Leukotriene B4 (LTB4) is a dihydroxy fatty acid derived from the 5-lipoxygenase pathway of arachidonic acid metabolism and is an important mediator of the inflammatory process. The benzophenone dicarboxylic acid derivative LY223982 is a potent BLT1 receptor antagonist. It inhibits the specific binding of radiolabeled-LTB4 to isolated human neutrophils with an IC50 value of 13.2 nM. LY223982 inhibits the leukotriene B4 (LTB4)-induced aggregation of guinea pig and human neutrophils with IC50 values of 74 and 100 nM, respectively. However, concentrations of LY223982 up to 10 μM do not inhibit binding of LTB4 to human BLT1 or BLT2 expressed in CHO cells.
