Modulation by drugs of leukotriene and prostaglandin production from mouse peritoneal macrophages

Leukotriene and prostaglandin production by mouse peritoneal macrophages was investigated. It could be shown that the tumour promoter 12-O-tetradecanoylphorbol-13-acetate, despite initiating the release of prostaglandin E2, had little effect on the release of leukotriene C4-like immunoreactivity. The divalent cation ionophore A 23187 at concentrations between 10(-6) and 10(-8) mol/l initiated prostaglandin as well as leukotriene release. This prostaglandin and leukotriene release could be modulated by drugs. Non-steroidal anti-inflammatory drugs inhibited prostaglandin release but enhanced leukotriene production. The experimental compound BW 755C inhibited prostaglandin and leukotriene production, whereas the antithrombotic compound nafazatrom inhibited the production of leukotriene C4-like immunoreactivity but enhanced the prostaglandin E2 production. Nordihydroguaiaretic acid inhibited prostaglandin and leukotriene production. The results show that the metabolism of arachidonic acid in macrophages via the cyclooxygenase or the lipoxygenase pathway is dependent on the stimulus applied. Both pathways can be inhibited conjointly or selectively by drugs. The experimental system described may be used for assessing the potency of drugs to inhibit the lipoxygenase and the cyclooxygenase pathway of arachidonic acid metabolism.