ABSTRACT
Objective To study counteracting effects of high frequency vibration on simulated weightlessness-induced atrophy of soleus muscles in rats. Methods Female Sprague-Dawley (SD) rats were assigned randomly to one of the three groups: simultaneous control (CON), simulated weightlessness (SUS), and SUS plus high frequency vibration (SUS+HFV). Soleus muscles were examined 7 days later. Sections were treated with adenosinetriphosphatase (ATPase) stain. The cross-sectional areas (CSA) of fibers, the relative proportion of types I and II were measured using Leica image analysis system. Results Compared with those of CON, the wet weight /body of soleus and the cross-sectional areas (CSA) of type I/II fibers in SUS were significantly reduced. The relative proportion of type I fibers in SUS was reduced and type II fibers increased. In SUS+HFV group, the wet weight/body of soleus and the cross-sectional areas (CSA) of type I/II fibers recovered completely. The relative proportion of type I/II fibers recovered completely. Conclusion The present study demonstrates that HFV is effective in counteracting the muscle atrophy induced by simulated weightlessness.