Anti-CD11b monoclonal antibody reduces ischemic cell damage after transient focal cerebral ischemia in rat

We investigated the effect of an anti‐CD11b monoclonal antibody (1B6c) on ischemic cell damage after transient middle cerebral artery occlusion. We divided animals into three groups: MAb 1 group (n = 5)—rats were subjected to 2 hours of transient occlusion and 1B6c (1 mg/kg) was administered intravenously at 0 and 22 hours of reperfusion; MAb 2 group (n = 5)—same experimental protocol as MAb 1 group, except that the initial dose of 1B6c was increased to 2 mg/kg; and control group (n = 5)—same experimental protocol as MAb 2 group, except that an isotype‐matched control antibody was administered. Animals were weighed and tested for neurological function before and after occlusion of the middle cerebral artery. Forty‐six hours after reperfusion, brain sections were stained with hematoxylin and eosin for histology evaluation. We observed a significant reduction of weight loss and improvement in neurological function after ischemia in the MAb 2 animals compared to MAb 1 and vehicle‐treated animals (p < 0.05). The lesion volume was significantly smaller in the MAb 2 group (19.5 ± 1.9%) compared to MAb1 (29.9 ± 2.6%) and vehicletreated (34.2 ± 5.4%) group (p < 0.01). Tissue polymorphonuclear cell numbers were reduced in both 1B6c‐administered groups. Our data demonstrate that administration of anti‐CD11b antibody results in a dose‐dependent, significant functional improvement and reduction of ischemic cell damage after transient focal cerebral ischemia in the rat.