Effect of erythromycin on ciliary motility in rabbit airway epithelium in vitro

The effect of erythromycin on ciliary beat frequency (CBF) of rabbit tracheal epithelium was studied by a microphoto-oscillation technique in vitro. Addition of erythromycin dose-dependently increased CBF, the maximal increase from the baseline value and EC50 being 23.3 +/- 4.5% (P less than 0.001) and 6.8 +/- 0.9 mg/L, respectively. This effect was not influenced by autonomic receptor antagonists, blockers of arachidonic acid metabolism, Ca(2+)-free medium, or inhibition of protein kinase C and protein kinase A activities.