Myogenin, MyoD and IGF-I regulate muscle mass but not fiber-type conversion during resistance training in rats

Página do item simplificado
dc.contributor.authorAguiar, A. F. [UNESP]
dc.contributor.authorVechetti-Júnior, I. J. [UNESP]
dc.contributor.authorAlves de Souza, R. W. [UNESP]
dc.contributor.authorCastan, E. P. [UNESP]
dc.contributor.authorMilanezi-Aguiar, R. C. [UNESP]
dc.contributor.authorPadovani, C. R. [UNESP]
dc.contributor.authorCarvalho, R. F. [UNESP]
dc.contributor.authorSilva, M. D P [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-27T11:27:29Z
dc.date.available2014-05-27T11:27:29Z
dc.date.issued2013-01-01
dc.description.abstractThe purpose of this study was to test the hypothesis that skeletal muscle adaptations induced by long-term resistance training (RT) are associated with increased myogenic regulatory factors (MRF) and insulin-like growth factor-I (IGF-I) mRNA expression in rats skeletal muscle. Male Wistar rats were divided into 4 groups: 8-week control (C8), 8-week trained (T8), 12-week control (C12) and 12-week trained (T12). Trained rats were submitted to a progressive RT program (4 sets of 10-12 repetitions at 65-75% of the 1RM, 3 day/week), using a squat-training apparatus with electric stimulation. Muscle hypertrophy was determined by measurement of muscle fiber cross-sectional area (CSA) of the muscle fibers, and myogenin, MyoD and IGF-I mRNA expression were measured by RT-qPCR. A hypertrophic stabilization occurred between 8 and 12 weeks of RT (control-relative % area increase, T8: 29% vs. T12: 35%; p>0.05) and was accompanied by the stabilization of myogenin (control-relative % increase, T8: 44.8% vs. T12: 37.7%, p>0.05) and MyoD (control-relative % increase, T8: 22.9% vs. T12: 22.3%, p>0.05) mRNA expression and the return of IGF-I mRNA levels to the baseline (control-relative % increase, T8: 30.1% vs. T12: 1.5%, p<0.05). Moreover, there were significant positive correlations between the muscle fiber CSA and mRNA expression for MyoD (r=0.85, p=0.0001), myogenin (r=0.87, p=0.0001), and IGF-I (r=0.88, p=0.0001). The significant (p<0.05) increase in myogenin, MyoD and IGF-I mRNA expression after 8 weeks was not associated with changes in the fiber-type frequency. In addition, there was a type IIX/D-to-IIA fiber conversion at 12 weeks, even with the stabilization of MyoD and myogenin expression and the return of IGF-I levels to baseline. These results indicate a possible interaction between MRFs and IGF-I in the control of muscle hypertrophy during long-term RT and suggest that these factors are involved more in the regulation of muscle mass than in fiber-type conversion. © Georg Thieme Verlag KG Stuttgart · New York.en
dc.description.affiliationMorphology Univ Estadual Paulista (UNESP), Rubião Júnior District 18618-970 Botucatu
dc.description.affiliationBioestatística Universidade Estadual Paulista, Botucatu
dc.description.affiliationInstituto de Biociências de Botucatu Universidade Estadual Paulista Júlio de Mesquita Filho Morphology, Botucatu
dc.description.affiliationUnespMorphology Univ Estadual Paulista (UNESP), Rubião Júnior District 18618-970 Botucatu
dc.description.affiliationUnespBioestatística Universidade Estadual Paulista, Botucatu
dc.description.affiliationUnespInstituto de Biociências de Botucatu Universidade Estadual Paulista Júlio de Mesquita Filho Morphology, Botucatu
dc.format.extent293-301
dc.identifierhttp://dx.doi.org/10.1055/s-0032-1321895
dc.identifier.citationInternational Journal of Sports Medicine, v. 34, n. 4, p. 293-301, 2013.
dc.identifier.doi10.1055/s-0032-1321895
dc.identifier.issn0172-4622
dc.identifier.issn1439-3964
dc.identifier.lattes8727897080522289
dc.identifier.lattes5406518799128485
dc.identifier.lattes4125344753100454
dc.identifier.orcid0000-0003-1270-7372
dc.identifier.scopus2-s2.0-84884212061
dc.identifier.urihttp://hdl.handle.net/11449/74204
dc.identifier.wosWOS:000316615100002
dc.language.isoeng
dc.relation.ispartofInternational Journal of Sports Medicine
dc.relation.ispartofjcr2.453
dc.relation.ispartofsjr1,217
dc.relation.ispartofsjr1,217
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectfiber-type
dc.subjectinsulin-like growth factor
dc.subjectmuscle hypertrophy
dc.subjectmyogenic regulatory factor
dc.subjectstrength training
dc.subjectmessenger RNA
dc.subjectMyoD protein
dc.subjectmyogenin
dc.subjectsomatomedin C
dc.subjectadaptation
dc.subjectanimal
dc.subjectanimal experiment
dc.subjectgenetics
dc.subjecthypertrophy
dc.subjectmale
dc.subjectmetabolism
dc.subjectmethodology
dc.subjectpathology
dc.subjectrat
dc.subjectreal time polymerase chain reaction
dc.subjectskeletal muscle
dc.subjectWistar rat
dc.subjectAdaptation, Physiological
dc.subjectAnimals
dc.subjectHypertrophy
dc.subjectInsulin-Like Growth Factor I
dc.subjectMale
dc.subjectMuscle Fibers, Skeletal
dc.subjectMuscle, Skeletal
dc.subjectMyoD Protein
dc.subjectMyogenin
dc.subjectPhysical Conditioning, Animal
dc.subjectRats
dc.subjectRats, Wistar
dc.subjectReal-Time Polymerase Chain Reaction
dc.subjectRNA, Messenger
dc.titleMyogenin, MyoD and IGF-I regulate muscle mass but not fiber-type conversion during resistance training in ratsen
dc.typeArtigo
dcterms.licensehttp://www.thieme.de/fz/_pdf/thieme_ir_policy_english.pdf
unesp.author.lattes8727897080522289[6]
unesp.author.lattes5406518799128485
unesp.author.lattes4125344753100454[7]
unesp.author.orcid0000-0002-7719-9682[6]
unesp.author.orcid0000-0003-1270-7372[7]
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Biociências, Botucatupt

Arquivos

Coleções

Artigos - Morfologia - IBB
Artigos - Bioestatística - IBB