Lipoxygenase inhibitors exert secretagogue-specific effects on mast cell exocytosis

The lipoxygenase inhibitors HTYA (5,8,11,14-henicosatetraynoic acid, 25-150 microM) and ITYA (4,7,10,13-icosatetraynoic acid, 25-75 microM), inhibited histamine secretion from rat mast cells evoked by concanavalin A but that elicited by compound 48/80 or polymyxin B. Arachidonic acid (100 microM) did not inhibit concanavalin A-induced histamine secretion. The results are consistent with the notion that lipoxygenase inhibitors affect an early stage of stimulus-secretion coupling in the mast cell, peculiar to antibody-directed secretagogues, perhaps that involving calcium influx.