可卡因—苯丙胺调节转录肽抗氧化减轻缺血性脑损伤的机制探讨

发布时间：2018-02-26 19:15

  本文关键词： 可卡因-苯丙胺调节转录肽 缺血性脑损伤 氧化应激 线粒体　出处：《南京医科大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的：探讨可卡因-苯丙胺调节转录肽(cocaine-and amphetamine-regulated transcript peptides, CART)抗氧化减轻缺血性脑损伤及其机制。 方法：健康雄性ICR小鼠随机分为四组：缺血／再灌注(Ischemia/Reperfusion,I/R)组、CART组、生理盐水(Normal Saline, NS)组、假手术组。插线法建立大脑中动脉闭塞(middle cerebral artery occlusion, MCAO)模型,CART组和NS组于缺血2小时再灌注前分别经尾静脉注射给予CART55-102和同体积NS,然后每隔24小时重复给药1次。再灌注不同时间点分别以TTC染色检测脑梗死体积,干／湿法测定脑组织含水率,酶联免疫吸附法检测梗死侧大脑皮质4-羟壬烯醛(HNE)、8-羟基-2’-脱氧鸟苷(8-OHdG)及3-硝基酪氨酸(3-NT)含量；采用流式细胞技术检测梗死侧大脑皮质氧自由基(ROS)含量和线粒体膜电位；采用比色法检测线粒体呼吸链复合物Ⅰ、Ⅱ、Ⅲ活性；实时聚合酶链式反应(RT-PCR)测定梗死侧大脑皮质线粒体DNA (mitochondrial DNA, mtDNA) mRNA表达。 结果：(1)与I/R组和NS组比较,CART组再灌注后各时间点脑梗死体积均不同程度减小,再灌注24h、48h、72h其差异均有统计学意义(均P0.05)。(2)与I/R组和NS组比较,CART在再灌注后各时间点(12h、24h、48h、72h)均可降低脑组织含水率(均P0.05)。(3)与I/R组和NS组比较,CART组在各时间点脑组织中的HNE、8-OHdG、3-NT含量均被下调：HNE在各时间点差异均有统计学意义(均P0.01),8-OHdG仅在12h差异有统计学意义(P0.05),3-NT在24h、48h及72h时间点差异有统计学意义(均P0.05)。(4)与I/R组和NS组比较,CART显著下调缺血脑组织ROS含量(P0.05)。(5)与I/R组和NS组比较,CART显著上调缺血脑组织线粒体膜电位(P0.01)、线粒体呼吸链复合物Ⅱ活性(P0.05)和mtDNA mRNA表达(P0.05)；线粒体呼吸链复合物Ⅰ、Ⅲ活性未被上调(P0.05)。 结论：CART抗氧化减轻缺血性脑损伤,其机制可能是通过稳定线粒体膜电位、上调线粒体呼吸链复合物Ⅱ活性和mtDNA表达发挥抑制氧化作用。
[Abstract]:Aim: to investigate the antioxidation effect of cocaine-amphetamine-regulated transcription peptide cocaine-and amphetamine-regulated transcript peptides (cart) on ischemic brain injury and its mechanism. Methods: healthy male ICR mice were randomly divided into four groups: ischemic / reperfusion Ischemia / reperfusion I / R group and normal Saline (NSN) group. The middle cerebral artery occlusion (MCAO) model of middle cerebral artery occlusion (MCAO) was established in sham-operation group. Before ischemia 2 hours after reperfusion, CART55-102 and NSN of the same volume were injected into the caudal vein, respectively, in the cart group and NS group, and then repeated every 24 hours. Cerebral infarction volume was measured by TTC staining at different time points of perfusion. The water content of brain tissue was measured by dry / wet method, and the contents of 8-OHdG and 3-nitrotyrosine were detected by enzyme-linked immunosorbent assay (Elisa) in the cerebral cortex of the infarcted side. The contents of 8-OHdG) and 3-nitrotyrosine were detected by enzyme-linked immunosorbent assay. The contents of oxygen free radical and mitochondrial membrane potential in cerebral cortex of infarct side were detected by flow cytometry, and the activities of respiratory chain complex 鈪，

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