尼莫地平对大鼠急性脑缺血再灌注损伤早期保护作用的研究

目的探讨尼莫地平对急性脑缺血再灌注损伤的早期保护作用。方法线栓法复制大鼠急性脑缺血模型。30只雄性Wistar大鼠随机分为假手术、模型、尼莫地平3组。模型组采取缺血2h再灌注2h。尼莫地平组大鼠在缺血0时刻起每小时腹腔注射给药一次,剂量为5mg/kg。各组大鼠在手术4h后实验结束后,行腹主动脉采血,同时取完整脑组织。脑组织切片进行TTC染色,并比较各组脑组织梗死面积。检测各组大鼠血清及脑组织匀浆中SOD、MDA、NO含量。结果与模型组相比,尼莫地平组大鼠脑组织梗死面积显著减少。血清生化指标显示,模型组SOD含量显著低于假手术组,给予尼莫地平治疗后,SOD含量增加明显。模型组MDA、NO含量明显高于假手术组,尼莫地平组明显降低血清中MDA、NO。结论尼莫地平对大鼠急性脑缺血再灌注损伤有保护作用,这种保护作用与NO和氧化应激密切相关。     

丁苯肽软胶囊对大鼠急性脑缺血再灌注损伤脑组织含水及含钙量的影响

目的 研究丁苯肽软胶囊对大鼠急性脑缺血再灌注损伤脑组织含水量及含钙量的影响.方法 选取健康SD大鼠60只,按照随机数字表随机分为6组,采用4血管法造脑缺血再灌注损伤模型,给药组分别给予不同剂量的丁苯肽软胶囊和复方丹参注射液,观察丁苯肽软胶囊对大鼠急性脑缺血再灌注损伤脑组织含水量及含钙量的影响.结果 丁苯肽软胶囊高剂量组可降低大鼠急性脑缺血再灌注损伤脑组织含水量（75.60%）及含钙量（114.53 pg/g）;中剂量组降低大鼠急性脑缺血再灌注损伤脑组织含水量（80.03%）,降低大鼠急性脑缺血再灌注损伤脑组织含钙量（132.33 pg/g）;低剂量组对大鼠急性脑缺血再灌注损伤脑组织含水量（73.93）及含钙量（106.35 pg/g）有降低趋势,但差异无统计学意义（P＞0.05）.结论 丁苯肽软胶囊能降低大鼠急性脑缺血再灌注损伤脑组织含水量及含钙量,具有脑保护作用.     

木犀草素对大鼠脑缺血再灌注损伤的保护作用

目的 观察木犀草素对大鼠急性脑缺血再灌注损伤的保护作用.方法 采用大鼠急性不完全性脑缺血再灌注损伤模型,测定大鼠协调性运动评分和脑缺血体积的变化.结果 木犀草素对恢复缺血再灌注大鼠的协调性运动功能,减少脑缺血体积有显著疗效.结论 木犀草素具有保护脑缺血再灌注性损伤的作用.     

醒脑通脉颗粒对脑缺血再灌注损伤大鼠TNF-a和炎性细胞因子的干预研究

目的 探讨醒脑通脉颗粒对急性脑梗死的神经保护作用.方法 采用线栓法制作大鼠局灶性脑缺血再灌注模型,检测各缺血区的TNF-a、IL-1β、IL-6和IL-8的含量,评价醒脑通脉颗粒及尼莫地平的干预作用.结果 醒脑通脉颗粒小剂量(250mg/kg)、大剂量(1000mg/kg)组均能降低脑组织中TNF-a及IL-1β、IL-6和IL-8等炎性细胞因子的含量(P<0.05,P<0.01),较尼莫地平为优.结论 醒脑通脉颗粒对大鼠局灶性脑缺血再灌注损伤有保护作用(以大剂量组为优),其作用机制与降低TNF-a和炎性细胞因子的含量有关.     

