Hypertension Unit, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil.
Maturitas. 2010 Mar;65(3):267-71. doi: 10.1016/j.maturitas.2009.11.007. Epub 2009 Dec 8.
Menopause is recognized as a period of increased risk for coronary heart disease. Although the benefits of exercise training in lowering cardiovascular risk factors are well established, the risks and benefits of hormone therapy have been questioned. The purpose of the present study was to investigate the effects of estrogen therapy (HT) associated or not with exercise training (ET) in autonomic cardiovascular control in ovariectomized (OVX) rats. Female rats were divided into: control, OVX, OVX+HT, OVX+ET and OVX+HT+ET. HT was performed using a 0.25mg 8-weeks sustained release pellet. Trained groups were submitted to an 8-week exercise training protocol on treadmill. Baroreflex sensitivity (BRS) was evaluated by heart rate responses to arterial pressure (AP) changes, and vagal and sympathetic tonus by pharmacological blockade. Ovariectomy induced an AP increase (123+/-2mmHg vs. 108+/-2mmHg), BRS impairment ( approximately 69%), sympathetic activation ( approximately 100%) and vagal tonus reduction ( approximately 77%) compared to controls. HT or ET normalized the changes in parasympathetic tonus. However, only the association HT+ET was able to promote normalization of AP, BRS and sympathetic tonus, as compared to controls. These results indicate that ET induces cardiovascular and autonomic benefits in OVX rats under HT, suggesting a positive role of this association in the management of cardiovascular risk factor in postmenopausal women.
绝经被认为是冠心病风险增加的时期。虽然运动训练降低心血管危险因素的益处已得到证实，但激素治疗的风险和益处一直存在争议。本研究的目的是研究雌激素治疗（HT）联合或不联合运动训练（ET）对去卵巢（OVX）大鼠自主心血管控制的影响。雌性大鼠分为：对照组、OVX 组、OVX+HT 组、OVX+ET 组和 OVX+HT+ET 组。HT 使用 0.25mg 8 周持续释放丸进行。训练组在跑步机上进行 8 周的运动训练方案。通过心率对动脉压（AP）变化的反应评估压力反射敏感性（BRS），并通过药理学阻断评估迷走神经和交感神经张力。与对照组相比，卵巢切除术导致 AP 增加（123+/-2mmHg 对 108+/-2mmHg）、BRS 受损（约 69%）、交感神经兴奋（约 100%）和迷走神经张力降低（约 77%）。HT 或 ET 使副交感神经张力的变化正常化。然而，只有 HT+ET 的联合才能促进 AP、BRS 和交感神经张力的正常化，与对照组相比。这些结果表明，ET 在 HT 下诱导 OVX 大鼠心血管和自主获益，提示这种联合在绝经后妇女管理心血管危险因素方面具有积极作用。
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