Pulmonary Nociceptors are Potentially Connected with Neuroepithelial Bodies

  • J. YU
  • S.X. LIN
  • J.W. ZHANG
  • J.F. WALKER
Part of the ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY book series (AEMB, volume 580)

Abstract

Airway sensory receptors regulate cardiopulmonary function by providing constant information about the mechanical and chemical status of the lung to the central nervous system (CNS). There are at least three airway sensor types: slowly adapting receptors (SARs), rapidly adapting receptors (RARs), and C-fiber receptors (CFRs). We recently identified additional A-delta fiber receptors in intact rabbits that are different from SARs and RARs. Having a high mechanical threshold, they respond to hypertonic saline and are termed high threshold A-delta receptors (HTARs). SARs and RARs monitor airway mechanical changes, whereas HTARs and CFRs sense chemical alterations and may serve as nociceptors. As with nociceptors in other tissue, the latter are activated during lung inflammatory processes. Also, the airway houses neuroendocrine cells aggregated in organoids called neuroepithelial bodies (NEBs). NEBs are richly innervated by nerve fibers from different origins. Similar in structure to the carotid bodies, NEBs are believed to be sensors, with at least some sensory fibers that have cell bodies in the nodose ganglia. Therefore, they may serve CNS reflex functions. Strategically located at airway bifurcations, NEBs may signal the chemical composition of or presence of irritants in the air. This study intends to explore the possibility that NEBs are associated with nociceptors.

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References

  1. 1.
    Coleridge HM, Coleridge JC. Pulmonary reflexes: neural mechanisms of pulmonary defense. Annu Rev Physiol 1994; 56: 69–91.PubMedCrossRefGoogle Scholar
  2. 2.
    Yu J. An overview of vagal airway receptors. Acta Physiologica Sinica 2002; 54(6): 451–459.PubMedGoogle Scholar
  3. 3.
    Belvisi MG. Sensory nerves and airway inflammation: role of A delta and C-fibres 1. Pulm Pharmacol Ther 2003; 16(1): 1–7.PubMedCrossRefGoogle Scholar
  4. 4.
    Coleridge JCG, Coleridge HM. Afferent vagal C fibre innervation of the lungs and airways and its functional significance. Rev Physiol Biochem Pharmacol 1984; 99: 1–110PubMedCrossRefGoogle Scholar
  5. 5.
    Lee LY, Pisarri TE. Afferent properties and reflex functions of bronchopulmonary C-fibers. Respir Physiol 2001; 125(1–2): 47–65.PubMedCrossRefGoogle Scholar
  6. 6.
    Undem BJ, Carr MJ. Pharmacology of airway afferent nerve activity. Respir Res 2001; 2(4): 234–244.PubMedCrossRefGoogle Scholar
  7. 7.
    Van Lommel A, Lauweryns JM, Berthoud HR. Pulmonary neuroepithelial bodies are innervated by vagal afferent nerves: an investigation with in vivo anterograde DiI tracing and confocal microscopy. Anat Embryol (Berl) 1998; 197(4): 325–330.CrossRefGoogle Scholar
  8. 8.
    Adriaensen D, Brouns I, Van Genechten J et al. Functional morphology of pulmonary neuroepithelial bodies: Extremely complex airway receptors. Anat Rec 2003; 270(1): 25–40.CrossRefGoogle Scholar
  9. 9.
    Yu J, Zhang J, Wang Y et al. Neuroepithelial bodies not connected to pulmonary slowly adapting stretch receptors. Respir Physiol Neurobiol 2004; 144(1): 1–14.PubMedCrossRefGoogle Scholar
  10. 10.
    Wang Y, Yu J. Structural survey of airway sensory receptors in the rabbit using confocal microscopy. Acta Physiol sinica 2004; 56(2): 119–129.PubMedGoogle Scholar
  11. 11.
    Yu J, Wang YF, Zhang JW. Structure of slowly adapting pulmonary stretch receptors in the lung periphery. J Appl Physiol 2003; 95(1): 385–393.PubMedGoogle Scholar
  12. 12.
    Wang Y, Cheng Z, Zhang JW et al. A novel approach to investigate pulmonary receptors. 2002: A453.Google Scholar
  13. 13.
    Yu J. Airway mechanosensors. Respir Physiol Neurobiol 2005.Google Scholar
  14. 14.
    Fu XW, Nurse CA, Wong V et al. Hypoxia-induced secretion of serotonin from intact pulmonary neuroepithelial bodies in neonatal rabbit. J Physiol 2002; 539(Pt 2): 503–510.PubMedCrossRefGoogle Scholar
  15. 15.
    Van Lommel A, Lauweryns JM, De Leyn P et al. Pulmonary neuroepithelial bodies in neonatal and adult dogs: histochemistry, ultrastructure, and effects of unilateral hilar lung denervation. Lung 1995; 173(1): 13–23.PubMedCrossRefGoogle Scholar

Copyright information

© Springer 2006

Authors and Affiliations

  • J. YU
    • 1
  • S.X. LIN
    • 1
  • J.W. ZHANG
    • 1
  • J.F. WALKER
    • 1
  1. 1.Pulmonary MedicineUniversity of LouisvilleLouisvilleUSA

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