大鼠急性脑缺血再灌注损伤精氨酸加压素变化和脑水肿实验研究

应用大鼠急性脑缺血再灌注动物模型，观察精氨酸加压素（ＡＶＰ）在急性脑缺血再灌注损伤中的变化及与脑水肿关系，结果表明丘脑下部ＡＶＰ含量在脑缺血３０ｍｉｎ明显增加，再灌注６０ｍｉｎ后进一步增加，且与大脑皮层水含量是显著相关性。提示，ＡＶＰ参与急性脑缺血再灌注损伤，丘脑下部ＡＶＰ含量增高，可加重或促进脑缺血再灌注后脑水肿形成。     

老龄大鼠急性脑缺血再灌注对心肌组织的影响

目的:研究老龄大鼠急性脑缺血再灌注对心肌组织的影响。方法:参照Zea Longa线栓法建立老龄大鼠局灶性脑缺血再灌注模型,从心肌酶谱、心电图及心肌超微结构等方面观察对心脏的影响。结果:与对照组比,在脑缺血2 h再灌注3和6 h组AST和LDH升高明显;CPK和CPK-MB在3、6和12 h组均有显著性升高(t检验,P<0.05)。大脑中动脉阻塞后出现ECG异常发生率为53.13%,6、12 h组明显高于32、4 h组(χ2检验,P<0.05),主要表现为S-T段的上抬和各种心律失常,在脑缺血30 min即可出现,70.59%发生在脑缺血后2 h和再灌注6 h内。心肌超微结构的改变在脑缺血2 h再灌注3和6 h组最明显,表现心肌缺血性损害和胞质中糖原颗粒明显减少。结论:急性脑缺血及再灌注后对心肌有明显损伤作用,以脑缺血2 h和再灌注6 h内最明显。     

大鼠局灶性脑缺血与缺血再灌注损伤IL—8的研究

目的　探讨IL-8在脑缺血损伤及缺血再灌注损伤中的作用。方法　(1)采用改良ZeaLonga线栓法大鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)模型。(2)应用双抗体夹心间接ELISA法检测脑缺血组与缺血再灌注组大鼠受损脑组织和血清中IL-8的浓度。结果　(1)脑缺血再灌注组受损脑组织中IL-8含量比脑缺血组高(P<0.05)，二者IL-8含量的变化均呈时间依赖性。前者于再灌注22h达高峰之后很快下降；后者于缺血6h达高峰，之后缓慢下降。(2)脑缺血再灌注组血清IL-8浓度于再灌注1h达峰值（7.08±1.36）pg/mL，之后很快降至较低水平；而在脑缺血组3h最高，为(3.61±0.81)pg/mL，随后缓慢下降。结论　脑缺血和脑缺血再灌注损伤均有IL-8参与，IL-8在脑缺血再灌注损伤中所起的作用较在脑缺血损伤中大。     

兔脑缺血再灌注后尼莫地平对脑微循环影响的实验研究

在夹闭双侧颈总动脉和椎动脉造成严重脑缺血２０分钟的基础上，应用微循环闭路电视显微系统行颅骨开窗法对兔脑软脑膜微循环录像，直接动态观察钙拮抗剂尼莫地平对脑复苏后微循环的影响。再灌注期，尼莫地平能显著地扩张微动脉，并持续１００分钟以上，明显地延缓延迟性低灌注时相。结果提示：尼莫地平具有不同程度地改善脑缺血后微循环异常，增加脑组织血液供给，减轻再灌注损伤。     

棓丙酯对大鼠急性脑缺血再灌注损伤的保护作用

目的探讨棓丙酯注射液对大鼠急性脑缺血-再灌注损伤的保护作用及其可能机制。方法采用线栓法制备大鼠右侧大脑中动脉栓塞所致的缺血-再灌注模型。观测神经功能学评分、脑梗死面积、光镜和电镜下形态结构、超氧化物歧化酶活性及丙二醛含量变化。结果与模型组相比,棓丙酯注射液能降低大鼠急性脑缺血-再灌注后神经功能学评分、梗死面积、缺血区脑组织MDA含量,并且能够减轻脑组织形态学和超微结构损伤、升高SOD活性。结论棓丙酯注射液对大鼠急性局灶性脑缺血-再灌注损伤有保护作用,其机制可能与升高SOD活性、清除自由基有关。     

复方水蛭合剂对大鼠脑缺血再灌注损伤的影响

急性脑梗死 6小时内溶栓疗法已在国内外广泛展开 ,对抗溶栓后的再灌注损伤 ,目前还没有确切有效的药物。复方水蛭合剂主要由水蛭、黄芪、田七、赤芍、川芎等组成 ,药性有补气活血化瘀作用。一些补气活血化瘀药除有活血化瘀作用外 ,对缺血组织具有保护作用[1～ 3 ] 。本实验探讨复方水蛭合剂对脑缺血 再灌注大鼠脑匀浆、血清一氧化氮 (ＮＯ)、丙二醛 (ＭＤＡ)、超氧化物歧化酶(ＳＯＤ)的影响 ,了解本方剂抗脑缺血 再灌注的自由基损伤作用及对脑缺血 再灌注损伤的保护作用 ,为临床寻找新的抗脑缺血 再灌注损伤药物提供实验依据。1　资料1 1　…     

