title: [Changes of COX-2 expression in the dorsal horn of the spinal cord during formalin-induced inflammatory pain and hyperalgesia in rats].
abstract: OBJECTIVE
  To observe the changes of cyclooxygenase-2 (COX-2) expression and especially the time course of the changes in dorsal horn of the spinal cord during formalin-induced inflammatory pain and hyperalgesia in rats.
  
  
  METHODS
  COX-2 immunohistochemistry staining was used in rat formalin pain model.
  
  
  RESULTS
  Compared with control group the number and immunostaining density of COX-2 immunoreactive cells in the laminae I-VI of the dorsal horn of the spinal cord increased significantly 4 h, 1 d and 3 d after formalin injection (P < 0.05). The most obvious increase was observed 1 d after the injection.
  
  
  CONCLUSIONS
  COX-2 in the dorsal horn of the spinal cord is involved in the formalin-induced inflammatory pain and hyperalgesia.
authors.affiliation: Department of Pathophysiology, Institute of Basic Medicine, Hebei Medical University, Hebei Shijiazhuang 050017, China.
authors.forename: Shu-qin
authors.initials: SQ
authors.lastname: Li
authors.forename: Wen-bin
authors.initials: WB
authors.lastname: Li
authors.forename: Xiao-cai
authors.initials: XC
authors.lastname: Sun
authors.forename: Qing-jun
authors.initials: QJ
authors.lastname: Li
authors.forename: Xiao-ling
authors.initials: XL
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Ai
mesh_terms: D000818:Animals; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D005557:Formaldehyde / Q000009:adverse effects; D010146:Pain / Q000139:chemically induced / Q000378:metabolism*; D020671:Posterior Horn Cells / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism*
chemical_list: D005557:Formaldehyde; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat