Efeitos do exercício resistido no músculo sóleo após lesão compressiva do nervo isquiático de ratos wistar

Abstract

Peripheral nerves injuries result in interruption of the transmission of nerve impulses, with a decrease or loss of sensation and motor function in innervated area, directly affecting the muscle tissue and the individual's mobility. Annually in developed countries, their impact is significant and affects mainly the active economically peoples, leading to decrease in quality of life and socio-economic impacts. In the rehabilitation process physical exercises are used as a therapeutic modality that can assist in maintaining muscle properties and functional recovery. Thus, this study aimed to analyze the effects of resistance exercise with ladder climbing in the soleus muscle, after compression of the sciatic nerve of Wistar rats. For this purpose, 24 adult rats were used, randomly divided into 4 groups of 6 animals each: control; exercise; lesion; and exercise with lesion. Three days after the compression of the sciatic nerve, the animals in the exercise group and the exercise with lesion group were submitted to resistance exercise for 21 days. After this period, the animals were euthanized and the soleus muscle processed for histomorphometric analysis. The results showed an increase cross-sectional area of muscle fibers in group exercise as compared to the other groups, as well as an increase area in group exercise with lesion in relation the group lesion. In the measurement of smaller diameter of the fibers, higher values were observed in group exercise when compared to control and lesion. Also, an increase in the number of blood capillaries in group lesion in comparison with exercise and exercise with lesion, and decreased number of fibers in group exercise, when compared to lesion and exercise with lesion. There was a fewer of sarcomeres at 300 μm, while its length is increase in lesion and exercise with lesion, as compared to control. The morphology analysis revealed that group exercise, most of the fibers had hypertrophied, while in group lesion was evident muscle damage resulting from sciatic compression, with irregular fibers, nucleus central and with surrounding halo, disruption of fiber and muscle fascicle, myoblasts to the site of injury and increased blood capillaries. Since the group exercise with lesion, a significant improvement in muscle morfology was found, with few fibers altered characteristics. The AQP1 was imunolocalizada the endothelium of blood capillaries present in the muscle fibers of all groups. Thus, it is concluded that resistance exercise with ladder climbing initiated during the acute phase, was an effective therapeutic modality in the recovery of morfology in the soleus muscle after denervation.