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Chiari P, Durand M, Desebbe O, Fischer MO, Lena-Quintard D, Palao JC, Mercier C, Samson G, Varillon Y, Pozzi M, Mewton N, Maucort-Boulch D, Ovize M, Fellahi JL. Multimodal cardioprotective strategy in cardiac surgery (the ProCCard trial): Study protocol for a multicenter randomized controlled trial. Trials 2019; 20:560. [PMID: 31511041 PMCID: PMC6737694 DOI: 10.1186/s13063-019-3638-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/08/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Myocardial damage in patients undergoing cardiac surgery increases both morbidity and mortality. Different protective strategies dealing with either preconditioning or postconditioning or assessing a single aspect of cardioprotection have shown conflicting results. We tested the hypothesis that a multimodal approach would improve cardioprotection and limit myocardial damage following cardiac surgery with cardiopulmonary bypass. METHODS This study is a pragmatic multicenter (six French institutions), prospective, randomized, single-blinded, controlled trial. The randomization is stratified by centers. In the study, 210 patients scheduled for aortic valve surgery with or without coronary artery bypass grafting will be assigned to a control or a treatment group (105 patients in each group). In the control group, patients receive total intravenous anesthesia with propofol and liberal intraoperative blood glucose management (initiation of insulin infusion when blood glucose, measured every 60 min, is greater than 180 mg/dl), as a standard of care. The treatment group receives a bundle of care combining five techniques of cardioprotection: (1) remote ischemic preconditioning applied before aortic cross-clamping; (2) maintenance of anesthesia with sevoflurane; (3) tight intraoperative blood glucose management (initiation of insulin infusion when blood glucose, measured every 30 min, is greater than 140 mg/dl); (4) moderate respiratory acidosis (pH 7.30) at the end of cardiopulmonary bypass; and (5) a gentle reperfusion protocol following aortic unclamping. The primary outcome is myocardial damage measured by postoperative 72-h area under the curve of high-sensitivity cardiac troponin I. DISCUSSION The ProCCard study will be the first multicenter randomized controlled trial aiming to assess the role of a bundle of care combining several cardioprotective strategies to reduce myocardial damage in patients undergoing cardiac surgery with cardiopulmonary bypass. TRIAL REGISTRATION ClinicalTrials.gov, NCT03230136 . Registered on July 26, 2017. Last updated on April 17, 2019.
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Affiliation(s)
- Pascal Chiari
- Service d’Anesthésie-Réanimation, Hôpital Louis Pradel, Hospices Civils de Lyon, F-69677 Lyon, France
- Inserm U1060, Laboratoire CarMeN, IHU OPeRa, F-69394 Lyon, France
| | - Michel Durand
- Pole d’Anesthésie-Réanimation, Hôpital Albert Michallon, Centre Hospitalier Universitaire de Grenoble-Alpes, F-38043 Grenoble, France
| | - Olivier Desebbe
- Service d’Anesthésie-Réanimation, Clinique de la Sauvegarde, Ramsay Générale de Santé, F-69009 Lyon, France
| | - Marc-Olivier Fischer
- Service d’Anesthésie-Réanimation, Centre Hospitalier Universitaire de Caen, F-14033 Caen, France
- Université de Normandie, UNICAEN, Caen, France
| | - Diane Lena-Quintard
- Service d’Anesthésie-Réanimation, Institut Arnault Tzanck, F-06721 Saint Laurent du Var, France
| | - Jean-Charles Palao
- Service d’Anesthésie-Réanimation, Hôpital Nord, Centre Hospitalier Universitaire de Saint Etienne, F-42277 Saint Etienne, France
| | - Catherine Mercier
