Acute inhalation of ozone stimulates bronchial C-fibers and rapidly adapting receptors in dogs

J. C G Coleridge, H. M. Coleridge, Edward S Schelegle, J. F. Green

Research output: Contribution to journalArticle

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Abstract

To identify the afferents responsible for initiating the vagally mediated respiratory changes evoked by acute exposure to ozone, we recorded vagal impulses in anesthetized, open-chest, artificially ventilated dogs and examined the pulmonary afferent response to ozone (2-3 ppm in air) delivered to the lower trachea for 20-60 min. Bronchial C-fibers (BrCs) were the lung afferents most susceptible to ozone, the activity of 10 of 11 BrCs increasing from 0.2 ± 0.2 to 4.6 ± 1.3 impulses/s within 1-7 min of ozone exposure. Ten of 15 rapidly adapting receptors (RARs) were stimulated by ozone, their activity increasing from 1.5 ± 0.4 to 4.7 ± 0.7 impulses/s. Stimulation of RARs (but not of BrCs) appeared secondary to the ozone-induced reduction of lung compliance because it was abolished by hyperinflation of the lungs. Ozone had little effect on pulmonary C-fibers or slowly adapting pulmonary stretch receptors. Our results suggest that both BrCs and RARs contribute to the tachypnea and bronchoconstriction evoked by acute exposure to ozone when vagal conduction is intact and that BrCs alone are responsible for the vagally mediated tachypnea that survives vagal cooling to 7°C.

Original languageEnglish (US)
Pages (from-to)2345-2352
Number of pages8
JournalJournal of Applied Physiology
Volume74
Issue number5
StatePublished - 1993

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Keywords

  • control of breathing
  • lower airway afferents and ozone
  • pulmonary vagal afferents
  • rapid shallow breathing
  • reflex control of bronchomotor tone

ASJC Scopus subject areas

  • Endocrinology
  • Physiology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

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