Hickson R C, Galassi T M, Kurowski T T, Daniels D G, Chatterton R T
Am J Physiol. 1984 Jun;246(6 Pt 2):H761-7. doi: 10.1152/ajpheart.1984.246.6.H761.
Female rats were trained daily by means of two 2-h-long bouts of swimming separated by a 30- to 40-min rest period. Absolute ventricular weights of the swimmers were increased above sedentary control values by 6% after 2 days, 15% after 7 days, and 30% after 35 days of exercise. Resting levels of total and free serum testosterone and total 5 alpha-dihydrotestosterone were not altered by the training. Total serum corticosterone concentrations at rest were significantly lower in the 7-day (149 +/- 16 ng/ml) and 35-day (169 +/- 24) swimmers compared with the controls (293 +/- 26). However, free corticosterone was not significantly reduced from controls in any of the swimming groups. Ventricular muscle cytosol androgen receptor binding dissociation constants and receptor binding capacities, measured using [3H]methyltrienolone (R1881), were not significantly different from control values in the exercised groups. Glucocorticoid cytosol receptor binding capacity in ventricular tissue, determined using [3H]dexamethasone, was significantly increased as femtomoles per milligram protein (39.3 +/- 3.1 vs. 31.4 +/- 1.4) and femtomoles per milligram DNA (2,683 +/- 226 vs. 1,786 +/- 71). These findings show that glucocorticoids, rather than androgens, undergo adaptive changes in the circulation and in muscle during the development of exercise-induced cardiac hypertrophy.
雌性大鼠每天接受两次时长为2小时的游泳训练，两次训练之间有30至40分钟的休息时间。游泳组大鼠的绝对心室重量在训练2天后比静息对照组增加了6%，7天后增加了15%，35天后增加了30%。训练并未改变血清总睾酮、游离睾酮和总5α - 双氢睾酮的静息水平。与对照组（293±26）相比，7天（149±16 ng/ml）和35天（169±24）游泳组大鼠静息时的血清皮质酮总浓度显著降低。然而，任何游泳组的游离皮质酮与对照组相比均未显著降低。使用[3H]甲基三烯olone（R1881）测量的心室肌细胞质雄激素受体结合解离常数和受体结合容量，在运动组与对照组之间无显著差异。使用[3H]地塞米松测定的心室组织中糖皮质激素细胞质受体结合容量显著增加，以每毫克蛋白质飞摩尔数计（39.3±3.1对31.4±1.4），以每毫克DNA飞摩尔数计（2683±226对1786±71）。这些发现表明，在运动诱导的心脏肥大发展过程中，糖皮质激素而非雄激素在循环和肌肉中发生适应性变化。
