Document Detail

Enhanced calcium uptake of cardiac sarcoplasmic reticulum in exercise-trained old rats.
MedLine Citation:
PMID:  2137986     Owner:  NLM     Status:  MEDLINE    
To determine whether endurance exercise training initiated during senescence improves the slower calcium transport of cardiac sarcoplasmic reticulum in senescent rats, three groups of male Fischer 344 rats were used: sedentary mature (SM), 11-12 mo of age; sedentary old (SO), 23-24 mo of age; and exercised old (EO), 23-24 mo of age. The EO rats ran on a motor-driven treadmill 5 days/wk for 8-10 wk while two other groups remained sedentary. The contraction duration of isometrically contracting papillary muscle was prolonged in the SO rats compared with the SM group, resulting from both a longer time-to-peak tension and a longer half-relaxation time. Chronic exercise improved the papillary muscle contractile function of the EO group to that observed in the younger SM rats. More importantly, the exercise regime ameliorated the slower oxalate-supported, ATP-dependent calcium transport observed in the SO group so that the EO and SM groups were the same. In contrast, the calcium-activated myosin adenosinetriphosphatase activity, which was slower in the SO group, was not altered after exercise training, so that both senescent groups were slower than the SM rats. Thus the increased calcium transport by the cardiac sarcoplasmic reticulum may be one of the potential mechanisms underlying the improvement of myocardial performance with chronic exercise initiated during senescence.
C A Tate; G E Taffet; E K Hudson; S L Blaylock; R P McBride; L H Michael
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  258     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1990 Feb 
Date Detail:
Created Date:  1990-04-03     Completed Date:  1990-04-03     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H431-5     Citation Subset:  IM    
Department of Medicine, Baylor College of Medicine, Houston, Texas.
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MeSH Terms
Aging / metabolism,  physiology*
Biological Transport
Calcium / metabolism*,  pharmacology
Myocardial Contraction
Myocardium / enzymology,  metabolism*
Myosins / metabolism
Papillary Muscles / physiology
Physical Conditioning, Animal
Rats, Inbred F344
Sarcoplasmic Reticulum / metabolism*
Grant Support
Reg. No./Substance:
7440-70-2/Calcium; EC

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

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