RESUMO
Subcellular changes of the atrial cardiomyocytes of rats caused by cold showed a) altered mitochondria with edema and lysis of crests; b) myofibrils with marked heterogeneity of patterns and ruptures, c) myofilaments disarrangement, partial necrosis and disintegration of filaments, d) lesser concentration of atrial granules in the perinuclear area. Atrial muscle fibers of propranolol-treated rats previously stressed by cold showed a marked decrease of the morphological alterations observed in the animals submitted to cold stress without propranolol protection.
Assuntos
Temperatura Baixa/efeitos adversos , Átrios do Coração/efeitos dos fármacos , Miocárdio/ultraestrutura , Propranolol/farmacologia , Estresse Fisiológico/metabolismo , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/ultraestrutura , Animais , Grânulos Citoplasmáticos , Átrios do Coração/ultraestrutura , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Miofibrilas/efeitos dos fármacos , Miofibrilas/ultraestrutura , Necrose , Ratos , Ratos EndogâmicosRESUMO
The authors intended to study the fibers of atrial muscle of rats submitted to cold. The results specially showed the destruction of the mitochondria structure. The cristae are destroyed in part by the stress provoked. The possible factors that influence the stress provoked by the cold are discussed.