Bupha-Intr Tepmanas, Laosiripisan Jitanan, Wattanapermpool Jonggonnee
Department of Physiology, Faculty of Science, Mahidol Univ., Rama 6 Road, Bangkok 10400, Thailand.
J Appl Physiol (1985). 2009 Oct;107(4):1105-12. doi: 10.1152/japplphysiol.00407.2009. Epub 2009 Aug 13.
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.
通过测量去卵巢大鼠在进行9周中等强度跑步机跑步运动后肌浆网（SR）细胞内Ca2+清除活性的变化，评估规律运动对保护雌性激素剥夺导致的心脏恶化结果的影响。尽管假手术组和去卵巢大鼠运动组均诱导了心脏肥大，但运动训练对激素完整大鼠心脏的SR Ca2+摄取和SR Ca(2+)-ATP酶（SERCA）没有影响。然而，运动训练使去卵巢大鼠心脏中受抑制的最大SR Ca2+摄取和SERCA活性恢复正常。虽然运动训练使去卵巢大鼠的pCa（-log[Ca2+]）-SR Ca2+摄取关系的左移恢复正常，但在运动的假手术大鼠中未检测到影响。在SERCA和受磷蛋白（PLB）磷酸化水平上也观察到类似现象；去卵巢大鼠的运动训练增强了SERCA表达，使其达到假手术大鼠的水平，其中久坐组和运动组之间的SERCA和磷酸化PLB水平没有差异。此外，运动训练消除了去卵巢大鼠心肌中磷酸化苏氨酸（17）PLB的减少。这些结果表明，规律运动在正常生理条件下维持心脏SR Ca2+摄取的分子激活，并能够在卵巢性激素剥夺状态下对心脏SR Ca2+摄取产生保护作用。
