Journal article
Short-term exercise preserves myocardial glutathione and decreases arrhythmias after thiol oxidation and ischemia in isolated rat hearts
Journal of applied physiology (1985), Vol.111(6), pp.1751-1759
12/2011
DOI: 10.1152/japplphysiol.01214.2010
PMID: 21940849
Abstract
The purpose of this study was to determine if exercise (Ex) protects hearts from arrhythmias induced by glutathione oxidation or ischemia-reperfusion (I/R). Female Sprague-Dawley rats were divided into two experimental groups: sedentary controls (Sed) or short-term Ex (10 days of treadmill running). Twenty-four hours after the last session, hearts were excised and exposed to either perfusion with the thiol oxidant diamide (200 μM) or global I/R. Ex significantly delayed the time to the onset of ventricular arrhythmia after irreversible diamide perfusion. During a shorter diamide perfusion protocol with washout, Ex significantly decreased the incidence of arrhythmia, as evidenced by a delayed time to the first observed arrhythmia, lower arrhythmia scores, and lower incidence of ventricular fibrillation. Ex hearts exposed to I/R (30-min ischemia/30-min reperfusion) also showed lower arrhythmia scores and incidence of ventricular fibrillation compared with Sed counterparts. Our finding that Ex protected intact hearts from thiol oxidation was corroborated in isolated ventricular myocytes. In myocytes from Ex animals, both the increase in H2O2 fluorescence and incidence of cell death were delayed after diamide. Although there were no baseline differences in reduced-to-oxidized glutathione ratios (GSH/GSSG) between the Sed and Ex groups, GSH/GSSG was better preserved in Ex groups after diamide perfusion and I/R. Myocardial glutathione reductase activity was significantly enhanced after Ex, and this was preserved in the Ex group after diamide perfusion. Our results show that Ex protects the heart from arrhythmias after two different oxidative stressors and support the hypothesis that sustaining the GSH/GSSG pool stabilizes cardiac electrical function during conditions of oxidative stress.
Details
- Title: Subtitle
- Short-term exercise preserves myocardial glutathione and decreases arrhythmias after thiol oxidation and ischemia in isolated rat hearts
- Creators
- Chad R Frasier - Departments of 1Physiology,, East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North CarolinaRuben C Sloan - Exercise and Sport Science, and, East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North CarolinaPhillip A Bostian - Departments of 1PhysiologyMichael D Gonzon - Exercise and Sport Science, andJennifer Kurowicki - Exercise and Sport Science, andSteven J LoPresto - Exercise and Sport Science, andEthan J Anderson - Pharmacology and Toxicology,, East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North CarolinaDavid A Brown - Departments of 1Physiology,, Exercise and Sport Science, and, East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.111(6), pp.1751-1759
- DOI
- 10.1152/japplphysiol.01214.2010
- PMID
- 21940849
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Language
- English
- Date published
- 12/2011
- Academic Unit
- Pharmaceutical Sciences and Experimental Therapeutics; Fraternal Order of Eagles Diabetes Research Center; Health and Human Physiology
- Record Identifier
- 9984065318202771
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