Cartee G D, Farrar R P
Department of Physical and Health Education, University of Texas, Austin 78712.
J Appl Physiol (1985). 1988 Jan;64(1):259-65. doi: 10.1152/jappl.1988.64.1.259.
Glycogen utilization during exercise appears to be related to muscle respiratory capacity. Since the decline in hindlimb muscle respiratory capacity that occurs in rats during old age is eliminated when young and old rats undergo an identical exercise training protocol, liver and gastrocnemius glycogen concentrations were determined in identically trained young and old Fischer 344 rats at rest and immediately after a 30-min run requiring approximately 75% of maximal O2 consumption. These values were also compared with untrained age-matched control animals. The animals, which were 10 or 24 mo old after 6 mo of training, were fasted for 24 h before they were killed. Resting gastrocnemius glycogen did not differ among the groups. After 30 min of running, gastrocnemius glycogen was lower in the untrained than the trained groups and was not different between the trained groups. Resting liver glycogen was lower in the old trained group than the untrained groups but not statistically different from the young trained group. The postrun liver glycogen did not differ among the groups. Estimated gastrocnemius and liver glycogen utilization during exercise was decreased in both trained groups compared with untrained age-matched controls. These results indicate that the training-induced glycogen sparing during exercise of the same relative intensity was not diminished with age in identically trained young and old rats.
运动期间糖原的利用似乎与肌肉呼吸能力有关。由于当年轻和年老的大鼠接受相同的运动训练方案时，老年大鼠后肢肌肉呼吸能力的下降会被消除，因此测定了经过相同训练的年轻和年老的Fischer 344大鼠在休息时以及在进行一次需消耗约75%最大耗氧量的30分钟跑步后立即处死时的肝脏和腓肠肌糖原浓度。这些值还与未训练的年龄匹配对照动物进行了比较。经过6个月训练后年龄为10或24个月的动物在处死前禁食24小时。各实验组间的静息腓肠肌糖原无差异。跑步30分钟后，未训练组的腓肠肌糖原低于训练组，而训练组之间无差异。老年训练组的静息肝糖原低于未训练组，但与年轻训练组无统计学差异。跑步后肝糖原在各实验组间无差异。与未训练的年龄匹配对照相比，两个训练组运动期间估计的腓肠肌和肝脏糖原利用均减少。这些结果表明，在相同相对强度的运动中，训练诱导的糖原节省在经过相同训练的年轻和年老大鼠中不会随年龄增长而减少。
