title: [Relationship between expression of MMP-9 and presyrinx state of experimental syringomyelia of rabbits].
abstract: OBJECTIVE
  To investigate the relationship between the expression of MMP-9 and the formation of spinal cord edema in presyrinx state of experimental syringomyelia in rabbits and evaluate the inhibitory function of doxycycline in the formation of spinal cord edema in presyrinx state.
  
  
  METHODS
  A total of 96 Chinese white rabbits were divided randomly into four groups:kaolin group (n = 24), doxycycline treatment group (n = 24), physiological saline group (n = 24) and control group (n = 24). Under ketamine anesthesia, 0.6 ml of 25% kaolin solution was injected into the cisterna magna in all rabbits of kaolin and doxycycline groups while 0.6 ml of 37°C physiological saline into the cistern in those of saline group; doxycycline (25 mg × kg(-1) × d(-1)) was applied post-operatively for doxycycline group. At Days 1, 3, 7 and 14 after kaolin injection, 6 rabbits of all four groups were selected randomly for sacrificing. Water content of spinal cord could be obtained. The expression of MMP-9 activity was measured by Western blot and immunohistochemistry.
  
  
  RESULTS
  At any time point, the water content of spinal cord and the expression of MMP-9 in kaolin group improved obviously more than those of saline and control groups (P < 0.01). At Day 1, there was no marked difference in the water content of spinal cord and the expression of MMP-9 between doxycycline and kaolin groups (P > 0.05). At other time points, the water content of spinal cord and the expression of MMP-9 in doxycycline group markedly decreased than those of kaolin group (P < 0.01).
  
  
  CONCLUSIONS
  In the model of experimental syringomyelia, MMP-9 plays an important role in causing edema in presyrinx state. Thus doxycycline may be used to prevent and treat syringomyelia.
authors.affiliation: Department of Spinal Surgery, Tianjin Union Medicine Center, Tianjin 300121, China. dshenqingfeng@yahoo.com.cn
authors.forename: Qing-feng
authors.initials: QF
authors.lastname: Shen
authors.forename: Qing-jun
authors.initials: QJ
authors.lastname: Zhang
authors.forename: Rong
authors.initials: R
authors.lastname: Tian
authors.forename: Ying-peng
authors.initials: YP
authors.lastname: Xia
authors.forename: Tian-tong
authors.initials: TT
authors.lastname: Xu
authors.forename: Gang
authors.initials: G
authors.lastname: Xia
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004487:Edema / Q000209:etiology*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D011817:Rabbits; D013595:Syringomyelia / Q000378:metabolism* / Q000473:pathology*
chemical_list: D020780:Matrix Metalloproteinase 9