Suman O E, Hasten D, Turner M J, Rinder M R, Spina R J, Ehsani A A
Section of Applied Physiology, Division of Geriatrics and Gerontology, and Claude D. Pepper Older Americans Independence Center, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Appl Physiol (1985). 2000 Feb;88(2):534-9. doi: 10.1152/jappl.2000.88.2.534.
To determine whether strength-trained individuals with physiological concentric left ventricular (LV) hypertrophy exhibit enhanced inotropic responses to catecholamines, we studied 11 bodybuilders, aged 33.0 +/- 2 (SE) yr old, and 10 sedentary healthy subjects, aged 31.3 +/- 2.4 yr old, at baseline and during infusion of incremental doses of dobutamine after atropine. The bodybuilders had larger LV mass, posterior wall and septal wall thicknesses, and wall thickness-to-radius ratio, assessed with two-dimensional echocardiography, than did the sedentary subjects. There was a significant correlation between LV mass and lean body mass irrespective of training status. Baseline LV fractional shortening was similar in the two groups. There was a greater inotropic response to dobutamine in the strength-trained individuals, as evidenced by a steeper slope of the fractional shortening-end-systolic wall stress relationship with a higher y-axis intercept and by a shallower end-systolic wall stress-end systolic diameter relationship without changes in end-diastolic diameter. The heart rate response to dobutamine was attenuated in the strength-trained athletes. There was a significant correlation (r = 0.604, P < 0.05) between the inotropic sensitivity to dobutamine and LV mass normalized for lean body mass in the bodybuilders. The data suggest that concentric LV physiological hypertrophy in the resistance-trained individuals is associated with enhanced inotropic but not chronotropic responses to catecholamines.
为了确定患有生理性向心性左心室（LV）肥厚的力量训练者是否对儿茶酚胺表现出增强的变力反应，我们研究了11名年龄为33.0±2（SE）岁的健美运动员和10名年龄为31.3±2.4岁的久坐不动的健康受试者，在基线时以及在阿托品后输注递增剂量的多巴酚丁胺期间进行研究。通过二维超声心动图评估，健美运动员的左心室质量、后壁和室间隔厚度以及壁厚与半径比均大于久坐不动的受试者。无论训练状态如何，左心室质量与去脂体重之间均存在显著相关性。两组的基线左心室缩短分数相似。力量训练者对多巴酚丁胺的变力反应更大，表现为缩短分数与收缩末期壁应力关系的斜率更陡，y轴截距更高，以及收缩末期壁应力与收缩末期直径关系更平缓，而舒张末期直径无变化。力量训练的运动员对多巴酚丁胺的心率反应减弱。健美运动员对多巴酚丁胺的变力敏感性与去脂体重标准化的左心室质量之间存在显著相关性（r = 0.604，P < 0.05）。数据表明，阻力训练个体的向心性左心室生理性肥厚与对儿茶酚胺的变力反应增强有关，但与变时反应无关。
