人参皂苷F组对急性脑缺血大鼠细胞凋亡及VEGF表达的影响

目的研究F组人参皂苷对急性脑缺血大鼠脑细胞凋亡及VEGF表达的影响。方法参照ZeaLonga线栓法制作右侧大脑中动脉栓塞模型。选用健康雄性Wistar大鼠70只,随机分为5组:假手术组、盐水对照组、小剂量给药组、中剂量给药组、大剂量给药组。给药组分别于术前30m in及术后30m in、3h给予不同剂量的F组人参皂苷腹腔内注射。应用TTC染色及图像分析系统测定脑缺血24h后的梗死体积、TUNEL染色观察各组间细胞凋亡的差异及免疫组化染色检测VEGF表达的变化。结果与盐水对照组相比,药物干预组局部脑缺血后在相同时间内梗死灶体积减小(P<0.05);神经细胞凋亡减少(P<0.05),且随剂量的增加凋亡细胞减少更加明显(P<0.01);VEGF表达明显增加(P<0.01),且在实验剂量范围内其表达随药物剂量的增加而增多(P<0.01)。结论F组人参皂苷对脑缺血损伤具有保护作用,其机制为减少细胞凋亡及增加VEGF表达。     

CGRP和NGF对脑局部缺血再灌注大鼠脑组织神经元凋亡及PKCmRNA表达的调节作用

目的研究大鼠脑缺血再灌注后蛋白激酶C信使RNA(PKCmRNA)的表达,探讨降钙素基因相关肽(CGRP)和神经生长因子(NGF)对脑组织缺血再灌注的保护作用及机制。方法采用颈动脉负压分流法制作大鼠脑缺血再灌注模型,采用TUNEL法、原位杂交方法及显微图像分析检测海马及皮质内神经元凋亡和PKCmRNA的表达。结果大鼠缺血再灌注海马及顶叶皮质内神经元凋亡数及PKCmRNA反应产物较正常组增多(P<0.05),而注射CGRP或NGF后神经元凋亡数及PKCmRNA反应产物明显低于缺血再灌注组(P<0.01),二者联合应用效果更加显著(P<0.05)。结论CGRP和NGF抑制缺血神经元凋亡,参与PKCmRNA的调节,二者对缺血神经元有协同修复作用。     

ACEI对肾性高血压大鼠脑缺血再灌注后细胞凋亡的影响

目的观察血管紧张素转化酶抑制剂(ACEI)对肾性高血压大鼠脑缺血再灌注后神经功能和细胞凋亡的影响,探讨ACEI的脑保护机制。方法采用狭窄肾动脉方法建立肾性高血压大鼠模型,随机分依那普利组(A组)和高血压缺血再灌注组(B组);正常血压组分为假手术组(C组)和缺血再灌注组(D组)。用线栓法造成大脑缺血再灌注模型,缺血时间为2h,再灌注时间22h。用免疫组织化学技术检测脑组织bcl-2、bax的表达,TUNEL法检测细胞凋亡。结果(1)脑缺血再灌注后神经功能评分:A组神经功能评分较B组和D组降低(P<0.05,);D组神经功能评分低于B组(P<0.05)。(2)A组与B组和D组比较bcl-2表达明显增多(P<0.05),bax表达显著降低(P<0.05),神经细胞凋亡明显减少(P<0.05);B组与D组比较,bcl-2表达明显降低(P<0.05),bax表达明显增加(P<0.05),而神经细胞凋亡明显增多(P<0.05)。结论ACEI明显改善局灶性脑缺血大鼠的神经功能,减少神经细胞凋亡,上调脑组织bcl-2表达,抑制bax表达,提示对脑缺血再灌注损伤有脑保护作用。     

