Therapeutic immobilization is a common treatment for the locomotor system; however, it causes loss of muscle due to disuse, leading to protein degradation and generating atrophy of muscle cells, ultimately changing functionality. In this sense, it is important for remobilization to be initiated early and performed with appropriate therapeutic strategies that enable tissue and functional recovery. One method of remobilization is physical exercise, among which whole body vibration (WBV) has been highlighted and mainly applied in people with reduced mobility. However, there are gaps on the morphological effects WBV has on muscle tissue, so in this study we analyzed the histomorphometry of the tibialis anterior muscle (TA) of Wistar rats remobilized using WBV. For the experiment, 32 male Wistar rats were used and divided into four groups (n = 8/group). Groups consisted of: control (CG), immobilized (IG), immobilized and remobilized freely (FG), and immobilized and remobilized with WBV (WG). After the experimental period, the TA was collected and processed for analysis in light microscopy. When compared to the control group, significant morphological changes were observed, which characterize muscle atrophy and reduction of all histomorphometric parameters of the TA of the immobilized animals. Remobilized animals showed improvement in all parameters, and the WBV was not different from the free remobilization, except for the reduction of central nuclei, which can be related to acceleration of the process of tissue regeneration. Thus, we can conclude that the WBV can have an impact on the acceleration of the muscle regenerative process, and may be beneficial in people with reduced mobility.

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Aim: To evaluate the effects of whole-body vibration in the sciatic nerve of oophorectomized Wistar rats, on nociceptive and morphological parameters, such as fiber, axon, and myelin sheath diameters, G ratio, number of nerve fiber and nuclei of Schwann cells, and percentage of connective tissue. Method: Sixty-four rats were used in the groups sham-operate and oophorectomy (n = 32/group); after surgical procedures, each group was subdivided into four: euthanized in the 12 th week, untreated and treated for four weeks; and euthanized in the 16 th week, untreated and treated for eight weeks. The treatment with vibration was performed with a 60 Hz frequencies, for 10 minutes, three days a week, with duration of 4 or 8 weeks. Nociception was evaluated later, in the right paw, by means of a digital analgesimeter, prior to surgery, at the beginning and at the end of the protocol. After the trial period, the sciatic nerve was dissected for examination of the general morphology of the tissue and morphometric analysis; later, the animals were euthanized. Results: Regarding nociception and the morphometry of the sciatic nerve, independent of oophorectomy and treatment time, there was no statistically significant difference within and between groups. Also, the general morphology of the tissue in all groups had characteristics that were preserved. Conclusion: The mechanical vibration did not alter the nociceptive threshold and the morphological aspects of nerve fibers in oophorectomized Wistar rats.

Objective  To evaluate the neuromuscular junctions (NMJs) and the type of muscle fibers of the soleus muscle of oophorectomized Wistar rats submitted to a mechanical vibration protocol. Methods  A total of 36 randomized rats were used in the pseudo-oophorectomy without and with treatment and oophorectomy without and with treatment groups. The treatment was performed with a vibratory platform, frequency of 60 Hz and duration of 10 minutes, 3 times a week, for 4 weeks. At the end of the intervention period, the animals were euthanized and the soleus muscles were collected and processed for analysis of the NMJs and fiber type. The data were analyzed for normality by the Shapiro-Wilk test and analysis of the 3-way variance using the post-hoc Tukey test, when necessary, and a significance level of 5% was adopted. Results  In the analysis of the NMJs, the oophorectomy group presented a smaller area than the pseudo-oophorectomy group, but the oophorectomy with treatment group was equal to the pseudo-oophorectomy with treatment group. For the larger diameter of the joints, the oophorectomy group was also different from the others; however, the oophorectomy and treatment animals were larger than those of the pseudo-oophorectomy and treatment group. There was no distinction of the types of fibers, with the muscle presenting fibers of the oxidative type. Conclusion  Hormonal deprivation reduced the area and diameter of the NMJs, with reversion of this process in the groups that underwent vibratory platform treatment for 4 weeks, and both surgery and treatment did not influence the type of soleus muscle fiber, composed of oxidative fibers.

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