Effects of moderate heart failure and functional overload on rat plantaris muscle.
It is thought that changes in sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) of skeletal muscle contribute to alterations in skeletal muscle function during congestive heart failure (CHF). It is well established that exercise training can improve muscle function. However, it is unclear whether similar adaptations will result from exercise training in a CHF patient. Therefore, the purpose of this study was to determine whether skeletal muscle during moderate CHF adapts to increased activity, utilizing the functional overload (FO) model. Significant increases in plantaris mass of the CHF-FO and sham-FO groups compared with the CHF and control (sham) groups were observed. Ca(2+) uptake rates were significantly elevated in the CHF group compared with all other groups. No differences were detected in Ca(2+) uptake rates between the CHF-FO, sham, and sham-FO groups. Increases in Ca(2+) uptake rates in moderate-CHF rats were not due to changes in SERCA isoform proportions; however, FO may have attenuated the CHF-induced increases through alterations in SERCA isoform expression. Therefore, changes in skeletal muscle Ca(2+) handling during moderate CHF may be due to alterations in regulatory mechanisms, which exercise may override, by possibly altering SERCA isoform expression.
Spangenburg
Espen E
EE
Muscular Function Laboratory, Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA. spangenburge@missouri.edu
Lees
Simon J
SJ
Otis
Jeff S
JS
Musch
Timothy I
TI
Talmadge
Robert J
RJ
Williams
Jay H
JH
D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000096:biosynthesis; D005260:Female; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology*; D006352:Heart Ventricles / Q000473:pathology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D009929:Organ Size / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000378:metabolism / Q000502:physiology; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases
D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium