The effect of IL-4 on mRNA expression for cPLA₂, 5-LO, FLAP, and LTA₄ hydrolase.

(A) Time-course study. After PMNs were incubated with 10 ng/mL of IL-4 for various periods of time, total RNA was isolated, and RT-PCR for cPLA₂, 5-LO, FLAP, and LTA₄hydrolase was performed as described in “Materials and methods.” The densities were measured and normalized by beta-actin. Results were shown as mean ± SEM (n = 4). *P < .05 versus control. (B) Dose-response study. After PMNs were incubated with various concentrations of IL-4 for 6 hours, total RNA was isolated, and RT-PCR for cPLA₂, 5-LO, FLAP, and LTA₄ hydrolase was performed.