- Service de Biostatistique - Bioinformatique, Pôle Santé Publique, Hospices Civils de Lyon, F-69003 Lyon, France
- Université de Lyon, F-69000 Lyon, France
- Université Lyon 1, F-69100 Villeurbanne, France
- CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, Équipe Biostatistique-Santé, F-69100 Villeurbanne, France
| | - Géraldine Samson
- Centre d’Investigation Clinique de Lyon (CIC 1407 Inserm), Hospices Civils de Lyon, F-69677 Lyon, France
| | - Yvonne Varillon
- Centre d’Investigation Clinique de Lyon (CIC 1407 Inserm), Hospices Civils de Lyon, F-69677 Lyon, France
| | - Matteo Pozzi
- Service de Chirurgie Cardiaque, Hôpital Louis Pradel, Hospices Civils de Lyon, F-69677 Lyon, France
| | - Nathan Mewton
- Inserm U1060, Laboratoire CarMeN, IHU OPeRa, F-69394 Lyon, France
- Centre d’Investigation Clinique de Lyon (CIC 1407 Inserm), Hospices Civils de Lyon, F-69677 Lyon, France
- Service d’Insuffisance Cardiaque, Lyon, France
| | - Delphine Maucort-Boulch
- Service de Biostatistique - Bioinformatique, Pôle Santé Publique, Hospices Civils de Lyon, F-69003 Lyon, France
- Université de Lyon, F-69000 Lyon, France
- Université Lyon 1, F-69100 Villeurbanne, France
- CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, Équipe Biostatistique-Santé, F-69100 Villeurbanne, France
| | - Michel Ovize
- Inserm U1060, Laboratoire CarMeN, IHU OPeRa, F-69394 Lyon, France
- Centre d’Investigation Clinique de Lyon (CIC 1407 Inserm), Hospices Civils de Lyon, F-69677 Lyon, France
- Service d’Explorations Fonctionnelles Cardiovasculaires, Lyon, France
| | - Jean-Luc Fellahi
- Service d’Anesthésie-Réanimation, Hôpital Louis Pradel, Hospices Civils de Lyon, F-69677 Lyon, France
- Inserm U1060, Laboratoire CarMeN, IHU OPeRa, F-69394 Lyon, France
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Teijido O, Rappaport SM, Chamberlin A, Noskov SY, Aguilella VM, Rostovtseva TK, Bezrukov SM. Acidification asymmetrically affects voltage-dependent anion channel implicating the involvement of salt bridges. J Biol Chem 2014; 289:23670-82. [PMID: 24962576 DOI: 10.1074/jbc.m114.576314] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the major pathway for ATP, ADP, and other respiratory substrates through the mitochondrial outer membrane, constituting a crucial point of mitochondrial metabolism regulation. VDAC is characterized by its ability to "gate" between an open and several "closed" states under applied voltage. In the early stages of tumorigenesis or during ischemia, partial or total absence of oxygen supply to cells results in cytosolic acidification. Motivated by these facts, we investigated the effects of pH variations on VDAC gating properties. We reconstituted VDAC into planar lipid membranes and found that acidification reversibly increases its voltage-dependent gating. Furthermore, both VDAC anion selectivity and single channel conductance increased with acidification, in agreement with the titration of the negatively charged VDAC residues at low pH values. Analysis of the pH dependences of the gating and open channel parameters yielded similar pKa values close to 4.0. We also found that the response of VDAC gating to acidification was highly asymmetric. The presumably cytosolic (cis) side of the channel was the most sensitive to acidification, whereas the mitochondrial intermembrane space (trans) side barely responded to pH changes. Molecular dynamic simulations suggested that stable salt bridges at the cis side, which are susceptible to disruption upon acidification, contribute to this asymmetry. The pronounced sensitivity of the cis side to pH variations found here in vitro might provide helpful insights into the regulatory role of VDAC in the protective effect of cytosolic acidification during ischemia in vivo.
