title: Protective effect of female gender-related factors on muscle force-generating capacity and fragility in the dystrophic mdx mouse.
abstract: BACKGROUND
  The dystrophic features in hindlimb skeletal muscles of female mdx mice are unclear.
  
  
  METHODS
  We analyzed force-generating capacity and force decline after lengthening contraction-induced damage (fragility).
  
  
  RESULTS
  Young (6-month-old) female mdx mice displayed reduced force-generating capacity (-18%) and higher fragility (23% force decline) compared with female age-matched wild-type mice. These 2 dystrophic features were less accentuated in young female than in young male mdx mice (-32% and 42% force drop). With advancing age, force-generating capacity decreased and fragility increased in old (20 month) female mdx mice (-21% and 57% force decline), but they were unchanged in old male mdx mice. Moreover, estradiol treatment had no effect in old female mdx mice.
  
  
  CONCLUSIONS
  Female gender-related factors mitigate dystrophic features in young but not old mdx mice. Further studies are warranted to identify the beneficial gender-related factor in dystrophic muscle.
authors.affiliation: Université Pierre et Marie Curie-Paris 6, UMR S794, INSERM, U974, CNRS UMR7215, Institut de Myologie, GH Pitié-Salpètrière, 47, Boulevard de l'HÔpital, Bâtiment Babinski, Paris, F-75013 France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Hourdé
authors.forename: Pierre
authors.initials: P
authors.lastname: Joanne
authors.forename: Phillippe
authors.initials: P
authors.lastname: Noirez
authors.forename: Onnik
authors.initials: O
authors.lastname: Agbulut
authors.forename: Gillian
authors.initials: G
authors.lastname: Butler-Browne
authors.forename: Arnaud
authors.initials: A
authors.lastname: Ferry
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009137:Muscular Dystrophy, Animal / Q000503:physiopathology* / Q000517:prevention & control*; D012727:Sex Characteristics