Pharmacological profile of AA-861, a 5-lipoxygenase inhibitor.

AA-861, a selective 5-lipoxygenase inhibitor, suppressed A23187-induced formations of 5-HETE and LTB4 in rat peritoneal macrophages. Immunologically-stimulated generation of SRS-A was also inhibited in guinea pig lung and rat peritoneal cavity. AA-861 had no effects on histamine release from rat mast cells or passive cutaneous anaphylaxis in rats. Essentially no antagonistic activity to LTD4 or histamine was observed. This compound exerted an obvious inhibition of allergic bronchoconstriction in guinea pigs and a moderate reduction of carrageenin-induced paw edema and pleurisy in rats. These findings suggest that SRS-A plays an important role in asthmatic and inflammatory reactions.