Remobilization in aquatic medium of rat soleus immobilized in lengthening

Abstract

Introduction: The aim of this study was to evaluate histomorphometrically two protocols of aquatic exercise on soleus of rats immobilized in dorsiflexion. Material and Methods: It was used 30 Wistar rats, randomly distributed in five groups: G1 -right hindlimb immobilized in maximum dorsiflexion, for 15 consecutive days, after this the animals were euthanized; G2 -also immobilized in maximum dorsiflexion, for 15 consecutive days, then the animals were freely remobilized; G3 -submitted to remobilization by free swim; G4 -submitted to remobilization with overload of 10% of body weight; G5 -remobilization by jumping in water with overload of 50% of body weight. The immobilization model used was made by plaster cast directly in the lower right limb of each animal. After removing the immobilization, the animals were submitted to remobilization for 10 days according to the group. At the end of the remobilization, the right and left soleus muscles were isolated, cleaned and weighed on an analytical balance, each muscle was sectioned longitudinally, and the medial part was used to evaluation of longitudinal parameters and the medial for cross-sectional assessment. Results: for the estimate of sarcomeres in series, muscular and sarcomere length there were not significant differences. For the muscle mass and fibers diameter there were difference between right and left soleus, but not for the groups. Conclusion: the used protocol of immobilization/remobilization was insufficient to cause changes in the overall longitudinal soleus, but the immobilization produced reduced mass and diameter of the fibers, which are not reversed with remobilization protocols.