Lung vagal afferent activity in rats with bleomycin-induced lung fibrosis

Edward S Schelegle, William F. Walby, Jim K. Mansoor, Andrew T. Chen

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Bleomycin treatment in rats results in pulmonary fibrosis that is characterized by a rapid shallow breathing pattern, a decrease in quasi-static lung compliance and a blunting of the Hering-Breuer Inflation Reflex. We examined the impulse activity of pulmonary vagal afferents in anesthetized, mechanically ventilated rats with bleomycin-induced lung fibrosis during the ventilator cycle and static lung inflations/deflations and following the injection of capsaicin into the right atrium. Bleomycin enhanced volume sensitivity of slowly adapting stretch receptors (SARs), while it blunted the sensitivity of these receptors to increasing transpulmonary pressure. Bleomycin treatment increased the inspiratory activity, while it decreased the expiratory activity of rapidly adapting stretch receptors (RARs). Pulmonary C-fiber impulse activity did not appear to be affected by bleomycin treatment. We conclude that the fibrosis-related shift in discharge profile and enhanced volume sensitivity of SARs combined with the increased inspiratory activity of RARs contributes to the observed rapid shallow breathing of bleomycin-induced lung fibrosis.

Original languageEnglish (US)
Pages (from-to)9-27
Number of pages19
JournalRespiration Physiology
Issue number1
StatePublished - 2001


  • Disease, lung fibrosis, pulmonary afferents
  • Mammals, rat
  • Pattern of breathing, rapid shallow
  • Pharmacological agents, bleomycin, capsaicin
  • Receptors, pulmonary stretch

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine


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