Inhalation of acid aerosol or aspiration of acid solution evokes a stimulatory effect on airway C-fiber and Aδ afferents, which in turn causes airway irritation and triggers an array of defense reflex responses (e.g., cough, reflex bronchoconstriction, etc.). Tissue acidosis can also occur locally in the respiratory tract as a result of ischemia or inflammation, such as in the airways of asthmatic patients during exacerbation. The action of proton on the airway sensory neurons is generated by activation of two different current species: a transient (rapidly activating and inactivating) current mediated through the acid-sensing ion channels, and a slowly activating and sustained current mediated through the transient receptor potential vanilloid type 1 (TRPV1) receptor. In view of the recent findings that the expression and/or sensitivity of TRPV1 are up-regulated in the airway sensory nerves during chronic inflammatory reaction, the proton-evoked irritant effects on these nerves may play an important part in the manifestation of various symptoms associated with airway inflammatory diseases.
|Number of pages||7|
|Journal||Pulmonary Pharmacology and Therapeutics|
|State||Published - Oct 2013|
Bibliographical noteFunding Information:
Authors thank Ruei-Lung Lin for his assistance. The work was supported in part by the NIH grants HL96914 (to L.Y.L.), HL107462 (to F.X.), AI076714 (to Q.G.) and the Department of Defense DMRDP/ARATD award administered by the U.S. Army Medical Research & Materiel Command (USAMRMC) Telemedicine & Advanced Technology Research Center (TATRC) under Contract Number W81XWH-10-2-0189 (to L.Y.L.).
- Acid-sensing ion channels (ASICs)
- Airway irritation
- Transient receptor potential vanilloid type 1 receptor (TRPV1)
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Biochemistry, medical
- Pharmacology (medical)