Platelet-endothelial cell interactions during I/R of the small intestine in vivo. Platelet-endothelial cell interactions were investigated in arterioles (A) and venules (B) using intravital fluorescence microscopy. Sham-operated animals served as controls. According to their interaction with the endothelial cell lining, platelets were classified into rolling or firmly adherent cells. Rolling platelets (upper panels) are presented as the number of cells per second and millimeters of vessel diameter; adherent platelets (lower panels) are given per square millimeter of vessel surface. Mean ± SEM, n = 6 experimental animals per group. *P < .01 versus sham, ^#P < .01 versus anti-CD62P MoAb, Dunn's method.