Figure 1

Leukotriene formation was blocked in FLAP knockout mice. Bone marrow cells obtained from wild type and FLAP knockout animals were incubated with 50 μM AA and 20 μM calcium ionophore A23187 for 20 min at 37°C. Reactions were stopped with ice cold methanol and supernatants were analyzed by RP-HPLC as described in Materials and Methods. The absorbance at 270 nm, corrected for stray absorbance at 360 nm, was recorded versus time. Retention times in minutes are indicated for each component in the chromatograms. Upper panel: analysis of synthetic LTB₄ and LTC₄. Middle panel: LTB₄ was formed by bone marrow cells from wild type mice, but not from knockout mice (lower panel).