It was our objective to analyse the effects of resistance exercise (climbing steps), which was started in the acute phase, on the histomorphometry and the expression of aquaporin 1 (AQP1) in the soleus muscle after sciatic nerve injury in Wistar rats. Twenty-four adult rats were randomly divided into the following four groups, containing six animals each: control (G1); exercise (G2); injury (G3); and exercise with injury (G4). Three days after the compression of the sciatic nerve, the animals in G2 and G4 were submitted to resistance exercise for 21 non-consecutives days. The exercise was conducted in two series of 10 consecutive ascents of the ladder, with an additional weight of 100g and with an interval of 60 seconds between sets for rest. After this period, the animals were sacrificed, and the soleus muscle was processed. The number of blood capillaries in G3 was 65.7% and 76.86% higher when compared with the G2 and G4, respectively. The morphological analysis revealed muscle damage in G3, hypertrophy in G2 and significant improvement in the muscle in G4. The AQP1 was immunolocalized in the endothelium of blood capillaries present in the muscle fibres, with different expressions in the groups. Resistance exercise initiated in the acute phase was an effective therapeutic modality in the recovery of morphological aspects in the soleus muscle after denervation.

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Objective To evaluate the action of vanillin (Vanilla planifolia) on the morphology of tibialis anterior and soleus muscles after peripheral nerve injury.Methods Wistar rats were divided into four groups, with seven animals each: Control Group, Vanillin Group, Injury Group, and Injury + Vanillin Group. The Injury Group and the Injury + Vanillin Group animals were submitted to nerve injury by compression of the sciatic nerve; the Vanillin Group and Injury + Vanillin Group, were treated daily with oral doses of vanillin (150mg/kg) from the 3rd to the 21st day after induction of nerve injury. At the end of the experiment, the tibialis anterior and soleus muscles were dissected and processed for light microscopy and submitted to morphological analysis.Results The nerve compression promoted morphological changes, typical of denervation, and the treatment with vanillin was responsible for different responses in the studied muscles. For the tibialis anterior, there was an increase in the number of satellite cells, central nuclei and fiber atrophy, as well as fascicular disorganization. In the soleus, only increased vascularization was observed, with no exacerbation of the morphological alterations in the fibers.Conclusion The treatment with vanillin promoted increase in intramuscular vascularization for the muscles studied, with pro-inflammatory potential for tibialis anterior, but not for soleus muscle.

ObjectiveTo analyze the combined effects of the silk protein sericin and swimming exercise on histomorphometry of the plantar muscle in Wistar rats.MethodsForty adult rats were randomly allocated into 5 groups comprising 8 animals each, as follows: Control, Injury, Sericin, Swim, and Swim plus Sericin. Three days after crushing of the sciatic nerve the rats in the Swim and Swim plus Sericin Groups were submitted to swimming exercise for 21 days. Rats were then euthanized and the plantar muscle harvested and processed.ResultsCross-sectional area, peripheral nuclei and muscle fiber counts, nucleus/fiber ratio and smallest muscle fiber width did not differ significantly between groups. Morphological analysis revealed hypertrophic fibers in the Swim Group and evident muscle damage in the Swim plus Sericin and Injury Groups. The percentage of intramuscular collagen was apparently maintained in the Swim Group compared to remaining groups.ConclusionCombined treatment with sericin and swimming exercise did not improve muscle properties. However, physical exercise alone was effective in maintaining intramuscular connective tissue and preventing progression of deleterious effects of peripheral nerve injury.

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.

Both modalities showed antinociceptive effects.

Background. Due to the deleterious effects of obesity on muscle tissue and the search for tools to reverse these losses, it is important to understand the effect of physical exercises on the muscle structure of obese individuals. This study aimed to analyze the effect of wholebody vibration (WBV) on the histomorphological parameters of the anterior tibial muscle using the monosodium l-glutamate (MSG) obesity model. Methods. MSG-obese rats that were exposed to WBV on a vibrating platform with a frequency of 60 Hz, the amplitude of 2 mm, three times/week, 10 min/day, for eight weeks (from postnatal day (PN) 80 to PN136). The histomorphology of the anterior tibial muscle was evaluated. Results. When performing a WBV exercise, the animals showed altered structural responses in the MSG animals, such as reduced muscle mass, increased connective tissue, and nuclear activity. The WBV reduced the extracellular matrix and the nuclear activity in the MSG animals, showing efficiency in the protocol. Conclusions. Even with the aggressive character of the MSG model, the WBV exercise was able to induce repair to the muscle tissue of these animals, thus being a safe protocol for use in similar conditions.