FIG. 7.

Dexamethasone reduces β-defensin mRNA expression in bronchial biopsy specimens from dexamethasone-treated calves. Calves were injected with 0.1 mg/kg dexamethasone (black bars) or saline (white bars) every 24 h for 6 days, and then LPS (500 μg in 10 ml PBS) was infused into a bronchus in the caudal lung lobe. Total mRNA extracted from bronchial biopsy specimens was then used to quantify TAP (A) or LAP (B) mRNA expression using real-time RT-PCR. Data represent the mean ± SEM ratios of TAP or LAP mRNA expression relative to GAPDH mRNA from four separate animals. Significance is based on repeated-measures ANOVA with post hoc Bonferroni on log-transformed data (*, P < 0.05 for saline- versus dexamethasone-treated calves each day).