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Hoeker GS, James CC, Tegge AN, Gourdie RG, Smyth JW, Poelzing S. Attenuating loss of cardiac conduction during no-flow ischemia through changes in perfusate sodium and calcium. Am J Physiol Heart Circ Physiol 2020; 319:H396-H409. [PMID: 32678707 DOI: 10.1152/ajpheart.00112.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myocardial ischemia leads to conduction slowing, cell-to-cell uncoupling, and arrhythmias. We previously demonstrated that varying perfusate sodium (Na+) and calcium (Ca2+) attenuates conduction slowing and arrhythmias during simulated ischemia with continuous perfusion. Cardioprotection was selectively associated with widening of the perinexus, a gap junction adjacent nanodomain important to ephaptic coupling. It is unknown whether perfusate composition affects the perinexus or ischemic conduction during nonsimulated ischemia, when coronary flow is reduced or halted. We hypothesized that altering preischemic perfusate composition could facilitate perinexal expansion and attenuate conduction slowing during global ischemia. To test this hypothesis, ex vivo guinea pig hearts (n = 49) were Langendorff perfused with 145 or 153 mM Na+ and 1.25 or 2.0 mM Ca2+ and optically mapped during 30 min of no-flow ischemia. Altering Na+ and Ca2+ did not substantially affect baseline conduction. Increasing Na+ and decreasing Ca2+ both lowered pacing thresholds, whereas increasing Ca2+ narrowed perinexal width (Wp). A least squares mean estimate revealed that reduced perfusate Na+ and Ca2+ resulted in the most severe conduction slowing during ischemia. Increasing Na+ alone modestly attenuated conduction slowing, yet significantly delayed the median time to conduction block (10 to 16 min). Increasing both Na+ and Ca2+ selectively widened Wp during ischemia (22.7 vs. 15.7 nm) and attenuated conduction slowing to the greatest extent. Neither repolarization nor levels of total or phosphorylated connexin43 correlated with conduction slowing or block. Thus, perfusate-dependent widening of the perinexus preserved ischemic conduction and may be an adaptive response to ischemic stress.NEW & NOTEWORTHY Conduction slowing during acute ischemia creates an arrhythmogenic substrate. We have shown that extracellular ionic concentrations can alter conduction by modulating ephaptic coupling. Here, we demonstrate increased extracellular sodium and calcium significantly attenuate conduction slowing during no-flow ischemia. This effect was associated with selective widening of the perinexus, an intercalated disc nanodomain and putative cardiac ephapse. These findings suggest that acute changes in ephaptic coupling may serve as an adaptive response to ischemic stress.
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Affiliation(s)
- Gregory S Hoeker
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia
| | - Carissa C James
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia.,Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Roanoke, Virginia
| | - Allison N Tegge
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia.,Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - Robert G Gourdie
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia.,Virginia Tech Carilion School of Medicine, Roanoke, Virginia.,Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - James W Smyth
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia.,Virginia Tech Carilion School of Medicine, Roanoke, Virginia.,Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - Steven Poelzing
- Center for Heart and Reparative Medicine Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia.,Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Roanoke, Virginia.,Virginia Tech Carilion School of Medicine, Roanoke, Virginia.,Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
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Pagel PS, Crystal GJ. The Discovery of Myocardial Preconditioning Using Volatile Anesthetics: A History and Contemporary Clinical Perspective. J Cardiothorac Vasc Anesth 2018; 32:1112-1134. [DOI: 10.1053/j.jvca.2017.12.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Indexed: 12/24/2022]
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Ma L, Zhu J, Gao Q, Rebecchi MJ, Wang Q, Liu L. Restoring Pharmacologic Preconditioning in the Aging Heart: Role of Mitophagy/Autophagy. J Gerontol A Biol Sci Med Sci 2017; 72:489-498. [PMID: 27565512 DOI: 10.1093/gerona/glw168] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 07/27/2016] [Indexed: 12/16/2022] Open
Abstract
We previously reported that pretreatment with the potent antioxidant TEMPOL improves mitochondrial function and restores preconditioning in the aging heart. Because mitophagy is implicated in cardiac preconditioning and declines with age, this study was designed to investigate how age influences mitophagy in response to preconditioning and whether TEMPOL pretreatment improves it. Old (22-24 months) rats were pretreated with or without 4-week TEMPOL and compared with young (4-6 months) untreated rats. Cardioprotection induced by isoflurane (ISO) in vivo and in isolated cardiomyocytes in vitro was assessed following ischemia/reperfusion and simulated hypoxia/reoxygenation, respectively. Mitophagy was determined by comparing the levels/subcellular locations of key mitophagic markers using Western blotting and immunofluorescence techniques. ISO preconditioned the young but not old heart in vivo and in vitro. Aging impaired ISO-induced mitochondrial accumulation of PINK1 and Parkin, as well as mitochondrial ubiquitination, and baseline and ISO-induced autophagic flux assessed by LC3 puncta, membrane associated LC3-II and p62. Pretreatment with TEMPOL improved these processes and restored ISO preconditioning. Inhibition of autophagy abolished ISO-induced protection in cardiomyocytes from young and TEMPOL pretreated old rats. Thus, antioxidant pretreatment significantly improves mitophagic response to ISO in old myocardium, which may contribute to restoration of cardioprotection in senescent animals.
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Affiliation(s)
- Li Ma
- Department of Anesthesiology, School of Medicine, Stony Brook University, New York
| | - Jiang Zhu
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Qun Gao
- Department of Anesthesiology, School of Medicine, Stony Brook University, New York
| | - Mario J Rebecchi
- Department of Anesthesiology, School of Medicine, Stony Brook University, New York
| | - Qiang Wang
- Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China
| | - Lixin Liu
- Department of Anesthesiology, School of Medicine, Stony Brook University, New York
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Chen HSV, Body SC, Shernan SK. Myocardial Preconditioning: Characteristics, Mechanisms, and Clinical Applications. Semin Cardiothorac Vasc Anesth 2016. [DOI: 10.1177/108925329900300205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Perioperative myocardial ischemia and dysfunction re main prevalent after cardiac surgery despite the use of conventional measures to provide myocardial protec tion. Myocardial preconditioning is a powerful, endog enously regulated means of myocardial protection that may also have some clinical usage for patients undergo ing cardiac surgical procedures. The paradoxical con cept of using ischemia as a stimulus for myocardial protection has been studied extensively in animals and humans. The specific characteristics and constituents of preconditioning have been well identified. The mecha nism remains to be completely elucidated due to differ ences among species and experimental models. Some pharmacologic agents are capable of mimicking the classic mechanism of ischemic preconditioning. Pharma cologic and ischemic preconditioning may have signifi cant clinical use and therapeutic efficacy as a means of providing myocardial protection during cardiac surgery, especially in procedures that do not use cardioplegia and cardiopulmonary bypass, such as minimally inva sive coronary artery bypass grafting. This article re views the characteristics, mechanisms, potential clini cal applications, and therapeutic efficacy of myocardial preconditioning.
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Affiliation(s)
- Huei-Sheng Vincent Chen
- Departments of Medicine and Anesthesiology, Perioperative and Pain Medicine at Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Simon C. Body
- Departments of Medicine and Anesthesiology, Perioperative and Pain Medicine at Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Stanton K. Shernan
- Departments of Medicine and Anesthesiology, Perioperative and Pain Medicine at Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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Yang Y, Chen X, Min H, Song S, Zhang J, Fan S, Yi L, Wang H, Gu X, Ma Z, Gao Q. Persistent mitoKATP Activation Is Involved in the Isoflurane-induced Cytotoxicity. Mol Neurobiol 2016; 54:1101-1110. [DOI: 10.1007/s12035-016-9710-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 01/11/2016] [Indexed: 01/27/2023]
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Chen Q, Lesnefsky EJ. Blockade of electron transport during ischemia preserves bcl-2 and inhibits opening of the mitochondrial permeability transition pore. FEBS Lett 2011; 585:921-6. [PMID: 21354418 DOI: 10.1016/j.febslet.2011.02.029] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/01/2011] [Accepted: 02/22/2011] [Indexed: 12/31/2022]
Abstract
Myocardial ischemia damages the electron transport chain and augments cardiomyocyte death during reperfusion. To understand the relationship between ischemic mitochondrial damage and mitochondrial-driven cell death, the isolated perfused heart underwent global stop-flow ischemia with and without mitochondrial protection by reversible blockade of electron transport. Ischemic damage to electron transport depleted bcl-2 content and favored mitochondrial permeability transition (MPT). Reversible blockade of electron transport preserved bcl-2 content and attenuated calcium-stimulated mitochondrial swelling. Thus, the damaged electron transport chain leads to bcl-2 depletion and MPT opening. Chemical inhibition of bcl-2 with HA14-1 also dramatically increased mitochondrial swelling, augmented by exogenous H(2)O(2) stress, indicating that bcl-2 depleted mitochondria are poised to undergo MPT during the enhanced oxidative stress of reperfusion.