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Affiliation(s)
- Oscar Teijido
- From the Program in Physical Biology, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - Shay M Rappaport
- From the Program in Physical Biology, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - Adam Chamberlin
- the Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 2N4, Canada, and
| | - Sergei Y Noskov
- From the Program in Physical Biology, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, Maryland 20892, the Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 2N4, Canada, and
| | - Vicente M Aguilella
- the Department of Physics, Universitat Jaume I, 12080 Castelló de la Plana, Spain
| | - Tatiana K Rostovtseva
- From the Program in Physical Biology, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, Maryland 20892,
| | - Sergey M Bezrukov
- From the Program in Physical Biology, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, Maryland 20892
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Halestrap AP, Clarke SJ, Khaliulin I. The role of mitochondria in protection of the heart by preconditioning. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1007-31. [PMID: 17631856 PMCID: PMC2212780 DOI: 10.1016/j.bbabio.2007.05.008] [Citation(s) in RCA: 299] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 05/18/2007] [Accepted: 05/23/2007] [Indexed: 12/16/2022]
Abstract
A prolonged period of ischaemia followed by reperfusion irreversibly damages the heart. Such reperfusion injury (RI) involves opening of the mitochondrial permeability transition pore (MPTP) under the conditions of calcium overload and oxidative stress that accompany reperfusion. Protection from MPTP opening and hence RI can be mediated by ischaemic preconditioning (IP) where the prolonged ischaemic period is preceded by one or more brief (2–5 min) cycles of ischaemia and reperfusion. Following a brief overview of the molecular characterisation and regulation of the MPTP, the proposed mechanisms by which IP reduces pore opening are reviewed including the potential roles for reactive oxygen species (ROS), protein kinase cascades, and mitochondrial potassium channels. It is proposed that IP-mediated inhibition of MPTP opening at reperfusion does not involve direct phosphorylation of mitochondrial proteins, but rather reflects diminished oxidative stress during prolonged ischaemia and reperfusion. This causes less oxidation of critical thiol groups on the MPTP that are known to sensitise pore opening to calcium. The mechanisms by which ROS levels are decreased in the IP hearts during prolonged ischaemia and reperfusion are not known, but appear to require activation of protein kinase Cε, either by receptor-mediated events or through transient increases in ROS during the IP protocol. Other signalling pathways may show cross-talk with this primary mechanism, but we suggest that a role for mitochondrial potassium channels is unlikely. The evidence for their activity in isolated mitochondria and cardiac myocytes is reviewed and the lack of specificity of the pharmacological agents used to implicate them in IP is noted. Some K+ channel openers uncouple mitochondria and others inhibit respiratory chain complexes, and their ability to produce ROS and precondition hearts is mimicked by bona fide uncouplers and respiratory chain inhibitors. IP may also provide continuing protection during reperfusion by preventing a cascade of MPTP-induced ROS production followed by further MPTP opening. This phase of protection may involve survival kinase pathways such as Akt and glycogen synthase kinase 3 (GSK3) either increasing ROS removal or reducing mitochondrial ROS production.
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Affiliation(s)
- Andrew P Halestrap
- Department of Biochemistry and Bristol Heart Institute, University of Bristol, School of Medical Sciences, University Walk, Bristol BS8 1TD, UK.
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4
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Kelly RF. Current strategies in lung preservation. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2000; 136:427-40. [PMID: 11128744 DOI: 10.1067/mlc.2000.110906] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Current methods of lung preservation allow for effective, expeditious transplantation as a treatment for end-stage pulmonary disease. However, the utilization of hypothermia, hyperkalemia, and pulmonary artery distension as a single rapid flush for perfusion is less than ideal. All these interventions result in increased pulmonary vascular resistance and suboptimal preservation of lung function. The ability to preserve lungs for longer time intervals and with less risk of tissue injury would provide significant advantages. There would be a greater likelihood that rare size or blood types could find matches by enlarging the area of organ distribution. Optimal preservation would also improve the perioperative outcomes in regard to primary graft failure and subsequently reduce the later complication of chronic rejection and graft lung dysfunction. Finally, through a better understanding of the mechanisms of lung injury during preservation and by developing means to limit the injury, it would be possible to utilize organs from donors that at this time would not be considered optimal. This would increase the donor pool without compromising the recipient's outcome.