脑缺血后处理对缺血再灌注脑组织线粒体通透性转换的影响

目的观察线粒体通透性转化在脑缺血后处理干预下的改变情况。方法采用SD大鼠局灶脑缺血模型,设立假手术组、缺血/再灌注组、缺血后处理组及延迟缺血后处理组。于大脑中动脉缺血30min,再灌注30min后检测脑组织中丙二醛含量和线粒体通透性转换的改变情况,再灌注24h后检测脑梗死面积。结果脑缺血后处理组脑梗死面积明显减少(P<0.05),脑组织中丙二醛含量减少(P<0.05),线粒体通透性转换减轻(P<0.05);延迟脑缺血后处理组与缺血再灌注组相比无明显改变。结论脑缺血后处理有明显的脑保护作用,但其保护作用有时间依赖性,其机制可能与抑制线粒体通透性转换孔开放有关。     

依达拉奉对糖尿病脑缺血再灌注大鼠细胞凋亡及缺氧诱导因子表达的影响

目的 探讨依达拉奉对糖尿病急性脑缺血再灌注大鼠细胞凋亡及缺氧诱导因子表达的影响.方法 选取健康雄性SD大鼠70只,采用腹腔内一次性注入新鲜配制的1%链尿佐菌素(STZ)及线栓法建立糖尿病大鼠大脑中动脉闭塞再灌注模型.随机分成依达拉奉干预脑缺血再灌注组(干预组)30只、非依达拉奉干预脑缺血再灌注组(非干预组)30只、假手术组5只和正常组5只.前两组又分为缺血2h再灌注1h、6h、12h、24h、48h、72h亚组,每亚组5只.用TUNEL法检测细胞凋亡的变化,用免疫组化法检测缺氧诱导因子(HIF-1α)的表达水平.结果 依达拉奉干预组各个时间点脑皮质区凋亡细胞数及缺氧诱导因子表达量均低于非依达拉奉干预组(P<0.05).结论 依达拉奉可明显减少糖尿病急性脑缺血再灌注大鼠脑神经细胞凋亡数,同时可减少缺氧诱导因子的表达.在糖尿病脑缺血再灌注过程中具有明显神经保护作用.     

侧脑室注射重组人血管生长素对脑缺血再灌注大鼠的影响

目的观察经大鼠侧脑室注射重组人血管生长素(Angiogen in,ANG)对脑缺血再灌注大鼠的影响。方法线栓法制备大鼠脑缺血再灌注模型,大鼠随机分成4组:ANG治疗组、牛血清白蛋白对照组、MCAO对照组及假手术组,观察大鼠体重的变化,并于治疗3d后进行HE染色、细胞凋亡检测以及vWF因子免疫组织化学染色。结果脑缺血再灌注3d后ANG治疗组大鼠与MCAO对照组及牛血清白蛋白对照组相比,体重显著降低(P<0.05),缺血脑区神经元变性、坏死、间质水肿以及胶质细胞增生程度减轻,凋亡阳性细胞数明显减少(P<0.05),微血管计数增加(P<0.05)。结论侧脑室注射ANG可改善脑缺血大鼠脑内间质水肿和神经元变性,降低凋亡细胞数量,增加微血管数量。ANG可降低脑缺血大鼠体重。     

bFGF对大鼠局灶性缺血再灌注脑组织的保护作用

目的探讨bFGF对大鼠脑缺血再灌注损伤后神经细胞凋亡和脑组织中SOD、MDA含量变化的影响。方法应用线栓法制作大鼠局灶性脑缺血再灌注模型,大脑中动脉阻塞1h再灌注损伤24h,检测假手术组、缺血再灌注组和bFGF组的凋亡细胞数和脑组织中SOD、MDA的含量。结果假手术组偶见凋亡细胞,缺血再灌注组和bFGF组凋亡细胞数分别是26.35±5.67和18.65±5.91,与缺血再灌注组相比,bFGF组缺血区皮质凋亡神经元明显减少(P<0.05)。SOD,MDA测定结果显示三组间比较,具有显著性差异(P<0.01和P<0.05)。结论抗氧化作用可能是bFGF减少大鼠脑缺血再灌注损伤后细胞凋亡的分子机制之一。     

