2018 Volume 25 Issue 1 Pages 57-62
Neuromuscular electrical stimulation (NMES) is an effective intervention for prevention of muscle atrophy via muscle contraction. Despite the fact that pulsed magnetic stimulation (MS) is also a muscle contraction method, no studies have compared NMES and MS for the prevention of muscle atrophy. Therefore, this comparative study investigated the effects of NMES and MS on the prevention of muscle atrophy via the inhibition of muscle-specific ring finger protein-1 (MuRF-1) of the ubiquitin-proteasome protein degradation pathway in rat soleus muscle. Male Sprague-Dawley rats were assigned randomly either to a control (CON), or to one of three groups: 2 weeks hindlimb unloading (HU), HU plus NMES on the left calf muscles (HU+NMES), or HU plus MS on the right calf muscles (HU+MS). Muscle mass, relative weight ratio, fiber cross-sectional area (FCSA), and MuRF-1 expression were examined in the soleus muscles of all rats. HU resulted in a decrease in the FCSA and an increase in the MuRF-1 expression. Meanwhile, NMES attenuated an increase in MuRF-1 expression and a decrease in the FCSA caused by unloading. Furthermore, MS significantly reduced the expression level of MuRF-1 protein, resulting in an increase of the FCSA. These results suggest that MS could prevent muscle atrophy via inhibiting MuRF-1, but NMES was insufficient to prevent atrophy.