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Affiliation(s)
- Qun Chen
- Department of Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298, USA
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Lemoine S, Buléon C, Rouet R, Ivascau C, Babatasi G, Massetti M, Gérard JL, Hanouz JL. Bradykinin and adenosine receptors mediate desflurane induced postconditioning in human myocardium: role of reactive oxygen species. BMC Anesthesiol 2010; 10:12. [PMID: 20670410 PMCID: PMC2919536 DOI: 10.1186/1471-2253-10-12] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Accepted: 07/29/2010] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Desflurane during early reperfusion has been shown to postcondition human myocardium, in vitro. We investigated the role of adenosine and bradykinin receptors, and generation of radical oxygen species in desflurane-induced postconditioning in human myocardium. METHODS We recorded isometric contraction of human right atrial trabeculae hanged in an oxygenated Tyrode's solution (34 degrees Celsius, stimulation frequency 1 Hz). After a 30-min hypoxic period, desflurane 6% was administered during the first 5 min of reoxygenation. Desflurane was administered alone or with pretreatment of N-mercaptopropionylglycine, a reactive oxygen species scavenger, 8-(p-Sulfophenyl)theophylline, an adenosine receptor antagonist, HOE140, a selective B2 bradykinin receptor antagonist. In separate groups, adenosine and bradykinin were administered during the first minutes of reoxygenation alone or in presence of N-mercaptopropionylglycine. The force of contraction of trabeculae was recorded continuously. Developed force at the end of a 60-min reoxygenation period was compared (mean +/- standard deviation) between the groups by a variance analysis and post hoc test. RESULTS Desflurane 6% (84 +/- 6% of baseline) enhanced the recovery of force after 60-min of reoxygenation as compared to control group (51 +/- 8% of baseline, P < 0.0001). N-mercaptopropionylglycine (54 +/- 3% of baseline), 8-(p-Sulfophenyl)theophylline (62 +/- 9% of baseline), HOE140 (58 +/- 6% of baseline) abolished desflurane-induced postconditioning. Adenosine (80 +/- 9% of baseline) and bradykinin (83 +/- 4% of baseline) induced postconditioning (P < 0.0001 vs control), N-mercaptopropionylglycine abolished the beneficial effects of adenosine and bradykinin (54 +/- 8 and 58 +/- 5% of baseline, respectively). CONCLUSIONS In vitro, desflurane-induced postconditioning depends on reactive oxygen species production, activation of adenosine and bradykinin B2 receptors. And, the cardioprotective effect of adenosine and bradykinin administered at the beginning of reoxygenation, was mediated, at least in part, through ROS production.
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Affiliation(s)
- Sandrine Lemoine
- Laboratory of Experimental Anesthesiology and Cellular Physiology, IFR 146 ICORE, Université de Caen Basse Normandie, CHU Caen, Avenue de la Cote de Nacre, 14033 Caen, France.
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Role of caveolin-3 and glucose transporter-4 in isoflurane-induced delayed cardiac protection. Anesthesiology 2010; 112:1136-45. [PMID: 20418694 DOI: 10.1097/aln.0b013e3181d3d624] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Caveolae are small, flask-like invaginations of the plasma membrane. Caveolins are structural proteins found in caveolae that have scaffolding properties to allow organization of signaling. The authors tested the hypothesis that delayed cardiac protection induced by volatile anesthetics is caveolae or caveolin dependent. METHODS An in vivo mouse model of ischemia-reperfusion injury with delayed anesthetic preconditioning (APC) was tested in wild-type, caveolin-1 knockout, and caveolin-3 knockout mice. Mice were exposed to 30 min of oxygen or isoflurane and allowed to recover for 24 h. After 24 h recovery, mice underwent 30-min coronary artery occlusion followed by 2 h of reperfusion at which time infarct size was determined. Biochemical assays were also performed in excised hearts. RESULTS Infarct size as a percent of the area at risk was reduced by isoflurane in wild-type (24.0 +/- 8.8% vs. 45.1 +/- 10.1%) and caveolin-1 knockout mice (27.2 +/- 12.5%). Caveolin-3 knockout mice did not show delayed APC (41.5 +/- 5.0%). Microscopically distinct caveolae were observed in wild-type and caveolin-1 knockout mice but not in caveolin-3 knockout mice. Delayed APC increased the amount of caveolin-3 protein but not caveolin-1 protein in discontinuous sucrose-gradient buoyant fractions. In addition, glucose transporter-4 was increased in buoyant fractions, and caveolin-3/glucose transporter-4 colocalization was observed in wild-type and caveolin-1 knockout mice after APC. CONCLUSIONS These results show that delayed APC involves translocation of caveolin-3 and glucose transporter-4 to caveolae, resulting in delayed protection in the myocardium.
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Raphael J. Physiology and Pharmacology of Myocardial Preconditioning. Semin Cardiothorac Vasc Anesth 2010; 14:54-59. [DOI: 10.1177/1089253210363008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Perioperative myocardial ischemia and infarction are not only major sources of morbidity and mortality in patients undergoing surgery but also important causes of prolonged hospital stay and resource utilization. Ischemic and pharmacological preconditioning and postconditioning have been known for more than two decades to provide protection against myocardial ischemia and reperfusion and limit myocardial infarct size in many experimental animal models, as well as in clinical studies (1-3). This paper will review the physiology and pharmacology of ischemic and drug-induced preconditioning and postconditioning of the myocardium with special emphasis on the mechanisms by which volatile anesthetics provide myocardial protection. Insights gained from animal and clinical studies will be presented and reviewed and recommendations for the use of perioperative anesthetics and medications will be given.
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Affiliation(s)
- Jacob Raphael
- University of Virginia Health Center, Charlottesville, VA, USA,
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Tao X, Lu LQ, Xu Q, Li SR, Lin MT. Cardioprotective effects of anesthetic preconditioning in rats with ischemia-reperfusion injury: propofol versus isoflurane. J Zhejiang Univ Sci B 2010; 10:740-7. [PMID: 19816998 DOI: 10.1631/jzus.b0920119] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE We compare the cardioprotective effects of anesthetic preconditioning by propofol and/or isoflurane in rats with ischemia-reperfusion injury. METHODS Male adult Wistar rats were subjected to 60 min of anterior descending coronary artery occlusion followed by 120 min of reperfusion. Before the long ischemia, anesthetics were administered twice for 10 min followed by 5 min washout. Isoflurane was inhaled at 1 MAC (0.016) in I group, whereas propofol was inhaled intravenously at 37.5 mg/(kg(h) in P group. A combination of isoflurane and propofol was administered simultaneously in I+P group. RESULTS In control (without anesthetic preconditioning, C group), remarkable myocardial infarction and apoptosis accompanied by an increased level of cardiac troponin T were noted 120 min after ischemia-reperfusion. As compared to those of control group, I and P groups had comparable cardioprotection. In addition, I+P group shares with I and P groups the comparable cardioprotective effects in terms of myocardial infarction and cardiac troponin T elevation. CONCLUSION A combination of isoflurane and propofol produced no additional cardioprotection.
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Affiliation(s)
- Xing Tao
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100069, China
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Huffmyer J, Raphael J. Physiology and pharmacology of myocardial preconditioning and postconditioning. Semin Cardiothorac Vasc Anesth 2009; 13:5-18. [PMID: 19329471 DOI: 10.1177/1089253208330709] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Perioperative myocardial ischemia and infarction are not only major sources of morbidity and mortality in patients undergoing surgery but also important causes of prolonged hospital stay and resource utilization. Ischemic and pharmacological preconditioning and postconditioning have been known for more than 2 decades to provide protection against myocardial ischemia and reperfusion and limit myocardial infarct size in many experimental animal models, as well as in clinical studies. This article reviews the physiology and pharmacology of ischemic and drug-induced preconditioning and postconditioning of the myocardium with special emphasis on the mechanisms by which volatile anesthetics provide myocardial protection. Insights gained from animal and clinical studies are reviewed and recommendations given for the use of perioperative anesthetics and medications.
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Affiliation(s)
- Julie Huffmyer
- Department of Anesthesiology, University of Virginia Health Sciences System, Charlottesville, Virginia 22908, USA
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Early Anesthetic Preconditioning in Mixed Cortical Neuronal-Glial Cell Cultures Subjected to Oxygen-Glucose Deprivation: The Role of Adenosine Triphosphate Dependent Potassium Channels and Reactive Oxygen Species in Sevoflurane-Induced Neuroprotection. Anesth Analg 2009; 108:955-63. [DOI: 10.1213/ane.0b013e318193fee7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kitagawa H, Yamazaki T, Akiyama T, Nosaka S, Mori H. Isoflurane attenuates myoglobin release during ischemic and/or reperfusion periods. Acta Anaesthesiol Scand 2008; 52:650-7. [PMID: 18419719 DOI: 10.1111/j.1399-6576.2008.01601.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Recently, we have developed cardiac microdialysis for detection of protein leakage from the injured myocardium. We examined whether the exposures to isoflurane would exert a beneficial effect on myocardial injury caused by ischemia or reperfusion. METHODS A dialysis probe was implanted into the left ventricle free wall in the rabbits. The dialysate myoglobin level served as an index of myocardial interstitial myoglobin levels. Rabbits were randomly assigned to one of three groups: (1) without exposure to isoflurane (vehicle, n=6), (2) inhale 1 MAC isoflurane once for 30 min (ISO30-1, n=6), and (3) twice for 30 min (ISO30-2, n=6). All rabbits underwent 30 min of coronary occlusion and 60 min of reperfusion. To determine whether the isoflurane induced myocardial protection against chemical hypoxia, sodium cyanide (30 mM) was administered and dialysate myoglobin levels were measured with (n=6) and without pre-exposure to isoflurane twice for 30 min (n=6). RESULTS In all three groups dialysate myoglobin levels were increased by coronary occlusion and furthermore augmented by reperfusion. In comparison with the vehicle group, the ISO30-1 group suppressed only the increase in the dialysate myoglobin level during reperfusion. The ISO30-2 group suppressed during both the ischemic and reperfusion periods. Cyanide induced increases in dialysate myoglobin levels. These increments in dialysate myoglobin levels were suppressed by repeated exposure to isoflurane. CONCLUSION Repeated exposure to isoflurane suppressed myocardial myoglobin release caused by both ischemia and reperfusion injury. Isoflurane may provide protection against myocardial ischemia/reperfusion and hypoxic injuries.
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Affiliation(s)
- H Kitagawa
- Department of Anesthesiology, Shiga University of Medical Science, Shiga, Japan.
