Document Detail


Reactive oxygen species are not a required trigger for exercise-induced late preconditioning in the rat heart.
MedLine Citation:
PMID:  22955056     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Reactive oxygen species (ROS) have been reported to play a primary role in triggering the cardioprotective adaptations by some preconditioning procedures, but whether they are required for exercise-induced preconditioning is unclear. Thus in this study we used the free radical scavenger N-(2-mercaptopropionyl)glycine (MPG) to test the hypothesis that ROS is the trigger for exercise-induced preconditioning of the heart against ischemia-reperfusion injury. Male F344 rats were assigned to four groups: sedentary (SED, n = 7), SED/MPG (100 mg/kg ip daily for 2 days, n = 12), exercised on a treadmill for 2 days at 20 m/min, 6° grade, for 60 min (RUN, n = 7), and RUN/MPG with 100 mg/kg MPG injected 15 min before exercise (n = 10). Preliminary experiments verified that MPG administration maintained myocardial redox status during the exercise bout. Twenty-four hours postexercise or MPG treatment isolated perfused working hearts were subjected to global ischemia for 22.5 min followed by reperfusion for 30 min. Recovery of myocardial external work (percentage of preischemic systolic pressure times cardiac output) for SED (50.4 ± 4.5) and SED/RUN (54.7 ± 6.6) was similar and improved in both exercise groups (P < 0.05) to 77.9 ± 3.0 in RUN and 76.7 ± 4.5 in RUN/MPG. A 2 × 2 ANOVA also revealed that exercise decreased lactate dehydrogenase release from the heart during reperfusion (marker of cell damage) without MPG effects or interactions. Expression of the cytoprotective protein inducible heat shock protein 70 increased by similar amounts in the left ventricles of RUN and RUN/MPG compared with sedentary groups (P < 0.05). We conclude that ROS are not a necessary trigger for exercise-induced preconditioning in rats.
Authors:
Ryan P Taylor; Joseph W Starnes
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2012-09-05
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  303     ISSN:  1522-1490     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-05     Completed Date:  2013-03-29     Revised Date:  2013-11-05    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R968-74     Citation Subset:  IM    
Affiliation:
Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Free Radical Scavengers / pharmacology
Heart / drug effects,  physiology
Ischemic Preconditioning, Myocardial*
Male
Models, Animal
Myocardial Reperfusion Injury / metabolism,  physiopathology*,  prevention & control*
Myocardium / metabolism
Oxidation-Reduction
Physical Conditioning, Animal / physiology*
Rats
Rats, Inbred F344
Reactive Oxygen Species / metabolism*
Tiopronin / pharmacology
Grant Support
ID/Acronym/Agency:
AG-02220/AG/NIA NIH HHS
Chemical
Reg. No./Substance:
0/Free Radical Scavengers; 0/Reactive Oxygen Species; 1953-02-2/Tiopronin
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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