Spina R J, Rashid S, Dávila-Román V G, Ehsani A A
Division of Geriatrics and Gerontology, Claude D. Pepper Older Americans Independence Center, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Appl Physiol (1985). 2000 Dec;89(6):2300-5. doi: 10.1152/jappl.2000.89.6.2300.
To determine whether endurance exercise training can alter the beta-adrenergic-stimulated inotropic response in older women, we studied 10 postmenopausal healthy women (65.4 +/- 0.9 yr old) who exercised for 11 mo. Left ventricular (LV) function was evaluated with two-dimensional echocardiography during infusion of isoproterenol after atropine. Maximal O(2) consumption increased 23% in response to training (from 1.35 +/- 0.06 to 1.66 +/- 0.07 l/min; P = 0.004). Training had no effect on baseline LV function, end-diastolic diameter, LV wall thickness, or LV mass. The increase in LV systolic function in response to isoproterenol was unaffected by training. Furthermore, neither the systolic shortening-to-end-systolic wall stress relationship nor the end-systolic wall stress-to-end-systolic diameter relationship during isoproterenol infusion changed with training. We conclude that older postmenopausal women can increase their maximal O(2) consumption with exercise training without eccentric LV hypertrophy or enhancement of beta-adrenergic-mediated LV contractile function. These observations provide an explanation for the finding that maximal cardiac output and stroke volume are not increased in older women in response to training.
为了确定耐力运动训练是否能改变老年女性β-肾上腺素能刺激的变力反应，我们研究了10名绝经后健康女性（年龄65.4±0.9岁），她们进行了11个月的运动。在给予阿托品后输注异丙肾上腺素期间，用二维超声心动图评估左心室（LV）功能。训练后最大耗氧量增加了23%（从1.35±0.06升/分钟增至1.66±0.07升/分钟；P = 0.004）。训练对基线LV功能、舒张末期直径、LV壁厚度或LV质量没有影响。训练不影响异丙肾上腺素引起的LV收缩功能增加。此外，异丙肾上腺素输注期间的收缩期缩短与收缩末期壁应力关系以及收缩末期壁应力与收缩末期直径关系均未因训练而改变。我们得出结论，绝经后老年女性通过运动训练可增加其最大耗氧量，而不会出现偏心性LV肥厚或增强β-肾上腺素能介导的LV收缩功能。这些观察结果解释了老年女性训练后最大心输出量和每搏输出量未增加的现象。
