title: Gender differences in contractile and passive properties of mdx extensor digitorum longus muscle.
abstract: BACKGROUND
  Duchenne muscular dystrophy (DMD) is a severe, muscle-wasting disease caused by mutations in the dystrophin gene. The mdx mouse is the first and perhaps the most commonly used animal model for study of DMD. Both male and female mdx mice are used. However, it is not completely clear whether gender influences contraction and the passive mechanical properties of mdx skeletal muscle.
  
  
  METHODS
  We compared isometric tetanic forces and passive forces of the extensor digitorum longus muscle between male and female mdx mice.
  
  
  RESULTS
  At age 6 months, female mdx mice showed better-preserved specific tetanic force. Interestingly, at 20 months of age, female mdx muscle appeared stiffer.
  
  
  CONCLUSIONS
  Our results suggest that gender may profoundly influence physiological measurement outcomes in mdx mice.
authors.affiliation: Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, One Hospital Drive, Columbia, Missouri 65212, USA.
authors.forename: Chady H
authors.initials: CH
authors.lastname: Hakim
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Duan
mesh_terms: D000818:Animals; D001835:Body Weight / Q000235:genetics; D005260:Female; D008297:Male; D051379:Mice; D018101:Mice, Inbred mdx; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009137:Muscular Dystrophy, Animal / Q000503:physiopathology*; D012727:Sex Characteristics; D013314:Stress, Mechanical