Motor Unit Changes Seen With Skeletal Muscle Sarcopenia in Oldest Old Rats
Motor Unit Changes Seen With Skeletal Muscle Sarcopenia in Oldest Old Rats
复制标题
DOI：
10.1093/gerona/glt135
复制
发表时间：
2014-06-01
影响因子：
5.1
通讯作者：
Faulkner, John A.
中科院分区：
文献类型：
--
作者：
Kung, Theodore A.;Cederna, Paul S.;Faulkner, John A.
肌肉减少症导致骨骼肌的许多变化，导致萎缩、力量不足和随后的虚弱。本研究的目的是表征运动单位重塑相关的肌肉减少症中看到的极端老年。在19只成年（11-13个月）和12只老年（36-37个月）Brown-Norway大鼠中测量了整个趾长伸肌和运动单位的收缩特性。与成年大鼠相比，年龄最大的老年大鼠每块肌肉的运动单位明显较少，肌肉横截面积较小，肌肉比力较低。然而，平均运动单位力的产生是相似的两组之间，由于神经支配的比例增加的最古老的老年大鼠。这些研究结果表明，即使在极端的老年，快速和缓慢收缩运动单位保持进行运动单位重塑的能力，抵消了肌肉减少症的一些影响。
Sarcopenia leads to many changes in skeletal muscle that contribute to atrophy, force deficits, and subsequent frailty. The purpose of this study was to characterize motor unit remodeling related to sarcopenia seen in extreme old age. Whole extensor digitorum longus muscle and motor unit contractile properties were measured in 19 adult (11-13 months) and 12 oldest old (36-37 months) Brown-Norway rats. Compared with adults, oldest old rats had significantly fewer motor units per muscle, smaller muscle cross-sectional area, and lower muscle specific force. However, mean motor unit force generation was similar between the two groups due to an increase in innervation ratio by the oldest old rats. These findings suggest that even in extreme old age both fast-and slow-twitch motor units maintain the ability to undergo motor unit remodeling that offsets some effects of sarcopenia.