Time course of SA-induced 5-LO product formation and p38 MAPK activation.
(A) 5-LO product formation. Freshly isolated PMNLs (5 × 106 in 1 mL PGC buffer) were stimulated with 10 μM SA at 37°C. After the indicated times, 40 μM AA was added, the samples were incubated for another 5 minutes, and 5-LO products were determined by HPLC. Results are given as mean + SE (n = 3). (B) Activation of p38 MAPK. Freshly isolated PMNLs (5 × 106 in 100 μL PGC buffer) were stimulated with 10 μM SA at 37°C. After the indicated times, incubations were terminated by addition of SDS-b and samples were analyzed for dually phosphorylated p38 MAPK by immunoblotting (upper panel); equal amounts of protein were evaluated with anti-p38 MAPK antibodies (lower panel). Results are representative of at least 3 separate experiments.
