title: Immunohistochemical changes in the expression of HSP27 in exercised human vastus lateralis muscle.
abstract: OBJECTIVE
  The role of HSP27 in the adaptive process of skeletal muscle to exercise, especially in humans, is not well understood. The objective of this study was to investigate immunohistochemical changes in HSP27 expression in human vastus lateralis muscle following resistance and endurance exercises.
  
  
  METHODS
  Two different exercise protocols were used: (1) one-leg ergometer cycling (EC, n = 6) consisting of two 30-min bouts at 40% and 75% of peak oxygen uptake, respectively, and (2) leg extension resistance exercise (RE, n = 9) including 10 sets of eight repetitions at a load corresponding to 70% of one maximal repetition (1RM). Immunohistochemistry using specific monoclonal antibodies was used to determine the location of HSP27 protein in muscle biopsies from human vastus lateralis.
  
  
  RESULTS
  Our results show that RE, but not EC, induced a significant appearance of scattered accumulations of HSP27 protein in muscle fibres from five of nine subjects. The number of fibres with accumulation of HSP27 in RE ranged from 0% to 32% with a mean of 6.3% of the total number of fibres.
  
  
  CONCLUSIONS
  We conclude that this rapid HSP27 protein relocation after RE is an important player in the cellular remodelling of human muscle fibres in response to exercise involving high-force contractions, but not in response to endurance exercises.
authors.affiliation: School of Health and Medical Sciences, Orebro University, Orebro, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Folkesson
authors.forename: A L
authors.initials: AL
authors.lastname: Mackey
authors.forename: L
authors.initials: L
authors.lastname: Holm
authors.forename: M
authors.initials: M
authors.lastname: Kjaer
authors.forename: G
authors.initials: G
authors.lastname: Paulsen
authors.forename: T
authors.initials: T
authors.lastname: Raastad
authors.forename: J
authors.initials: J
authors.lastname: Henriksson
authors.forename: F
authors.initials: F
authors.lastname: Kadi
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D052097:Quadriceps Muscle / Q000378:metabolism* / Q000502:physiology; D055815:Young Adult
chemical_list: D055551:HSP27 Heat-Shock Proteins