Effects of anisodamine on altered [Ca~(2+)]i and cerebral cortex ultrastructure following acute cerebral ischemia/reperfusion injury in rabbits

BACKGROUND： Calcium ion （Ca^2＋） overload plays an important role in cerebral ischemia/reperfusion injury. Anisodamine, a type of alkaloid, can protect the myocardium from ischemia and reperfusion injury by inhibiting intracellular calcium [Ca^2＋]i overload. OBJECTIVE： To investigate effects of anisodamine on [Ca^2＋]i concentration and cortex ultrastructure following acute cerebral ischemia/reperfusion in rabbits. DESIGN, TIME AND SETTING： Randomized and controlled trial was performed at the Department of Emergency, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology from September to December 2006. MATERIALS： Forty healthy rabbits were used to establish models of acute cerebral ischemia/reperfusion. Anisodamine was provided by Lianyungang Dongfeng Pharmaceutical Factory; Fura-2 was purchased from Nanjing Jiancheng Bioengineering Institute; dual-wave length fluorescent spectrophotometry system and DM-300 software were provided by Bio-Rad, USA; OPTON-EM10C transmission electron microscope was product of Siemens, Germany. METHODS： Forty rabbits were randomly divided into the following groups： sham operation, ischemia, ischemia/reperfusion, and anisodamine, with ten rabbits in each group. Models of complete cerebral ischemia injury were established. In addition, blood was collected from the femoral artery of rats in the ischemia/reperfusion and anisodamine groups to induce hypotension and establish repeffusion injury models. The bilateral common carotid artery clamp was removed from the anisodamine group 20 minutes after ischemia, and anisodamine （10 mg/kg body mass） was injected via the femoral vein. Rabbits in the sham operation group underwent only venous cannulation. MAIN OUTCOME MEASURES： [Ca^2＋]i concentration was determined using a dual-wave length fluorescent spectrophotometry system, and cortical ultrastructure was observed following uranyl-lead citrate staining. RESULTS： The levels of [Ca^2＋]i in the ischemia and ischemia/reperfusion gro     

Direct evidence for calcium-induced ischemic and reperfusion injury

Changes in cytosolic free calcium [( Ca2+]i) in the cat cortex were measured in vivo by indo-1 fluorometry during cerebral ischemia and reperfusion and were correlated to the histopathological ischemic changes. These changes were most pronounced in stroke cases with an increase in [Ca2+]i throughout the ischemic and reperfusion periods. Cases without a [Ca2+]i increase showed no histopathological change in the cortical gyrus in which [Ca2+]i was measured. The data support the hypothesis that an increase in [Ca2+]i during cerebral ischemia and reperfusion leads to neuronal damage.     

Lipid peroxidation in rat cerebral cortex during post-ischemic reperfusion: effect of exogenous antioxidants and Ca(++)-antagonist drugs.

Although the role of oxidant-antioxidant metabolism in total ischemia and reperfusion in the central nervous system and cardiac myocardium have been well studied, less is known about the consequences of partial ischemic episodes. Here we show that reperfusion contributes to free radical formation as judged by conjugated diene formation. Also, antioxidants and Ca++ antagonists were able to reduce free radical formation. These results would suggest that free radical generation following ischemia and reperfusion may result from more than one injury process in cerebral cortex.     

硫酸镁对大鼠急性脑缺血再灌注损伤时ATP酶的影响

目的　探讨镁剂在动物实验性急性脑缺血再灌注 (cerebral ischemia-reperfusion,CIR)过程中对 ATP酶的影响。方法　选用 Wistar大鼠 ,按改良的 Pulsinelli法建立了大鼠颈总动脉 CIR损伤模型 ;CIR损伤 1 5 min后 ,断髓处死鼠 ,取额叶脑组织测定 ATP酶含量。结果　急性 CIR早期 ,脑中 Na -K -ATP酶活性降低极显著(P <0 .0 1 ) ,Mg2 -ATP酶和 Ca2 -ATP酶活性降低显著 (P <0 .0 5 ) ;预先应用 Mg SO4 能稳定 ATP酶的活性(Mg2 -ATP酶 ,P <0 .0 1 ;Ca2 -ATP酶、Na -K -ATP酶 ,P <0 .0 5 )。结论　 Mg SO4 对大鼠 CIR损伤的脑保护作用与防止脑内多种 ATP酶活性降低有关。     

