“…It was also demonstrated that PMNL stimulated with the ionophore A23187 in the presence of platelets transform platelet-derived 12S-hydroxy-5, 8,10,14-(Z,Z,E,Z)-eicosatetraenoic acid (12-HETE) into 5S,12S-dihydroxy-6,8,10,14(E,Z,E,Z)-eicosatetraenoic acid (5S, 12S-DiHETE) Marcus et al, 1982), and arachidonic acid into LTB4 (Marcus et al, 1982) via the 5-lipoxygenase pathway. In addition, 12-HETE synthesized in platelets is metabolized to 12S,8,10,14(Z,Z,E, by unstimulated neutrophils (Marcus et al, 1984). In previous studies we have also shown that incubation of PMNL with high concentration of exogenous arachidonic acid in the presence of platelelets results in increased synthesis of 5-lipoxygenase products.…”