Document Detail


Exercise training modifies myocardial mitochondria and myofibril growth in spontaneously hypertensive rats.
MedLine Citation:
PMID:  3970178     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We tested the hypothesis that exercise training provides a stimulus that could modify the decrement in mitochondria-to-myofibril volume ratio characteristic of myocardial cells hypertrophied in response to a pressure overload. Spontaneously hypertensive rats (SHR) were trained 5 days/wk on a treadmill at 70-90% maximal VO2 between the ages of 6 and 16 wk corresponding to the development of hypertension and cardiac hypertrophy. The training program increased maximal VO2 and effected a resting bradycardia but did not alter blood pressure, left ventricular hypertrophy, or peak cardiac output. Our stereological data from electron micrographs shows that the decrement in mitochondrial volume density and the increase in myofibril volume density characteristic of SHR compared with their normotensive controls (WKY, Wistar-Kyoto rats) were reversed. Thus the relative volumes of mitochondria and myofibrils and their ratio in trained SHR were similar to those of the WKY group. The similarity was noted in myocytes from both the subepicardium and subendocardium. These data suggest that exercise training facilitates a proportional growth of energy-producing and energy-consuming organelles in SHR and that this effect is not secondary to modification of blood pressure or left ventricular mass.
Authors:
R P Crisman; R J Tomanek
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  248     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1985 Jan 
Date Detail:
Created Date:  1985-02-25     Completed Date:  1985-02-25     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H8-14     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Cell Division
Growth
Hemodynamics
Hypertension / physiopathology*
Microscopy, Electron
Mitochondria, Heart / pathology*
Myocardium / pathology
Myofibrils / physiology*
Organ Size
Oxygen Consumption
Physical Conditioning, Animal*
Physical Endurance
Rats
Rats, Inbred SHR
Rats, Inbred Strains
Grant Support
ID/Acronym/Agency:
HL-18629/HL/NHLBI NIH HHS

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


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