Titre:	Effect of resistance training on extracellular matrix adaptations in skeletal muscle of older rats
Auteur(s):	Guzzoni, Vinicius Ribeiro, Manoel Benício Teixeira Lopes, Gisele N. Marqueti, Rita de Cássia Andrade, Rosângela Vieira de Selistre-de-Araujo, Heloisa Sobreiro Durigan, João Luiz Quagliotti
Assunto::	Treinamento de força Envelhecimento Músculos - desempenho Tecido conjuntivo
Date de publication:	11-avr-2018
Référence bibliographique:	GUZZONI, Vinicius et al. Effect of resistance training on extracellular matrix adaptations in skeletal muscle of older rats. Frontiers in Physiology, Lausana, v. 9, artigo 374, 2018. DOI 10.3389/fphys.2018.00374. Disponível em: https://www.frontiersin.org/articles/10.3389/fphys.2018.00374/full. Acesso em: 16 jan. 2019.
Abstract:	Accumulation of connective tissue, particularly extracellular matrix (ECM) proteins, has been observed in skeletal muscles with advancing age. Resistance training (RT) has been widely recommended to attenuate age-induced sarcopenia, even though its effects on the components that control ECM turnover in skeletal muscles remain to be elucidated. Thus, the aim of this study was to determine the effects of RT on connective tissue content and gene expression of key components of ECM in the skeletal muscles of aged rats. Young (3 mo.) and older (21 mo.) adult male Wistar rats were submitted to a RT protocol (ladder climbing with 65, 85, 95, and 100% load), 3 times a week for 12 weeks. Forty-eight hours post-training, the soleus (SOL) and gastrocnemius (GAS) muscles were dissected for histological and mRNA analysis. RT mitigated the age-associated increase of connective tissue content in both muscles, even though mRNA levels of COL-1 and−3 were elevated in older trained rats. Overall, RT significantly elevated the gene expression of key components of connective tissue deposition (TGFβ and CTGF; MMP-2 and-9; TIMP-1 and−2) in the GAS and SOL muscles of older rats. In conclusion, RT blunted the age-induced accumulation of connective tissue concomitant to the upregulation of genes related to synthesis and degradation of the ECM network in the SOL and GAS muscles of older rats. Although our findings indicate that RT plays a crucial role reducing connective tissue accumulation in aged hindlimb muscles, key components of ECM turnover were paradoxically elevated. The phenotypic responses induced by RT were not accompanied by the gene expression of those components related to ECM turnover.
metadata.dc.description.unidade:	Faculdade de Educação Física (FEF)
Licença::	Copyright © 2018 Guzzoni, Ribeiro, Lopes, de Cássia Marqueti, de Andrade, Selistre-de-Araujo and Durigan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Fonte: https://www.frontiersin.org/articles/10.3389/fphys.2018.00374/full. Acesso em: 16 jan. 2019.
DOI:	https://dx.doi.org/10.3389/fphys.2018.00374
Collection(s) :	Artigos publicados em periódicos e afins

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