Efeitos do ultrassom terapêutico associados ao alongamento estático sobre parâmetros histomorfométricos longitudinais de sóleos imobilizados de ratos

Abstract

The muscle tissue is endowed with plasticity that adapts to different stimuli. Immobilization causes damage to the musculature including atrophy, loss of muscle strength and extensibility. The stretching and ultrasound treatment modalities are used to speed up muscle repair process as they can increase protein synthesis and improve extensibility. Objective: To compare the use of therapeutic thermal and non thermal ultrasound, associated with stretching, in the remobilization of the soleus muscle of rats subjected to position of muscle shortening on aspects histomorphometric longitudinal muscle. Methods: 28 rats were immobilized for 15 days, later released from the apparatus and divided into four groups: group AG only remobilized by stretching for 10 days and the others were subjected to 10 days of therapeutic intervention 1MHz of ultrasound at 1.0W/cm² (GAUS 1.0), 0.5W/cm² (GAUS 0.5), and 0.2 W/cm² (GAUS 0.2), and further stretching to the soleus. At the end of treatment, the animals were sacrificed and their soleus muscles were removed for later histological analysis of longitudinal parameters (count of sarcomeres). Results: At intragroup analysis on the muscle length, only the group GAUS 0.5 did not present significant difference. The count of sarcomeres in the groups GA and GAUS 0.2 was statistically different. The size of the sarcomeres in both groups had no statistically significant difference. In inter-group analysis both groups had no statistically significant difference for any of the variables. Conclusion: The stretching was insufficient to reverse the effects of immobilization. When associated with therapeutic ultrasound, the dose 0.5 W/cm² recovered muscle length significantly, and the doses 1.0 and 0.5 W/cm² contributed to the significant increase of the number of sarcomeres in immobilized muscles.

Hepatic glycogen levels in female rats submitted to aquatic therapy after muscle disuse

“…Two weeks of immobilization can cause loss of myofibrils and decrease of the size of muscle fibers (Ploug et al, 1995), changes in the morphology of the fibers and muscle mechanics . Skeletal muscles can be affected by external influences, such as therapeutic immobilization, which changes their biochemical and structural characteristics (Artifon et al, 2012). In a previous study on energy metabolism in muscle atrophy (Stein & Wade, 2005) results showed an increase in enzyme expression values related to gluconeogenesis in the liver, indicating a higher consumption of liver glycogen, which supports the data obtained in this study, considering that a decrease in liver glycogen in immobilized animals was also observed.…”

Mecanismos de regeneração muscular estimulados pela terapia por ultrassom

“…-Não houve alteração na expressão de mRNA de MyoD no grupo US em relação aos demais grupos para nenhum período de tempo analisado. Artifon, et al, 2012 Imobilização em flexão plantar máxima do membro posterior direito de ratos por 15 dias. 4 grupos de 7 animais: grupo -Alongamento: Flexão dorsal máxima manual do tornozelo até o limite de tensão tecidual em 3 séries de 30 s por 10 dias;…”