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Affiliation(s)
- R F Kelly
- Division of Cardiovascular and Thoracic Surgery, University of Minnesota, Minneapolis, USA
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5
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Carini R, De Cesaris MG, Splendore R, Bagnati M, Bellomo G, Albano E. Alterations of Na(+) homeostasis in hepatocyte reoxygenation injury. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1500:297-305. [PMID: 10699371 DOI: 10.1016/s0925-4439(99)00114-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Reperfusion injury represents an important cause of primary graft non-function during liver transplantation. However, the mechanism responsible for cellular damage during reoxygenation has not yet been completely understood. We have investigated whether changes in intracellular Na(+) distribution might contribute to cause hepatocyte damage during reoxygenation buffer after 24 h of cold storage. Hepatocyte reoxygenation resulted in a rapid increase in cellular Na(+) content that was associated with cytotoxicity. Na(+) accumulation and hepatocyte death were prevented by the omission of Na(+) from the incubation medium, but not by the addition of antioxidants. Blocking Na(+)/H(+) exchanger and Na(+)/HCO(3)(-) co-transporter by, respectively, 5-(N,N-dimethyl)-amiloride or omitting HCO(3)(-) from the reoxygenation medium significantly decreased Na(+) overload and cytotoxicity. Stimulation of ATP re-synthesis by the addition of fructose also lowered Na(+) accumulation and cell death during reoxygenation. A significant protection against Na(+)-mediated reoxygenation injury was evident in hepatocytes maintained in an acidic buffer (pH 6.5) or in the presence of glycine. The cytoprotective action of glycine or of the acidic buffer was reverted by promoting Na(+) influx with the Na(+)/H(+) ionophore monensin. Altogether, these results suggest that Na(+) accumulation during the early phases of reoxygenation might contribute to liver graft reperfusion injury.
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Affiliation(s)
- R Carini
- Department of Medical Science, University 'A. Avogadro' of East Piedmont, Via Solaroli 17, 27100, Novara, Italy
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Abstract
The aim of this review is to provide basic information on the electrophysiological changes during acute ischemia and reperfusion from the level of ion channels up to the level of multicellular preparations. After an introduction, section II provides a general description of the ion channels and electrogenic transporters present in the heart, more specifically in the plasma membrane, in intracellular organelles of the sarcoplasmic reticulum and mitochondria, and in the gap junctions. The description is restricted to activation and permeation characterisitics, while modulation is incorporated in section III. This section (ischemic syndromes) describes the biochemical (lipids, radicals, hormones, neurotransmitters, metabolites) and ion concentration changes, the mechanisms involved, and the effect on channels and cells. Section IV (electrical changes and arrhythmias) is subdivided in two parts, with first a description of the electrical changes at the cellular and multicellular level, followed by an analysis of arrhythmias during ischemia and reperfusion. The last short section suggests possible developments in the study of ischemia-related phenomena.