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Kobayashi I, Kokita N, Namiki A. Propofol attenuates ischaemia-reperfusion injury in the rat heart in vivo. Eur J Anaesthesiol 2008; 25:144-51. [PMID: 17697397 DOI: 10.1017/s0265021507001342] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND We have previously demonstrated, in the isolated rat heart, that propofol attenuates hydrogen peroxide-induced damage and ischaemia-reperfusion injury, and that the beneficial effect of propofol is correlated with reduction of the lipid peroxidation. This study was designed to evaluate whether propofol has a cardioprotective effect against ischaemia-reperfusion injury in a rat model in vivo. METHODS Adult rats were anaesthetized with pentobarbital 10 mg kg(-1) h(-1) alone (control group), pentobarbital 10 or 20 mg kg(-1) h(-1) + Intralipid as a vehicle (Pent-10, Pent-20 group), propofol 10 or 20 mg kg(-1) h(-1) (Prop-10, Prop-20 group) intravenously throughout the experiment. The left anterior descending coronary artery was occluded for 30 min followed by 120 min of reperfusion. Infarct size was determined at the end of reperfusion. The tissue concentration of malondialdehyde was measured at 30 min after reperfusion to evaluate lipid peroxidation. RESULTS The infarct sizes (% of area at risk) were significantly smaller in the Prop-10 (54 +/- 11%; P < 0.01 vs. control) and Prop-20 (39 +/- 8%; P < 0.01 vs. control) groups than in the control (68 +/- 9%), Pent-10 (69 +/- 13%) and Pent-20 (68 +/- 14%) groups (n = 12). In the Pent-10 and Pent-20 groups, ischaemia-reperfusion produced significant increases in the values for tissue malondialdehyde (0.72 +/- 0.24 micromol mg protein-1; P < 0.05 and 0.63 +/- 0.33 micromol mg protein-1; P < 0.05 vs. 0.46 +/- 0.22 micromol mg protein-1 in non-ischaemic hearts, n = 8). However, the values of malondialdehyde in the Prop-10 and -20 groups were suppressed by 41% and 63%, respectively, compared with the Pent-10 group (P < 0.01). CONCLUSION Our results suggest that propofol could be cardioprotective against ischaemia-reperfusion injury dose dependently in a rat model in vivo and that the beneficial action of propofol may be correlated with its antioxidant effect.
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Affiliation(s)
- I Kobayashi
- Asahikawa Red Cross Hospital, Department of Anesthesiology, Asahikawa, Hokkaido, Japan.
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Pratt PF, Wang C, Weihrauch D, Bienengraeber MW, Kersten JR, Pagel PS, Warltier DC. Cardioprotection by volatile anesthetics: new applications for old drugs? Curr Opin Anaesthesiol 2006; 19:397-403. [PMID: 16829721 DOI: 10.1097/01.aco.0000236139.31099.b5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Pharmacological interventions may play a prominent role in reducing organ damage in response to physiologic stress. A growing body of evidence indicates that volatile anesthetics exert protective effects against ischemia-reperfusion injury in vivo. Administration of volatile anesthetics before prolonged coronary artery occlusion and reperfusion has been shown to produce cardioprotection, a phenomenon termed anesthetic-induced preconditioning. Endogenous signal transduction proteins, reactive oxygen species, mitochondria, and ion channels have been implicated in anesthetic-induced preconditioning, and new data regarding the triggering and effector roles for these various components have been discovered that advance our understanding of the mechanisms responsible for anesthetic-induced preconditioning. This review will update and integrate these recent data into the current mechanistic model of anesthetic-induced preconditioning. RECENT FINDINGS Despite a wealth of data from animal studies, the mechanism by which preconditioning with volatile anesthetics alleviates ischemic injury remains incompletely understood. Recent data have identified important interactions between reactive oxygen species and key intracellular signal transduction enzymes and proteins implicated in anesthetic-induced preconditioning. SUMMARY This review highlights the major recent findings examining mechanisms of volatile anesthetic cardioprotection.
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Affiliation(s)
- Phillip F Pratt
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Lee MC, Chen CH, Kuo MC, Kang PL, Lo A, Liu K. Isoflurane preconditioning-induced cardio-protection in patients undergoing coronary artery bypass grafting. Eur J Anaesthesiol 2006; 23:841-7. [PMID: 16507192 DOI: 10.1017/s0265021506000354] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2006] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVES Ischaemic preconditioning is commonly regarded as one of the most powerful protective mechanisms against a subsequent lethal ischaemic injury during coronary artery bypass graft surgery but is not practiced routinely. Experimentally, isoflurane, a commonly used volatile anaesthetic agent, provides myocardial protection through a signal transduction cascade that is remarkably similar to the pathways identified in ischaemic preconditioning. The aim of our study was to investigate whether pre-ischaemic administration of isoflurane exerted protection against prolonged ischaemia with functional recovery and reduced necrosis among patients undergoing coronary artery bypass graft surgery. METHODS Forty patients scheduled for elective coronary artery bypass graft operations were prospectively randomized into the control or isoflurane groups. In the isoflurane group, isoflurane 2.5 minimum alveolar concentration was administered for 15 min followed by a 5-min washout period before aortic cross-clamping. The control group received a time-matched period of isoflurane-free cardiopulmonary bypass. The conduction of anaesthesia and surgery were standardized in all patients. Haemodynamic data, troponin I release and inotropic support were measured and recorded perioperatively. RESULTS There were no adverse effects related to isoflurane administration. In the isoflurane group, the mean cardiac index after cardiopulmonary bypass was significantly higher than the pre-bypass value (P < 0.05), whereas no difference was found in the control group. At 15 min after cardiopulmonary bypass and 6 h after surgery, the changes in cardiac index and stroke volume index were significantly higher in the isoflurane group than in the control group (P < 0.05). There was a consistently lower release of troponin I in the isoflurane group compared to the control group. Compared to the controls, the mean troponin I level was significantly reduced in the isoflurane group at 24 h after surgery (P = 0.042). CONCLUSIONS The present results support the preconditioning effect of isoflurane in patients undergoing coronary artery bypass graft surgery as clinically feasible and providing optimal cardiac protection.
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Affiliation(s)
- M-C Lee
- Kaohsiung Veterans General Hospital, Department of Anesthesiology, Taiwan
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Fujita H, Ogura T, Tamagawa M, Uemura H, Sato T, Ishida A, Imamaki M, Kimura F, Miyazaki M, Nakaya H. A key role for the subunit SUR2B in the preferential activation of vascular KATP channels by isoflurane. Br J Pharmacol 2006; 149:573-80. [PMID: 17001304 PMCID: PMC2014679 DOI: 10.1038/sj.bjp.0706891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE It has been postulated that isoflurane, a volatile anaesthetic, produces vasodilatation through activation of ATP-sensitive K+ (KATP) channels. However, there is no direct evidence for the activation of vascular KATP channels by isoflurane. This study was conducted to examine the effect of isoflurane on vascular KATP channels and compare it with that on cardiac KATP channels. EXPERIMENTAL APPROACH Effects of isoflurane on KATP channels were examined in aortic smooth muscle cells and cardiomyocytes of the mouse using patch clamp techniques. Effects of the anaesthetic on the KATP channels with different combinations of the inward rectifier pore subunits (Kir6.1 and Kir6.2) and sulphonylurea receptor subunits (SUR2A and SUR2B) reconstituted in a heterologous expression system were also examined. KEY RESULTS Isoflurane increased the coronary flow in Langendorff-perfused mouse hearts in a concentration-dependent manner, which was abolished by 10 microM glibenclamide. In enzymically-dissociated aortic smooth muscle cells, isoflurane evoked a glibenclamide-sensitive current (i.e. KATP current). In isolated mouse ventricular cells, however, isoflurane failed to evoke the KATP current unless the KATP current was preactivated by the K+ channel opener pinacidil. Although isoflurane readily activated the Kir6.1/SUR2B channels (vascular type), the volatile anesthetic could not activate the Kir6.2/SUR2A channels (cardiac type) expressed in HEK293 cells. Isoflurane activated a glibenclamide-sensitive current in HEK293 cells expressing Kir6.2/SUR2B channels. CONCLUSION AND IMPLICATIONS Isoflurane activates KATP channels in vascular smooth muscle cells and produces coronary vasodilation in mouse hearts. SUR2B may be important for the activation of vascular-type KATP channels by isoflurane.
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MESH Headings
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/physiology
- Anesthetics, Inhalation/pharmacology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiology
- Cell Line
- Cells, Cultured
- Coronary Circulation/drug effects
- Dose-Response Relationship, Drug
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/genetics
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/physiology
- Glyburide/pharmacology
- Humans
- In Vitro Techniques
- Isoflurane/pharmacology
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Mice
- Mice, Inbred C57BL
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- Patch-Clamp Techniques/methods
- Pinacidil/pharmacology
- Potassium Channels/genetics
- Potassium Channels/physiology
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/physiology
- Receptors, Drug/genetics
- Receptors, Drug/physiology
- Sulfonylurea Receptors
- Theophylline/pharmacology
- Transfection/methods
- Vasodilation/drug effects
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Affiliation(s)
- H Fujita
- Department of Pharmacology, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
- Department of General Surgery, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - T Ogura
- Department of Pharmacology, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - M Tamagawa
- Department of Pharmacology, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - H Uemura
- Department of Pharmacology, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - T Sato
- Department of Pharmacology, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - A Ishida
- Department of General Surgery, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - M Imamaki
- Department of General Surgery, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - F Kimura
- Department of General Surgery, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - M Miyazaki
- Department of General Surgery, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
| | - H Nakaya
- Department of Pharmacology, Chiba University Graduate School of Medicine Chuo-ku, Chiba, Japan
- Author for correspondence:
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Masui K, Kashimoto S, Furuya A, Oguchi T. Isoflurane and sevoflurane during reperfusion prevent recovery from ischaemia in mitochondrial KATP channel blocker pretreated hearts. Eur J Anaesthesiol 2006; 23:123-9. [PMID: 16426466 DOI: 10.1017/s0265021505002024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2005] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE Inhalation anaesthetics given only during post-ischaemic reperfusion have some protective effect against reperfusion injury in the heart. Adenosine triphosphate-regulated mitochondrial potassium channels have been shown to be an important mediator of cardioprotection. Thus, we investigated whether 5-hydroxydecanoate, a putative mitochondrial potassium channel blocker, prevents the cardioprotective effect of volatile anaesthetics. METHODS Forty rats were randomly allocated to four groups of equal size: control group, 5-hydroxydecanoate group, 5-hydroxydecanoate + sevoflurane group and 5-hydroxydecanoate + isoflurane group. Seven minutes after the start of perfusion, normal saline (control group) or 5-hydroxydecanoate (the other groups) was administered. Ten minutes after the start of perfusion, the heart was rendered globally ischaemic for 10 min. One minute before the end of the ischaemic period, 2.7% sevoflurane or 1.4% isoflurane were administered in the 5-hydroxydecanoate + sevoflurane or 5-hydroxydecanoate + isoflurane groups respectively. The heart was reperfused for 10 min. RESULTS Adenosine triphosphate content at the end of reperfusion in the 5-hydroxydecanoate + sevoflurane group was significantly lower (P < 0.05) than those in the control and the 5-hydroxydecanoate + isoflurane groups (19.9 +/- 8.7, 28.1 +/- 3.4 and 30.4 +/- 2.3 micromol g(-1), respectively). In addition, the combination of inhalation anaesthetics and 5-hydroxydecanoate decreased the ratios of recovered hearts from ischaemia (5-hydroxydecanoate + sevoflurane group: 40%, 5-hydroxydecanoate + isoflurane group 50%). CONCLUSION 5-hydroxydecanoate alone caused no significant changes in haemodynamics and myocardial metabolism. However, the combination of 5-hydroxydecanoate and volatile anaesthetics impaired the recovery from ischaemia. Although animal data cannot be extrapolated to human beings, we suggest that more attention be paid to patients on sulphonylurea drugs, which inhibit potassium channels, when they are anaesthetized with volatile anaesthetics.