联合应用骨髓基质细胞与bcl-2基因对脑缺血大鼠的神经保护作用

目的 探讨联合应用骨髓基质细胞(MSC)与bcl-2基因对大鼠脑缺血再灌注损伤后神经细胞凋亡和细胞色素C蛋白表达的影响.方法 采用改良线栓法制成大脑中动脉闭塞大鼠模型.将30只Wistar大鼠随机分为空白对照组、MSC组及MSC+bcl-2组3组,每组10只.MSC+bcl-2组于大鼠脑缺血再灌注3 h后经颈动脉注入pLXSN-bcl-2质粒,MSC组及MSC+bcl-2组于大鼠脑缺血再灌注24 h后经尾静脉植入MSC.各组于再灌注后7 d进行神经功能评分,采用免疫组化法检测脑组织细胞色素C蛋白表达,通过TUNEL法检测细胞凋亡情况.结果 再灌注7 d后,MSC组和MSC+bcl-2组大鼠神经功能缺损评分明显低于空白对照组(P<0.05),MSC+bcl-2组大鼠神经功能评分明显低于MSC组(P<0.05);MSC组和MSC+bcl-2组大鼠细胞色素C免疫反应阳性细胞较空白对照组明显减少(P<0.05),MSC+bcl-2组大鼠细胞色素C免疫反应阳性细胞较MSC组明显减少(P<0.05);空白对照组大鼠缺血侧凋亡细胞明显多于MSC组和MSC+bcl-2组(P<0.05),MSC+bcl-2组大鼠凋亡细胞明显少于MSC组(P<0.05).结论 MSC和bcl-2基因联合治疗脑缺血大鼠可下调其组织细胞色素C表达及抑制神经细胞凋亡,促进大鼠神经功能恢复.     

高张盐水在局灶性脑缺血再灌注损伤中的作用及其机制

目的 研究高张盐水对大鼠局灶性脑缺血再灌注损伤后脑含水量、肿瘤坏死因子-α(TNF-α)含量以及脑细胞凋亡的影响,探讨高张盐水在脑缺血再灌注损伤中的作用和机制. 方法 健康SD雄性大鼠96只按随机数字表法分为4组,即假手术组(P组)、单纯缺血再灌注组(IR组)、7.5%高张盐水组(HS-A组)、4.2%高张盐水组(HS-B组),每组各24只.采用线栓法制作大脑中动脉缺血模型,再灌注前经股静脉分别给予7.5%NaCl(HS-A组)或4.2%NaCl(HS-B组),P组和IR组不给任何药.检查再灌注前,再灌注后30 min、60 min、90 min时的血清Na+浓度.再灌注22 h后,对大鼠进行神经功能缺陷评分,然后断头取脑检测左右两侧脑含水量;取缺血侧前脑皮质测TNF-α含量;取梗死灶周围脑组织,用TUNEL法检测神经元凋亡情况. 结果输入高张盐水后,HS-A组和HS-B组大鼠血清Na+浓度明显升高,HS-A组持续到再灌注后90min,HS-B组在再灌注60min后基本恢复正常.IR组大鼠两侧脑含水量较假手术组增加,缺血侧增加更明显,比较差异有统计学意义(P<0.05).HS-A组和HS-B组大鼠两侧脑含水量较IR组相比明显减少,并以缺血侧减少更明显,比较差异有统计学意义(P<0.05);同IR组相比,HS-A组和HS-B组大鼠脑组织TNF-α含量明显降低,凋亡细胞计数明显下降,神经缺陷评分也明显下降,比较差异均有统计学意义(P<0.05).结论 高张盐水可减少缺血再灌注后脑含水量和脑组织TNF-α含量,减轻脑细胞凋亡,改善缺血再灌注损伤后神经功能.     

血塞通对缺血再灌注大鼠脑细胞凋亡的影响

目的 观察血塞通预处理对大鼠脑缺血再灌注损伤脑细胞凋亡的影响.方法 采用线栓法复制大鼠大脑中动脉脑缺血再灌注损伤模型,检测再灌注后缺血脑细胞凋亡情况, 并测定脑组织Ca2 含量变化.结果 血塞通能减轻缺血脑组织脑细胞的凋亡(P<0.01),能降低脑组织Ca2 含量(P<0.01).结论 血塞通对大鼠大脑中动脉缺血再灌注损伤具有保护作用,可能与其降低脑组织钙含量、减轻脑细胞凋亡有关.     

