Fujita Naoto, Murakami Shinichiro, Fujino Hidemi
Department of Rehabilitation Science, Graduate School of Health Sciences Kobe University, 7-10-2 Tomogaoka, Suma-Ku, Kobe 654-0142, Japan.
J Biomed Biotechnol. 2011;2011:401493. doi: 10.1155/2011/401493. Epub 2011 Oct 5.
High-load isometric exercise is considered an effective countermeasure against muscle atrophy, but therapeutic electrical stimulation for muscle atrophy is often performed without loading. In the present study, we investigated the combined effectiveness of electrical stimulation and high-load isometric contraction in preventing muscle atrophy induced by hindlimb unloading. Electrical stimulation without loading resulted in slight attenuation of muscle atrophy. Moreover, combining electrical stimulation with high-load isometric contraction enhanced this effect. In electrical stimulation without loading, inhibition of the overexpression of calpain 1, calpain 2, and MuRF-1 mRNA was confirmed. On the other hand, in electrical stimulation with high-load isometric contraction, inhibition of the overexpression of cathepsin L and atrogin-1 mRNA in addition to calpain 1, calpain 2, and MuRF-1 mRNA was confirmed. These findings suggest that the combination of electrical stimulation and high-load isometric contraction is effective as a countermeasure against muscle atrophy.
高负荷等长运动被认为是对抗肌肉萎缩的有效对策，但针对肌肉萎缩的治疗性电刺激通常是在无负荷情况下进行的。在本研究中，我们调查了电刺激与高负荷等长收缩相结合在预防后肢卸载诱导的肌肉萎缩方面的综合效果。无负荷的电刺激导致肌肉萎缩略有减轻。此外，将电刺激与高负荷等长收缩相结合可增强这种效果。在无负荷的电刺激中，证实了钙蛋白酶1、钙蛋白酶2和肌肉萎缩相关泛素连接酶-1（MuRF-1）mRNA的过表达受到抑制。另一方面，在高负荷等长收缩的电刺激中，除了钙蛋白酶1、钙蛋白酶2和MuRF-1 mRNA外，还证实了组织蛋白酶L和肌肉萎缩相关基因1（atrogin-1）mRNA的过表达受到抑制。这些发现表明，电刺激与高负荷等长收缩相结合作为对抗肌肉萎缩的对策是有效的。
