本文選題：缺血性腦卒中 + 缺血再灌注�。� 參考：《蘇州大學》2014年碩士論文

【摘要】：目的：迅速溶栓復流治療是缺血性腦卒中急性期治療成功的前提和基礎，但是該過程引起的氧化應激是導致腦組織二次傷害即缺血/再灌注(I/R)損傷的重要因素。而NADPH氧化酶，尤其是其中的Nox2和Nox4在I/R引起的氧化應激中發(fā)揮著重要作用。褪黑素是迄今為止最強的內源性自由基清除劑，且有文獻報道表明褪黑素可以抑制腦缺血再灌注引起的腦損傷，但是其作用機制尚不明確。我們擬利用本研究探討在缺血再灌注條件下，，褪黑素發(fā)揮腦保護作用的具體機制，明確褪黑素是否通過調節(jié)Nox2和Nox4發(fā)揮作用。 方法：利用30只雄性Sprague-Dawley (SD)大鼠，將其隨機分為三組：假手術組，缺血再灌注組，褪黑素預處理+缺血再灌注組。利用線栓法制備大鼠大腦中動脈栓塞(MCAO)模型（通過大鼠大腦中動脈栓塞后相應神經(jīng)功能障礙表現(xiàn)驗證模型制備成功）。 然后利用熒光分光光度計檢測腦組織ROS水平、TUNEL染色檢測腦組織細胞凋亡情況、Western blot檢測Nox2和Nox4蛋白水平、同時檢測TUNEL與Nox2、Nox4的免疫熒光共染的細胞數(shù)目。相應實驗數(shù)據(jù)結果應用SPSS18.0統(tǒng)計分析軟件，對數(shù)據(jù)進行統(tǒng)計學分析。 結果： 1）與假手術組相比，缺血再灌注組ROS水平顯著提高，尤其是在缺血半球尤為顯著，褪黑素預處理可以顯著抑制缺血再灌注引起的缺血半球以及對側半球中ROS水平的上升。 2）與假手術組相比，缺血再灌注組凋亡細胞顯著增多，尤其是在缺血半球尤為顯著；而褪黑素預處理可以顯著抑制缺血再灌注引起的缺血半球以及對側半球中細胞的凋亡。 3)與假手術組相比，缺血再灌注組Nox2和Nox4的蛋白水平顯著上升；而褪黑素預處理可以顯著抑制缺血再灌注引起的Nox2和Nox4的蛋白水平上升。提示：褪黑素可能通過降低Nox2和Nox4的表達，抑制ROS的產(chǎn)生，進而抑制細胞凋亡。 4）免疫熒光共染表明：TUNEL陽性細胞伴隨著Nox2或者Nox4的高表達；褪黑素預處理顯著降低了Nox2/TUNEL雙陽性細胞和Nox4/TUNEL雙陽性細胞的數(shù)目。 結論： 在腦缺血再灌注過程中，褪黑素可能通過抑制Nox2和Nox4的表達發(fā)揮抗氧化和抗凋亡的作用。
[Abstract]:Objective: rapid thrombolytic reflow therapy is the premise and foundation of successful treatment in acute phase of ischemic stroke, but oxidative stress induced by this process is an important factor leading to secondary injury of brain tissue, I. E. ischemia / reperfusion injury. NADPH oxidase, especially Nox2 and Nox4, plays an important role in I / R induced oxidative stress. Melatonin is the strongest endogenous free radical scavenger so far, and it has been reported that melatonin can inhibit brain injury induced by cerebral ischemia and reperfusion, but its mechanism is not clear. We intend to use this study to explore the specific mechanism of melatonin in cerebral protection under ischemia-reperfusion conditions, and to determine whether melatonin plays a role by regulating Nox2 and Nox4. Methods: thirty male Sprague-Dawley SD rats were randomly divided into three groups: sham operation group, ischemia reperfusion group and melatonin preconditioning ischemia reperfusion group. The MCAO model of middle cerebral artery embolization (MCAO) was established by the method of thread embolization. Then the Ros level of brain tissue was detected by fluorescence spectrophotometer and Tunel staining was used to detect the apoptosis of brain tissue. Western blot was used to detect the levels of Nox2 and Nox4 proteins, and the number of Tunel and Nox2Nox4 immunofluorescence co-stained cells were also detected. The corresponding experimental data were analyzed by SPSS 18.0 statistical analysis software. Results: 1) compared with sham operation group, Ros level in ischemia reperfusion group was significantly higher than that in sham operation group, especially in ischemic hemisphere. Melatonin pretreatment significantly inhibited the increase of Ros levels in the ischemic and contralateral hemispheres induced by ischemia and reperfusion. Melatonin preconditioning significantly inhibited apoptosis in ischemic and contralateral hemispheres induced by ischemia and reperfusion. 3) compared with sham operation group, melatonin preconditioning significantly inhibited apoptosis in ischemic and contralateral hemispheres. The protein levels of Nox2 and Nox4 increased significantly in ischemia-reperfusion group, while melatonin preconditioning significantly inhibited the protein levels of Nox2 and Nox4 induced by ischemia-reperfusion. These results suggest that melatonin inhibits the production of Ros by decreasing the expression of Nox2 and Nox4, and thus inhibits apoptosis. 4) Immunofluorescence co-staining indicates that the high expression of Nox2 or Nox4 is associated with the expression of Nox2 or Nox4 in the cells with positive cells. Melatonin pretreatment significantly decreased the number of Nox2 / Tunel double positive cells and Nox4 / Tunel double positive cells. Conclusion: melatonin may inhibit the expression of Nox2 and Nox4 during cerebral ischemia-reperfusion.
【學位授予單位】：蘇州大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：R743.31

【參考文獻】

相關期刊論文 前1條

1 王威;唐圣松;;吞噬細胞NADPH氧化酶活性的調控[J];國際病理科學與臨床雜志;2009年04期

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