title: Exercise does not influence myostatin and follistatin messenger RNA expression in young women.
abstract: We evaluated changes in myostatin, follistatin, and MyoD messenger RNA (mRNA) gene expression using eccentric exercise (EE) and concentric exercise (CE) as probes to better understand the mechanisms of muscle hypertrophy in young women. Twelve women performed single-leg maximal eccentric (n = 6, 25 +/- 1 years, 59 +/- 7 kg) or concentric (n = 6, 24 +/- 1 years, 65 +/- 7 kg) isokinetic knee extension exercise for 7 sessions. Muscle biopsies were taken from the vastus lateralis at baseline, 8 hours after the first exercise session, and 8 hours after the seventh exercise session. In the EE group, there were no changes in myostatin and follistatin (p > or = 0.17); however, MyoD expression increased after 1 exercise bout (p = 0.02). In the CE group, there were no changes in myostatin, follistatin, or MyoD mRNA gene expression (p > or = 0.07). Differences between the EE and CE groups were not significant (p > or = 0.05). These data suggest that a single bout or multiple bouts of maximal EE or CE may not significantly alter myostatin or follistatin mRNA gene expression in young women. However, MyoD mRNA expression seems to increase only after EE.
authors.affiliation: Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, California, USA.
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Jensky
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Sims
authors.forename: Christina M
authors.initials: CM
authors.lastname: Dieli-Conwright
authors.forename: Fred R
authors.initials: FR
authors.lastname: Sattler
authors.forename: Judd C
authors.initials: JC
authors.lastname: Rice
authors.forename: E Todd
authors.initials: ET
authors.lastname: Schroeder
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001706:Biopsy; D015444:Exercise / Q000502:physiology*; D005260:Female; D038681:Follistatin / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D018482:Muscle, Skeletal / Q000378:metabolism*; D055435:Myostatin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D038681:Follistatin; D055435:Myostatin; D012333:RNA, Messenger