Honda Akiko, Sogo Naota, Nagasawa Seigo, Kato Takeru, Umemura Yoshihisa
School of Health and Sport Sciences, Chukyo Univ., 101 Tokodachi, Kaizu-cho, Toyota, Aichi, 470-0393 Japan.
J Appl Physiol (1985). 2008 Sep;105(3):849-53. doi: 10.1152/japplphysiol.00902.2007. Epub 2008 Jul 3.
We investigated the osteogenic responses to jump training and subsequent detraining in young and adult male rats to test the following hypotheses: 1) jump training has skeletal benefits; 2) these skeletal benefits are preserved with subsequent detraining throughout bone morphometric changes; and 3) there are no differences between young and adult rats during detraining in terms of the maintenance of exercise-induced changes. Twelve-week-old (young) and 44-wk-old (adult) rats were divided into the following four groups: young-sedentary, young-exercised, adult-sedentary, and adult-exercised. The exercised groups performed jump training (height = 40 cm, 10 jumps/day, 5 days/wk) for 8 wk followed by 24 wk of being sedentary. Tibial bone mineral content and bone mineral density in vivo significantly increased with jump training, and the effects were maintained after detraining in both the young and adult exercised groups, although the benefits of training became somewhat diminished. After 24 wk of detraining, the beneficial effects of training on bone mass and strength were preserved and associated with morphometric changes, such as periosteal perimeter, cortical area, and moment of inertia. There were no significant age-exercise interactions in such parameters, except for the periosteal perimeter. These results suggest that there are few differences in bone accommodation and maintenance by training and detraining between young and adult rats.
我们研究了年轻和成年雄性大鼠对跳跃训练及随后的停训的成骨反应，以检验以下假设：1）跳跃训练对骨骼有益；2）在整个骨形态计量学变化过程中，这些骨骼益处会在随后的停训过程中得以保留；3）在停训期间，年轻和成年大鼠在维持运动诱导变化方面没有差异。将12周龄（年轻）和44周龄（成年）的大鼠分为以下四组：年轻 sedentary组、年轻运动组、成年 sedentary组和成年运动组。运动组进行8周的跳跃训练（高度 = 40厘米，每天10次跳跃，每周5天），随后24周保持 sedentary状态。跳跃训练后，体内胫骨骨矿物质含量和骨矿物质密度显著增加，并且在年轻和成年运动组停训后，这些效果得以维持，尽管训练的益处有所减弱。停训24周后，训练对骨量和强度的有益影响得以保留，并与形态计量学变化相关，如骨膜周长、皮质面积和惯性矩。除骨膜周长外，这些参数中没有显著的年龄 - 运动相互作用。这些结果表明，年轻和成年大鼠在通过训练和停训对骨骼的适应和维持方面几乎没有差异。
