LY255283 is selective, competitive antagonist of BLT2 receptors (IC50 values are ~ 1 and > 10 μM at human recombinant BLT2 and BLT1 receptors respectively), and inhibits LTB4-induced contraction of lung parenchyma (pA2 = 7.2), and reduces LTB4-mediated airway obstruction in guinea pigs following i.v. and oral administration.