Involvement of lipoxygenases in the activation of mouse macrophages by endotoxin.

Preincubation with lipopolysaccharides stimulated the phagocytic capacity of mouse peritoneal macrophages. Treatment of cell cultures with inhibitors of lipoxygenases which affect this pathway specifically (diethylcarbamazine) or compounds which block lipoxygenases and cyclooxygenase (BW 755 C, eicosatetraynoic acid) inhibited the increase, while inhibitors of cyclooxygenase (indomethacin, aspirin) did not affect the LPS induced enhancement of the phagocytic capacity. It is, therefore, concluded that lipoxygenase products are required for the activation of macrophages by endotoxins.