Análise dos receptores de acetilcolina (nAChRs) na musculatura esquelética de ratos com insuficiência cardíaca submetidos ao treinamento aeróbico
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Data
2012-02-17
Autores
Souza, Paula Aiello Tomé de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A insuficiência cardíaca (IC) é uma síndrome iniciada por uma redução na função cardíaca e caracterizada pela ativação de mecanismos compensatórios e atrofia. Fadiga e dispnéia são os sintomas mais comuns desta doença, e estão associados à miopatia do músculo esquelético; ocorre redução da capacidade oxidativa, mudança nas fibras do tipo I para tipo II, alteração na expressão dos fatores reguladores miogênicos (MRFs) e na JNM. O treinamento físico aeróbico é considerado uma conduta amplamente aceita para minimizar as consequências dos sintomas causados pela IC, com melhora na qualidade de vida e pode reverter anormalidades do músculo cardíaco e esquelético, além de modular a junção neuromuscular. O músculo diafragma é o mais importante músculo inspiratório dos mamíferos sendo um dos mais acometidos na IC; o treinamento físico aeróbico altera as propriedades eletrofisiológicas do diafragma durante a fadiga e favorece a resistência muscular. A hipótese do presente estudo é que as alterações fenotípicas musculares que ocorrem na IC estão associadas com alterações na distribuição e expressão dos nAChRs e que o treinamento físico aeróbico atenue estas alterações. O objetivo deste trabalho foi avaliar a distribuição e expressão dos nAChRs em ratos com IC submetidos ao treinamento aeróbico. Foram utilizados 44 ratos Wistar machos (90 a 100g), divididos em quatro grupos experimentais: controle (C), treinamento aeróbico (TR), estenose aórtica (EAo) e estenose aórtica com treinamento aeróbico (EAoTR). A estenose aórtica foi induzida pela inserção de um clip de prata de 0.6 mm de diâmetro na aorta ascendente. Após 18 semanas da cirurgia, os animais com EAo, foram avaliados por ecocardiograma para verificar a hipertrofia do VE. Os demais animais foram divididos aleatoriamente em...
Heart failure (HF) is a syndrome initiated by a reduction in cardiac function and characterized by the activation of compensatory mechanisms and muscle myopathy. Fatigue and dyspnea are the most common symptoms of this disease, associated with the reduction of the oxidative capacity, changes in the fibers type I to type II, alterations in the expression of myogenic regulatory factors (MRFs) and in the neuromuscular junction (NMJs). Aerobic training is considered a widely accepted practice to minimize the consequences of the symptoms caused by HF, improving the life quality and can reverse abnormalities of cardiac and skeletal muscle, and modulate the NMJ. The diaphragm is the most important inspiratory muscle in mammals and is one of the most affected in HF; aerobic training changes the electrophysiological properties of the diaphragm during fatigue and promotes muscle endurance. Thus, the hypothesis of this study is that the changes that occur in HF are associated with alterations in the NMJs, in the expression of nAChRs and aerobic training can attenuate these changes. The aim of this study was to evaluate the distribution and the expression of nAChRs subunits in rats with HF submitted to an aerobic training. We used 44 male wistar rats (90 to 100g), divided into four groups: Control (C), Aerobic Training (TR), Aortic Stenosis (AS) and Aortic Stenosis with Aerobic Training (ASTR). Aortic stenosis was induced by the insertion of a silver clip of 0.6 mm in diameter in the ascending aorta. After 18 weeks of surgery, the animals with AS were evaluated by echocardiography for evaluating LV hypertrophy. The others were randomly divided into C, TR and ASTR groups. The animals of TR and ASTR groups were submitted to aerobic training on a treadmill for 10 weeks (5 days/ week). The diaphragm muscle was used to assess the expression... (Complete abstract click electronic access below)
Heart failure (HF) is a syndrome initiated by a reduction in cardiac function and characterized by the activation of compensatory mechanisms and muscle myopathy. Fatigue and dyspnea are the most common symptoms of this disease, associated with the reduction of the oxidative capacity, changes in the fibers type I to type II, alterations in the expression of myogenic regulatory factors (MRFs) and in the neuromuscular junction (NMJs). Aerobic training is considered a widely accepted practice to minimize the consequences of the symptoms caused by HF, improving the life quality and can reverse abnormalities of cardiac and skeletal muscle, and modulate the NMJ. The diaphragm is the most important inspiratory muscle in mammals and is one of the most affected in HF; aerobic training changes the electrophysiological properties of the diaphragm during fatigue and promotes muscle endurance. Thus, the hypothesis of this study is that the changes that occur in HF are associated with alterations in the NMJs, in the expression of nAChRs and aerobic training can attenuate these changes. The aim of this study was to evaluate the distribution and the expression of nAChRs subunits in rats with HF submitted to an aerobic training. We used 44 male wistar rats (90 to 100g), divided into four groups: Control (C), Aerobic Training (TR), Aortic Stenosis (AS) and Aortic Stenosis with Aerobic Training (ASTR). Aortic stenosis was induced by the insertion of a silver clip of 0.6 mm in diameter in the ascending aorta. After 18 weeks of surgery, the animals with AS were evaluated by echocardiography for evaluating LV hypertrophy. The others were randomly divided into C, TR and ASTR groups. The animals of TR and ASTR groups were submitted to aerobic training on a treadmill for 10 weeks (5 days/ week). The diaphragm muscle was used to assess the expression... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Insuficiencia cardiaca, Coração - Doenças, Exercícios físicos
Como citar
SOUZA, Paula Aiello Tomé de. Análise dos receptores de acetilcolina (nAChRs) na musculatura esquelética de ratos com insuficiência cardíaca submetidos ao treinamento aeróbico. 2012. 88 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2012.