Cilostazol inhibits leukocyte-endothelial cell interactions in murine microvessels after transient bilateral common carotid artery occlusion.

Leukocyte behavior in the cerebral microvasculature following vessel occlusion has not been fully elucidated. The purpose of this study was to investigate the effects of cilostazol on leukocyte behavior (rolling and adhesion) in murine cerebral microvessels following transient bilateral carotid artery occlusion using intravital fluorescence microscopy. Four groups of mice were assigned: a sham group (n=16); an ischemia (induced by 15-min occlusion of bilateral common carotid arteries) and reperfusion (I/R) group (n=13); I/R+cilostazol (I/R+CZ3 mg/kg) group (I/R after oral administration of cilostazol at 3 mg/kg) (n=8); and I/R+cilostazol (I/R+CZ30 mg/kg) group (I/R after oral administration of cilostazol at 30 mg/kg) (n=12). Leukocytes labeled with 0.05% acridine orange were administered intravenously and their behavior was investigated at 3 and 6 h after reperfusion. Numbers of rolling or adherent leukocytes were expressed as the count per square millimeter per 30s. Numbers of rolling and adherent leukocytes at 3 and 6h after reperfusion were significantly higher in the I/R group than in the sham or I/R+CZ30 mg/kg groups in both pial veins (P<0.05) and pial arteries (P<0.05). Cilostazol (30 mg/kg) inhibited leukocyte-endothelial interactions following cerebral ischemia and reperfusion.