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Affiliation(s)
- E Carmeliet
- Centre for Experimental Surgery and Anesthesiology, University of Leuven, Leuven, Belgium
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7
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Preckel B, Schlack W, Obal D, Barthel H, Ebel D, Grunert S, Thämer V. Effect of acidotic blood reperfusion on reperfusion injury after coronary artery occlusion in the dog heart. J Cardiovasc Pharmacol 1998; 31:179-86. [PMID: 9475258 DOI: 10.1097/00005344-199802000-00002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A prolongation of the intracellular acidosis after myocardial ischemia can protect the myocardium against reperfusion injury. In isolated hearts, this was achieved by prolongation of the extracellular acidosis. The aim of this study was to investigate whether regional reperfusion with acidotic blood after coronary artery occlusion can reduce infarct size and improve myocardial function in vivo. Anesthetized open-chest dogs were instrumented for measurement of regional myocardial function, assessed by sonomicrometry as systolic wall thickening (sWT). Infarct size was determined by triphenyltetrazolium staining after 3 h of reperfusion. The left anterior descending coronary artery (LAD) was perfused through a bypass from the left carotid artery. The animals underwent 1 h of LAD occlusion and subsequent bypass-reperfusion with normal blood (control, n = 6) or blood equilibrated to pH = 6.8 by using 0.1 mM HCl during the first 30 min of reperfusion (HCl, n = 5). Regional collateral blood flow (RCBF) at 30-min occlusion was measured by using colored microspheres. There was no difference in recovery of sWT in the LAD-perfused area between the two groups at the end of the experiments [-2.8+/-1.2% (HCl) vs. -4.4+/-2.5% (control); mean +/- SEM; p = NS]. RCBF was comparable in both groups. Infarct size (percentage of area at risk) was reduced in the treatment group (12.8+/-2.8%) compared with the control group (26.2+/-4.8%; p < 0.05). These results indicate that reperfusion injury after coronary artery occlusion can be reduced by a prolonged local extracellular acidosis in vivo.
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Affiliation(s)
- B Preckel
- Physiologisches Institut I, Abteilung für Herz- und Kreislauf-Physiologie, Heinrich-Heine-Universität Düsseldorf, Germany
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8
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Wey HE, Richards D, Tirmenstein MA, Mathias PI, Toraason M. The role of intracellular calcium in antimony-induced toxicity in cultured cardiac myocytes. Toxicol Appl Pharmacol 1997; 145:202-10. [PMID: 9221838 DOI: 10.1006/taap.1997.8175] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Trivalent antimony, delivered as potassium antimonyl tartrate (PAT), has been previously shown to induce an oxidative stress and toxicity in cultured neonatal rat cardiac myocytes. The present study investigates the effect of PAT on intracellular free calcium ([Ca2+]i), which has been implicated in the toxicity of agents inducing oxidative stress, and explores its role in PAT toxicity. Exposure to 50 or 200 microM PAT led to progressive elevation in diastolic or resting [Ca2+]i and eventually a complete loss of [Ca2+]i transients that occurred well before cell death as assessed by LDH release. Prior loading of myocytes with the intracellular calcium chelator BAPTA (10 to 40 microM), protected against PAT toxicity in the presence and absence of extracellular calcium, and demonstrated a crucial role for [Ca2+]i in PAT toxicity. Exposure to 200 microM PAT in the absence of extracellular calcium slightly elevated [Ca2+]i, but only to levels comparable to resting [Ca2+]i for cells in 1.8 mM extracellular calcium. This demonstrated that although PAT toxicity was dependent on [Ca2+]i, a large increase above resting levels was not needed, and also that some calcium was mobilized from intracellular stores. However, the caffeine-releasable pool of sarcoplasmic reticulum calcium was increased, not depleted, by exposure to 200 microM PAT. These results demonstrate that PAT disrupts [Ca2+]i handling and support a role for a calcium-dependent event, but do not support the necessity of events in PAT-induced cell death that are mediated by a large elevation in [Ca2+]i.
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Affiliation(s)
- H E Wey
- Division of Biomedical and Behavioral Science, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio 45226, USA
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Okamura T, Ayajiki K, Toda N. Hypoxia-induced inhibition of the response to nitroxidergic nerve stimulation in canine cerebral arteries. J Cereb Blood Flow Metab 1997; 17:807-13. [PMID: 9270498 DOI: 10.1097/00004647-199707000-00011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In isolated canine middle cerebral arteries contracted with prostaglandin F2 alpha, transmural electrical stimulation (TES), nicotine, and substance P produced relaxations. Transmural electrical stimulation- and nicotine-induced endothelium-independent responses are mediated by nitric oxide (NO) liberated from perivascular nerve, whereas substance P-induced relaxations are mediated by endothelium-derived NO. These responses were attenuated by replacement of 95% O2 and 5% CO2 gas (about 550 mm Hg of partial O2 pressure) with 95% N2 and 5% CO2 gas (about 40 mm Hg); inhibition of the response to TES was stabilized 30 minutes later. Reoxygenation partially reversed the response. Relaxations caused by exogenous NO were not influenced by hypoxia. Inhibition by hypoxia of the response to TES was not affected by superoxide dismutase. However, the inhibitory effect was prevented by amiloride and dimethyl-amiloride, Na(+)-H+ exchange inhibitors, or acidosis caused by the addition of HCl. The inhibition by hypoxia was reversed by amiloride. It is concluded that depression by hypoxia of the response mediated by endogenous NO is associated with impaired membrane function caused by restoration of normal intracellular pH by Na(+)-H+ exchanger.
