Ischemic preconditioning relieves the ischemia/reperfusion injury of neurons in hippocampus by inhibiting the expression of p53

AIM: To examine whether ischemic preconditioning (IPC) can protect against apoptosis in CA1 subfield of hippocampus following reperfusion of a lethal ischemia in rats and explore the role of IPC by inhibiting the expression of p53 in this process. METHODS: Wistar rats were used in the experiment. A global ischemia/reperfusion model was induced by 4-vessel occlusion. The rats were divided into the following three groups randomly: (1) ischemic preconditioning group (IPC group); (2) ischemia/reperfusion group (IR group); (3) control group. The histopathological changes, the percentage of apoptosis and the expression of p53 gene in CA1 region of rat hippocampus were examined by HE staining, FCM, RT-PCR and immunohistochemistry techniques. RESULTS: The neuronal density of CA1 region in IPC group [(217±9)/0.72 mm2] was significantly higher than that in IR group [(29±5)/0.72 mm2, P0.01]. The percentage of apoptotic neurons in IPC group (2.07%±0.21%) was lower than that in IR group (4.26%±0.08%), P0.01. Compared with IR group, the expression of p53 gene in IPC group was significantly weakened. CONCLUSION: Ischemic preconditioning protects the ischemic neurons in CA1 region of rat hippocampus by inhibiting the expression of p53 gene.