Referenced in: none

Automatically associated channels: TRP , TRPA , TRPA1 , TRPM , TRPM8 , TRPV , TRPV1

Title: Sensitivity of bronchopulmonary receptors to cold and heat mediated by transient receptor potential cation channel subtypes in an ex vivo rat lung preparation.

Authors: Yun Zhou, Biying Sun, Qian Li, Pin Luo, Li Dong, Weifang Rong

Journal, date & volume: Respir Physiol Neurobiol, 2011 Aug 15 , 177, 327-32

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/21621010

Abstract
Changes in airway temperature can result in respiratory responses such as cough, bronchoconstriction and mucosal secretion after cold exposure and hyperventilation after heat exposure. In the present investigation, we examined the activity of bronchopulmonary receptors in response to activators of thermo-sensitive transient receptor potential (TS-TRP) cation channels using an ex vivo rat lung preparation. Receptive fields in small bronchioles were probed with von Frey hair monofilaments, warm (50°C) or cold (8°C) saline or saline containing TS-TRP agonists. Among 233 fibers tested, 159 (68.2%) responded to heat (50°C). A large proportion of heat-responsive receptors (107/145) were also activated by capsaicin. Heat and capsaicin-evoked responses were both blocked by TRPV1 antagonist, capsazepine. Only 15.3% of airway receptors responded to cold, which was associated with sensitivity to TRPM8 agonist menthol but not to TRPA1 agonist cinnamaldehyde (CA). Moreover, cold-evoked responses was unaffected by TRPA1 antagonist HC-03001. Our observations suggest that TRPV1 and TRPM8 are involved in transducing heat and cold in the lower respiratory tract, respectively.