Effects of SB203580 on 5-LO product formation.

Freshly isolated PMNLs (5 × 10⁶ in PGC buffer) were preincubated with the indicated concentrations of SB203580 for 30 minutes at 37°C. SA (○, 10 μM) and NaCl (▾, 0.3 M) were added 3 minutes prior to addition of 40 μM AA; ionophore A23187 (●, 2.5 μM) and thapsigargin (thaps, ▿, 1 μM) were added simultaneously with AA, final volume was 1 mL. After 5 minutes at 37°C, 5-LO products were determined. Results are given as mean + SE (n = 3).