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Affiliation(s)
- T Okamura
- Department of Pharmacology, Shiga University of Medical Sciences, Ohtsu, Japan
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Bagchi D, Wetscher GJ, Bagchi M, Hinder PR, Perdikis G, Stohs SJ, Hinder RA, Das DK. Interrelationship between cellular calcium homeostasis and free radical generation in myocardial reperfusion injury. Chem Biol Interact 1997; 104:65-85. [PMID: 9212776 DOI: 10.1016/s0009-2797(97)03766-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This review describes the interrelationship between two important biological factors, intracellular calcium overloading and oxygen-derived free radicals, which play a crucial role in the pathogenesis of myocardial ischemic reperfusion injury. Free radicals are generated during the reperfusion of ischemic myocardium, and polyunsaturated fatty acids in the membrane phospholipids are the likely targets of the free radical attack. On the other hand, activation of phospholipases can provoke the breakdown of membrane phospholipids which results in the activation of arachidonate cascade leading to the generation of prostaglandins, and oxygen free radicals can be produced during the interconversion of the prostaglandins. In conclusion, it has been emphasized that the two seemingly different causative factors of reperfusion injury, intracellular calcium overloading and free radical generation are, in fact, highly interrelated.
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Affiliation(s)
- D Bagchi
- Department of Surgery, Creighton University, Omaha, NE, USA
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Is ventilator-induced lung injury a promoter of multiple organ failure in adult respiratory distress syndrome? The effect of permissive hypercapnia on oxygenation and outcome. J Anesth 1997; 11:50-64. [DOI: 10.1007/bf02480005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Harrison-Shostak DC, Lemasters JJ, Edgell CJ, Herman B. Role of ICE-like proteases in endothelial cell hypoxic and reperfusion injury. Biochem Biophys Res Commun 1997; 231:844-7. [PMID: 9070907 DOI: 10.1006/bbrc.1997.6129] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Because of its location between blood and tissue, the endothelium is particularly vulnerable to hypoxic/reperfusion injury, but the mechanisms responsible for this injury are not known. A number of recent findings suggest that hypoxia and reperfusion injures neuronal cells via apoptosis. Apoptosis has recently been shown to depend on the activation of a class of proteases with homology to Interleukin-1 beta converting enzyme (ICE) protease. Therefore, we examined the effect of specific inhibitors of ICE-like proteases on hypoxic and reperfusion injury in cultured EAhy926 endothelial cells. Pretreatment of cells with ICE inhibitor II (Ac-YVAD-CMK), ICE inhibitor III (Z-Asp-2,6-dichlorobenzoyloxy-methylketone-Z-Asp-CH2-DCB+ ++), or ICE inhibitor IV (Ac-YVKD-CHO) (all at 10-100 microM) did not protect cells from hypoxic injury. However, pretreatment of cells with ICE inhibitor III and to a lesser extent with ICE inhibitor II, but not with ICE inhibitor IV, protected cells from reperfusion injury. The protective effect of ICE inhibitor III was not dependent upon pH, but was associated with decreased release of arachidonic acid from cells. These findings suggest that reperfusion injury to EAhy926 endothelial cells involves ICE-like proteases. The identity of the protease(s) is not known but it does not appear to be a YAMA-type protease based upon ICE inhibitor specificity. Our data also indicate that a potential target of this protease is phospholipase A2 (PLA2).
