Freeze-frames from in vivo microscopy video recordings obtained 60 min after microinjection of PAF (A), 60 min intrascrotal injection of PAF (B), and 60 min microinjection of PAF in combination with superfusion of the Rho kinase inhibitor Y27632 for 30 min (C; objective magnification 40×). A: directional locomotion of a leukocyte towards the attractant with protrusions of lamellipodia at the front and a trailing uropod after microinjection of PAF. B: polarized leukocyte during random migration in the interstitial tissue after intrascrotal injection of PAF. C: blocking effect of Rho kinase inhibitor Y27632 on leukocyte polarization induced by microinjection of PAF. D: leukocyte polarization was measured as cell eccentricity: long axis (shown in black line)/short axis (depicted as interrupted line). Quantitative data of cell eccentricity after microinjection of saline, MIP-1α, PAF, E. coli, intrascrotal injection of PAF, as well as after microinjection of PAF with superfusion of Y27632; mean±SEM; *p<0.05 vs. saline, # p<0.05 vs. Y27632; n = 15.