Anti–Intercellular Adhesion Molecule–1 Antibody Reduces Ischemic Cell Damage After Transient But Not Permanent Middle Cerebral Artery Occlusion in the Wistar Rat

BACKGROUND AND PURPOSE: Postischemic cerebral inflammation may contribute to ischemic cell damage. Intercellular adhesion molecule-1 (ICAM-1) is a glycoprotein expressed on endothelial cells that facilitates leukocyte adhesion. We investigated the effect of administration of an anti-ICAM-1 antibody (1A29) on ischemic cell damage after transient (2-hour) or permanent middle cerebral artery (MCA) occlusion in the Wistar rat. METHODS: Groups studied were as follows: (1) transient MCA occlusion: rats were subjected to 2 hours of MCA occlusion, and after 1 hour of reperfusion they were treated with 1A29 (n = 11) or an isotype control antibody (n = 9); and (2) permanent MCA occlusion: rats were treated with 1A29 (n = 9) or an isotype control antibody (n = 7) 2 hours after onset of MCA occlusion. All animals were killed 1 week after onset of ischemia. Brain sections were stained with hematoxylin and eosin for histological evaluation. RESULTS: Significant reductions (P < .05) in both volume (44%) of the ischemic lesion and weight loss were found in animals subjected to transient MCA occlusion and treated with 1A29 compared with vehicle-treated animals. In contrast, in animals subjected to permanent MCA occlusion the lesion and the temporal profile of body weight were not altered by 1A29 administration. CONCLUSIONS: Ischemic cell damage is promoted by postischemic inflammatory response after 2 hours of transient MCA occlusion, and ischemic cell damage is reduced by administration of an anti-ICAM-1 antibody during reperfusion.