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Affiliation(s)
- K Masui
- University of Yamanashi, Faculty of Medicine, Department of Anesthesiology, Yamanashi, Japan.
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20
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Buchinger H, Grundmann U, Ziegeler S. [Myocardial preconditioning with volatile anesthetics. General anesthesia as protective intervention?]. Anaesthesist 2005; 54:861-70. [PMID: 16044231 DOI: 10.1007/s00101-005-0902-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Reduction of the perioperative cardiovascular risk with pharmacological interventions plays a prominent role in routine anesthesia practice. For example, perioperative beta-blockade is well established in anesthesiological treatment of patients. There is a growing body of evidence supporting the cardioprotective effects of volatile anesthetics known as anesthetic-induced preconditioning. There are numerous and complex data from animal studies. The mechanisms of anesthetic-induced preconditioning have been extensively studied but have still not been clearly identified. Initial clinical data show the cardioprotective effects of volatile agents by looking at parameters of myocardial function and laboratory values and therefore, the question of the relevance of these data for routine clinical practice has been raised. This review gives a summary of the currently available data focusing on the mechanisms of anesthesiological preconditioning and clinical studies.
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Affiliation(s)
- H Buchinger
- Klinik für Anästhesiologie und Intensivmedizin, Universitätsklinikum des Saarlandes, 66421 Homburg/Saar, Germany
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21
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Raphael J, Rivo J, Gozal Y. Isoflurane-induced myocardial preconditioning is dependent on phosphatidylinositol-3-kinase/Akt signalling. Br J Anaesth 2005; 95:756-63. [PMID: 16286350 DOI: 10.1093/bja/aei264] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Isoflurane and other volatile anaesthetics have a cardioprotective effect and limit myocardial infarct size to the same extent as ischaemic preconditioning. Phosphatidylinositol-3-kinase (PI3K) was found to play a key role in myocardial protection by ischaemic preconditioning. The aim of the present investigation was to evaluate whether isoflurane-induced myocardial preconditioning is dependent on PI3K signalling. METHODS Using a model of regional myocardial ischaemia and reperfusion, New Zealand White rabbits were subjected to 40 min of regional myocardial ischaemia followed by 120 min of reperfusion. The rabbits were randomly assigned to one of the following six experimental groups: sham-operated controls (n=5); ischaemia and reperfusion controls (n=8); isoflurane preconditioning (n=8); a PI3K inhibitor, wortmannin (0.6 mg kg(-1) i.v.) + isoflurane (n=8); and wortmannin+ischaemia and reperfusion (n=8). An additional control group of sham operation+ wortmannin (n=5) was also included. Myocardial injury was assessed by measuring the serum concentration of the MB fraction of creatine kinase (CK-MB) and infarct size was assessed by 2,3,5-triphenyl tetrazolium chloride staining. Phosphorylation of Akt, a downstream target of PI3K, was assessed by western blotting. RESULTS Isoflurane preconditioning was seen as reduced infarct size compared with control animals: 24 (4) and 41 (5)% respectively (P<0.05). Wortmannin inhibited this cardioprotective effect with myocardial infarct size at 44 (3)% (not significant). Akt phosphorylation was increased after isoflurane preconditioning, but administration of wortmannin blocked this effect. CONCLUSIONS Our data demonstrate that isoflurane protects the heart against ischaemia and decreases myocardial infarction by activation of PI3K.
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Affiliation(s)
- J Raphael
- Department of Anesthesiology and Critical Care Medicine, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
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22
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Park HP, Jeon YT, Hwang JW, Kang H, Lim SW, Kim CS, Oh YS. Isoflurane preconditioning protects motor neurons from spinal cord ischemia: its dose-response effects and activation of mitochondrial adenosine triphosphate-dependent potassium channel. Neurosci Lett 2005; 387:90-4. [PMID: 16076524 DOI: 10.1016/j.neulet.2005.06.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Revised: 06/24/2005] [Accepted: 06/25/2005] [Indexed: 11/21/2022]
Abstract
We examined in a rabbit model of transient spinal cord ischemia (SCI) whether isoflurane (Iso) preconditioning induces ischemic tolerance to SCI in a dose-response manner, and whether this effect is dependent on mitochondrial adenosine triphosphate-dependent potassium (K(ATP)) channel. Eighty-six rabbits were randomly assigned to 10 groups: Control group (n=8) received no pretreatment. Ischemic preconditioning (IPC) group (n=8) received 5 min of IPC 30 min before SCI. The Iso 1, Iso 2 and Iso 3 groups (n=10, 9, 8) underwent 30 min of 1.05, 2.1 and 3.15% Iso inhalation commencing 45 min before SCI. The Iso 1HD, Iso 2HD and Iso 3HD groups (n=9, 9, 8) each received a specific mitochondrial K(ATP) channel blocker, 5-hydroxydecanoic acid (5HD, 20mg/kg), 5 min before each respective Iso inhalation. The 5HD group (n=8) received 5HD without Iso inhalation. The sham group (n=9) had no SCI. SCI was produced by infra-renal aortic occlusion via the inflated balloon of a Swan-Ganz catheter for 20 min. The Iso 1, Iso 2 and Iso 3 groups showed a better neurologic outcome and more viable motor nerve cells (VMNCs) in the anterior spinal cord 72 h after reperfusion than the control group (p<0.05). Iso 3 group showed a better neurologic outcome and more VMNCs than Iso 1 group (p<0.05). And, the Iso 1, Iso 2 and Iso 3 groups showed a better neurologic outcome and higher VMNC numbers than the corresponding Iso 1HD, Iso 2HD and Iso 3HD groups (p<0.05). This study demonstrates that Iso preconditioning protects the spinal cord against neuronal damage due to SCI in a dose-response manner via the activation of mitochondrial K(ATP) channels.
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Affiliation(s)
- Hee-Pyoung Park
- Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Seongnam 463-707, Republic of Korea
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23
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Weber NC, Schlack W. The concept of anaesthetic-induced cardioprotection: mechanisms of action. Best Pract Res Clin Anaesthesiol 2005; 19:429-43. [PMID: 16013692 DOI: 10.1016/j.bpa.2005.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mechanisms by which ischaemia reperfusion injury can be influenced have been the subject of extensive research in the last decades. Early restoration of arterial blood flow and surgical measures to improve the ischaemic tolerance of the tissue are the main therapeutic options currently in clinical use. In experimental settings ischaemic preconditioning has been described as protecting the heart, but the practical relevance of interventions by ischaemic preconditioning is strongly limited to these experimental situations. However, ischaemia reperfusion of the heart routinely occurs in a variety of clinical situations, such as during transplantations, coronary artery bypass grafting or vascular surgery. Moreover, ischaemia reperfusion injury occurs without any surgical intervention as a transient myocardial ischaemia during a stressful anaesthetic induction. Besides ischaemic preconditioning, another form of preconditioning was discovered over 10 years ago: the anaesthetic-induced preconditioning. There is increasing evidence that anaesthetic agents can interact with the underlying pathomechanisms of ischaemia reperfusion injury and protect the myocardium by a preconditioning mechanism. Hence, the anaesthetist himself can substantially influence the critical situation of ischaemia reperfusion during the operation by choosing the right anaesthetic. A better understanding of the underlying mechanisms of anaesthetic-induced cardioprotection not only reflects an important increase in scientific knowledge but may also offer the new perspective of using different anaesthetics for targeted intraoperative myocardial protection. There are three time windows when a substance may interact with the ischaemia reperfusion injury process: (1) during ischaemia, (2) after ischaemia (i.e. during reperfusion), and (3) before ischaemia (preconditioning).
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Affiliation(s)
- Nina C Weber
- Department of Anaesthesiology, University of Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany.
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24
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Weber NC, Preckel B, Schlack W. The effect of anaesthetics on the myocardium - new insights into myocardial protection. Eur J Anaesthesiol 2005; 22:647-57. [PMID: 16163910 DOI: 10.1017/s0265021505001080] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A variety of laboratory and clinical studies clearly indicate that exposure to anaesthetic agents can lead to a pronounced protection of the myocardium against ischaemia-reperfusion injury. Several changes in the protein structure of the myocardium that may mediate this cardioprotection have been identified. Ischaemia-reperfusion of the heart occurs in a variety of clinical situations including transplantations, coronary artery bypass grafting or vascular surgery. Ischaemia may also occur during a stressful anaesthetic induction. Early restoration of arterial blood flow and measures to improve the ischaemic tolerance of the tissue are the main therapeutic options (i.e. cardioplegia and betablockers). There exists increasing evidence that anaesthetic agents interact with the mechanisms of ischaemia-reperfusion injury and protect the myocardium by a 'preconditioning' and a 'postconditioning' mechanism. Hence, the anaesthesiologist may substantially influence the critical situation of ischaemia-reperfusion during surgery by choosing the appropriate anaesthetic agent. This review summarizes the current understanding of the mechanisms of anaesthetic-induced myocardial protection. In this context, three time windows of anaesthetic-induced cardioprotection are discussed: administration (1) during ischaemia, (2) after ischaemia-during reperfusion (postconditioning) and (3) before ischaemia (preconditioning). Possible clinical implications of these interventions will be reviewed.
