Reflex tracheal contraction induced by stimulation of bronchial C-fibers in dogs

A. M. Roberts, Marc Kaufman, D. G. Baker, J. K. Brown, H. M. Coleridge, J. C. Coleridge

Research output: Contribution to journalArticlepeer-review

59 Scopus citations


Bradykinin stimulates the afferent vagal endings of bronchial C-fibers but has little effect on other pulmonary vagal afferents. In anesthetized dogs with open chest, we recorded transverse tension in the posterior wall (trachealis muscle) of an upper cervical tracheal segment and stimulated bronchial C-fibers selectively by injecting bradykinin (19 ng-3 μg) into a bronchial artery. The recurrent and pararecurrent laryngeal nerves were cut so that the superior laryngeal nerves provided the motor supply to the segment. Bradykinin caused a dose-dependent increase in tracheal muscle tension and often a conspicuous decrease in heart rate, which were abolished by vagotomy or administration of atropine. Injection of bradykinin still evoked tracheal contraction when myelinated lung afferents were blocked by cooling the midcervical vagi to 7°C, but contraction was abolished when unmyelinated lung afferents were blocked by cooling to 0-1°C, the effects of cooling being reversible. Our results indicate that stimulation of bronchial C-fibers, like that of pulmonary C-fibers, evokes reflex contraction of airway smooth muscle and reflex cardiac slowing.

Original languageEnglish (US)
Pages (from-to)485-493
Number of pages9
JournalUnknown Journal
Issue number2
StatePublished - 1981

All Science Journal Classification (ASJC) codes

  • Physiology
  • Endocrinology


Dive into the research topics of 'Reflex tracheal contraction induced by stimulation of bronchial C-fibers in dogs'. Together they form a unique fingerprint.

Cite this