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High-intensity resistance training with insufficient recovery time between bouts induce atrophy and alterations in myosin heavy chain content in rat skeletal muscle.
De Souza, Rodrigo Wagner Alves; Aguiar, Andreo Fernando; Carani, Fernanda Regina; Campos, Gerson Eduardo Rocha; Padovani, Carlos Roberto; Silva, Maeli Dal Pai.
Afiliação
  • De Souza RW; Department of Morphology, Institute of Biosciences, São Paulo State University, Botucatu, Brazil.
Anat Rec (Hoboken) ; 294(8): 1393-400, 2011 Aug.
Article em En | MEDLINE | ID: mdl-21714108
The aim of this study was to test whether high-intensity resistance training with insufficient recovery time between bouts, could result in a decrease of muscle fiber cross-sectional area (CSA), alter fiber-type frequencies and myosin heavy chain (MHC) isoform content in rat skeletal muscle. Wistar rats were divided into two groups: trained (Tr) and control (Co). Tr group were subjected to a high-intensity resistance training program (5 days/week) for 12 weeks, involving jump bouts into water, carrying progressive overloads based on percentage body weight. At the end of experiment, animals were sacrificed, superficial white (SW) and deep red (DR) portions of the plantaris muscle were removed and submitted to mATPase histochemical reaction and SDS-PAGE analysis. Throughout the experiment, both groups increased body weight, but Tr was lower than Co. There was a significant reduction in IIA and IID muscle fiber CSA in the DR portion of Tr compared to Co. Muscle fiber-type frequencies showed a reduction in Types I and IIA in the DR portion and IID in the SW portion of Tr compared to Co; there was an increase in Types IIBD frequency in the DR portion. Change in muscle fiber-type frequency was supported by a significant decrease in MHCI and MHCIIa isoforms accompanied by a significant increase in MHCIIb isoform content. MHCIId showed no significant differences between groups. These data show that high-intensity resistance training with insufficient recovery time between bouts promoted muscle atrophy and a transition from slow-to-fast contractile activity in rat plantaris muscle.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Atrofia Muscular / Músculo Esquelético / Cadeias Pesadas de Miosina / Treinamento Resistido Limite: Animals Idioma: En Revista: Anat Rec (Hoboken) Assunto da revista: ANATOMIA Ano de publicação: 2011 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Atrofia Muscular / Músculo Esquelético / Cadeias Pesadas de Miosina / Treinamento Resistido Limite: Animals Idioma: En Revista: Anat Rec (Hoboken) Assunto da revista: ANATOMIA Ano de publicação: 2011 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos