Change in the contractile behavior of muscle fibers in subjects with primary muscle dysfunction

Autor(es)

Nuernberg Back, Claudio Gregorio ^[1] ; Benedini-Elias, Priscila C. O. ^[1] ; Mattiello, Stela M. ^[2] ; Sobreira, Claudia ^[3] ; Martinez, Edson Z. ^[4] ; Mattiello-Sverzut, Ana Claudia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Biomech, BR-14049800 Ribeirao Preto, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Physiotherapy, BR-13560 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Neurol, BR-14049800 Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Social Med, BR-14049800 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: NEUROREHABILITATION; v. 32, n. 3, p. 601-608, 2013.
• Citações Web of Science: 0

Resumo

The mechanical and metabolic characteristics of skeletal muscle fibers can interfere with muscle contractile performance in healthy subjects. Few studies have investigated the degree of association between muscle function and muscle fiber morphology in patients with myopathy. A biopsy was obtained from the left biceps brachii muscle of 12 subjects with myopathic disorders. The relative cross-sectional area of type 2 fibers and their subtypes was determined by the ATPase technique. Relative torque (RT) was calculated by dividing isokinetic elbow flexion peak torque (PT) values (90 and 180 degrees s(-1)) by isometric PT values. Correlations were analyzed using Spearman's coefficient (r). The relative cross-sectional area of type 2b fibers was positively correlated with RT90 (r = 0.71, P = 0.009) and RT180 (r = 0.73, P = 0.007). The relative cross-sectional area of type 2a fibers showed a moderate and negative correlation with RT180 (r = -0.62, P = 0.03) and a low correlation with RT90 (r = -0.57, P = 0.05). In contrast to healthy subjects, patients with myopathy presented changes in the contractile behavior of type 2a fibers and compensatory adaptations in type 2b fibers. The results suggest that RT in combination with morphometric parameters provides data regarding muscle function in patients with myopathic disorders and can contribute to the establishment of therapeutic exercises. (AU)

• Processo FAPESP: 03/10468-8 - Estudo de correlacao entre diferentes metodos quantitativos de avaliacao muscular obtidos de individuos com hipotese clinica de miopatia.
• Beneficiário: Priscila Cacao Benedini de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 03/10529-7 - Estudo de correlacao entre diferentes metodos quantitativos de avaliacao muscular obtidos de individuos com hipotese clinica de miopatia.
• Beneficiário: Ana Cláudia Mattiello-Sverzut
• Modalidade de apoio: Auxílio à Pesquisa - Regular