Effect of resistance training on neuromuscular junctions of young and aged muscles featuring different recruitment patterns.
Effect of resistance training on neuromuscular junctions of young and aged muscles featuring different recruitment patterns.
复制标题
DOI：
10.1002/jnr.23495
复制
发表时间：
2015-03
影响因子：
4.2
通讯作者：
Harris, M. Brennan
中科院分区：
文献类型：
--
作者：
Deschenes, Michael R.;Sherman, E. Grace;Roby, Mackenzie A.;Glass, Emily K.;Harris, M. Brennan
为了研究增龄对耐力训练(即举重)神经肌肉适应性的影响，青年(9个月龄)和老年(20个月龄)雄性大鼠分别参加了6周的爬梯加尾部附加重量的训练，或作为对照组(N=10只/组)。实验结束后，对大鼠实施安乐死，并迅速取出后肢肌肉进行冰冻，以备日后分析。收集比目鱼肌和足底肌纵切面，用免疫荧光染色方法显示神经肌肉接头突触前和突触后的特征。对相同肌肉的横截面进行组织化学染色，以确定肌纤维的轮廓(纤维类型和大小)。统计分析采用双因素方差分析(年龄和治疗的主效应)，显著性设为P≤0.05。结果显示，训练诱导的NMJ重构仅在比目鱼肌快速抽动肌纤维的突触后终板区域明显。相反，衰老与足底快慢抽动肌纤维突触前和突触后的重塑有关。尽管比目鱼肌和足底肌都没有表现出训练或衰老相关的肌纤维大小变化，但老化的足底肌表现出I型(慢抽动)肌纤维表达增加，而II型(快抽动)肌纤维百分比减少，这表明早期肌纤维减少。总体而言，这些数据表明，突触改变对运动和衰老的反应具有高度的特异性，稀少招募的足底肌比更频繁招募的比目鱼肌更容易受到衰老的影响。
To examine the effects of aging on neuromuscular adaptations to resistance training (i.e. weight lifting), young (9 mo old) and aged (20 mo old) male rats either participated in a 6 week ladder climbing protocol with additional weight attached to their tails, or served as controls (N=10/group). At the conclusion, rats were euthanized and hindlimb muscles were quickly removed and frozen for later analysis. Longitudinal sections of the Soleus and Plantaris muscles were collected and pre- and post-synaptic features of neuromuscular junctions (NMJs) were visualized with immunofluorescent staining procedures. Cross-sections of the same muscles were histochemically stained to determine myofiber profiles (fiber type and size). Statistical analysis was performed with a 2 way ANOVA (main effects of age and treatment) with significance set at P≤0.05. Results revealed that training-induced remodeling of NMJs was evident only at the post-synaptic endplate region of Soleus fast-twitch myofibers. In contrast, aging was associated with pre- and post-synaptic remodeling in fast- and slow-twitch myofibers of the Plantaris. Although both the Soleus and Plantaris muscles failed to display either training or aging-related alterations in myofiber size, aged Plantaris muscles exhibited an increased expression of Type I (slow-twitch) myofibers in conjunction with a reduced percentage of Type II (fast-twitch) myofibers suggesting early stages of sarcopenia. Overall, these data demonstrate the high degree of specificity of synaptic modifications made in response to exercise and aging, and that the sparsely recruited Plantaris is more vulnerable to the effects of aging than the more frequently recruited Soleus muscle.
登录
查看更多内容
DOI：
10.1093/geronj/44.2.b43
发表时间：
1989-03-01
期刊：
JOURNALS OF GERONTOLOGY
影响因子：
--
作者：
ANDONIAN, MH;FAHIM, MA
通讯作者：
FAHIM, MA
影响因子：
3.3
作者：
Allen, Jeralyn;Morelli, Vincent
通讯作者：
Morelli, Vincent
影响因子：
3.3
作者：
Fahim, MA
通讯作者：
Fahim, MA
影响因子：
3
作者：
Desveaux, Laura;Beauchamp, Marla;Brooks, Dina
通讯作者：
Brooks, Dina
影响因子：
--
作者：
LAUGHLIN, MH;ARMSTRONG, RB
通讯作者：
ARMSTRONG, RB