远隔缺血后适应对大鼠脑缺血的保护作用

发布时间：2019-04-25 07:52

【摘要】：目的制备稳定的大鼠大脑中动脉阻塞（MCAO）线栓模型，初步探讨无创性肢体缺血后适应（RPC）对大鼠急性期脑缺血损伤是否具有保护作用，并从凋亡及炎症两方面初步探讨其机制。方法90只健康雄性SD大鼠（体重260g~280g），随机分为5组：1假手术组（Sham组）：单纯暴露血管，不行插线缺血操作、不进行无创性肢体缺血后适应干预。2缺血2h再灌注组（I/R组）：大鼠MCAO2h再灌注24h，不给予无创性RPC，不阻断双侧后肢股动脉血流。3缺血原位后适应组（IP组）：在大鼠MCAO2h再灌注开始的同时将鱼线拔出5mm，恢复脑血流20s，再插线放进5mm，阻塞血流20s，循环3次，再灌注24h。4缺血即刻后适应组（I-RPC组）：在大鼠MCAO制备过程中线栓成功阻塞大鼠MCA的同时给予无创性RPC，缺血2h以后再灌注24h。5再灌注即刻后适应组（R-RPC组）：大鼠MCAO2h后于拔出线栓的同时立即给予无创性RPC。无创性RPC的方法是：用止血带结扎大鼠双侧后肢根部阻断双侧股动脉血流，以不能触及股动脉搏动为缺血成功标志，止血带结扎10min，放开10min，如此循环3次。各组大鼠分别于再灌注24h行神经功能评分，评分结束后处死大鼠，采用干湿称重法测脑含水量、TTC染色计算脑梗死体积、HE染色光镜观察形态学、TUNEL法测凋亡细胞、免疫组化方法检测超敏C反应蛋白（Hs-CRP）水平。结果1线栓法成功建立大鼠MCAO缺血再灌注模型；2与I/R组相比，IP组、I-RPC组、R-RPC组大鼠神经功能评分有所改善（P0.05），海马区凋亡神经元数目减少（P0.05），脑水肿程度减轻（P0.05），缺血侧脑梗死体积减少（P0.05），海马区神经元病理改变程度改善（P0.05），海马区Hs-CRP表达水平降低（P0.05）；但IP组、I-RPC组、R-RPC组3组之间两两比较无统计学意义（P0.05）。结论本研究通过建立了稳定的大鼠大脑中动脉线栓模型，，证实无创性远隔肢体缺血后适应对大鼠急性脑缺血具有神经保护作用，其机制可能是通过降低海马区神经元凋亡程度及抑制炎症反应（Hs-CRP的表达）来实现的。
[Abstract]:Objective to establish a stable model of middle cerebral artery occlusion (MCAO) with (MCAO) thread embolus in rats and to explore the protective effect of adaptive (RPC) after noninvasive limb ischemia on acute cerebral ischemia injury in rats. The mechanism of apoptosis and inflammation were also discussed. Methods 90 healthy male SD rats (weight 260g~280g) were randomly divided into 5 groups: 1sham operation group (Sham group): exposure of blood vessels only, but no ischemia operation by inserting thread, the rats were divided into 5 groups at random: 1 sham operation group (Sham group); (2) ischemia 2 h reperfusion group (I R group): MCAO2h reperfusion for 24 h, no noninvasive RPC, was given to rats. The blood flow of femoral artery in both hind limbs was not blocked. 3After ischemia in situ group (IP group): at the beginning of reperfusion of MCAO2h in rats, the fish line was pulled out 5 mm, the cerebral blood flow was restored to 20 s, then inserted into 5 mm, the occluded blood flow was 20 s, circulation was 3 times. Reperfused 24h.4 immediately after ischemia group (I-RPC group): non-invasive RPC, was administered simultaneously with successful occlusion of rat MCA during the preparation of MCAO in rats. Group R-RPC: rats were treated with non-invasive RPC. immediately after reperfusion of 24h.5 after 2 hours of ischemia (R-RPC group). After MCAO2h was removed, non-invasive RPC. was given immediately at the same time as the wire thrombus was pulled out. The method of non-invasive RPC was to block the blood flow of bilateral femoral artery by ligating the root of bilateral hind limbs of rats with tourniquet, which could not touch the pulsatile of femoral artery as a successful sign of ischemia. The tourniquet was ligated for 10 minutes and released for 10 minutes, so that the circulation was three times. After 24 hours of reperfusion, the rats in each group were sacrificed. The brain water content was measured by dry-wet weighing method, the infarct volume was calculated by TTC staining, the morphology was observed by HE staining, and the apoptotic cells were measured by TUNEL method. The level of hypersensitive C-reactive protein (Hs-CRP) was detected by immunohistochemistry. Results 1the ischemia-reperfusion model of MCAO was successfully established by thread embolus method in rats. 2Compared with I / R group, IP group, I-RPC group and R-RPC group improved the scores of neural function (P0.05), decreased the number of apoptotic neurons in hippocampus (P0.05), and reduced the degree of brain edema (P0.05). The infarct volume of ischemic side was decreased (P0.05), the degree of neuronal pathological changes in hippocampus was improved (P0.05), and the expression of Hs-CRP in hippocampus was decreased (P0.05). But there was no significant difference among IP group, I-RPC group and R-RPC group (P0.05). Conclusion in this study, we established a stable model of middle cerebral artery occlusion in rats, and confirmed the neuroprotective effect of adaptation after non-invasive distal limb ischemia on acute cerebral ischemia in rats. The mechanism may be achieved by decreasing the degree of apoptosis and inhibiting the expression of Hs-CRP in hippocampal neurons.
【学位授予单位】：河北联合大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R743.3

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