Signaling Pathway Activation After Exercise in Patients With Chronic Obstructive Pulmonary Disease (SIM)

• Post-exercise signaling proteins phosphorylation level in the quadriceps of COPD patients and age-matched healthy controls [ Time Frame: 2 hours post-exercise ] [ Designated as safety issue: No ]
  Phosphorylation status of key proteins (Akt, p70, mTOR, p38, JNK, ERK) will be lesser modulated in the quadriceps of patients with COPD compare to healthy controls. The phosphorylated as well as the total protein levels will be measured by western blot. The data will be presented as arbitrary units and compared with values obtained in healthy age-matched healthy controls.
  
  

Other: exercise
resistance training exercise, 1 session, 3 exercises, 80% of max

Our objective is to investigate the impact of an acute bout of resistance training on key signaling pathways involved in the regulation of muscle mass in moderate to severe COPD (FEV1 under 60% of predicted). Key proteins of signaling intramuscular pathways involved in protein synthesis and degradation will be measured before after 72 contractions of the quadriceps. The exercise protocol was designed to match the actual exercise prescription model use in the context of pulmonary rehabilitation. A squat, leg press and leg extension will be done at 80% of max with one minute rest between sets. A biopsy of the quadriceps will be done before and after exercise in order to measure phosphorylated kinases, total protein content and mRNA expressions. All our patients will undergo a thorough baseline assessment in pulmonary capacity, muscle force and body composition.