Platelet adhesion in response to I/R of the small intestine in vivo (ischemia time, 90 minutes). Platelet-endothelial cell interactions were investigated in arterioles (A) and venules (B) using IVM. Platelet adhesion was assessed following I/R, after pretreatment with an antibody directed to fibrinogen (-Fbg), or with control antibody (Ctrl-Ab), as well as in ICAM-1–deficient mice (CD54−/−), or after infusion of GRGDSP peptide (RGD), respectively. Sham-operated animals (Sham) served as controls. The number of adherent platelets is given per mm² vessel surface. Mean ± SEM, n = 6 experimental animals per group. *P < .01 vsham, Dunn’s method.