Leon A S, Bloor C M
Adv Cardiol. 1976;18(0):81-92. doi: 10.1159/000399514.
Exercise conditioning of young male rats by swimming for 1 h, 5 times per week for 10 weeks results in a reduced gain in body weight, cardiac hypertrophy and hyperplasia, an increase in myocardial capillary density, and an increase in cross-sectional laminal areas of extracoronary collateral arteries. The effects of partial or complete deconditioning on these changes were studied by randomizing young male rats exercise-conditioned for 10 weeks to groups either kept sedentary or subjected to varying amounts of exercise for a second 10-week period. Their hearts were compared with those of unexercised controls using quantitative histologic measurements. During the second 10 weeks, exercise conditioning was found not to continue to suppress weight gain. However, frequent relative short-duration exercise sessions (as little as 15 min per session) frequently prevented an accelerated increase in body weight associated with deconditioning. A complete regression of exercise-induced cardiovascular adaptive changes occurred when wxercise was discontinued completely for 10 weeks or the duration of sessions was cut to 15 min. In order to maintain cardiac hypertrophy, exercise had to be continued for 1 h, 5 times per week while hyperplasia could be maintained with shorter duration, less frequent sessions (30 min, twice a week). The maintenance of increased myocardial capillary density required a similar amount of exercise, and at least 1 h of exercise once a week was necessary to maintain the enlargement of ECA.20
对年轻雄性大鼠进行运动训练，即每周游泳1小时，共5次，持续10周，结果导致体重增加减少、心脏肥大和增生、心肌毛细血管密度增加以及冠状动脉外 collateral 动脉横截面积增加。通过将经过10周运动训练的年轻雄性大鼠随机分为久坐不动组或在第二个10周期间进行不同运动量运动的组，研究了部分或完全去适应对这些变化的影响。使用定量组织学测量方法将它们的心脏与未运动的对照组的心脏进行比较。在第二个10周期间，发现运动训练不再继续抑制体重增加。然而，频繁的相对短时间运动（每次运动仅15分钟）经常可防止与去适应相关的体重加速增加。当完全停止运动10周或将运动时间缩短至15分钟时，运动诱导的心血管适应性变化会完全消退。为了维持心脏肥大，运动必须持续每周5次，每次1小时，而增生可以通过较短时间、较少频率的运动（每周两次，每次30分钟）来维持。维持增加的心肌毛细血管密度需要相似的运动量，并且每周至少进行1小时运动对于维持冠状动脉外 collateral 动脉的增大是必要的。20
