Lack of beta(2)-AR improves exercise capacity and skeletal muscle oxidative phenotype in mice

Autor(es)

Voltarelli, V. A. ; Bacurau, A. V. N. ; Bechara, L. R. G. ; Bueno Junior, C. R. ^[1] ; Bozi, L. H. M. ; Mattos, K. C. ; Salemi, V. M. C. ^[2] ; Brum, P. C. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Human Genome Res Ctr, Biosci Inst, BR-05508900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Cardiomyopathy Unit, Heart Inst InCor, Sch Med, BR-05508900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Dept Biodinam Movimento Corpo Humano, Escola Educ Fis & Esporte, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS; v. 22, n. 6, p. e125-e132, DEC 2012.
• Citações Web of Science: 5

Resumo

beta(2)-adrenergic receptor (beta(2)-AR) agonists have been used as ergogenics by athletes involved in training for strength and power in order to increase the muscle mass. Even though anabolic effects of beta(2)-AR activation are highly recognized, less is known about the impact of beta(2)-AR in endurance capacity. We presently used mice lacking beta(2)-AR {[}beta(2)-knockout (beta(2) KO)] to investigate the role of beta(2)-AR on exercise capacity and skeletal muscle metabolism and phenotype. beta(2) KO mice and their wild-type controls (WT) were studied. Exercise tolerance, skeletal muscle fiber typing, capillary-to-fiber ratio, citrate synthase activity and glycogen content were evaluated. When compared with WT, beta 2KO mice displayed increased exercise capacity (61%) associated with higher percentage of oxidative fibers (21% and 129% of increase in soleus and plantaris muscles, respectively) and capillarity (31% and 20% of increase in soleus and plantaris muscles, respectively). In addition, beta 2KO mice presented increased skeletal muscle citrate synthase activity (10%) and succinate dehydrogenase staining. Likewise, glycogen content (53%) and periodic acid-Schiff staining (glycogen staining) were also increased in beta 2KO skeletal muscle. Altogether, these data provide evidence that disruption of beta(2)AR improves oxidative metabolism in skeletal muscle of beta 2KO mice and this is associated with increased exercise capacity. (AU)

• Processo FAPESP: 08/56483-1 - Papel dos receptores B2-adrenérgicos nas alterações músculo-esqueléticas desencadeadas pela insuficiência cardíaca
• Beneficiário: Vanessa Azevedo Voltarelli
• Modalidade de apoio: Bolsas no Brasil - Mestrado