title: Strength training with blood flow restriction diminishes myostatin gene expression.
abstract: OBJECTIVE
  The aim of the study was to determine whether the similar muscle strength and hypertrophy responses observed after either low-intensity resistance exercise associated with moderate blood flow restriction or high-intensity resistance exercise are associated with similar changes in messenger RNA (mRNA) expression of selected genes involved in myostatin (MSTN) signaling.
  
  
  METHODS
  Twenty-nine physically active male subjects were divided into three groups: low-intensity (20% one-repetition maximum (1RM)) resistance training (LI) (n = 10), low-intensity resistance exercise associated with moderate blood flow restriction (LIR) (n = 10), and high-intensity (80% 1RM) resistance exercise (HI) (n = 9). All of the groups underwent an 8-wk training program. Maximal dynamic knee extension strength (1RM), quadriceps cross-sectional area (CSA), MSTN, follistatin-like related genes (follistatin (FLST), follistatin-like 3 (FLST-3)), activin IIb, growth and differentiation factor-associated serum protein 1 (GASP-1), and MAD-related protein (SMAD-7) mRNA gene expression were assessed before and after training.
  
  
  RESULTS
  Knee extension 1RM significantly increased in all groups (LI = 20.7%, LIR = 40.1%, and HI = 36.2%). CSA increased in both the LIR and HI groups (6.3% and 6.1%, respectively). MSTN mRNA expression decreased in the LIR and HI groups (45% and 41%, respectively). There were no significant changes in activin IIb (P > 0.05). FLST and FLST-3 mRNA expression increased in all groups from pre- to posttest (P < 0.001). FLST-3 expression was significantly greater in the HI when compared with the LIR and LI groups at posttest (P = 0.024 and P = 0.018, respectively). GASP-1 and SMAD-7 gene expression significantly increased in both the LIR and HI groups.
  
  
  CONCLUSIONS
  We concluded that LIR was able to induce gains in 1RM and quadriceps CSA similar to those observed after traditional HI. These responses may be related to the concomitant decrease in MSTN and increase in FLST isoforms, GASP-1, and SMAD-7 mRNA gene expression.
authors: School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
authors: Gilberto Candido
authors: GC
authors: Laurentino
authors: Carlos
authors: C
authors: Ugrinowitsch
authors: Hamilton
authors: H
authors: Roschel
authors: Marcelo Saldanha
authors: MS
authors: Aoki
authors: Antonio Garcia
authors: AG
authors: Soares
authors: Manoel
authors: M
authors: Neves
authors: André Yui
authors: AY
authors: Aihara
authors: Artur da Rocha Correa
authors: Ada R
authors: Fernandes
authors: Valmor
authors: V
authors: Tricoli
mesh_terms: D030301:Activin Receptors, Type II / Q000235:genetics; D000222:Adaptation, Physiological; D001706:Biopsy; D003250:Constriction; D038681:Follistatin / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology*; D055435:Myostatin / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012039:Regional Blood Flow; D055070:Resistance Training / Q000379:methods*; D051906:Smad7 Protein / Q000235:genetics; D055815:Young Adult
chemical_list: D038681:Follistatin; D036341:Intercellular Signaling Peptides and Proteins; C525911:MSTN protein, human; D055435:Myostatin; D011506:Proteins; D012333:RNA, Messenger; C497806:SMAD7 protein, human; D051906:Smad7 Protein; C424444:WFIKKN2 protein, human; D030301:Activin Receptors, Type II