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Affiliation(s)
- D C Harrison-Shostak
- Department of Cell Biology and Anatomy, School of Medicine, University of North Carolina at Chapel Hill 27599-7090, USA
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Saris NE, Eriksson KO. Mitochondrial dysfunction in ischaemia-reperfusion. ACTA ANAESTHESIOLOGICA SCANDINAVICA. SUPPLEMENTUM 1995; 107:171-6. [PMID: 8599272 DOI: 10.1111/j.1399-6576.1995.tb04353.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mitochondrial dysfunction in ischaemia-reperfusion is shortly reviewed. During ischaemia the ATP level and pH drops, phospholipids are degraded, membrane permeabilities increased and the cytosolic levels of Na+ and Ca2+ raised. During the following reperfusion the Ca2+ levels may further increase while pH is raised. The oxidative phosphorylation is resumed and the ATP used for membrane repair and ion pumping. The mitochondrial Ca2+ handling is important in removing Ca2+ from the cytosol since the mitochondria are able to take up substantial amounts of Ca2+. However, if a certain threshold is exceeded, mitochondria undergo a so-called permeability transition (MPT), release their Ca2+, undergo swelling and become uncoupled. MPT has been shown to be due to the opening of large pore allowing passage of substances with a M(R) < 1500. Data are presented showing by electron microscopy swelling of mitochondria in cells in perfused liver before other gross morphological changes have taken place. There are a number of factors lowering the threshold for Ca2+ in inducing the MPT: inorganic phosphate, pro-oxidants that oxidize membrane SH-groups, oxidation of NAD(P)H and GSH, while a protective effect is exerted by Mg2+, ADP (and ATP), some antioxidants, carnitine, decrease in pH, and cyclosporin A that binds to cyclophilin. The potential benefit of these in minimizing reperfusion-induced tissue damage is discussed.
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Affiliation(s)
- N E Saris
- Department of Medical Chemistry, University of Helsinki, Finland
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Hickling KG, Joyce C. Permissive hypercapnia in ARDS and its effect on tissue oxygenation. ACTA ANAESTHESIOLOGICA SCANDINAVICA. SUPPLEMENTUM 1995; 107:201-8. [PMID: 8599278 DOI: 10.1111/j.1399-6576.1995.tb04359.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Many experimental studies have shown that mechanical ventilation with high tidal volumes (Vt) or with a low end-expiratory volume allowing repeated end-expiratory collapse, can result in acute parenchymal lung injury and probably an inflammatory response. Low volume ventilation with permissive hypercapnia has been used in an attempt to avoid such injury in ARDS. Such management can affect oxygenation in many complex ways. The right-shift of the haemoglobin-oxygen dissociation curve during acute respiratory acidosis may increase venous oxygen tension (PvO2) which could allow increased O2 uptake in ischaemic tissues. Acidosis may reduce intrapulmonary shunt (Qs/Qt) by potentiating hypoxic pulmonary vasoconstriction, and there may also be direct and autonomically mediated effects of hypercapnia both on the lung vasculature and on the airways. Cardiac output usually increases as a consequence of hypercapnia and perhaps as a result of reduced intrathoracic pressure, further increasing PvO2 and CvO2, but the increase in cardiac output (CO) may tend to increase Qs/Qt as flow increases preferentially in unventilated lung. The reduction of mean airway pressure may directly increase Qs/Qt. Hypercapnia may affect the distribution of systemic blood flow both within organs and between organs. Limited clinical studies suggest that tissue oxygenation is usually unchanged or improved during permissive hypercapnia with increased CO, reduced arterio-venous O2 content difference and reduced blood lactate concentration. However, acute hypercapnia per se can reduce lactate production. Further studies are required of this complex issue.
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Affiliation(s)
- K G Hickling
- Department of Intensive Care, Christchurch Hospital, New Zealand
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