Introduction Upper limb movements are affected frequently by brain ischemia (BI). Mechanisms involved in recovery and compensatory movements have developed several studies. However, less attention is given to skeletal muscles, where neuromuscular junction (NMJ) has an important role on muscle tropism and functional performance. Methods Animals were divided into two groups: control (C) and BI. Then, animals were skilled to perform single‐pellet retrieval task, following these procedures: habituation, shaping, and single‐pellet retrieval task. BI was induced using stereotaxic surgery in order to apply endothelin‐1 in motor cortex, representative of movements of dominant paw. Reaching task performance was evaluated by single‐pellet retrieval task 1 day before BI induction, 4 and 15 days after BI induction. After that, biceps, triceps, fingers flexor, and extensor muscles were extracted. NMJ was assessed in morphometric characteristics (total area, total perimeter, and feret). Muscle fiber cross‐sectional area and connective tissue percentage were also evaluated for characterization. Student's t test was used for comparisons between C and BI groups. Tau Kendall's correlation was applied among variables from BI group. Results An increase in all NMJ morphometric parameters, as well as increase of atrophy and fibrosis in BI group compared with C. There was a high level of direct correlation between mean values of NMJ morphometry with percentage of success in reaching task in BI group. Conclusion Brain ischemia‐induced NMJ compensatory expansion, muscle atrophy, and fibrosis in forelimb muscles that are related to reaching performance.
The functionality in ederly is determined by components of body composition (fat mass/fat free mass), as well as issues related to physical fitness performance (muscle strength, joint mobility), exhibited by the elderly, making it independent for activities of the environment in which it operates. The objective of this research was to establish the relationship between joint behavioral characteristics (lower limb), with values of fat mass/fat free mass in older women doing the test jump " Squat Jump". The results were considered as indicators of the functionality in the population evaluated.
Diabetes mellitus affects the skeletal muscle connective tissue and leads to significant physical performance impairment. The use of mesenchymal stromal cells (MSCs) is an attractive strategy to modify the microenvironment and promote tissue repair and regeneration. Male Wistar rats (225 ± 25 g) were randomly assigned to 3 groups: Control (C), Diabetic (DM) and Diabetic treated with MSCs (DM-MSCs). Diabetes was induced by Streptozotocin (50 µg/kg). Bone marrow cells were isolated from the tibia and femur. After 10 weeks of DM induction, DM-MSC rats received 4 i.p. injections of MSCs (1 x 106). Ten weeks after MSC transplantation motor performance was evaluated by Rota Rod test and the anterior tibial (TA) muscles were collected for morphometric and quantification of collagen birefringence by polarizing microscopy analysis. Statistical significance was set at 0.05. Fasting glycemia was significantly higher and body mass was significantly lower in the Diabetic (DM) and Diabetic treated with MSCs (DM + MSCs) groups compared with control group. Motor performance of the DM group (30.1 ± 9.6 s) was significantly reduced when compared to the C group (727.2 ± 92 s) and increased significantly in DM + MSCs group (786.8 ± 109.5 s). The TA muscle mass was significantly reduced in DM and DM + MSCs groups compared with C group. The muscle fiber cross sectional area followed the same pattern. The connective tissue increased in DM group compared with C group and decreased in DM + MSCs. The percentage collagen birefringence quantified in the connective tissue of the TA muscle decreased significantly in DM group when compared to C group and increased in DM + MSCs group. Motor performance was positively correlated with collagen birefringence (r = 0.83; P < 0.0001) and negatively correlated with percentage of connective tissue (r = -0.94; P < 0.0001). The results indicate that improves both motor function and the collagen macromolecular organization in type 1 DM. Disclosure G.L. Luna: None. M.A. Sabadine: None. Y. Estrada-Bonilla: None. F. Freitas Aníbal: None. Â.M. Leal: None. Funding Conselho Nacional de Desenvolvimen to Científico e Tecnológico Processo (447518/2014-3)
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