Neuroanatomical evidence for a putative autocrine/paracrine signaling system involving nicotinic acetylcholine receptors, purinergic receptors, and nitric oxide synthase in the airways.

Journal Article (Journal Article)

Nicotine in tobacco smoke is thought to stimulate sensory nerve fibers by receptors that are located on airway epithelial cells and on terminal branches of C-fiber afferents, but the exact neurochemical substrate that mediates the sensory effects of nicotine associated with cigarette smoking is not clear. ATP and nitric oxide (NO) have both been implicated in lung responsiveness to airborne chemicals such as nicotine. However, the neuroanatomical and functional relationships between nicotinic acetylcholine receptors (nAChRs), purinergic signaling, and NO are not known, and the main source of NO in the airways is not clear. In the present study, we performed RT-PCR to confirm the presence of mRNA for all three isoforms of nitric oxide synthase (NOS), neuronal (n-NOS), endothelial (e-NOS), and inducible (i-NOS), in the lung. Sequential double labeling was performed to assess the site of expression of the different NOS isoforms with respect to nAChRs and purinergic receptors (P2X3R) of the intrapulmonary airways. RT-PCR confirmed the presence of n-NOS, e-NOS, and i-NOS in the lung, and immunohistochemical studies verified their expression by epithelial cells at all levels of the intrapulmonary airways, including the terminal and respiratory bronchioles. Sequential double labeling demonstrated coexpression of n-NOS and/or i-NOS with nAChR- and P2X3R-expressing cells. These neuroanatomical findings suggest that bronchial epithelial cells may be a primary source of NO in the intrapulmonary airways and that the production and release of NO may be regulated by an autocrine/paracrine signaling system involving nAChRs and P2X3Rs.

Full Text

Duke Authors

Cited Authors

  • Rose, JE; Dehkordi, O; Fatemi, M; Raghupathi, R; Millis, RM; Jayam-Trouth, A

Published Date

  • April 2012

Published In

Volume / Issue

  • 90 / 4

Start / End Page

  • 849 - 859

PubMed ID

  • 22420037

Electronic International Standard Serial Number (EISSN)

  • 1097-4547

Digital Object Identifier (DOI)

  • 10.1002/jnr.22817


  • eng

Conference Location

  • United States