title: Hyperalgesic activity of kisspeptin in mice.
abstract: BACKGROUND
  Kisspeptin is a neuropeptide known for its role in the hypothalamic regulation of the reproductive axis. Following the recent description of kisspeptin and its 7-TM receptor, GPR54, in the dorsal root ganglia and dorsal horns of the spinal cord, we examined the role of kisspeptin in the regulation of pain sensitivity in mice.
  
  
  RESULTS
  Immunofluorescent staining in the mouse skin showed the presence of GPR54 receptors in PGP9.5-positive sensory fibers. Intraplantar injection of kisspeptin (1 or 3 nmol/5 μl) induced a small nocifensive response in naive mice, and lowered thermal pain threshold in the hot plate test. Both intraplantar and intrathecal (0.5 or 1 nmol/3 μl) injection of kisspeptin caused hyperalgesia in the first and second phases of the formalin test, whereas the GPR54 antagonist, p234 (0.1 or 1 nmol), caused a robust analgesia. Intraplantar injection of kisspeptin combined with formalin enhanced TRPV1 phosphorylation at Ser800 at the injection site, and increased ERK1/2 phosphorylation in the ipsilateral dorsal horn as compared to naive mice and mice treated with formalin alone.
  
  
  CONCLUSIONS
  These data demonstrate for the first time that kisspeptin regulates pain sensitivity in rodents and suggest that peripheral GPR54 receptors could be targeted by novel drugs in the treatment of inflammatory pain.
authors: Department of Clinical and Molecular Biomedicine, University of Catania, Italy.
authors: Simona
authors: S
authors: Spampinato
authors: Angela
authors: A
authors: Trabucco
authors: Antonella
authors: A
authors: Biasiotta
authors: Francesca
authors: F
authors: Biagioni
authors: Giorgio
authors: G
authors: Cruccu
authors: Agata
authors: A
authors: Copani
authors: William H
authors: WH
authors: Colledge
authors: Maria Angela
authors: MA
authors: Sortino
authors: Ferdinando
authors: F
authors: Nicoletti
authors: Santina
authors: S
authors: Chiechio
mesh_terms: D000818:Animals; D019084:Fluorescent Antibody Technique, Indirect; D006930:Hyperalgesia / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D059648:Kisspeptins / Q000378:metabolism*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009479:Neuropeptides / Q000378:metabolism*; D017288:Pain Threshold; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D000074502:Receptors, Kisspeptin-1
chemical_list: C492248:Kiss1r protein, mouse; D059648:Kisspeptins; D009479:Neuropeptides; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1