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This Article Full Text Full Text (PDF) All Versions of this Article: 107/4/1105    most recent 00407.2009v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Bupha-Intr, T. Articles by Wattanapermpool, J. PubMed PubMed Citation Articles by Bupha-Intr, T. Articles by Wattanapermpool, J.

Moderate intensity of regular exercise improves cardiac SR Ca²⁺ uptake activity in ovariectomized rats

Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand

Submitted 18 April 2009 ; accepted in final form 9 August 2009

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 Ca²⁺-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-Thr¹⁷ 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.

treadmill running; SR Ca²⁺-ATPase; phospholamban