CP-195543

CP-195543 is a potent, selective and orally active leukotriene B4 (LTB4) receptor antagonist with IC₅₀s of 6.8, 37.0 nM for human neutrophils and murine spleen membranes, respectively. CP-195543 blocks CD11b up-regulation. CP-195543 inhibits LTB4-mediated neutrophil infiltration^[1]. In Vitro:CP-195543 inhibits human and mouse neu-trophil chemotaxis mediated by LTB4 with IC₅₀ values of 2.4 nM, 7.5 nM, respectively^[1].
CP-195543 (0.1 nM-10 µM; 60 min) blocks CD11b up-regulation on human neutrophils (HN) and murine neutrophils with IC₅₀s of 270, 420 nM for human monocytes and eosinophils, respectively^[1]. In Vivo:CP-195543 (0.01, 0.1, 1, 10 mg/kg for guinea pig; 0.01, 0.1, 1, 10, 100 mg/kg for mice; P.o.; 1 h before injection of LTB4) inhibits LTB4-mediated neutrophil infiltration in guinea pigskin in a dose-dependent manner^[1].