title: Cervical intervertebral disc degeneration induced by unbalanced dynamic and static forces: a novel in vivo rat model.
abstract: METHODS
  Establishment of a novel in vivo animal model of cervical spondylosis.
  
  
  OBJECTIVE
  To investigate apoptotic, degenerative, and inflammatory changes occurring in the cervical intervertebral discs of rats.
  
  
  BACKGROUND
  Cervical degeneration occurs as the result of imbalance of both static and dynamic spinal stabilizers. The disc degeneration that occurs is characterized by increased local inflammation and increased apoptosis of intervertebral disc cells.
  
  
  METHODS
  By excising the paraspinal musculature and posterior cervical spinal ligaments of rats, both static and dynamic cervical stabilizers were disrupted. The resultant biomechanical imbalance resulted in biochemical and histologic changes, which were characterized by light microscopy, electron microscopy, immunostaining, enzyme-linked immunosorbent assay, polymerase chain reaction, and in situ hybridization.
  
  
  RESULTS
  Histologic analysis showed characteristic degenerative changes of the intervertebral discs and vertebral endplates following surgery. Ultrastructural examination revealed apoptotic changes, which were verified by immunostaining. Instability also resulted in significant up-regulation of inflammatory factors, as shown by enzyme-linked immunosorbent assay, polymerase chain reaction, and in situ hybridization.
  
  
  CONCLUSIONS
  By creating static and dynamic posterior instability of the cervical spine, this novel model of cervical spondylosis results in rapid intervertebral disc degeneration characterized by increased apoptosis and local inflammation, such as that seen clinically.
authors.affiliation: Institute of Spine, ShangHai University of Traditional Chinese Medicine. Shanghai, China. yjwang88@hotmail.com
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Shi
authors.forename: W W
authors.initials: WW
authors.lastname: Lu
authors.forename: K C M
authors.initials: KC
authors.lastname: Cheung
authors.forename: Michael
authors.initials: M
authors.lastname: Darowish
authors.forename: Tian-Fang
authors.initials: TF
authors.lastname: Li
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Dong
authors.forename: Chong-Jian
authors.initials: CJ
authors.lastname: Zhou
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Hu
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Qin
authors.initials: Q
authors.lastname: Bian
authors.forename: Chen-Guang
authors.initials: CG
authors.lastname: Li
authors.forename: K D K
authors.initials: KD
authors.lastname: Luk
authors.forename: J C Y
authors.initials: JC
authors.lastname: Leong
mesh_terms: D000818:Animals; D017209:Apoptosis; D002574:Cervical Vertebrae / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D017364:Collagenases / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D018836:Inflammation Mediators / Q000378:metabolism; D007403:Intervertebral Disc / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013128:Spinal Osteophytosis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D019714:Tissue Inhibitor of Metalloproteinases; D017364:Collagenases