Thermal sensitivity of isolated vagal pulmonary sensory neurons

Role of transient receptor potential vanilloid receptors

Dan Ni, Qihai Gu, Hong Zhen Hu, Na Gao, Michael X. Zhu, Lu Yuan Lee*

*Corresponding author for this work

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

A recent study has demonstrated that increasing the intrathoracic temperature from 36°C to 41°C induced a distinct stimulatory and sensitizing effect on vagal pulmonary C-fiber afferents in anesthetized rats (J Physiol 565: 295-308, 2005). We postulated that these responses are mediated through a direct activation of the temperature-sensitive transient receptor potential vanilloid (TRPV) receptors by hyperthermia. To test this hypothesis, we studied the effect of increasing temperature on pulmonary sensory neurons that were isolated from adult rat nodose/jugular ganglion and identified by retrograde labeling, using the whole cell perforated patchclamping technique. Our results showed that increasing temperature from 23°C (or 35°C) to 41°C in a ramp pattern evoked an inward current, which began to emerge after exceeding a threshold of ∼34.4°C and then increased sharply in amplitude as the temperature was further increased, reaching a peak current of 173 ± 27 pA (n = 75) at 41°C. The temperature coefficient, Q 10, was 29.5 ± 6.4 over the range of 35-41°C. The peak inward current was only partially blocked by pretreatment with capsazepine (ΔI = 48.1 ± 4.7%, n = 11) or AMG 9810 (ΔI = 59.2 ± 7.8%, n = 8), selective antagonists of the TRPV1 channel, but almost completely abolished (ΔI = 96.3 ± 2.3%) by ruthenium red, an effective blocker of TRPV1-4 channels. Furthermore, positive expressions of TRPV1-4 transcripts and proteins in these neurons were demonstrated by RT-PCR and immunohistochemistry experiments, respectively. On the basis of these results, we conclude that increasing temperature within the normal physiological range can exert a direct stimulatory effect on pulmonary sensory neurons, and this effect is mediated through the activation of TRPV1, as well as other subtypes of TRPV channels.

Original languageEnglish
Pages (from-to)541-550
Number of pages10
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume291
Issue number3
DOIs
Publication statusPublished - 2006
Externally publishedYes

Keywords

  • Airway reflexes
  • C fibers
  • Capsaicin
  • Exercise
  • Fever
  • Temperature

Fingerprint Dive into the research topics of 'Thermal sensitivity of isolated vagal pulmonary sensory neurons: Role of transient receptor potential vanilloid receptors'. Together they form a unique fingerprint.

  • Cite this