Durable Changes to Airway Mucus Secretion Following a Single Cholinergic Challenge

Cholinergic signaling in the airway elicits robust airway smooth muscle contraction and mucus secretion. In our previous work, we showed that re‐exposure of the airways to a cholinergic agonist 48 hours post initial challenge exaggerated airway narrowing. Here we test the hypothesis that re‐exposure to a cholinergic agonist exaggerates mucus secretion. To test this hypothesis, we challenged male and female pig airways with the synthetic cholinergic agonist bethanechol. Forty‐eight hours later, we re‐exposed the airways and assessed mucus secretion ex vivo using jacalin lectins . We found that re‐exposure mildly increased mucus secretion. The increase in mucus secretion was not associated with an impairment or alteration in mucociliary transport. We also stained tracheal cross sections with antibodies directed against mucin5B and mucin5AC, the major secreted glycoproteins that comprise mucus. Our ongoing studies suggest that cholinergic challenge had no major effect on the amounts of mucin5B or mucin5AC. Critical next steps include measuring the amount of mucins in the lung lavage fluid, as well as examining key components of the cholinergic signaling cascade. Support or Funding Information HL119560, OD023854