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Affiliation(s)
- N C Weber
- University Hospital Düsseldorf, Department of Anaesthesiology, Düsseldorf, Germany
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Gozal Y, Raphael J, Rivo J, Berenshtein E, Chevion M, Drenger B. Isoflurane does not mimic ischaemic preconditioning in decreasing hydroxyl radical production in the rabbit. Br J Anaesth 2005; 95:442-7. [PMID: 16040636 DOI: 10.1093/bja/aei203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Reactive oxygen species are an important mediator in isoflurane-induced myocardial preconditioning. However, hydroxyl radicals are also released during reperfusion after regional ischaemia. The purpose of the present study was to test whether ischaemic preconditioning and isoflurane would influence the production of hydroxyl radicals during reperfusion. METHODS After i.v. administration of salicylate 100 mg kg(-1) and a 30 min stabilization period, New Zealand White rabbits were subjected to 40 min of regional myocardial ischaemia and 2 h of reperfusion. Ischaemic preconditioning was elicited by 5 min ischaemia followed by 10 min reperfusion (before the 40 min ischaemia). In another group, isoflurane (2.1%) was administered for 30 min, followed by 15 min washout, before the long ischaemia. Area at risk and infarct size were assessed by blue dye injection and tetrazolium chloride staining. We quantified the level of OH-mediated conversion of salicylate to its dihydrobenzoate derivatives (2,3- and 2,5-DHBAs). Normalized values of the DHBAs (ng DHBA per mg salicylate) were calculated. RESULTS Mean (se) infarct size was 57 (6)% of the risk area in the untreated controls. This was significantly smaller in the ischaemic preconditioning and isoflurane groups: 22 (5) and 23 (6)% respectively. At 10 min of reperfusion, ischaemic preconditioning limited the mean increase in 2,3-DHBA to 24% from baseline, compared with 81% in control and 74% in the isoflurane group. Normalized 2,5-DHBA was maximally increased by 75% in the untreated group, 4 min after reperfusion. Ischaemic preconditioning significantly inhibited this increase (24% increase from baseline, P<0.01). However, the increase observed in the isoflurane group was not different from control (71%). CONCLUSIONS As already known, ischaemic preconditioning and isoflurane markedly reduced infarct size. However, only ischaemic preconditioning decreased postischaemic production of hydroxyl radicals. These different effects suggest different protective mechanisms at the cellular level.
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Affiliation(s)
- Y Gozal
- Department of Anesthesiology and Critical Care Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
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Isoflurane may not influence postoperative cardiac troponin I release and clinical outcome in adult cardiac surgery. Eur J Anaesthesiol 2004. [DOI: 10.1097/00003643-200409000-00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Nakae Y, Kohro S, Hogan QH, Bosnjak ZJ. Intracellular Mechanism of Mitochondrial Adenosine Triphosphate-Sensitive Potassium Channel Activation with Isoflurane. Anesth Analg 2003; 97:1025-1032. [PMID: 14500152 DOI: 10.1213/01.ane.0000077072.67502.cc] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
UNLABELLED The precise mechanism of isoflurane and mitochondrial adenosine triphosphate-sensitive potassium channel (mitoK(ATP)) interaction is still unclear, although the mitoK(ATP) is involved in isoflurane-induced preconditioning. We examined the role of various intracellular signaling systems in mitoK(ATP) activation with isoflurane. Mitochondrial flavoprotein fluorescence (MFF) was measured to quantify mitoK(ATP) activity in guinea pig cardiomyocytes. To confirm isoflurane-induced MFF, cells were exposed to Tyrode's solution containing either isoflurane (1.0 +/- 0.1 mM) or diazoxide and then both drugs together (n = 10 each). In other studies, the following drugs were each added during isoflurane administration: adenosine or the adenosine receptor antagonist 8-(p-sulfophenyl)-theophylline (SPT); the protein kinase C (PKC) activators phorbol-12-myristate-13-acetate (PMA) and phorbol-12,13-dibutyrate (PDBu); the PKC inhibitors polymyxin B and staurosporine; the tyrosine kinase inhibitor lavendustin A; or the mitogen-activated protein kinase inhibitor SB203580 (n = 10 each). Isoflurane potentiated MFF induced by diazoxide (100 micro M), and diazoxide also increased isoflurane-induced MFF. PMA (0.2 micro M), PDBu (1 micro M), and adenosine (100 micro M) induced MFF. However, SPT (100 micro M), polymyxin B (50 micro M), staurosporine (200 nM), lavendustin A (0.5 micro M), and SB203580 (10 micro M) all failed to inhibit the effect of isoflurane. Our results show that isoflurane, adenosine, and PKC activate mitoK(ATP). However, our data do not support an action of isoflurane through pathways involving adenosine, PKC, tyrosine kinase, or mitogen-activated protein kinase. These results suggest that isoflurane may directly activate mitoK(ATP). IMPLICATIONS Our results show that isoflurane activates mitochondrial adenosine triphosphate-sensitive potassium (mitoK(ATP)) channels, but not through pathways involving adenosine, protein kinase C, tyrosine kinase, or p38 mitogen-activated protein kinase. Isoflurane may directly activate mitoK(ATP) channels.
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Affiliation(s)
- Yuri Nakae
- Departments of *Anesthesiology and †Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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Nakae Y, Kwok WM, Bosnjak ZJ, Jiang MT. Isoflurane activates rat mitochondrial ATP-sensitive K+ channels reconstituted in lipid bilayers. Am J Physiol Heart Circ Physiol 2003; 284:H1865-71. [PMID: 12573994 DOI: 10.1152/ajpheart.01031.2002] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activation of mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channels is critical in myocardial protection induced by preconditioning with volatile anesthetics or brief periods of ischemia. In this study, we characterized rat mitoK(ATP) channels reconstituted in lipid bilayers and examined their direct regulation by isoflurane. Mitochondria and the inner membrane fraction were isolated from rat ventricles and fused into lipid bilayers. On the basis of their inhibition by 5-hydroxydecanoate (5-HD)/ATP or activation by diazoxide, mitoK(ATP) channels of several conductance states were observed in symmetrical (150 mM) potassium glutamate (26, 47, 66, 83, and 105 pS). Isoflurane (0.8 mM) increased the cumulative open probability from 0.09 +/- 0.02 at baseline to 0.50 +/- 0.09 (P < 0.05, n = 5), which was inhibited by 5-HD. Isoflurane caused a dose-dependent rightward shift in ATP inhibition of mitoK(ATP) channels, which increased the IC(50) for ATP from 335 +/- 4 to 940 +/- 34 microM at 0.8 mM (P < 0.05, n = 5 approximately 8). We conclude that direct activation of the mitoK(ATP) channel by isoflurane is likely to contribute to volatile anesthetic-induced myocardial preconditioning.
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Affiliation(s)
- Yuri Nakae
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Xiong L, Zheng Y, Wu M, Hou L, Zhu Z, Zhang X, Lu Z. Preconditioning with Isoflurane Produces Dose-Dependent Neuroprotection via Activation of Adenosine Triphosphate-Regulated Potassium Channels After Focal Cerebral Ischemia in Rats. Anesth Analg 2003. [DOI: 10.1213/00000539-200301000-00047] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Xiong L, Zheng Y, Wu M, Hou L, Zhu Z, Zhang X, Lu Z. Preconditioning with isoflurane produces dose-dependent neuroprotection via activation of adenosine triphosphate-regulated potassium channels after focal cerebral ischemia in rats. Anesth Analg 2003; 96:233-7, table of contents. [PMID: 12505958 DOI: 10.1097/00000539-200301000-00047] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED In this study, we determined whether repeated brief isoflurane (Iso) anesthesia induces ischemic tolerance to focal cerebral ischemia in a dose-response manner and whether the effect is dependent on adenosine triphosphate-regulated potassium channels. In Experiment 1, 40 rats were randomly assigned to 4 groups: control animals received 100% oxygen 1 h/d for 5 days, whereas the isoflurane (Iso)1, Iso2, and Iso3 groups received 0.75%, 1.5%, or 2.25% Iso in oxygen 1 h/d for 5 days. In Experiment 2, 36 rats were randomly assigned to 4 groups: controls received 100% oxygen 1 h/d for 5 days; animals in the Iso and I+G (Iso+glibenclamide) groups received 2% Iso in oxygen 1 h/d for 5 days, and the I+G group received glibenclamide (GLB) (5 mg/kg intraperitoneally) before each Iso pretreatment. Animals in the GLB group received GLB (5 mg/kg intraperitoneally) once a day for 5 days. Twenty-four hours after the last pretreatment, the right middle cerebral artery was occluded for 120 min. Neurologic deficit scores (NDS) and brain infarct volumes were evaluated at 24 h. The NDS and infarct volumes of Iso2 and Iso3 were less than those of the controls (P < 0.05). The infarct volume in Iso3 was smaller than in Iso2 (P < 0.05). The NDS and infarct volume in the Iso group were less than in the control and I+G groups (P < 0.05). There was no statistical difference among the control, I+G, and GLB groups. The study demonstrated that repeated Iso anesthesia induces ischemic tolerance in rats in a dose-response manner. GLB, an adenosine triphosphate-regulated potassium channel blocker, abolished the tolerance induced by Iso. IMPLICATIONS Brief isoflurane anesthesia induces ischemic tolerance in the brain. The effect was found to be dose dependent in a rat focal cerebral ischemia model. Ischemic tolerance induced by isoflurane preconditioning is dependent on activation of adenosine triphosphate-regulated potassium channels.
