Vanilloid receptor loss is independent of the messenger plasticity that follows systemic resiniferatoxin administration

Brain Res. 1996 May 6;719(1-2):213-8. doi: 10.1016/0006-8993(96)00065-0.

Abstract

Resiniferatoxin (RTX) depletes vanilloid (capsaicin) receptors from lumbar dorsal root ganglia (DRG) of the rat. In addition, RTX causes changes in neuropeptide and nitric oxide synthase expression in lumbar DRG neurons, similar to those described following axotomy; this latter phenomenon is referred to as messenger plasticity. These findings suggested that vanilloid receptor loss may be part of the plasticity that follows RTX treatment. Here we show that vanilloid receptor expression, as detected by [3H]RTX autoradiography, is not changed in lumbar DRGs of axotomized rats, nor is it altered in a rat model (chronic constriction injury) of neuropathic pain. Thus, the in vivo expression of vanilloid receptors detected by specific [3H]RTX binding does not require the presence of intraaxonally transported trophic factors such as nerve growth factor. We conclude that messenger plasticity and vanilloid receptor loss are mediated by distinct mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoradiography
  • Capsaicin*
  • Diterpenes / pharmacology*
  • Female
  • Galanin / analysis
  • Ganglia, Spinal / cytology
  • Ganglia, Spinal / drug effects*
  • Ganglia, Spinal / enzymology
  • Lumbosacral Region
  • Neuronal Plasticity / drug effects*
  • Neurotoxins / pharmacology*
  • Nitric Oxide Synthase / biosynthesis
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Drug / analysis
  • Receptors, Drug / drug effects*
  • Vasoactive Intestinal Peptide / analysis

Substances

  • Diterpenes
  • Neurotoxins
  • Receptors, Drug
  • Vasoactive Intestinal Peptide
  • Galanin
  • resiniferatoxin
  • Nitric Oxide Synthase
  • Capsaicin