Peripheral inflammation induces up-regulation of TRPV2 expression in rat DRG

Pain. 2005 Dec 15;119(1-3):225-232. doi: 10.1016/j.pain.2005.10.002. Epub 2005 Nov 17.

Abstract

The transient receptor potential vanilloid subfamily member 2 (TRPV2) is a cation channel activated by temperatures above 52 degrees C. To analyze the contribution of TRPV2 to the development of inflammation-induced hyperalgesia, the expression of TRPV2 in primary sensory neurons was analyzed after intraplantar injection of complete Freund's adjuvant (CFA). Using specific antibodies, an increase in TRPV2-expressing neurons was identified after inflammation. TRPV2 expression is concentrated in a subset of medium-sized dorsal root ganglion neurons, independent of transient receptor potential vanilloid subfamily member 1 (TRPV1) expression. A similar distribution of TRPV2 was observed after inflammation. Intraplantar injection of nerve growth factor increased TRPV1 expression but not TRPV2, suggesting that induction of TRPV2 expression is driven by a mechanism distinct from that for TRPV1. Heat hyperalgesia assessment after chemical desensitization of TRPV1 by resiniferatoxin demonstrates a possible role for TRPV2 in inflammation at high temperatures (>56 degrees C). These results suggest that TRPV2 upregulation contributes to peripheral sensitization during inflammation and is responsible for pain hypersensitivity to noxious high temperature stimuli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal*
  • Freund's Adjuvant
  • Ganglia, Spinal / drug effects
  • Ganglia, Spinal / metabolism*
  • Hyperalgesia / etiology
  • Hyperalgesia / metabolism*
  • Inflammation / chemically induced
  • Inflammation / complications
  • Inflammation / metabolism*
  • Male
  • Neuralgia / etiology
  • Neuralgia / metabolism*
  • Neurons / drug effects
  • Neurons / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • TRPV Cation Channels / metabolism*
  • Up-Regulation / drug effects

Substances

  • TRPV Cation Channels
  • Trpv2 protein, rat
  • Freund's Adjuvant