阿魏酸钠对慢性脑缺血大鼠的神经保护作用机制研究

Experimental study of the sodium ferulate in chronic cerebral ischemic rats

目的探讨阿魏酸钠对慢性脑缺血大鼠的神经保护作用及其机制。方法以双侧颈总动脉结扎(2-VO)法制备慢性脑缺血模型,于术后6周分别给予阿魏酸钠和PBS干预,分为阿魏酸钠干预组和模型对照组。另设假手术组(仅分离双侧颈总动脉,但不结扎)作为空白对照。术后8周行Morris水迷宫实验,评价大鼠的空间学习记忆功能,同时观察双侧颞叶内侧缺血区脑组织血管密度、激光共聚焦法检测毛细血管内径、缺血边界地区的毛细血管分支点数目和微血管总面积等指标、海马细胞增殖情况(免疫组化法)和血浆血管内皮生长因子(VEGF)水平(ELISA法检测),以探讨其可能的机制。结果 Morris水迷宫结果显示,阿魏酸钠干预组第2、3、4、5天逃避潜伏期[分别为(43.55±6.34)s、(38.11±1.20)s、(34.75±5.30)s、(24.39±3.93)s]明显短于模型对照组[分别为(50.89±6.31)s、(43.72±8.21)s、(50.79±9.36)s、(44.39±3.93)s,均P<0.01];阿魏酸钠干预组第一象限游泳时间明显长于模型对照组[分别为(27.36±3.89)s、(14.68±2.36)s,P=0.002]。阿魏酸钠干预组毛细血管内径与模型对照组比较变短[分别为(3.02±0.21)μm、(3.35±0.18)μm,P=0.003],阿魏酸钠干预组缺血边界地区的毛细血管分支点数目与模型对照组同源组织区比较显著增加(分别为205.80±12.70、158.42±10.92,P=0.001),0.002mm3体积内阿魏酸钠干预组微血管总面积与模型对照组比较明显增加[分别(83389±4026)μm2、(73349±3986)μm2,P=0.004]。阿魏酸钠干预组缺血脑组织内的BrdU阳性细胞数明显高于模型对照组(分别为23.82±3.05、10.26±2.89,t=18.26,P=0.004)。阿魏酸钠干预组VEGF水平明显高于模型对照组[分别为(67.58±9.61)pg/mL、(21.90±5.16)pg/mL,P=0.008]。结论阿魏酸钠可以显著改善慢性脑缺血大鼠的空间学习记忆能力,其机制可能与VEGF介导的血管密度增加有关。

Objective To explore the effect of Sodium ferulate on chronic cerebral ischemia in rats,and its possible mechanism.Methods Chronic cerebral ischemia（2-VO）model were prepared and given Sodium ferulate or PBS after 6 weeks.8 weeks after the operation,Morris water maze were carried out to evaluate the learning and memory ability of the rats.The cell proliferation,diameter of capillaries,the number of capillary branches,the total area of capillaries,cell morphological changes in ischemic area,and the plasma vascular endothelial growth factor（VEGF）were detected to explore the possible mechanisms.Results Morris water maze test showed that the escape latency in the sodium ferulate group（for the 2^ nd to the 5^ th day of the Morris water maze test were：（43.55±6.34）s,（38.11±1.20）s,（34.75±5.30）s,（24.39±3.93）s respectively,which were significantly shorter than the control group [（50.89±6.31）s,（43.72±8.21）s,（50.79±9.36）s,（44.39±3.93）s respectively],F value were10.277,23.530,38.312,35.045,respectively,P value were0.007,0.004,0.005,0.002,respectively.The first quadrant swimming time in the experimental group was significantly longer than the control group [（27.36 ± 3.89）s,（14.68±2.36）s,P =0.002].Cerebrovascular confocal detection results showed that：the sodium ferulate group had a shorter diameter of capillaries than the control group [（3.02±0.21）μm,（3.35±0.18）μm,P=0.003].In the ischemic border regions,the number of capillary branches in the sodium ferulate group（205.80±12.70）was significantly increased than the control group（158.42±10.92,P=0.001）,the sodium ferulate group had significantly increased total area of capillaries compared with the control group[（83389±4026）μm^2/0.002 mm^3,（73349±3986）μm^2/0.002 mm^3,P =0.004）.The difference of BrdU-positive cell numbers in ischemic brain tissue between the control group（10.26±2.89）and the sodium ferulate group（23.82±3.05）was statistically significant（t=18.26,P=0.004）.VEGF concentration in the sodium ferulate group was higher than the control group [（67.58±9.61）pg/mL,（21.90±5.16）pg/mL,P=0.008].Conclusions Sodium ferulate can significantly improve the learning and memory ability of the chronic cerebral ischemic rat,and its possible mechanism maybe involve the nerve protection and regeneration of the vascular.