Barnard R J, Corre K, Cho H
Eur J Appl Physiol Occup Physiol. 1976 Sep 23;35(4):285-9. doi: 10.1007/BF00423288.
Adult male rats were progressively trained 5 days/weeks on a motor-driven treadmill. The training period lasted 12 weeks and consisted of 60 min/day of wind-sprints and endurance work. No significant difference in resting heart rates was observed between the control and exercise groups during week 1 (394 +/- 7 vs. 388 +/- 5). However, at week 12 the exercise group had a lower resting heart rate (359 +/- 6 vs. 331 +/- 4). Heart rates observed following saline, propranolol, atropine, and propranolol plus atropine injections were lower in the exercise group in all cases. The difference in heart rates between the control and exercise groups was 19 beats/min following propranolol plus atropine which was less than the 28 beats/min difference observed under control conditions. With atropine and then with propranolol the differences were 33 and 27 beats/min. These heart rate differences were observed without the presence of cardiac hypertrophy as assesssed from ventricle weights. Our data indicate that the bradycardia resulting from exercise training is due primarily to changes other than neural influences on the heart.
成年雄性大鼠每周5天在电动跑步机上进行渐进式训练。训练期持续12周，包括每天60分钟的冲刺跑和耐力训练。在第1周时，对照组和运动组的静息心率无显著差异（394±7对388±5）。然而，在第12周时，运动组的静息心率较低（359±6对331±4）。在所有情况下，运动组注射生理盐水、普萘洛尔、阿托品以及普萘洛尔加阿托品后的心率均较低。在普萘洛尔加阿托品注射后，对照组和运动组的心率差异为19次/分钟，小于对照条件下观察到的28次/分钟的差异。使用阿托品后再使用普萘洛尔时，差异分别为33次/分钟和27次/分钟。从心室重量评估来看，在没有心脏肥大的情况下观察到了这些心率差异。我们的数据表明，运动训练导致的心动过缓主要是由于心脏受到神经影响之外的其他变化所致。
