Specific force deficit in skeletal muscles of old rats is partially explained by the existence of denervated muscle fibers
Specific force deficit in skeletal muscles of old rats is partially explained by the existence of denervated muscle fibers
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DOI：
10.1093/gerona/56.5.b191
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发表时间：
2001-05-01
影响因子：
5.1
通讯作者：
Kuzon, WM
中科院分区：
文献类型：
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作者：
Urbanchek, MG;Picken, EB;Kuzon, WM
我们测试了以下假设：去神经肌纤维是老年 (OA) 哺乳动物肌肉中观察到的特定力量 (sF(0)) 缺陷的一部分，对 OA 和年轻成年 (YA) 大鼠的趾长伸肌 (EDL) 肌肉的整体肌肉力量 (F-0) 进行了量化。 EDL 肌肉 sF(0) 通过将 F-0 除以总肌纤维横截面积 (CSA) 或除以受神经支配的纤维 CSA 来计算。受神经支配的纤维 CSA 是根据标记有神经细胞粘附分子的 EDL 肌肉横截面估计的，神经细胞粘附分子的存在是肌纤维去神经的标志。 OA 大鼠的 EDL 肌肉比 YA 大鼠的肌肉含有明显更多的去神经纤维（占总 CSA 的 5.6% vs 1.1%），与 YA 肌肉相比，油肌表现出 F-0 的缺陷为 34.1%，sF(0) 的缺陷为 28.3%，sF(0) 的缺陷为 24.9%（以受神经支配的 CSA 为分母计算）。正常 YA 和 OA 骨骼肌之间的比力差异为 11.3%，除去神经支配外的其他机制解释了衰老导致的 sF(0) 缺陷的大部分。
We tested the hypothesis that denervated muscle fibers account for part of the specific force (sF(0)) deficit observed in muscles from old adult (OA) mammals, Whole muscle force (F-0) was quantified for extensor digitorum longus (EDL) muscles of OA and young adult (YA) rats. EDL muscle sF(0) was calculated by dividing F-0 by either total muscle fiber cross-sectional area (CSA) or by innervated fiber CSA. Innervated fiber CSA was estimated from EDL muscle cross sections labeled for neural cell adhesion molecules, whose presence is a marker for muscle fiber denervation. EDL muscles from OA rats contained significantly more denervated fibers than muscles from YA rats (5.6% vs 1.1% of total CSA), When compared with YA muscle, oil muscle demonstrated deficits of 34.1% for F-0, 28.3% for sF(0), and 24.9 % for sF(0) calculated by using innervated CSA as the denominator, Denervated muscle fibers accounted for 11.3% of the specific force difference between normal YA and OA skeletal muscle, Other mechanisms in addition to denervation account for the majority of the sF(0) deficit with aging.