HPLC profiles of 5-oxo-eicosanoids formed by platelets in the presence and absence of phenazine methosulfate. Platelets (2 × 10⁸/mL) were preincubated for 5 minutes at 37°C in the absence (A) or presence (B and C) of PMS (100 μmol/L) and then incubated for a further 30 minutes with 5-HETE (2 μmol/L; A and B) or 5S,12S-diHETE (2 μmol/L; C). The products were analyzed by precolumn extraction/RP-HPLC as described in Materials and Methods.