Capsaicin: actions on nociceptive C-fibres and therapeutic potential.

Abstract

Recent work on the excitatory action of capsaicin on somatic and visceral afferent neurones shows that depolarization is selective for C-fibre polymodal nociceptor afferents and involves opening a non-selective cation channel. Exposure to significantly suprathreshold amounts of capsaicin causes permanent degeneration of C-fibre afferents in adult rats. Functional changes in rats (hypalgesia, diminished neurogenic inflammation) are likely to be a direct consequence of the loss of C-fibre nociceptors, and so are the reductions in neuropeptide levels that follow adult capsaicin treatment. Clinical trials of topical capsaicin treatment for post-herpetic neuralgia have yielded promising results. The selective nature of the action of capsaicin in reducing just C-nociceptor activity may make it particularly useful for treating pain states triggered by C-fibre input.

• Authors: Bruce Lynn
• Journal: Pain (Pain) Vol. 41 Issue 1 Pg. 61-69 (Apr 1990) ISSN: 0304-3959 [Print] United States
• PMID: 2162021 (Publication Type: Journal Article, Review)

Chemical References

• Neuropeptides
• Capsaicin

Topics

• Administration, Topical
• Animals
• Capsaicin (pharmacology, therapeutic use)
• Herpesviridae Infections (physiopathology)
• Humans
• Nerve Block
• Nerve Degeneration
• Nerve Fibers (drug effects)
• Neural Conduction (drug effects)
• Neurons, Afferent (drug effects)
• Neuropeptides (metabolism)
• Nociceptors (drug effects)
• Pain (drug therapy)
• Skin (drug effects)