title: A rat model of radicular pain induced by chronic compression of lumbar dorsal root ganglion with SURGIFLO.
abstract: BACKGROUND
  Radicular pain is a common and debilitating clinical pain condition. To date, the mechanisms of radicular pain remain unclear, partly because of the lack of suitable preclinical models. The authors report a modified rat model of radicular pain that could mimic a subset of clinical radicular pain conditions induced by the soft tissue compression on dorsal root ganglion.
  
  
  METHODS
  A rat model of radicular pain was produced by infiltrating the L5 intervertebral foramen with 60 microl of a hemostatic matrix (SURGIFLO; Johnson & Johnson, Somerville, NJ) resulting in chronic compression of lumbar dorsal root ganglion. Thermal hyperalgesia and mechanical allodynia were measured with or without epidural treatment with triamcinolone. Western blot was used to assess the expression of the NR1 subunit of the N-methyl-D-aspartate receptor and inhibitory factor kappabeta-alpha, an inflammatory marker, within the affected L5 dorsal root ganglion and spinal cord dorsal horn.
  
  
  RESULTS
  Chronic compression of lumbar dorsal root ganglion resulted in: (1) persistent mechanical allodynia and thermal hyperalgesia up to 4 or 5 postoperative weeks and (2) up-regulation of the N-methyl-D-aspartate receptor and inhibitory factor kappabeta-alpha within the ipsilateral L5 dorsal root ganglion and spinal cord dorsal horn. Epidural administration of triamcinolone (6.25-100 microg) on postoperative day 3 dose-dependently attenuated both thermal hyperalgesia and mechanical allodynia in rats with chronic compression of lumbar dorsal root ganglion.
  
  
  CONCLUSIONS
  The data suggest that this modified rat model of chronic compression of lumbar dorsal root ganglion may be a useful tool to explore the mechanisms as well as new therapeutic options of radicular pain.
authors.affiliation: Department of Anesthesiology, Drum Tower Hospital, Nanjing, People's Republic of China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Gu
authors.forename: Liling
authors.initials: L
authors.lastname: Yang
authors.forename: Shuxing
authors.initials: S
authors.lastname: Wang
authors.forename: Backil
authors.initials: B
authors.lastname: Sung
authors.forename: Grewo
authors.initials: G
authors.lastname: Lim
authors.forename: Ji
authors.initials: J
authors.lastname: Mao
authors.forename: Qing
authors.initials: Q
authors.lastname: Zeng
authors.forename: Chang
authors.initials: C
authors.lastname: Yang
authors.forename: Jianren
authors.initials: J
authors.lastname: Mao
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004195:Disease Models, Animal; D005727:Ganglia, Spinal / Q000187:drug effects / Q000473:pathology*; D006490:Hemostatics / Q000008:administration & dosage / Q000009:adverse effects*; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000473:pathology; D008297:Male; D009408:Nerve Compression Syndromes / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology*; D011843:Radiculopathy / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014221:Triamcinolone / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D006490:Hemostatics; D014221:Triamcinolone