Electroacupuncture reduces apoptotic index and inhibits p38 mitogen-activated protein kinase signaling pathway in the hippocampus of rats with cerebral ischemia/reperfusion injury

Electroacupuncture attenuates cerebral hypoxia and neuronal apoptosis induced by cerebral ischemia/reperfusion injury. To further iden-tify the involved mechanisms, we assumed that electroacupuncture used to treat cerebral ischemia/reperfusion injury was associated with the p38 mitogen-activated protein kinase (MAPK) signaling pathway. We established rat models of cerebral ischemia/reperfusion injury using the modified Zea-Longa's method. At 30 minutes before model establishment, p38 MAPK blocker SB20358 was injected into the left lateral ventricles. At 1.5 hours after model establishment, electroacupuncture was administered at acupoints of Chize (LU5), Hegu (LI4), Zusanli (ST36), and Sanyinjiao (SP6) for 20 minutes in the affected side. Results showed that the combination of EA and SB20358 injec-tion significantly decreased neurologic impairment scores, but no significant differences were determined among different interventional groups. Hematoxylin-eosin staining also showed reduced brain tissue injuries. Compared with the SB20358 group, the cells were regularly arranged, the structures were complete, and the number of viable neurons was higher in the SB20358 + electroacupuncture group. Termi-nal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling assay showed a decreased apoptotic index in each group, with a significant decrease in the SB20358 + electroacupuncture group. Immunohistochemistry revealed reduced phosphorylated p38 expression at 3 days in the electroacupuncture group and SB20358 + electroacupuncture group compared with the ischemia/reperfusion group. There was no significant difference in phosphorylated p38 expression between the ischemia/reperfusion group and SB20358 group. These find-ings confirmed that the electroacupuncture effects on mitigating cerebral ischemia/reperfusion injury are possibly associated with the p38 MAPK signaling pathway. A time period of 3 days could promote the repair of ischemic cerebral nerves.     

Large-conductance Ca2+-activated K+ channel involvement in suppression of cerebral ischemia/reperfusion injury after electroacupuncture atShuigou (GV26) acupoint in rats

Excess activation and expression of large-conductance Ca2+-activated K+ channels (BKCa channels) may be an important mechanism for delayed neuronal death after cerebral ischemia/reperfusion injury. Electroacupuncture can regulate BKCa channels after cerebral ischemia/reperfusion injury, but the precise mechanism remains unclear. In this study, we established a rat model of cerebral ischemia/reperfusion injury. Model rats received electroacupuncture of 1 mA and 2 Hz atShuigou (GV26) for 10 minutes, once every 12 hours for a total of six times in 72 hours. We found that in cerebral ischemia/reperfusion injury rats, ischemic changes in the cerebral cortex were mitigated after electroacupuncture. Moreover, BKCa channel protein and mRNA expression were reduced in the cerebral cortex and neurological function noticeably improved. These changes did not occur after electroacupuncture at a non-acupoint (5 mm lateral to the left side of Shuigou). Thus, our ifndings indicate that electroacupuncture atShuigou improves neurological function in rats following cerebral ischemia/reperfu-sion injury, and may be associated with down-regulation of BKCa channel protein and mRNA expression. Additionally, our results suggest that theShuigou acupoint has functional speciifcity.     

