快速和延迟性远程缺血后处理对大鼠脑缺血保护作用研究

发布时间：2018-08-13 13:33

【摘要】：目的：近年来研究发现，缺血后处理（Ischemia postconditioning,IP）可以通过激活多种内源性途径对脑缺血发挥神经保护作用,减少大鼠脑缺血/再灌注（Ischemia/Reperfusion,I/R）损伤。而快速和延迟性远程缺血后处理（Remote ischemic postconditioning, RIP）的研究甚少。本课题研究目的是通过线栓法制备稳定的大鼠大脑中动脉阻塞（Middle cerebralartery occlusion, MCAO）模型，探讨快速和延迟性远程缺血后处理对大鼠局部脑缺血保护作用。方法：首先，建立稳定的大鼠大脑中动脉阻塞(MCAO）线栓模型，将32只健康雄性大鼠(Sprague Dawlay/SD，280-300g)随机分为4组:⑴假手术组（Sham,n=8）：大鼠行MCAO模型手术，离断颈外动脉后进栓，，并且立即拔除线栓，再灌注48小时;(2)照组（Control,n=8）：大鼠大脑中动脉阻塞90分钟，拔除栓线再灌注48小时;(3)R-RIP组（MCAO模型-快速性远程缺血后处理组,n=8）：大鼠大脑中动脉阻塞90分钟,拔除栓线再灌注后即刻给予远程缺血训练。(4)D-RIP组（MCAO模型-延迟性远程缺血后处理组,n=8）：大鼠大脑中动脉阻塞90分钟,拔除栓线再灌注后6小时给予远程缺血训练。远程缺血训练即钝性分离双侧股动脉，再灌注即刻或再灌注后6小时，用蛙心夹依次夹闭/放开10分钟，如此进行3个循环。分别在大脑中动脉闭塞后1小时、再灌注后12小时、24小时及48小时进行神经功能评分，再灌注48小时处死大鼠，脑组织制成蜡块并用HE染色测定脑梗塞体积。结果：⑴HE染色脑梗塞体积分析表明，相对于对照组，R-RIP和D-RIP组大鼠脑梗死体积明显减少，有统计学意义（P 0.05）；且R-RIP组较D-RIP组大鼠脑梗死体积也明显减少，有统计学意义（P0.05）。⑵各组大鼠大脑中动脉闭塞后1小时、再灌注后12小时、24小时及48小时进行神经功能评分结果显示，相对于对照组，R-RIP和D-RIP组神经功能评分明显增加，具有统计学意义（P0.05）。远程缺血后处理组在大鼠大脑中动脉闭塞后1小时、再灌注后12小时及24小时D-RIP组较R-RIP组神经功能评分有减少趋势，但无统计学差异（P0.05）；而再灌注后48小时D-RIP较R-RIP组的神经功能评分明显减少，有统计学意义（P0.05）。结论：本实验研究表明快速和延迟性远程缺血后处理均可以减少大鼠脑缺血梗死体积，改善神经功能评分，具有脑神经保护作用；且快速性远程缺血后处理更明显减少大鼠脑梗死体积而延迟性远程缺血后处理，尤其再灌注后48小时可以改善神经功能评分。
[Abstract]:Objective: in recent years, it has been found that Ischemia postconditioning IP can play a neuroprotective role in cerebral ischemia by activating a variety of endogenous pathways and reduce the injury of cerebral ischemia / reperfusion (I / R) in rats. However, there is little research on rapid and delayed long-distance ischemic (Remote ischemic postconditioning, RIP). The purpose of this study was to establish a stable (Middle cerebralartery occlusion, MCAO) model of middle cerebral artery occlusion (MCAO) in rats by the method of thread occlusion, and to investigate the protective effect of rapid and delayed remote ischemic postprocessing on local cerebral ischemia in rats. Methods: first of all, a stable middle cerebral artery occlusion model of (MCAO) was established in rats. Thirty-two healthy male rats (Sprague Dawlay / SD 280-300g) were randomly divided into 4 groups: sham 1 sham-operated group (Shamma nunnion 8): rats underwent MCAO model operation, and were removed from the external carotid artery. The middle cerebral artery (MCA) was occluded for 90 minutes, and the thrombus was removed for 48 hours. (3) R-RIP group (MCAO model-rapid remote ischemic postprocessing group): middle cerebral artery occlusion in rats for 90 minutes. (4) D-RIP group (MCAO model-delayed remote ischemic post-treatment group): middle cerebral artery occlusion was performed for 90 minutes in rats, and long distance ischemia training was given 6 hours after the removal of thrombus thread after reperfusion. The bilateral femoral arteries were obtuse separated by remote ischemic training. Immediately after reperfusion or 6 hours after reperfusion, the frog's heart clamp was used to clamp / release for 10 minutes in turn, and three circulations were carried out in this way. The neurological function was assessed at 1 hour after middle cerebral artery occlusion, 24 hours after reperfusion and 48 hours after reperfusion. The rats were killed at 48 hours after reperfusion, and the cerebral infarction volume was measured by HE staining. Results compared with the control group, the infarct volume of the rats in the R-RIP and D-RIP groups was significantly decreased (P 0.05), and the infarct volume in the R-RIP group was significantly lower than that in the D-RIP group (P 0.05), and the cerebral infarction volume in the R-RIP group was significantly lower than that in the D-RIP group (P < 0.05). There was statistical significance (P0.05). 2 the neurological function scores were significantly increased in the middle cerebral artery occlusion group 1 hour after reperfusion 12 hours after reperfusion 24 hours and 48 hours after reperfusion compared with the control group R-RIP and D-RIP group. There was statistical significance (P0.05). Compared with R-RIP group, the scores of nerve function in the remote ischemic post-treatment group decreased at 1 hour after middle cerebral artery occlusion, 12 hours and 24 hours after reperfusion, but there was no statistical difference (P0.05). 48 hours after reperfusion, the neurological function score of D-RIP group was significantly lower than that of R-RIP group (P0.05). Conclusion: this experimental study shows that both rapid and delayed remote ischemic postprocessing can reduce the volume of cerebral ischemia infarction, improve the neurological function score, and have neuroprotective effect. Rapid remote ischemic postprocessing significantly reduced the volume of cerebral infarction in rats, but delayed remote ischemic postprocessing, especially 48 hours after reperfusion, which could improve the neurological function score.
【学位授予单位】：桂林医学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R743.32


本文编号：2181147