title: Efficacy of anti-nerve growth factor therapy for discogenic neck pain in rats.
abstract: METHODS
  Immunohistological analysis of the cervical dorsal root ganglia (DRG).
  
  
  OBJECTIVE
  To investigate immunohistologically in rats whether intradiscal administration of anti-nerve growth factor (NGF) antibody in injured cervical intervertebral discs (IVDs) suppresses pain-related peptide expression in DRG neurons.
  
  
  BACKGROUND
  Neck pain can involve the entire neck and become chronic and intractable. Cervical disc degeneration is a primary cause of neck pain, and pain-related mediators, such as NGF, have been correlated with discogenic pain.
  
  
  METHODS
  We examined Sprague-Dawley rats that received 10 punctures in the C5-C6 IVD, and were treated with saline (puncture group) or an anti-NGF antibody (anti-NGF group). The retrograde neurotracer Fluoro-Gold (FG) was then injected into the C5-C6 IVD. In addition, we examined a sham group that did not receive punctures (disc nonpuncture). The C2-C7 DRG were harvested 1 week after surgery and immunostained for calcitonin gene-related peptide (CGRP), a marker for peptide-containing neurons. We determined for each group the percentages of FG-labeled DRG neurons that were CGRP-immunoreactive (CGRP-ir).
  
  
  RESULTS
  FG-labeled neurons innervating the C5-C6 IVD were found in all C2-C7 DRG examined. The percentage of FG-labeled CGRP-ir DRG neurons in the puncture group was significantly higher than that observed in the sham (P < 0.001) and anti-NGF groups (P < 0.001), but there was no significant difference between the sham and anti-NGF groups (P > 0.05). Therefore, intradiscal administration of anti-NGF antibody suppressed CGRP expression the cervical DRG.
  
  
  CONCLUSIONS
  Neurons located in the C2-C7 DRG innervated the C5-C6 IVD. These findings indicate that neck pain may be derived from degenerated IVDs. Furthermore, intradiscal administration of anti-NGF antibody suppressed CGRP expression in the cervical DRG innervating the injured IVD. Therefore, inhibiting NGF upregulation in the cervical IVD may be an efficient treatment for discogenic neck pain.
  
  
  METHODS
  N/A.
authors.affiliation: *Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan †Department of Orthopaedic Surgery, Kitasato University, Kanagawa, Japan ‡Department of Orthopaedic Surgery, Chiba Cancer Center, Chiba, Japan §Department of Orthopaedic Surgery, Sammu Medical Center, Chiba, Japan ¶Department of Orthopaedic Surgery, Toho University Sakura Medical Center, Chiba, Japan; and ‖Department of Orthopaedic Surgery, Teikyo University Chiba Medical Center, Chiba, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sainoh
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakuma
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyagi
authors.forename: Sumihisa
authors.initials: S
authors.lastname: Orita
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Gen
authors.initials: G
authors.lastname: Inoue
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kamoda
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Miyako
authors.initials: M
authors.lastname: Suzuki
authors.forename: Go
authors.initials: G
authors.lastname: Kubota
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Oikawa
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Inage
authors.forename: Jun
authors.initials: J
authors.lastname: Sato
authors.forename: Junichi
authors.initials: J
authors.lastname: Nakamura
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Aoki
authors.forename: Masashi
authors.initials: M
authors.lastname: Takaso
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Toyone
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohtori
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002574:Cervical Vertebrae / Q000294:innervation*; D004195:Disease Models, Animal; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000378:metabolism; D007403:Intervertebral Disc / Q000294:innervation / Q000378:metabolism; D055959:Intervertebral Disc Degeneration / Q000150:complications / Q000188:drug therapy*; D008297:Male; D019547:Neck Pain / Q000188:drug therapy* / Q000209:etiology; D020932:Nerve Growth Factor / Q000276:immunology* / Q000378:metabolism; D017207:Rats, Sprague-Dawley
chemical_list: D000906:Antibodies; D020932:Nerve Growth Factor; D015740:Calcitonin Gene-Related Peptide