title: Tetanus toxin preserves skeletal muscle contractile force and size during limb immobilization.
abstract: BACKGROUND
  We examined the possibility that tetanus toxin can prevent muscle atrophy associated with limb immobility in rats.
  
  
  METHODS
  While the knee and ankle joints were immobilized unilaterally, the tibialis anterior (TA) muscle on the immobilized side was injected with 1 μl saline or with 1 ng tetanus toxin. After 2 weeks, TA wet weights, contractile forces, and myofiber sizes from the immobilized sides were compared with those from body weight-matched normal animals.
  
  
  RESULTS
  Saline group wet weights decreased and produced less absolute twitch and tetanic force and normalized tetanic force compared with the toxin or normal groups. Cross-sectional areas of saline group type I, IIa, and IId myofibers, and the masses of saline group IIa, IId, IIb, and toxin group IIb myofibers, were smaller compared with the normal group.
  
  
  CONCLUSIONS
  Tetanus toxin prevented common signs of muscle atrophy and may become a useful adjunct to current rehabilitation strategies.
authors.affiliation: Research Service, VA Maryland Health Care System, 10 North Greene Street, Baltimore, Maryland, 21201, USA; Department of Neurology, School of Medicine, University of Maryland, Baltimore, Maryland, USA.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Matthews
authors.forename: Richard M
authors.initials: RM
authors.lastname: Lovering
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Bowen
authors.forename: Paul S
authors.initials: PS
authors.lastname: Fishman
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005121:Extremities / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality / Q000187:drug effects; D007103:Immobilization / Q000009:adverse effects*; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D009498:Neurotoxins / Q000494:pharmacology / Q000627:therapeutic use*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013744:Tetanus Toxin / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D009498:Neurotoxins; D013744:Tetanus Toxin; D000251:Adenosine Triphosphatases
keywords: atrophy; contractile; immobilization; myofiber; myosin; rat; skeletal muscle; tetanus toxin; tibialis anterior