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Affiliation(s)
- Lize Xiong
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
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Thompson K, Wisenberg G, Sykes J, Thompson RT. Similar long-term cardiovascular effects of propofol or isoflurane anesthesia during ischemia/ reperfusion in dogs. Can J Anaesth 2002; 49:978-85. [PMID: 12419729 DOI: 10.1007/bf03016887] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To compare the long-term functional and metabolic effects of propofol or isoflurane general anesthesia in a canine model of ischemia/reperfusion. METHODS Using magnetic resonance (MR) techniques, we monitored both regional metabolism ((31)P MR spectroscopy) and systolic function of the heart ((1)H MR imaging) throughout a two-hour occlusion of the left anterior descending coronary artery and ten days of reperfusion. Twenty-two beagles were randomized into isoflurane and propofol general anesthesia groups (n = 10, n = 12 respectively). Contrast-enhanced MR imaging was used to measure infarct size (% of left ventricle that was necrotic) and coronary blood flow was determined using radioactively labelled microspheres. RESULTS Cardiac metabolism, as monitored by intracellular pH and high-energy phosphate ratios, was not significantly different between the two groups throughout the protocol. Relative to propofol, isoflurane reduced the depression of left ventricular ejection fraction (EF) during the ischemic period [isoflurane 68.5% +/- 4.2%, propofol 58.3% +/- 2.0% of baseline (B); P = 0.04], propofol increased the recovery of EF at day three (isoflurane 63.9% +/- 4.3%, propofol 74.0% +/- 2.5% of B; P = 0.05). By day ten, EF in both groups was similar. Infarct sizes were also similar at day ten (isoflurane 15.7% +/- 3.0%, propofol 13.2% +/- 2.2%). Normalizing these by the region at risk (volume of tissue with low blood flow during the occlusion) to assess infarct ratios was also not significant (isoflurane 0.58% +/- 0.08%, propofol 0.54% +/- 0.07%). CONCLUSIONS There were no significant differences between the two anesthetic groups at day ten, suggesting that any apparent dissimilarities in early cardiovascular effects were short-term only. These results indicate that isoflurane and propofol produce equivalent long-term cardiovascular effects following ischemia/reperfusion.
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Affiliation(s)
- Kerry Thompson
- Imaging Division, Lawson Health Research Institute. the Division of Cardiology, Faculty of Medicine and Dentistry, University of Western Ontario. St. Joseph's Health Care, London, Canada.
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Kato R, Foëx P. Myocardial protection by anesthetic agents against ischemia-reperfusion injury: an update for anesthesiologists. Can J Anaesth 2002; 49:777-91. [PMID: 12374705 DOI: 10.1007/bf03017409] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
PURPOSE The aim of this review of the literature was to evaluate the effectiveness of anesthetics in protecting the heart against myocardial ischemia-reperfusion injury. SOURCE Articles were obtained from the Medline database (1980-, search terms included heart, myocardium, coronary, ischemia, reperfusion injury, infarction, stunning, halothane, enflurane, desflurane, isoflurane, sevoflurane, opioid, morphine, fentanyl, alfentanil sufentanil, pentazocine, buprenorphine, barbiturate, thiopental, ketamine, propofol, preconditioning, neutrophil adhesion, free radical, antioxidant and calcium). PRINCIPAL FINDINGS Protection by volatile anesthetics, morphine and propofol is relatively well investigated. It is generally agreed that these agents reduce the myocardial damage caused by ischemia and reperfusion. Other anesthetics which are often used in clinical practice, such as fentanyl, ketamine, barbiturates and benzodiazepines have been much less studied, and their potential as cardioprotectors is currently unknown. There are some proposed mechanisms for protection by anesthetic agents: ischemic preconditioning-like effect, interference in the neutrophil/platelet-endothelium interaction, blockade of Ca2+ overload to the cytosolic space and antioxidant-like effect. Different anesthetics appear to have different mechanisms by which protection is exerted. Clinical applicability of anesthetic agent-induced protection has yet to be explored. CONCLUSION There is increasing evidence of anesthetic agent-induced protection. At present, isoflurane, sevoflurane and morphine appear to be most promising as preconditioning-inducing agents. After the onset of ischemia, propofol could be selected to reduce ischemia-reperfusion injury. Future clinical application depends on the full elucidation of the underlying mechanisms and on clinical outcome trials.
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Affiliation(s)
- Rie Kato
- Department of Anesthesiology (B1), Graduate School of Medicine, Chiba University, Chiba, Japan.
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Novalija E, Varadarajan SG, Camara AKS, An J, Chen Q, Riess ML, Hogg N, Stowe DF. Anesthetic preconditioning: triggering role of reactive oxygen and nitrogen species in isolated hearts. Am J Physiol Heart Circ Physiol 2002; 283:H44-52. [PMID: 12063273 DOI: 10.1152/ajpheart.01056.2001] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We postulated that anesthetic preconditioning (APC) is triggered by reactive oxygen/nitrogen species (ROS/RNS). We used the isolated guinea pig heart perfused with L-tyrosine, which reacts with ROS and RNS to form strong oxidants, principally peroxynitrite (ONOO(-)), and then forms fluorescent dityrosine. ROS scavengers superoxide dismutase, catalase, and glutathione (SCG) and NO. synthesis inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) were given 5 min before and after sevoflurane preconditioning stimuli. Drugs were washed out before 30 min of ischemia and 120 min of reperfusion. Groups were control (nontreated ischemia control), APC (two, 2-min periods of perfusion with 0.32 +/- 0.02 mM of sevoflurane; separated by a 6-min period of perfusion without sevoflurane), SCG, APC + SCG, L-NAME, and APC + L-NAME. Effluent dityrosine at 1 min reperfusion was 56 +/- 6 (SE), 15 +/- 5, 40 +/- 5(++), 39 +/- 4(++), 35 +/- 4(++) , and 33 +/- 5(++) units ((++)P< 0.05 vs. APC), respectively; left ventricular pressure (%baseline) at 60 min of reperfusion was 30 +/- 5(++), 60 +/- 4, 35 +/- 5(++), 37 +/- 5(++), 44 +/- 4, and 47 +/- 4; and infarct size (%total heart weight) was 50 +/- 5(++), 19 +/- 2, 48 +/- 3(++), 46 +/- 4(++), 42 +/- 4(++), and 45 +/- 2(++). Thus APC is initiated by ROS as shown by improved function, reduced infarct size, and reduced dityrosine on reperfusion; protective and ROS/RNS-reducing effect of APC were attenuated when bracketed by ROS scavengers or NO* inhibition.
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Affiliation(s)
- Enis Novalija
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, 53226, USA.
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Tanaka K, Kehl F, Gu W, Krolikowski JG, Pagel PS, Warltier DC, Kersten JR. Isoflurane-induced preconditioning is attenuated by diabetes. Am J Physiol Heart Circ Physiol 2002; 282:H2018-23. [PMID: 12003806 DOI: 10.1152/ajpheart.01130.2001] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Volatile anesthetics stimulate, but hyperglycemia attenuates, the activity of mitochondrial ATP-regulated K(+) channels. We tested the hypothesis that diabetes mellitus interferes with isoflurane-induced preconditioning. Acutely instrumented, barbiturate-anesthetized dogs were randomly assigned to receive 0, 0.32, or 0.64% end-tidal concentrations of isoflurane in the absence or presence of diabetes (3 wk after administration of alloxan and streptozotocin) in six experimental groups. All dogs were subjected to a 60-min left anterior descending coronary artery occlusion followed by 3 h of reperfusion. Myocardial infarct size (triphenyltetrazolium staining) was 29 +/- 3% (n = 8) of the left ventricular area at risk in control experiments. Isoflurane reduced infarct size (15 +/- 2 and 13 +/- 1% during 0.32 and 0.64% concentrations; n = 8 and 7 dogs, respectively). Diabetes alone did not alter infarct size (30 +/- 3%; n = 8) but blocked the protective effects of 0.32% (27 +/- 2%; n = 7) and not 0.64% isoflurane (18 +/- 3%; n = 7). Infarct size was directly related to blood glucose concentrations in diabetic dogs, but this relationship was abolished by higher concentrations of isoflurane. The results indicate that blood glucose and end-tidal isoflurane concentrations are important determinants of infarct size during anesthetic-induced preconditioning.
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Affiliation(s)
- Katsuya Tanaka
- Department of Anesthesiology, Milwaukee, Wisconsin 53226
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Abstract
The term 'preconditioning' refers to the paradoxical phenomenon that pretreatment with a potential noxious stress-stimulus can increase cellular tolerance to subsequent noxious stress-stimuli. This was first described in an experimental model in dogs in which short-lasting periods of myocardial ischemia resulted in reduced infarction during a subsequent long-lasting coronary artery occlusion. Similar observations have also been made in other species and in other organs. During the last few years, the term preconditioning has been expanded to include pretreatment with other physical stress-stimuli or pharmacological agents that can increase cellular resistance to injury. The phenomenon probably represents a general adaptive response to cellular stress, but mechanisms involved are not fully clarified. This review focuses on preconditioning in the heart. Firstly, we want to address the observation that activation of endogenous defence mechanisms can increase cellular tolerance to several potentially noxious stimuli. Based on results from experimental research, we will give an overview of intracellular mechanisms that is currently in focus. Secondly, we want to address the potential role of preconditioning in clinical practice. We will present results from studies in patients with coronary artery disease and discuss possible clinical implications. Results show that the phenomenon probably exists in the human myocardium. In the future, this might be exploited in patients with acute coronary syndromes, especially since advanced techniques are now available for acute revascularization. Additionally, identification of possible mechanisms involved may influence the choice of medical treatment in high-risk patients with stable coronary artery disease. Preconditioning can also be exploited during elective surgical procedures. This should be of great interest, as the extent of elective surgery in patients at high-risk for coronary events is increasing. In this respect it is important to note that opioid-receptors are probably involved in preconditioning in humans. The last part of this review will address the possible relation between preconditioning and different anesthetic agents and sedatives.
