Description
Antagonists of the chemotactic and inflammatory lipoxygenase product leukotriene B
4 (LTB
4) have been potential drug development targets for several years. The tetrazole LY255283 is a competitive antagonist of the BLT
2 receptor. It displaces radiolabeled LTB
4 from guinea pig lung membrane, with an IC
50 of about 100 nM. LY255283 exhibits IC
50 values of ~950 nM and >10 μM at human recombinant BLT
2 and BLT
1 receptors, respectively. LY255283 inhibits eosinophil chemotaxis by 80% at a concentration of 10 μM, and inhibits the binding of radiolabeled LTB
4 to eosinophil membranes with an IC
50 of 260 nM.
Biological Activity
Selective, competitive antagonist of BLT 2 receptors (IC 50 values are ~ 1 and > 10 μ M at human recombinant BLT 2 and BLT 1 receptors respectively). Inhibits LTB 4 -induced contraction of lung parenchyma (pA 2 = 7.2), and reduces LTB 4 -mediated airway obstruction in guinea pigs following i.v. and oral administration.