A synergistic effect of simultaneous TRPA1 and TRPV1 activations on vagal pulmonary C-fiber afferents

Yu Jung Lin, Ruei Lung Lin, Ting Ruan, Mehdi Khosravi, Lu Yuan Lee

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Transient receptor potential ankyrin type 1 (TRPA1) and vanilloid type 1 (TRPV1) receptors are coexpressed in vagal pulmonary C-fiber sensory nerves. Because both these receptors are sensitive to a number of endogenous inflammatory mediators, it is conceivable that they can be activated simultaneously during airway inflammation. This study aimed to determine whether there is an interaction between these two polymodal transducers upon simultaneous activation, and how it modulates the activity of vagal pulmonary C-fiber sensory nerves. In anesthetized, spontaneously breathing rats, the reflex-mediated apneic response to intravenous injection of a combined dose of allyl isothiocyanate (AITC, a TRPA1 activator) and capsaicin (Cap, a TRPV1 activator) was ∼202% greater than the mathematical sum of the responses to AITC and Cap when they were administered individually. Similar results were also observed in anesthetized mice. In addition, the synergistic effect was clearly demonstrated when the afferent activity of single vagal pulmonary C-fiber afferents were recorded in anesthetized, artificially ventilated rats; C-fiber responses to AITC, Cap and AITC + Cap (in combination) were 0.6 ± 0.1, 0.8 ± 0.1, and 4.8 ± 0.6 impulses/s (n = 24), respectively. This synergism was absent when either AITC or Cap was replaced by other chemical activators of pulmonary C-fiber afferents. The pronounced potentiating effect was further demonstrated in isolated vagal pulmonary sensory neurons using the Ca2+ imaging technique. In summary, this study showed a distinct positive interaction between TRPA1 and TRPV1 when they were activated simultaneously in pulmonary C-fiber sensory nerves.

Original languageEnglish
Pages (from-to)273-281
Number of pages9
JournalJournal of Applied Physiology
Issue number3
StatePublished - Feb 1 2015

Bibliographical note

Publisher Copyright:
Copyright © 2015 the American Physiological Society


  • AITC
  • Capsaicin
  • Inflammation
  • TRPA1
  • TRPV1

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


Dive into the research topics of 'A synergistic effect of simultaneous TRPA1 and TRPV1 activations on vagal pulmonary C-fiber afferents'. Together they form a unique fingerprint.

Cite this