FIG. 3.

Effect of azithromycin on MUC5AC production in cells activated by 3O-C₁₂-HSL. Cells were pretreated with 10 or 100 μg of azithromycin/ml for 30 min before exposure to 3O-C₁₂-HSL. (A) MUC5AC mRNA expression at 8 h after the addition of 3O-C₁₂-HSL was determined by RT-PCR. (B) MUC5AC protein was measured by an ELISA at 12 h after the addition of 3O-C₁₂-HSL. Data are expressed as the mean and SEM for three experiments. An asterisk indicates a P value of <0.05 for a comparison with culture medium alone.