胰岛素对大鼠脑缺血再灌注后Caspase-3表达及细胞凋亡的影响

目的探讨胰岛素对大鼠脑缺血再灌注后Caspase-3表达及细胞凋亡的影响。方法将动物随机分为假手术组、缺血组及干预组,参照zea longa线栓法建立大鼠左侧大脑中动脉闭塞（mid-dle cerebral artery occlusion,MCAO）再灌注模型,干预组大鼠在脑缺血即刻给予胰岛素及葡萄糖腹腔注射,分别在左侧MCAO2h再灌注不同时间点断头取脑,脑皮质神经元Caspase-3的表达通过免疫组化法来测定,并采用TUNEL法原位标记DNA片段,检测TUNEL阳性细胞的变化。结果缺血组大鼠脑皮质Caspase-3的表达较假手术组显著增强（P〈0.01）,TUNEL阳性细胞数较假手术组显著增多（P〈0.01）;给予胰岛素处理后,Caspase-3的表达较缺血组明显减弱（P〈0.01）,TUNEL阳性细胞数较缺血组明显减少（P〈0.01）,但两者均显著高于假手术组（P〈0.01）。结论短暂的脑缺血再灌注可导致脑皮质神经元Caspase-3的表达增加,促进细胞凋亡,胰岛素可下调脑皮质神经元Caspase-3的表达,发挥神经保护作用。     

Effects of acupoint versus non-acupoint electroacupuncture on cerebral cortical neuronal Bcl-2, Bax and caspase-3 expression in a rat model of focal cerebral ischemia

BACKGROUND： Several studies have demonstrated that electroacupuncture by acupoint selection can inhibit cerebral cortical neuronal apoptosis following cerebral ischemia/reperfusion. OBJECTIVE： To validate the effects of electroacupuncture by acupoint selection on the expression level of cortical neuronal anti-apoptotic Bcl-2 protein and the apoptotic executive protein, caspase-3, in rat models of focal cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING： This randomized grouping, neural cell and molecular biology animal experiment was performed at the Laboratory of Pharmacology of Traditional Chinese Medicine and the Laboratory Animal Center of Henan Institute of Traditional Chinese Medicine between November 2006 and May 2007. MATERIALS： Atotal of 40 healthy male adult Sprague-Dawley rats were randomly and evenly divided into four groups： sham-operated, model, electroacupuncture and non-aeupoint control. G6895 electro-acupuncture instruments were purchased from Shanghai Huayi Instrument Factory, China. Caspase-3, Bcl-2 and Bax kits were provided by Wuhan Boster Bioengineering Co., Ltd., China. METHODS： Middle cerebral artery occlusion was induced in the model, electroacupuncture and non-acupoint groups. In the electroacupuncture group, the acupoints Jianyu （LII5）, Waiguan （S J5）, Biguan （ST31）, and Zusanli （ST36） were given electroacupuncture. In the non-acupoint control group, at each time point （immediately after ischemia and after reperfusion, or 2 hours after reperfusion）, electroacupuncture was performed at the midpoints of Tianquan （PC2）-Quze （PC 3） line, Quze （PC 3）-Ximen （PC4） line, Zuwuli （LR10）-Yinbao （LR9） line, and Xiguan （LR7）-Zhongdu （LR6） line. Electroacupuncture parameters were set with a continuous wave with a frequency of 10 Hz, wave width 0.6 ms, voltage 1.5-3.0 V, and a duration of 10 minutes. The sham-operated and model groups received only animal fixation without electroacupuncture procedure. MAIN OUTCOME MEASURES： Five ra     

CpG-ODN对大鼠脑缺血/再灌注损伤的保护作用

目的 探讨CpG-ODN对大鼠脑缺血/再灌注（I/R）损伤的保护作用及其机制。方法 将54只大鼠随机分为假手术组、脑I/R模型组、CpG-ODN组,每组18只。采用大脑中动脉线栓法构建大鼠脑I/R模型。CpG-ODN组造模前1 h腹腔注射CpG-ODN（10 μg/25 g）,脑I/R模型组注射等量生理盐水。再灌注12 h采用Longa 5分评分法评估神经功能。再灌注24 h采用TTC染色测定脑梗死体积,HE染色观察组织结构,TUNEL染色分析细胞凋亡,PCR检测酪氨酸激酶（JAK）、信号转导和转录激活因子（STAT）mRNA表达水平,免疫印迹法分析Caspase3、Caspase7、JAK、p-JAK、STAT和p-STAT蛋白水平。结果 与假手术组比较,脑I/R模型组神经功能障碍严重,脑梗死体积显著增大,脑组织发生水肿、坏死等病变;与脑I/R模型组比较,CpG-ODN组明显改善。与假手术组比较,脑I/R模型组脑组织细胞凋亡率和Caspase3、Caspase7蛋白水平明显升高（P<0.05）,脑I/R模型组JAK、STAT mRNA水平和蛋白磷酸化程度显著上调（P<0.05）;与脑I/R模型组比较,CpG-ODN组细胞凋亡率和Caspase3、Caspase7蛋白水平明显降低（P<0.05）,JAK、STAT mRNA和蛋白磷酸化程度均明显下降（P<0.05）。结论 CpG-ODN能有效保护大鼠脑I/R损伤,其机制可能与影响JAK、STAT蛋白磷酸化抑制细胞凋亡有关。     

