Figure 5.

Relationship between EC₅₀ dose ratio of LTB₄-induced neutrophil CD11b upregulation and plasma concentration of CP-105,696 in normal human volunteers. CD11b expression in neutrophils was determined in whole blood using an ex vivo flow cytometric assay and CP-105,696 plasma concentrations were determined using h.p.l.c. (See Methods). EC₅₀ dose ratio for LTB₄-induced CD11b upregulation was determined by comparing the EC₅₀ value in whole blood samples obtained at 4 h following oral administration of CP-105,696 to that in predose blood of the same subject.