Moderate intensity of regular exercise improves cardiac SR Ca2+ uptake activity in ovariectomized rats.
The impact of regular exercise in protecting cardiac deteriorating results of female sex hormone deprivation was evaluated by measuring changes in intracellular Ca2+ removal activity of sarcoplasmic reticulum (SR) in ovariectomized rats following 9-wk treadmill running exercise at moderate intensity. Despite induction of cardiac hypertrophy in exercised groups of both sham-operated and ovariectomized rats, exercise training had no effect on SR Ca2+ uptake and SR Ca(2+)-ATPase (SERCA) in hormone intact rat heart. However, exercise training normalized the suppressed maximum SR Ca2+ uptake and SERCA activity in ovariectomized rat heart. While exercise training normalized the leftward shift in pCa (-log[Ca2+])-SR Ca2+ uptake relation in ovariectomized rats, no effect was detected in exercised sham-operated rats. Similar phenomena were also observed on SERCA and on phospholamban (PLB) phosphorylation levels; exercise training in ovariectomized rats enhanced SERCA expression to reach the level as that in sham-operated rats, in which there were no differences in SERCA and phospho-PLB levels between sedentary and exercised groups. In addition, the reduction in phospho-Thr(17) PLB in myocardium of ovariectomized rats was abolished by exercise training. These results showed that regular exercise maintains the molecular activation of cardiac SR Ca2+ uptake under normal physiological conditions and is able to induce a protective impact on cardiac SR Ca2+ uptake in ovarian sex hormone-deprived status.
Bupha-Intr
Tepmanas
T
Department of Physiology, Faculty of Science, Mahidol Univ., Rama 6 Road, Bangkok 10400, Thailand.
Laosiripisan
Jitanan
J
Wattanapermpool
Jonggonnee
J
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002155:Calsequestrin; D002352:Carrier Proteins / Q000378:metabolism; D005260:Female; D006352:Heart Ventricles / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*; D010052:Ovariectomy; D010766:Phosphorylation; D005082:Physical Exertion; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism*; D012694:Serine; D013912:Threonine; D000099211:Phospholamban
D002118:Calcium; D002135:Calcium-Binding Proteins; D002155:Calsequestrin; D002352:Carrier Proteins; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D012694:Serine; D013912:Threonine; D000099211:Phospholamban; C057137:Casq1 protein, rat