficient scavengers of *NO2 at physiological pH (k = (3-9) x 10(8) M(-1) s(-1)) and among the most effective metal-independent scavengers of CO3*- radicals (k = (2 - 6) x 10(8) M(-1) s(-1)). Their reactivity toward HO2*, though not toward *NO2 and CO3*-, depends on the nature of the ring side-chain and particularly on the ring-size. All nitroxide derivatives react slowly with O2*- and are relatively inefficient SOD mimics at physiological pH. Even piperidine nitroxides, having the highest SOD-like activity, demonstrate a catalytic activity of about 1000-fold lower than that of native SOD at pH 7.4. The present results do not indicate any correlation between the kinetics of HO2*/O2*-, *NO2 and CO3*- removal by nitroxides and their protective activity against biological oxidative stress and emphasize the importance of target-oriented nitroxides, i.e., interaction between the biological target and specific nitroxides.
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Affiliation(s)
- Sara Goldstein
- Department of Physical Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Hoffman A, Goldstein S, Samuni A, Borman JB, Schwalb H. Effect of nitric oxide and nitroxide SOD-mimic on the recovery of isolated rat heart following ischemia and reperfusion. Biochem Pharmacol 2003; 66:1279-86. [PMID: 14505807 DOI: 10.1016/s0006-2952(03)00441-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nitric oxide synthesized from L-arginine in cells has important salutary physiological roles, but can also exert deleterious effects. Nitric oxide (NO) can ameliorate post-ischemic reperfusion myocardial injury, yet formation from NO and O(2)z*(-) of peroxynitrite and its downstream toxic products, such as *OH, *NO(2) and CO(3)*(-), can ultimately exacerbate reperfusion damage. Nitroxide stable radicals, such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TPL), unlike SOD, readily penetrate cells and catalytically remove intracellular O(2)*(-). Hence, nitroxides by virtue of catalytic removal of O(2)*(-) would be expected to diminish the adverse effect of NO and lower post-ischemic reperfusion cardiac damage. We show that post-ischemic recovery of hemodynamic functions of isolated perfused rat hearts treated with L-arginine or TPL alone did not differ from that of the control hearts. However, the recovery of hearts treated with the combined regimen of L-arginine and TPL was significantly improved, e.g. the Work Index=(left ventricular developed pressure x heart rate) recovered to 92+/-1.6% (L-arginine and TPL) vs. 59.4+/-5.4% (Control), 60+/-2.9% (L-arginine) and 53.3+/-4.3% (TPL) of the pre-ischemic value; mean+/-SEM, N=10, P<0.001. The enhanced recovery of hemodynamic function of hearts treated with L-arginine and TPL was accompanied by an increased recovery of oxygen consumption during the reperfusion. The combined regimen of L-arginine and TPL reduces the negative effects of NO by either inhibiting the production of ONOO(-) or through reaction with CO(3)z.rad;(-) and *NO(2) radicals formed during the decomposition of peroxynitrite in the presence of bicarbonate, thus promoting cardioprotection following post-ischemic reperfusion.
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Affiliation(s)
- Azik Hoffman
- The Joseph Lunenfeld Cardiac Surgery Research Center Hadassah Hospital, P.O.B. 12000, Jerusalem 91120, Israel
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