title: Muscle function and running activity in mouse models of hereditary muscle dystrophy: impact of double knockout for dystrophin and the transcription factor MyoD.
abstract: BACKGROUND
  Mice that lack both the transcription factor MyoD and dystrophin display a more pronounced myopathic phenotype when compared with mdx mice. No data on skeletal muscle function and the impact of exercise training are available.
  
  
  METHODS
  Six-month-old wild-type, mdx, myoD(-/-), mdx:myoD(+/-), and mdx:myoD(-/-) mice were randomly assigned to either 4 weeks of voluntary running or sedentary behavior. The mdx:myoD(-/-) mice were not able to exercise at all and were kept sedentary.
  
  
  RESULTS
  The soleus muscle of sedentary 7-month-old mdx:myoD(-/-) mice showed a significantly lower force development compared with all other mice. Voluntary running beginning at the age of 6 months led to lower force development of soleus muscle in the mdx animals.
  
  
  CONCLUSIONS
  mdx:myoD(-/-) is not a suitable model to study exercise-induced effects on dystrophic muscles. Voluntary exercise in adult mdx mice seems to have detrimental effects on the function of soleus muscle.
authors.affiliation: Heart Center Leipzig, University of Leipzig, Struempellstrasse 39, D-04289 Leipzig, Germany. norman.mangner@med.uni-leipzig.de
authors.forename: Norman
authors.initials: N
authors.lastname: Mangner
authors.forename: Volker
authors.initials: V
authors.lastname: Adams
authors.forename: Marcus
authors.initials: M
authors.lastname: Sandri
authors.forename: Robert
authors.initials: R
authors.lastname: Hoellriegel
authors.forename: Rainer
authors.initials: R
authors.lastname: Hambrecht
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schuler
authors.forename: Stephan
authors.initials: S
authors.lastname: Gielen
mesh_terms: D019412:Anatomy, Cross-Sectional; D000818:Animals; D018450:Disease Progression; D016189:Dystrophin / Q000235:genetics*; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D018345:Mice, Knockout; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D009136:Muscular Dystrophies / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D017570:MyoD Protein / Q000235:genetics*; D010641:Phenotype; D012420:Running / Q000502:physiology*
chemical_list: D016189:Dystrophin; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein