title: Effects of low intensity vibration on bone and muscle in rats with spinal cord injury.
abstract: Spinal cord injury (SCI) causes rapid and marked bone loss. The present study demonstrates that low-intensity vibration (LIV) improves selected biomarkers of bone turnover and gene expression and reduces osteoclastogenesis, suggesting that LIV may be expected to benefit to bone mass, resorption, and formation after SCI.
  
  
  BACKGROUND
  Sublesional bone is rapidly and extensively lost following spinal cord injury (SCI). Low-intensity vibration (LIV) has been suggested to reduce loss of bone in children with disabilities and osteoporotic women, but its efficacy in SCI-related bone loss has not been tested. The purpose of this study was to characterize effects of LIV on bone and bone cells in an animal model of SCI.
  
  
  METHODS
  The effects of LIV initiated 28 days after SCI and provided for 15 min twice daily 5 days each week for 35 days were examined in female rats with moderate severity contusion injury of the mid-thoracic spinal cord.
  
  
  RESULTS
  Bone mineral density (BMD) of the distal femur and proximal tibia declined by 5 % and was not altered by LIV. Serum osteocalcin was reduced after SCI by 20 % and was increased by LIV to a level similar to that of control animals. The osteoclastogenic potential of bone marrow precursors was increased after SCI by twofold and associated with 30 % elevation in serum CTX. LIV reduced the osteoclastogenic potential of marrow precursors by 70 % but did not alter serum CTX. LIV completely reversed the twofold elevation in messenger RNA (mRNA) levels for SOST and the 40 % reduction in Runx2 mRNA in bone marrow stromal cells resulting from SCI.
  
  
  CONCLUSIONS
  The findings demonstrate an ability of LIV to improve selected biomarkers of bone turnover and gene expression and to reduce osteoclastogenesis. The study indicates a possibility that LIV initiated earlier after SCI and/or continued for a longer duration would increase bone mass.
authors.affiliation: Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Bramlett
authors.forename: W D
authors.initials: WD
authors.lastname: Dietrich
authors.forename: A
authors.initials: A
authors.lastname: Marcillo
authors.forename: L J
authors.initials: LJ
authors.lastname: Mawhinney
authors.forename: O
authors.initials: O
authors.lastname: Furones-Alonso
authors.forename: A
authors.initials: A
authors.lastname: Bregy
authors.forename: Y
authors.initials: Y
authors.lastname: Peng
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: J
authors.initials: J
authors.lastname: Pan
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: X E
authors.initials: XE
authors.lastname: Guo
authors.forename: W A
authors.initials: WA
authors.lastname: Bauman
authors.forename: C
authors.initials: C
authors.lastname: Cardozo
authors.forename: W
authors.initials: W
authors.lastname: Qin
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000818:Animals; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis / Q000235:genetics; D004195:Disease Models, Animal; D005260:Female; D005269:Femur / Q000503:physiopathology; D005786:Gene Expression Regulation / Q000502:physiology; D005819:Genetic Markers / Q000235:genetics; D018482:Muscle, Skeletal / Q000473:pathology; D009929:Organ Size; D015675:Osteocalcin / Q000097:blood; D010010:Osteoclasts / Q000502:physiology; D010024:Osteoporosis / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D012333:RNA, Messenger / Q000235:genetics; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000150:complications* / Q000378:metabolism; D013977:Tibia / Q000503:physiopathology; D014732:Vibration / Q000627:therapeutic use*
chemical_list: D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; D050659:Core Binding Factor Alpha 1 Subunit; D005819:Genetic Markers; D012333:RNA, Messenger; C493717:Runx2 protein, rat; C486031:Sost protein, rat; D015675:Osteocalcin