Stability of chemokine-induced neutrophil adherence to EC exposed to different shear forces. PMN were stimulated with 10 μmol/L PF-4 (▪; back), 100 nmol/L IL-8 (□), or left unstimulated (▪; front) in the presence of EC in a series of identically treated assay plates. After 20 minutes, individual assay plates were centrifuged at 1 of the relative shear forces indicated and the number of PMN remaining attached to the EC layer was determined. Data represent the mean of 3 independent experiments, each performed in duplicate. The SD varied between 5% and 17% for the values given.