论文部分内容阅读
目的观察p-Akt、p53在小鼠局灶性脑缺血再灌注(I/R)及缺血后处理(IPO)后在脑皮质区的表达规律,探讨p-Akt、p53与IPO保护作用的关系。方法采用线栓法制备大脑中动脉栓塞的局灶性脑缺血模型,将272只小鼠随机分为假手术(Sham)组、缺血再灌(I/R)组、PI-3K/Akt抑制剂LY294002(LY)组和缺血后处理(IPO)组。I/R组、LY组与IPO组均实施缺血90min之后再灌注,IPO组在持续再灌前采取再灌15s、缺血15s、再灌15s的循环,共3个循环。于再灌后30min、1h、3h、6h、24h、48h分别取材,2,3,5-氯化三苯基四氮唑(TTC)染色法测定脑梗死体积;免疫组织化学法观察p-Akt,p53蛋白的表达及分布;免疫印迹法检测皮质区p-Akt和p53蛋白表达量。结果 Sham组、I/R组和IPO组的非缺血脑半球皮质p-Akt有微量表达。与Sham组相比,I/R组再灌后30min缺血区皮质p-Akt增加,1h达高峰,6h逐渐降低,24h降至Sham组水平并持续;p53再灌后6h增加,24h达高峰,48h回落。各相应时间点IPO组较I/R组p-Akt增高(P<0.05),p53降低(P<0.05)。LY组p-Akt低于I/R组(P<0.05),p53高于I/R组(P<0.05)。顶叶脑组织的免疫印迹分析结果与免疫组织化学结果规律一致。结论缺血后处理对缺血再灌注性脑损伤有保护作用,其机制与降低p53表达及增强p-Akt表达有关。
Objective To observe the expression of p-Akt and p53 in cerebral cortex after focal cerebral ischemia-reperfusion (I / R) and post-ischemic postconditioning (IPO) in mice and to explore the protective effect of p-Akt, p53 and IPO Relationship. Methods Focal cerebral ischemia model of middle cerebral artery occlusion was established by thread occlusion. 272 mice were randomly divided into sham group, I / R group, PI-3K / Akt Inhibitor LY294002 (LY) group and the ischemic postconditioning (IPO) group. The I / R group, LY group and IPO group were both reperfused after 90min of ischemia, and the IPO group was given 15s of reperfusion, 15s of ischemia and 15s of reperfusion before continuous reperfusion for 3 cycles. The volume of cerebral infarction was determined by TTC staining with 2,3,5,5-triphenyltetrazolium chloride (TTC) at 30min, 1h, 3h, 6h, 24h and 48h after reperfusion. The expression of p-Akt , p53 protein expression and distribution; Western blotting detection of cortex p-Akt and p53 protein expression. Results There was a slight expression of p-Akt in non-ischemic cerebral hemisphere cortex in Sham group, I / R group and IPO group. Compared with Sham group, p-Akt in ischemic cortex of I / R group increased 30min after reperfusion, peaked at 1h, decreased gradually at 6h, decreased to Sham group at 24h and increased at 6h after reperfusion , 48h down. The IPO group had higher p-Akt (P <0.05) and lower p53 (P <0.05) than the I / R group at each time point. The level of p-Akt in LY group was lower than that in I / R group (P <0.05), but higher than that in I / R group (P <0.05). Immunoblot analysis of parietal lobe brain tissue was consistent with immunohistochemical results. Conclusion Ischemic postconditioning has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism is related to the decrease of p53 expression and the increase of p-Akt expression.