EFFECTS OF CD11B 18 MONOCLONAL-ANTIBODY ON RATS WITH PERMANENT MIDDLECEREBRAL-ARTERY OCCLUSION/

The progression of a lesion front ischemic injury to infarct, after th e permanent occlusion of a middle cerebral artery, may be influenced b y the influx of leukocytes into the ischemic territory. We aimed to ev aluate the effectiveness of treating rats that hadpemtanent middle cer ebral artery occlusion with a single dose of an anti-CD11b/l8 monoclon al antibody injected 1 hour after the arterial occlusion. To mimic the clinical situation of patients with ischemic strokes who may be treat ed within 1 hour of the ischemic event, the artery remained occluded. Forty-one adult Wistar rats had permanent middle cerebral artery occlu sion, and one was subjected to a sham operation. One hour later, 22 ra ts received CD11b/18 monoclonal antibody and an additional 20 were inj ected either with a nonspecific antibody (n = 10) or a buffer solution (n = 10). Experiments were terminated at intervals ranging 12 to 96 h ours after the arterial occlusion. Endpoints included neurological tes ting, daily evaluation of body weight, counts of white blood cells in the peripheral blood, measurement of the area of pallor in the ischemi c hemisphere, counts of necrotic neurons, and counts of leukocytes seq uestered in the ischemic hemisphere. In experiments terminated 12 hour s after the arterial occlusion (n = 4), there were fewer necrotic neur ons in the group treated with the CD11b/18 monoclonal antibody compare d with the two controls (P <.05), but this difference was not reflecte d in the neurological scores. Numbers of necrotic neurons in experimen ts terminated >12 hours later were not different among the three subgr oups. White blood cell counts in peripheral blood were lower in animal s with arterial occlusion injected with the monoclonal antibody CD11b/ 18 (P <.05); numbers of leukocytes sequestered in the ischemic hemisph ere were not different in the three groups. Neither changes in body we ight nor in the volume of the area of pallor were significantly differ ent among the three groups.