Reduction of edema and infarction by memantine and MK-801 after focal cerebral ischaemia and reperfusion in rat

N-methyl-D-aspartate (NMDA) receptor antagonists have been found to be prot ective after cerebral ischemia. However most of these drugs have limited va lue as neuroprotectives in clinical therapy because of their side effects. Memantine is a noncompetitive NMDA receptor antagonist and it has been used for the treatment of various cerebral disorders with relatively few side e ffects. We investigated the beneficial effects of Memantine and compared it s effect with MK-801 in a temporary focal cerebral ischemia model. As cerebral ischemia model three hours middle cerebral artery occlusion (MC AO) with intraluminal thread and three hours reperfusion was used. 78 male Sprague-Dawley rats were divided into three groups as follows: Control (Sal ine), treatment 1 (MK-801), and treatment 2 (Memantine) groups. In the trea ted groups, 15 minutes after MCAO, MK-801 and Memantine were administered i n amounts of 1 mg/kg and 10 mg/kg intraperitoneally respectively. After a 3 hour period of reperfusion, the animals were examined for neurological def icits and then killed. The following values were measured; cerebral water c ontent, blood brain barrier (BBB) permeability at the core and periphery of the ischemic hemisphere and contralateral hemisphere and infarct volumes. The severity of neurological deficit (p < 0.001) and infarct volume (p < 0. 001) was reduced in both Memantine and MK-801 treated groups compared with saline treated groups. Memantine attenuated brain edema formation and BBB p ermeability at the periphery (p < 0.01), MK-801 both at the core (p < 0.05) and the periphery (p < 0.01) of the ischemia. These results demonstrated that the NMDA receptor antagonists Memantine and MK-801 were neuroprotective when given 15 min after MCAO in temporary foca l cerebral ischemia.