电针对局灶性脑缺血大鼠缺血灶周围区星形胶质细胞的影响

BACKGROUND： Astrocytes react sensitively to cerebral ischemia, causing reactive proliferation and activation, which may contribute to their effect in protecting or injuring neuronal regeneration. Whether acupuncture, as a treatment for cerebral ischemia, regulates the activated state of astrocytes has become a focus of recent investigations. OBJECTIVE： To observe the effects of electroacupuncture （EA） on ultrastructure changes and reactive proliferation of astrocytes in the marginal zone of focal cerebral ischemia in rats. DESIGN, TIME AND SETTING： Randomized, controlled animal study. This study was performed at the Experimental Animal Center of Guangzhou University of Traditional Chinese Medicine between December 2007 and July 2008. MATERIALS： A total of 90 male Wistar rats were randomly divided into sham operated, model and EA groups. Each group was subdivided into 1 hour, 1, 3, 7, and 21 days post-cerebral ischemia groups, with six animals for each time point. Rabbit anti-rat glial fibrillary acidic protein （GFAP） and goat anti-rabbit IgG/tetramethylrhodamine isothiocyanate were provided by Beijing Biosynthesis Biotechnology. The G-6805 electric acupuncture apparatus was provided by Shanghai Huayi. METHODS： Heat-coagulation-induced occlusion of the middle cerebral artery was performed to establish a model of focal cerebral ischemia, in the model and EA groups. Middle cerebral arteries were exposed without occlusion in sham operated group. EA was applied immediately after surgery in the EA group, 4/20 Hz, 2.0-3.0 V, 1-3 mA, to Baihui（GV 20） and Dazhui（GV 14）, for 30 minutes. The treatment was performed once a day. The sham operated and model groups did not receive acupuncture. MAIN OUTCOME MEASURES： In the marginal zone of focal cerebral ischemia in rats at different time points after intervention, the ultrastructure changes of astrocytes were observed by using transmission electronic microscopy. GFAP expression in astrocytes was also measured by laser confocal scanning microscopy. RESULTS： Cell swelling and rapid proliferation of astrocytes were observed following cerebral ischemia. In comparison to the model group, the degree of swelling of astrocytes was significantly decreased in the EA group. Compared with the sham operated group at hour 1 post-surgery, there was no significant difference in the expression of average fluorescence intensity of GFAP between the EA and model groups （P 〉 0.05）, while the expression of GFAP in both the EA and model groups increased significantly at days 1, 3, 7 and 21 post-surgery （P 〈 0.01）. The expression of GFAP in EA group was also significantly lower than in the model group （P 〈 0.01, P 〈 0.05）. CONCLUSION： Ultrastructural changes and reactive proliferation of astrocytes appear in the marginal zone of focal cerebral ischemia in rats. EA can relieve the degree of swelling of astrocytes and inhibit GFAP overexpression by activated astrocytes. These effects may be related to its ability to regulate the activated state of astrocytes.     

