Figure 4. IL-13 expression is fed by asthma induction. Induction of asthma resulted in a dramatic increase in IL-13 gene expression which was resistant to steroid therapy. Application of NAC (320 mg/kg) every 12 hours starting 30 min before the first OVA challenge and finishing 12 hours after the last challenge prevented the expression of this chemokine and kept it to the control levels. Data are presented as means ± S.E. (error bars), n = 8; *p<0.05 for the comparisons to the respective control and ^#p<0.05 for the comparisons to the respective asthma group.