[³H]arachidonic acid release in MM6 cells and human PMNLs.

MM6 cells or freshly isolated human PMNLs (2 × 10⁶/mL in RPMI 1640 medium) were prelabeled with 0.25 μCi/mL [³H]AA for 90 minutes at 37°C and 5% CO₂. After the removal of unincorporated [³H]AA, cells (5 × 10⁶ in 1 mL PGC buffer, containing 2 mg/mL fatty acid-free albumin) were primed in the absence or presence of PMA or mezerein for 10 minutes at 37°C, A23187 was added at the indicated concentrations, and the incubations continued for another 10 minutes. Free (nonesterified) [³H]AA was determined by HPLC as described in “Materials and methods.” Results are given as mean ± SE; n = 3.