Laboratory of Physiology, School of Health Sciences, Toyohashi SOZO University, Toyohashi, Aichi, Japan.
Int J Med Sci. 2013 Aug 7;10(10):1286-94. doi: 10.7150/ijms.5985. eCollection 2013.
Microcurrent electrical nerve stimulation (MENS) has been used to facilitate recovery from skeletal muscle injury. However, the effects of MENS on unloading-associated atrophied skeletal muscle remain unclear. Effects of MENS on the regrowing process of unloading-associated atrophied skeletal muscle were investigated. Male C57BL/6J mice (10-week old) were randomly assigned to untreated normal recovery (C) and MENS-treated (M) groups. Mice of both groups are subjected to continuous hindlimb suspension (HS) for 2 weeks followed by 7 days of ambulation recovery. Mice in M group were treated with MENS for 60 min 1, 3, and 5 days following HS, respectively, under anesthesia. The intensity, the frequency, and the pulse width of MENS were set at 10 μA, 0.3 Hz, and 250 msec, respectively. Soleus muscles were dissected before and immediately after, 1, 3 and 7 days after HS. Soleus muscle wet weight and protein content were decreased by HS. The regrowth of atrophied soleus muscle in M group was faster than that in C group. Decrease in the reloading-induced necrosis of atrophied soleus was facilitated by MENS. Significant increases in phosphorylated levels of p70 S6 kinase and protein kinase B (Akt) in M group were observed, compared with C group. These observations are consistent with that MENS facilitated regrowth of atrophied soleus muscle. MENS may be a potential extracellular stimulus to activate the intracellular signals involved in protein synthesis.
微电流神经电刺激（MENS）已被用于促进骨骼肌损伤的恢复。然而，MENS 对去负荷相关萎缩骨骼肌的影响尚不清楚。本研究旨在探讨 MENS 对去负荷相关萎缩骨骼肌再生过程的影响。雄性 C57BL/6J 小鼠（10 周龄）被随机分为未处理的正常恢复（C）组和 MENS 处理（M）组。两组小鼠均接受连续后肢悬吊（HS）2 周，然后进行 7 天的步行恢复。M 组小鼠在 HS 后第 1、3 和 5 天分别接受 MENS 治疗 60 分钟，麻醉下进行。MENS 的强度、频率和脉冲宽度分别设定为 10μA、0.3Hz 和 250msec。在 HS 前后、HS 后 1、3 和 7 天分别解剖比目鱼肌。HS 导致比目鱼肌湿重和蛋白含量降低。与 C 组相比，M 组萎缩比目鱼肌的再生速度更快。MENS 促进了萎缩比目鱼肌再负荷诱导的坏死减少。与 C 组相比，M 组磷酸化 p70 S6 激酶和蛋白激酶 B（Akt）水平显著升高。这些观察结果与 MENS 促进萎缩比目鱼肌再生的结果一致。MENS 可能是一种潜在的细胞外刺激，可激活参与蛋白质合成的细胞内信号。
