Fig. 3. Effects of granulocyte colony-stimulating factor (G-CSF) stem cell factor (SCF) treatment on adhesion molecule expression and on chemotaxis. (A ) Using flow cytometry, circulating polymorphonuclear cells (PMN) were identified by size and granularity (sideward scatter [SSC]vs. forward scatter [FSC]; left, black lined gate ) and were analyzed for adhesion molecule expression (right , isotype-matched control antibody [mouse immunoglobulin (Ig) G2a, black area ], adhesion molecule antibody in control rats [thick black line ] and in rats treated with G-CSF+SCF [dashed line ], and fluorescein isothiocyanate (FITC)–conjugated antibodies were used). (B ) PMN of control animals (solvent; black bar ) expressed significantly more CD62L and less CD49d than PMN of animals treated with G-CSF+SCF (white bar ; determined as geometric mean fluorescence intensity [MFI]; *P < 0.05 and ***P < 0.001, respectively, n = 5). CD18 expression was unaffected by this treatment (P > 0.05 [not significant], all t test). (C ) In vitro migration of PMN toward the chemokine macrophage inflammatory protein-2 (MIP-2) was measured in a Boyden chamber in control rats and rats treated with G-CSF+SCF (black and white bars , respectively, n = 5). A migration index relative to baseline migration was calculated. Dose-dependent migration was observed in both sets of animals at low MIP-2 concentrations, but animals treated with G-CSF–SCF had significantly less PMN migration at high MIP-2 concentrations (*P < 0.05, two-way analysis of variance).