In vivo measurement of cytosolic free calcium during cerebral ischemia and reperfusion

An increase in cytosolic free calcium concentration ([Ca2+]i) may trigger irreversible cell injury following cerebral ischemia. We have measured changes in [Ca2+]i in cat cortex in vivo during ischemia produced by 1 hour of middle cerebral artery occlusion and during 30 minutes of reperfusion. Indo-1, a fluorescent Ca2+ indicator, was loaded into the exposed cortex by superfusion, and changes in the [Ca2+]i signal (400/506 nm ratio) were measured microfluorometrically during ultraviolet excitation (340 nm). The nicotinamide adenine dinucleotide/reduced nicotinamide adenine dinucleotide (NAD/NADH) redox state and hemodynamic changes were measured simultaneously. The animals showing severe deterioration in their electroencephalograms (EEG) showed a progressive increase in the [Ca2+]i signal during ischemia (baseline: 1.46 +/- 0.05; 60 minutes after occlusion: 2.99 +/- 0.37; n = 7). At 30 minutes following reperfusion, the animals showing little recovery in their EEG exhibited a further increase in [Ca2+]i (4.71 +/- 0.87, n = 3), whereas animals showing significant recovery in their EEG also showed recovery of [Ca2+]i (1.55 +/- 0.09, n = 4). By contrast, the moderate or mild stroke animals with less deterioration in their EEGs showed no increase in [Ca2+]i during either ischemia or reperfusion. These data suggest that the increase in [Ca2+]i might be closely related not only to deterioration of brain function during ischemia but also to poor recovery during the reperfusion period.     

Neuroprotective effect ofShenqi Fuzheng injection pretreatment in aged rats with cerebral ischemia/reperfusion injury

Shenqi Fuzheng injection is extracted from the Chinese herbs Radix Astragali and Radix Codonopsis. The aim of the present study was to investigate the neuroprotective effects of Shenqi Fuzheng injection in cerebral ischemia and reperfusion. Aged rats(20–22 months) were divided into three groups: sham, model, and treatment. Shenqi Fuzheng injection or saline(40 m L/kg) was injected into the tail vein daily for 1 week, after which a cerebral ischemia/reperfusion injury model was established. Compared with model rats that received saline, rats in the treatment group had smaller infarct volumes, lower brain water and malondialdehyde content, lower brain Ca2+ levels, lower activities of serum lactate dehydrogenase and creatine kinase, and higher superoxide dismutase activity. In addition, the treatment group showed less damage to the brain tissue ultrastructure and better neurological function. Our findings indicate that Shenqi Fuzheng injection exerts neuroprotective effects in aged rats with cerebral ischemia/reperfusion injury, and that the underlying mechanism relies on oxygen free radical scavenging and inhibition of brain Ca2+ accumulation.     

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.     

大鼠局灶性脑缺血再灌注后bcl-2蛋白在大脑皮质的表达

目的观察bcl-2蛋白在大鼠局灶性脑缺血再灌注(FCIR)后表达的变化。方法大脑中动脉内线栓法(MCAO)建立缺血再灌注(IR)模型,用免疫组化(SP)法观察bcl-2蛋白不同时间的表达。HE染色观察各个时间点细胞形态学变化。结果脑缺血2h再灌注2hbcl-2表达升高(P<0.01),IR6h达到高峰,IR12h开始下降。结论随着脑缺血再灌注时间延长脑损伤加重,bcl-2蛋白表达减少,bcl-2蛋白表达增加对细胞存亡有重要意义。     

Involvement of the Wnt signaling pathway and cell apoptosis in the rat hippocampus following cerebral ischemia/reperfusion injury

We investigated the role of the Wnt signaling pathway in cerebral ischemia/reperfusion injury by examining β-catenin and glycogen synthase kinase-3β protein expression in the rat hippocampal CA1 region following acute cerebral ischemia/reperfusion. Our results demonstrate that cell apoptosis increases in the CA1 region following ischemia/reperfusion. In addition, β-catenin and glycogen synthase kinase-3β protein expression gradually increases, peaking at 48 hours following reperfusion. Dickkopf-1 administration, after cerebral ischemia/reperfusion injury, results in decreased cell apoptosis, and β-catenin and glycogen synthase kinase-3β expression, in the CA1 region. This suggests that β-catenin and glycogen synthase kinase-3β, both components of the Wnt signaling pathway, participate in cell apoptosis following cerebral ischemia/reperfusion injury.