[Effects of inosine injection in expression of myosin heavy chain in intrafusal and extrafusal myofibers in soleus muscle of tail-suspended rats].

Aim: To study the effects of inosine on myosin heavy chain (MHC) activity in rats soleus muscle after tail-suspension.
Methods: Weightlessness was simulated by tail-suspension of rats. Using immunohistochemistry technique, changes of expression of MHC in intrafusal and extrafusal fibers in soleus muscle were detected.
Results: Expression of fast MHC in intrafusal and extrafusal fibers in soleus muscle increased after 14 d of simulated weightlessness, whereas in tail-suspended rats given inosine, the expression of fast MHC was not detected.
Conclusion: Inosine could counteract the changes in expression of MHC in intrafusal and extrafusal fibers of rats soleus under simulated weightless situation.