The Effect of Temporary Middle Cerebral Artery Occlusion on Reduction of Brain Injuries in Rat Stroke Model

Recent studies suggest that sub-lethal ischemia protect the brain from subsequent ischemic injuries. This study was an effort to identify and shed light on the nature of changes in the blood brain barrier permeability and brain edema. Rats were divided into four main experimental groups, each of 21 animals. The first group acted as a model of ischemic preconditioning which was subjected to 10 minutes of temporary middle cerebral artery occlusion in the first day (tMCAO) and in the second day, was subjected to 60 min middle cerebral artery occlusion (MCAO). The second group acted as a control group and did not receive any surgery except 60 min middle cerebral artery occlusion in the second day. The third group served as a sham group, and was subjected to surgery with 10 min of temporary middle cerebral artery occlusion (tMCAO) in the first day. The fourth group remained intact and was not subjected to any surgery. Each main group subdivided into three subgroups (n=7) for infarct volume (n=21), blood brain barrier permeability, and brain edema. After 24 hours, each main group was subjected to 60min of right MCAO occlusion. Then, neurologic deficit score (NDS), infarct volume, blood brain barrier permeability, and brain edema were assessed in the subgroups. Preconditioning with tMCAO decreased NDS and infarct volume, brain barrier permeability, and brain edema. Temporary middle cerebral artery occlusion (tMCAO) is associated with neurologic deficit scores, infarct, blood brain barrier permeability, and brain edema consistent with an active role in the genesis of ischemic protection.