P2X3-mediated peripheral sensitization of neuropathic pain in resiniferatoxin-induced neuropathy

Exp Neurol. 2012 May;235(1):316-25. doi: 10.1016/j.expneurol.2012.02.013. Epub 2012 Feb 28.


Patients suffering from sensory neuropathy due to skin denervation frequently have paradoxical manifestations of reduced nociception and neuropathic pain. However, there is a lack of satisfactory animal models to investigate these phenomena and underlying mechanisms. We developed a mouse system of neuropathy induced by resiniferatoxin (RTX), a capsaicin analog, and examined the functional significance of P2X3 receptor in neuropathic pain. From day 7 of RTX neuropathy, mice displayed mechanical allodynia (p<0.0001) and thermal hypoalgesia (p<0.0001). After RTX treatment, dorsal root ganglion (DRG) neurons of the peripherin type were depleted (p=0.012), while neurofilament (+) DRG neurons were not affected (p=0.62). In addition, RTX caused a shift in neuronal profiles of DRG: (1) increased in P2X3 receptor (p=0.0002) and ATF3 (p=0.0006) but (2) reduced TRPV1 (p=0.036) and CGRP (p=0.015). The number of P2X3(+)/ATF3(+) neurons was linearly correlated with mechanical thresholds (p=0.0017). The peripheral expression of P2X3 receptor in dermal nerves was accordingly increased (p=0.016), and an intraplantar injection of the P2X3 antagonists, A-317491 and TNP-ATP, relieved mechanical allodynia in a dose-dependent manner. In conclusion, RTX-induced sensory neuropathy with upregulation of P2X3 receptor for peripheral sensitization of mechanical allodynia, which provides a new therapeutic target for neuropathic pain after skin denervation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diterpenes
  • Ganglia, Spinal / metabolism
  • Ganglia, Spinal / physiopathology
  • Hyperalgesia / chemically induced
  • Hyperalgesia / metabolism*
  • Hyperalgesia / physiopathology
  • Male
  • Mice
  • Mice, Inbred ICR
  • Neuralgia / chemically induced
  • Neuralgia / metabolism*
  • Neuralgia / physiopathology
  • Neurons / metabolism
  • Pain Measurement
  • Peripheral Nervous System Diseases / chemically induced
  • Peripheral Nervous System Diseases / metabolism*
  • Peripheral Nervous System Diseases / physiopathology
  • Receptors, Purinergic P2X3 / metabolism*
  • Skin / innervation
  • Skin / metabolism
  • Skin / physiopathology


  • Diterpenes
  • Receptors, Purinergic P2X3
  • resiniferatoxin