Different Cilia Response to Adenosine Triphosphate or Benzalkonium Chloride Treatment in Mouse Nasal and Tracheal Culture

Abstract

Objectives: Our purpose was to compare the ciliary function between the upper and lower airway. Methods: Basal ciliary beat frequency (CBF) and changes in CBF in response to exogenous stimuli [adenosine triphosphate (ATP) or benzalkonium chloride (BAC)] of primary cultured mouse nasal and tracheal epithelial cells were quantified using digital microscopy combined with a beat-by-beat CBF analysis. Results: The basal CBF of the mouse tracheal culture was statistically higher than the nasal culture. Adding 10 or 100 µ<span style="font-variant:small-caps; text-transform:lowercase">m</span> ATP caused an increase of CBF in both mouse nasal and tracheal cultures; however, nasal culture induced a more robust increase of CBF than tracheal culture. Treatment with 0.001% BAC increased CBF within 2 min after treatment and then CBF gradually decreased; nasal and tracheal culture manifested a similar change in CBF. With a concentration of 0.01%, BAC induced a rapid and time-dependent decrease of CBF in both mouse nasal and tracheal cultures; however, tracheal culture showed a blunter response to this ciliotoxic agent, with the ciliary beating duration time distinguishably longer than in the nasal culture. Conclusion: The inherent ciliary and physiological function is different in the upper and lower airway in mice.