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Zhou S, Cao JM, Ohara T, KenKnight BH, Chen LS, Karagueuzian HS, Chen PS. Torsade de pointes and sudden death induced by thiopental and isoflurane anesthesia in dogs with cardiac electrical remodeling. J Cardiovasc Pharmacol Ther 2002; 7:39-43. [PMID: 12000977 DOI: 10.1177/107424840200700i106] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Many anesthetic agents are known to have cardiac effects. The effects of pentobarbital, thiopental and isoflurane on dogs with electrical remodeling are lacking. METHODS AND RESULTS We studied 12 dogs that underwent two anesthesias. First, anesthesia was induced (N=12) with intravenous thiopental (17 mg/kg) induction followed by isoflurane inhalation (1.5%-3% via endotracheal tube). For electrical remodeling, we created complete atrioventricular block (CAVB) and myocardial infarction (MI). In 6 of the 12 dogs we also infused nerve growth factor (NGF) to the right stellate ganglion. All dogs had an implantable cardioverter-defibrillator (ICD) implanted. A second anesthesia was done 66 +/- 20 days later. In 8 of the 12 dogs (6 without NGF), pentobarbital was used as the only anesthetic. In the remaining 4 dogs (all with NGF), 3 received thiopental and 1 received isoflurane. RESULTS During the first anesthesia, none of 12 dogs had cardiac arrhythmia. During the second anesthesia, none of the 8 dogs that received pentobarbital developed ventricular fibrillation (VF). In contrast, all the dogs receiving either thiopental or isoflurane died of VF within 2 to 3 minutes. QT and P-P intervals before VF were 440 +/- 36 milliseconds and 298 +/- 28 milliseconds, longer and shorter (respectively) than those obtained the day prior to surgery (315 +/- 25 milliseconds, P < 0.001; 330 +/- 22 milliseconds, P < 0.01, respectively). CONCLUSION Thiopental and isoflurane are not arrhythmogenic in normal dogs and dogs with acute MI and CAVB, but are extremely proarrhythmic in dogs with chronic MI and CAVB. Consistent with the results of in vitro studies, pentobarbital did not induce ventricular arrhythmia in dogs with cardiac electrical remodeling.
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Affiliation(s)
- Shengmei Zhou
- The Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, and UCLA, Los Angeles, CA, USA
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An J, Varadarajan SG, Novalija E, Stowe DF. Ischemic and anesthetic preconditioning reduces cytosolic [Ca2+] and improves Ca(2+) responses in intact hearts. Am J Physiol Heart Circ Physiol 2001; 281:H1508-23. [PMID: 11557539 DOI: 10.1152/ajpheart.2001.281.4.h1508] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca(+) loading during reperfusion after myocardial ischemia is linked to reduced cardiac function. Like ischemic preconditioning (IPC), a volatile anesthetic given briefly before ischemia can reduce reperfusion injury. We determined whether IPC and sevoflurane preconditioning (SPC) before ischemia equivalently improve mechanical and metabolic function, reduce cytosolic Ca(2+) loading, and improve myocardial Ca(2+) responsiveness. Four groups of guinea pig isolated hearts were perfused: no ischemia, no treatment before 30-min global ischemia and 60-min reperfusion (control), IPC (two 2-min occlusions) before ischemia, and SPC (3.5 vol%, two 2-min exposures) before ischemia. Intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured at the left ventricular (LV) free wall with the fluorescent probe indo 1. Ca(2+) responsiveness was assessed by changing extracellular [Ca(2+)]. In control hearts, initial reperfusion increased diastolic [Ca(2+)] and diastolic LV pressure (LVP), and the maximal and minimal derivatives of LVP (dLVP/dt(max) and dLVP/dt(min), respectively), O(2) consumption, and cardiac efficiency (CE). Throughout reperfusion, IPC and SPC similarly reduced ischemic contracture, ventricular fibrillation, and enzyme release, attenuated rises in systolic and diastolic [Ca(2+)], improved contractile and relaxation indexes, O(2) consumption, and CE, and reduced infarct size. Diastolic [Ca(2+)] at 50% dLVP/dt(min) was right shifted by 32-53 +/- 8 nM after 30-min reperfusion for all groups. Phasic [Ca(2+)] at 50% dLVP/dt(max) was not altered in control but was left shifted by -235 +/- 40 nM [Ca(2+)] after IPC and by -135 +/- 20 nM [Ca(2+)] after SPC. Both SPC and IPC similarly reduce Ca(2+) loading, while augmenting contractile responsiveness to Ca(2+), improving postischemia cardiac function and attenuating permanent damage.
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Affiliation(s)
- J An
- Anesthesiology Research Laboratories, Department of Anesthesiology, and Cardiovascular Research Center, The Medical College of Wisconsin, Milwaukee 53226, USA
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Müllenheim J, Molojavyi A, Preckel B, Thämer V, Schlack W. Thiopentone does not block ischemic preconditioning in the isolated rat heart. Can J Anaesth 2001; 48:784-9. [PMID: 11546720 DOI: 10.1007/bf03016695] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Ischemic preconditioning protects the heart against subsequent prolonged ischemia by opening of adenosine triphosphate-sensitive potassium (K(ATP)) channels. Thiopentone blocks K(ATP) channels in isolated cells. Therefore, we investigated the effects of thiopentone on ischemic preconditioning. METHODS Isolated rat hearts (n=56) were subjected to 30 min of global no-flow ischemia, followed by 60 min of reperfusion. Thirteen hearts underwent the protocol without intervention (control, CON) and in 11 hearts (preconditioning, PC), ischemic preconditioning was elicited by two five-minute periods of ischemia. In three additional groups, hearts received 1 (Thio 1, n=11), 10 (Thio 10, n=11) or 100 microg x mL(-1) (Thio 100, n=10) thiopentone for five minutes before preconditioning. Left ventricular (LV) developed pressure and creatine kinase (CK) release were measured as variables of myocardial performance and cellular injury, respectively. RESULTS Recovery of LV developed pressure was improved by ischemic preconditioning (after 60 min of reperfusion, mean +/- SD: PC, 40 +/- 19% of baseline) compared with the control group (5 +/- 6%, P <0.01) and this improvement of myocardial function was not altered by administration of thiopentone (Thio 1, 37 +/- 15%; Thio 10, 36 +/- 16%; Thio 100, 38 +/- 16%, P=0.87-0.99 vs PC). Total CK release over 60 min of reperfusion was reduced by preconditioning (PC, 202 +/- 82 U x g(-1) dry weight) compared with controls (CON, 383 +/- 147 U x g(-1), P <0.01) and this reduction was not affected by thiopentone (Thio 1, 213 +/- 69 U x g(-1); Thio 10, 211 +/- 98 U x g(-1); Thio 100, 258 +/- 128 U x g(-1), P=0.62-1.0 vs PC). CONCLUSION These results indicate that thiopentone does not block the cardioprotective effects of ischemic preconditioning in an isolated rat heart preparation.
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Affiliation(s)
- J Müllenheim
- Department of Anaesthesiology, Institut I Heinrich-Heine-Universität Düsseldorf Germany
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Han J, Kim N, Kim E. Trifluoroacetic acid activates ATP-sensitive K(+) channels in rabbit ventricular myocytes. Biochem Biophys Res Commun 2001; 285:1136-42. [PMID: 11478772 DOI: 10.1006/bbrc.2001.5291] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent in vivo experimental evidence suggests that isoflurane-induced cardioprotection may involve K(ATP) channel activation during myocardial ischemia. The actual effect of isoflurane on cardioprotective ion conductance, however, such as that mediated by the opening of K(ATP) channels, has been the subject of some controversy in the past. The investigation reported here used a patch-clamp technique to test the hypothesis that a metabolite of isoflurane, trifluoroacetic acid (TFA), contributes to isoflurane-induced cardioprotection via K(ATP) channel activation. TFA enhanced channel activity in a concentration-dependent fashion, exhibiting half-maximal activation at 0.03 mM. TFA increased the number of openings of the channel, but did not affect the single channel conductance of K(ATP) channels. Analysis of open and closed time distributions showed that TFA increased the burst duration and decreased the interburst interval without eliciting changes of less than 5 ms in open and closed time distributions. TFA diminished the ATP sensitivity of K(ATP) channels in a concentration-response relationship for ATP. These results imply that TFA could mediate isoflurane-induced cardioprotection via K(ATP) channel activation during myocardial ischemia and reperfusion.
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Affiliation(s)
- J Han
- Department of Physiology and Biophysics, College of Medicine, Inje University, 633-165 Gaegeum-Dong, Busanjin-Ku, Busan, 614-735, Korea
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Yao L, Kato R, Foëx P. Isoflurane-induced protection against myocardial stunning is independent of adenosine 1 (A(1)) receptor in isolated rat heart. Br J Anaesth 2001; 87:258-65. [PMID: 11493499 DOI: 10.1093/bja/87.2.258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Volatile anaesthetics can pharmacologically enhance the recovery of stunned myocardium, but the mechanism is still unknown. This study sought to determine whether isoflurane attenuates myocardial stunning, and whether the myocardial protection of isoflurane is mediated by adenosine A(1) receptors. Five groups (n=8) of isolated rat hearts were studied in the Langendorff apparatus. The control groups underwent 20-min ischaemia with or without adenosine receptor antagonist (DPCPX, A(1)()selective) treatment (Cont group and DPCPX group). In the isoflurane groups, isoflurane (1.5 MAC) was present throughout the experiment (Iso group) and DPCPX (200 nM) was administered from 10 min before ischaemia (Iso+DPCPX(pre-I) group) or the beginning of reperfusion (Iso+DPCPX(post-I) group) to the end of experiment. The isoflurane groups had a lower end-diastolic pressure than the control groups (P<0.05). Developed pressure recovered to 77, 76, and 82% in Iso, Iso+DPCPX(pre-I) and Iso+DPCPX(post-I) groups, respectively (P<0.05 compared with control groups). LV+dp/dt(max) recovered to 53, 86, 81, 84, and 60% of pre-ischaemic values in Cont, Iso, Iso+DPCPX(pre-I), Iso+DPCPX(post-I), and DPCPX groups. LV-dp/dt(min) recovered to 55, 84, 83, 81, and 62%, respectively. Both LV+dp/dt(max) and LV-dp/dt(min) were significantly different (P<0.05) between control and isoflurane groups during reperfusion. There were no significant differences among the isoflurane groups. Our data show that isoflurane enhances the post-ischaemic functional recovery of isolated rat heart and that block of A(1) receptors does not abolish the beneficial effects of isoflurane. We conclude that A(1)()receptors are not involved in isoflurane-induced myocardial protection in the isolated rat heart.
