Figure 7.

Direct effect of PAF on PSGL-1-mediated rolling in vivo. Velocity of the rolling leukocytes was analyzed in vivo as they passed through the transparent P-selectin-coated, chamber. Blood is pumped by the mouse heart through a biocompatible tube from the carotid artery to the chamber and then to the jugular vein on the opposite side. Ports in the tube provide a site for blood pressure monitoring and control as well as one for injecting experimental agents. A) Schematic of the experimental design illustrating the study of the immediate effect of PAF on rolling leukocytes, originally introduced by Hafezi-Moghadam et al. (17). B) Successive in vivo images of a rolling leukocyte on immobilized P-selectin before (top panel) and one after PAF infusion (0.6 μg in 100 μl saline; bottom panel). C) Cumulative histogram of the velocity of rolling leukocytes on immobilized P-selectin without, and 10 min after, PAF infusion. D) Representative micrographs of activated leukocytes (arrows) bound to P-selectin 10 min after PBS control or PAF infusion.