Fig. 1.

Pretreatment of bronchial epithelial cells (BECs) with β₂-agonists dose-responsively inhibits hog dust extract (HDE)-induced cytokine release. Cultured immortalized human bronchial epithelial (BEAS-2B; A) and primary human bronchial epithelial (NHBE; B) cells were exposed to various concentrations of the long-acting β₂-agonist salmeterol or the short-acting β₂-agonist salbutamol for 1 h and then to 5% HDE in the presence or absence of β₂-agonist for an additional 24 h. Supernatant medium was analyzed for IL-6 and IL-8 levels by ELISA. Values are means ± SE for 3 (A) or 4 (B) independent experiments. *P < 0.05 vs. HDE alone (by 1-way ANOVA and Tukey's posttest).