Electroacupuncture Alleviated Neuronal Apoptosis Following Ischemic Stroke in Rats via Midkine and ERK/JNK/p38 Signaling Pathway

This study aimed to evaluate the effects of electroacupuncture (EA) intervention administered at rats of middle cerebral artery occlusion (MCAO)/reperfusion. Fifty-four male Sprague-Dawley rats were divided into three groups, consisting of sham group, MCAO/R group, and EA group. EA treatment at Quchi and Zusanli acupoints was applied in rats of EA group at 24 h after MCAO once per day for 3 days. Our results indicated that EA treatment reduced infarct volumes and neurological deficits, as well alleviated the apoptotic cells in peri-infarct cortex, indicating that EA exerted neuroprotective effect in cerebral ischemic rats. Moreover, EA treatment may effectively reverse the upregulation of caspase-3 and Bim and alleviate the inhibition of Bcl-2 following 72-h ischemic stroke. EA may significantly reverse the promoted relative density level of p-ERK1/2, p-JNK, and p-p38 in the EA group compared with the MCAO/R group. In addition, the growth factor midkine (MK) was upregulated at 72 h after MCAO/R, and EA treatment may significantly prompt expression of MK. Our study demonstrated that EA exerted neuroprotective effect against neuronal apoptosis and the mechanism might involve in upregulation of MK and mediation of ERK/JNK/p38 signal pathway.     

人尿激肽原酶对大鼠脑缺血再灌注后神经细胞凋亡的影响

目的观察人尿激肽原酶(HUK)对大鼠脑缺血再灌注(I/R)后大脑皮质缺血灶周围区Caspase-3、凋亡诱导因子(AIF)的时相表达及对神经细胞凋亡的影响。方法将Wistar大鼠随机分为假手术组、模型组、HUK干预组,应用线栓法建立大鼠大脑中动脉阻塞(MCAO)再灌注模型。假手术组于术后,模型组、HUK干预组于缺血2h后再灌注6h、24h、48h、72h,应用免疫组化技术和原位末端标记法(TUNEL)检测不同时相各组缺血灶周围脑区Caspase-3、AIF和TUNEL阳性细胞的表达。结果大鼠I/R后在缺血灶周围区各个时间点均可见到Caspase-3、AIF和TUNEL阳性细胞的表达,HUK组与模型组相比较,两组Caspase-3、AIF和TUNEL阳性细胞的表达趋势基本一致,Caspase-3、AIF和TUNEL的表达高峰均在I/R后24h。HUK组各时间点Caspase-3、AIF和TUNEL阳性细胞的光密度值较模型组明显降低(均为P<0.05)。结论HUK对大鼠脑缺血再灌注损伤有保护作用,其作用机制可能与HUK抑制Caspase-3、AIF的表达,减轻迟发性神经元的凋亡有关。     

Electroacupuncture preconditioning protects against focal cerebral ischemia/reperfusion injury via suppression of dynamin-related protein 1

Electroacupuncture preconditioning at acupoint Baihui(GV20) can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynamin-related protein 1(Drp1) can trigger neuronal apoptosis following cerebral ischemia/reperfusion injury. Herein, we examined the hypothesis that electroacupuncture pretreatment can regulate Drp1, and thus inhibit mitochondrial fission to provide cerebral protection. Rat models of focal cerebral ischemia/reperfusion injury were established by middle cerebral artery occlusion at 24 hours after 5 consecutive days of preconditioning with electroacupuncture at GV20(depth 2 mm, intensity 1 m A, frequency 2/15 Hz, for 30 minutes, once a day). Neurological function was assessed using the Longa neurological deficit score. Pathological changes in the ischemic penumbra on the injury side were assessed by hematoxylin-eosin staining. Cellular apoptosis in the ischemic penumbra on the injury side was assessed by terminal deoxyribonucleotidyl transferase-mediated d UTP-digoxigenin nick end labeling staining. Mitochondrial ultrastructure in the ischemic penumbra on the injury side was assessed by transmission electron microscopy. Drp1 and cytochrome c expression in the ischemic penumbra on the injury side were assessed by western blot assay. Results showed that electroacupuncture preconditioning decreased expression of total and mitochondrial Drp1, decreased expression of total and cytosolic cytochrome c, maintained mitochondrial morphology and reduced the proportion of apoptotic cells in the ischemic penumbra on the injury side, with associated improvements in neurological function. These data suggest that electroacupuncture preconditioning-induced neuronal protection involves inhibition of the expression and translocation of Drp1.