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Affiliation(s)
- L Yao
- Nuffield Department of Anaesthetics, Oxford University, Radcliffe Infirmary, Woodstock Road, Oxford OX2 6HE, UK
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Haroun-Bizri S, Khoury SS, Chehab IR, Kassas CM, Baraka A. Does isoflurane optimize myocardial protection during cardiopulmonary bypass? J Cardiothorac Vasc Anesth 2001; 15:418-21. [PMID: 11505342 DOI: 10.1053/jcan.2001.24954] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To investigate the possible myocardial protective effect of isoflurane during aortic cross-clamp and cardioplegic cardiac arrest in patients undergoing conventional coronary artery bypass graft surgery. DESIGN Prospective, randomized. SETTING University medical center. PARTICIPANTS Forty-nine patients undergoing elective coronary artery bypass graft surgery divided into 2 groups: control group (n = 21) and isoflurane group (n = 28). INTERVENTION Isoflurane was administered in the pre-cardiopulmonary bypass (CPB) period to the isoflurane group. MEASUREMENTS AND MAIN RESULTS Hemodynamics and ST- segment variations were monitored in the pre-CPB period and after weaning from CPB in both groups. Incidence of reperfusion arrhythmias after release of aortic cross-clamp was compared. In the isoflurane group, the mean cardiac index after CPB was significantly higher than the pre-CPB value, whereas no difference between the 2 values was found in the control group. The higher cardiac index in the isoflurane group was associated with a lesser degree of ST- segment changes than in the control group. There was no significant difference between the 2 groups in the incidence of reperfusion arrhythmias after release of aortic cross-clamp. CONCLUSION The present report suggests that administration of isoflurane before aortic cross-clamping in patients undergoing coronary artery bypass graft surgery may optimize the myocardial protective effect of cardioplegia. Isoflurane may be particularly advantageous whenever prolonged periods of aortic cross-clamping or inadequate delivery of cardioplegia is expected.
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Affiliation(s)
- S Haroun-Bizri
- Anesthesiology Department, American University of Beirut Medical Center, Beirut, Lebanon
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Martini N, Preckel B, Thämer V, Schlack W. Can isoflurane mimic ischaemic preconditioning in isolated rat heart? Br J Anaesth 2001; 86:269-71. [PMID: 11573672 DOI: 10.1093/bja/86.2.269] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ischaemic preconditioning can protect the myocardium against ischaemic injury by opening of the adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel. Isoflurane is also thought to open this channel. The present investigation tested the hypothesis that pre-ischaemic treatment with isoflurane mimics ischaemic preconditioning (producing chemical preconditioning) and thereby protects the myocardium against ischaemic injury in an isolated rat heart model. Control hearts underwent 30 min of global no-flow ischaemia followed by 60 min of reperfusion. The hearts of the preconditioning group underwent two 5 min periods of no-flow ischaemia interspersed with 5 min of reperfusion before the sustained ischaemia. In three additional groups, hearts were subjected to 15 min of 1.5 minimal alveolar concentration (MAC) of isoflurane (ISO-1), 15 min 3 MAC (ISO-2) or 25 min 1.5 MAC (ISO-3) of isoflurane followed by 5 min washout before the global ischaemia. Left ventricular (LV) developed pressure and creatine kinase release were measured as variables of myocardial performance and cellular injury, respectively. Recovery of LV developed pressure was improved after ischaemic preconditioning [after 60 min reperfusion, mean 63 (SEM 6)% of baseline] compared with the control group [18 (4)% P<0.01] but not by isoflurane, independently of concentration or duration of administration [ISO-1, 17 (2)%, P=0.99 vs control; ISO-2, 12 (3)%, P=0.64; ISO-3, 4 (1)%, P=0.06]. Total creatine kinase release over 1 h of reperfusion was not significantly different between control [251 (36) U g(-1) dry weight] and all isoflurane groups [ISO-1, 346 (24) U g(-1), P=0.30; ISO-2, 313 (33) U g(-1), P=0.73; ISO-3, 407 (40) U g(-1), P=0.03]. These results indicate that pre-ischaemic administration of isoflurane does not cause anaesthetic-induced preconditioning in the isolated rat heart.
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Affiliation(s)
- N Martini
- Institut für Klinische Anaesthesiologie, Heinrich-Heine-Universität Düsseldorf, Germany
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Napoli C, Pinto A, Cirino G. Pharmacological modulation, preclinical studies, and new clinical features of myocardial ischemic preconditioning. Pharmacol Ther 2000; 88:311-31. [PMID: 11337029 DOI: 10.1016/s0163-7258(00)00093-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The term "ischemic preconditioning (PC)" was first applied to canine myocardium subjected to brief episodes of ischemia and reperfusion that tolerated a more prolonged episode of ischemia better than myocardium not previously exposed to ischemia. Protective effect of myocardial ischemic PC was demonstrated in several animal species, resulting in the strongest endogenous form of protection against myocardial injury, jeopardized myocardium, infarct size, and arrhythmias other than early reperfusion. New onset angina before acute myocardial infarction, episodes of myocardial ischemia during coronary angioplasty or bypass surgery, and the "warm-up" phenomenon may represent clinical counterparts of the PC phenomenon in humans. Here, we have attempted to summarize pharmacological modulation, preclinical studies, and new clinical features of ischemic PC. To date, the pathophysiological basis of the "chemical PC" is still not well established, and "putting PC in a bottle" for clinical applications still remains a new pharmacological venture.
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Affiliation(s)
- C Napoli
- Department of Medicine, Federico II University of Naples, P.O. Box, Naples 80131, Italy.
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Park KW, Dai HB, Comunale ME, Gopal A, Sellke FW. Dilation by isoflurane of preconstricted, very small arterioles from human right atrium is mediated in part by K(+)-ATP channel opening. Anesth Analg 2000; 91:76-81. [PMID: 10866890 DOI: 10.1097/00000539-200007000-00015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED The adenosine triphosphate (ATP)-sensitive potassium channels (K(+)-ATP channels) are activated by decreases in intracellular ATP and help to match blood flow to tissue needs. Such metabolism-flow coupling occurs predominantly in the smallest arterioles measuring 50 microm or less in diameter. Previous studies demonstrated that isoflurane may activate the K(+)-ATP channels in larger arteries. We examined whether isoflurane also activates the channels in the smallest arterioles of approximately 50 microm. Microvessels of approximately 50 microm were dissected from right atrial appendages from patients undergoing coronary artery bypass surgery and were monitored in vitro for diameter changes by videomicroscopy. With or without preconstriction with the thromboxane analog U46619 1 microM, vessels were exposed to isoflurane 0%-3% either in the presence or absence of the K(+)-ATP channel blocker glibenclamide 1 microM. Without preconstriction, isoflurane neither dilated nor constricted the vessels significantly. After preconstriction, isoflurane had a concentration-dependent dilation of the small arterioles (39 +/- 13% [mean +/- SD] dilation at 3% isoflurane) (P < 0.001), and this effect was significantly attenuated by glibenclamide (18 +/- 5% dilation at 3% isoflurane) (P < 0.01). In comparison, nitroprusside 10(-4) M produced 79 +/- 6% dilation, and adenosine diphosphate 10(-4) M produced 29 +/- 7% dilation. We conclude that isoflurane-mediated dilation of the smallest resistance arterioles may be in part based on activation of the K(+)-ATP channels when the arterioles are relatively constricted. IMPLICATIONS Vasodilation of very small coronary arterioles by isoflurane depends on preexisting tone and may in part be mediated by the K(+)-ATP channels.
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Affiliation(s)
- K W Park
- Departments of Anesthesia and Critical Care and Surgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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Park KW, Dai HB, Comunale ME, Gopal A, Sellke FW. Dilation by Isoflurane of Preconstricted, Very Small Arterioles from Human Right Atrium Is Mediated in Part by K+-ATP Channel Opening. Anesth Analg 2000. [DOI: 10.1213/00000539-200007000-00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Toller WG, Kersten JR, Pagel PS, Warltier DC. Ischemic preconditioning, myocardial stunning and anesthesia. Curr Opin Anaesthesiol 2000; 13:35-40. [PMID: 17016277 DOI: 10.1097/00001503-200002000-00006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Brief periods of ischemia have been shown to protect the heart against a subsequent prolonged ischemic insult, a phenomenon known as ischemic preconditioning. The protective effects of preconditioning markedly reduce myocardial ischemic injury in vivo. Volatile anesthetics have been shown to protect myocardium against infarction by a mechanism similar to that of ischemic preconditioning. Contractile dysfunction occurs after a brief period of myocardial ischemia, despite restoration of coronary blood flow in the absence of tissue necrosis. This process is known as myocardial stunning and has important clinical ramifications. Evidence indicates that adenosine triphosphate-regulated potassium channel function plays a central role in ischemic preconditioning, stunned myocardium, and in anesthetic-induced protection against ischemic injury.
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Affiliation(s)
- W G Toller
- Department of Anesthesiology, the Medical College of Wisconsin and the Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin 53226, USA
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Mellor A. Isoflurane - induced myocardial preconditioning. Crit Care 1999. [DOI: 10.1186/ccf-1999-341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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