title: Skeletal muscle adaptation in response to supervised exercise training for intermittent claudication.
abstract: OBJECTIVE
  There is evidence that the improvement following supervised exercise for claudication results from skeletal muscle adaptation. The myosin heavy chain (MHC) determines muscle fibre type and therefore efficiency. Immunohistochemical analysis has failed to take account of hybrid MHC expression within myofibres. This study sought evidence of differential MHC protein expression following supervised exercise for claudication.
  
  
  METHODS
  38 claudicants were recruited. Subjects undertook a three-month supervised exercise programme. Controls were patients awaiting angioplasty for claudication.
  
  
  METHODS
  Subjects underwent paired gastrocnemius biopsy. Relative expression of MHC proteins was determined by SDS-PAGE electrophoresis. Non-parametric data is presented as median with the inter-quartile range and parametric as the mean ± standard deviation.
  
  
  RESULTS
  Upon completion of the exercise programme there was a 94% increase (124 (106-145) to 241 (193-265) metres, p = 0.002) in maximum walking distance, which was not evident in the control group. An 11.1% (p = 0.02) increase in MHC I expression was observed in the exercise but not the control group (34.3% ± 6.8 to 45.4% ± 4.4). There was a positive correlation between the change in MHC I expression and the improvement in claudication distance (r = 0.69, p < 0.05).
  
  
  CONCLUSIONS
  Supervised exercise training for claudication results in an increase in the proportion of MHC type I expression within the symptomatic gastrocnemius muscle.
authors: Department of Vascular Surgery, Bristol Royal Infirmary, UK. tim_beckitt@yahoo.com
authors: T A
authors: TA
authors: Beckitt
authors: J
authors: J
authors: Day
authors: M
authors: M
authors: Morgan
authors: P M
authors: PM
authors: Lamont
mesh_terms: D000222:Adaptation, Physiological; D000368:Aged; D001706:Biopsy; D004591:Electrophoresis, Polyacrylamide Gel; D004739:England; D005080:Exercise Test; D005081:Exercise Therapy; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D020033:Protein Isoforms; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation; D016138:Walking
chemical_list: D020033:Protein Isoforms; D018995:Myosin Heavy Chains