Efeitos da atividade física, antes e após a indução de isquemia cerebral transitória, sobre o desempenho motor e a histomorfometria de músculos dos membros torácico e pélvico de ratos

• Ano de defesa: 2012
• Autor(a) principal: Melo, Raphael Teixeira Rocha
• Orientador(a): Maldonado, Izabel Regina dos Santos Costa
• Banca de defesa: Carlo, Ricardo Junqueira Del , Matta, Sérgio Luis Pinto da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Biologia Celular e Estrutural
• Departamento: Análises quantitativas e moleculares do Genoma; Biologia das células e dos tecidos
• País: BR
• Palavras-chave em Português: Atrofia muscular; Função motora; Infarto cerebral; Treinamento em esteira
• Palavras-chave em Inglês: Muscular atrophy; Motor function; Cerebral infarction; Training treadmill
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://locus.ufv.br/handle/123456789/2351

Cerebral ischemia is a reduction of blood flow in the brain, which causes hypoxia and consequent neuronal damage. It is the cause of the most common type of stroke, a disorder that can lead to death, or determine several sequels, mainly motor impairment of thoracic and pelvic members, in the contralateral hemisphere to the injured. Although physical activity is an preventive alternative and treatment for various cerebrovascular diseases, there is little information regarding the effects of exercise on skeletal muscle and motor performance of animals with cerebral ischemia. In this study, tests were performed for motor evaluation (foot fault test and parallel bars test), besides the histomorphometry of the biceps brachii, soleus and anterior tibial muscles of rats subjected to physical exercise on a treadmill before and after induction of cerebral ischemia by middle cerebral artery oclusion (MCAO). 36 Wistar rats were divided into six groups: CS: sedentary control animals (n = 6) who underwent a fake surgery (there were no MCAO); CEA: control animals exercised before the fake surgery (n = 6) ; CED: control animals trained after the fake surgery (n = 6); IS: sedentary ischemic animals (n = 6), IEA: exercised animals before induction of ischemia (n = 6) and IED: ischemic animals trained after induction of ischemia (n = 6). The exercise treadmill training consisted of six weeks, 30 minutes/day (five days/week) at a speed of 14 m/min for CEA and IEA groups, and 8m/min for CED and IED groups. Histomorphometry of skeletal muscles was performed, determining the frequency and area of muscle fibers type I and II as well as the density of muscle fibers with cytological alterations and component of interstitial of muscles. The sedentary-ischemic animals showed poorer performance on functional tests. Rats submitted to exercise after ischemia, showed significant recovery of motor performance. There was an increase in the frequency of type I fibers in the soleus muscle, both in sedentary-ischemic animals, as in the exercised animals before and after MCAO surgery. Type I fiber atrophy occurred in the biceps and anterior tibial muscles, and type I and II in the soleus of sedentary-ischemic animals, whereas in animals trained after ischemia, exercise attenuated muscle atrophy. Exercise promotes improvement in motor performance of ischemic animals, attenuates muscle atrophy caused by cerebral ischemia and can stimulate angiogenesis in skeletal muscle.