RESUMO
Background: Stroke is the most important reason of cerebral ischemia and following reperfusion lead to programmed cell death. Harm to hippocampus causes major disruption in the performance of active memory tests. So in this study, we investigated the effect of losartan [angiotensin antagonists II] on spatial memory deficits and neuronal damage caused by ischemia /reperfusion in rats
Materials and methods: In this experimental study, animals were divided into 4 groups as follow: control, ischemia, experimental and vehicle. 20 minutes before ischemia, 5mg/kg losartan was injected to animals in experimental group. Ischemia was done by both common carotid occlusion for 20 minutes followed by reperfusion. After a week, rats were tested by Morris water maze and histological changes of CA1 pyramidal cells were studied by Nissl and Tunnel staining
Results: Results of Morris water maze showed significant difference between control and ischemia groups, while this difference was not significant between control and experimental groups. There was significant difference in the number of viable pyramidal neurons and apoptotic cells in CA1 region of hippocampus between control and experimental groups compared with vehicle and ischemia groups
Conclusion: 5mg/kg losartan improves pyramidal cells and histological changes of CA1 region caused by ischemia/ reperfusion and can prevent apoptosis, but this dose cannot reduce behavioral disorders caused by cerebral ischemia