亚低温对大鼠脑缺血再灌注损伤后热休克蛋白70及胶质纤维酸性蛋白表达的影响

目的观察亚低温对大鼠脑缺血再灌注损伤后热休克蛋白70(HSP70)及胶质纤维酸性蛋白(GFAP)表达的影响。方法将雄性Wistar大鼠30只分为假手术组、常温组和亚低温组。制作右侧大脑中动脉阻塞(MCAO)模型,观察缺血2h再灌注48h后各组大鼠脑组织学改变和HSP70及GFAP的表达。结果常温组大鼠脑皮质下神经元严重坏死,亚低温组皮质下神经元坏死严重程度明显较常温组轻,假手术组未见神经元坏死。常温组大鼠脑组织GFAP和HSP70阳性细胞较多,假手术组、亚低温组GFAP和HSP70阳性细胞少于常温组,假手术组偶见HSP70阳性细胞;图像分析显示,常温组大鼠脑组织GFAP、HSP70表达的平均光密度较假手术组和亚低温组明显增高(均P<0.01)。结论亚低温能减轻大鼠脑缺血再灌注损伤,降低脑组织HSP70及GFAP蛋白的表达。     

亚低温对大鼠脑缺血再灌注损伤后HSP70mRNA表达及损伤神经细胞凋亡的影响

目的 探讨亚低温对大鼠脑缺血再注损伤后HSP70mRNA、HSP70（热休克蛋白70）表达及损伤神经细胞凋亡的影响。方法 采用大鼠局灶性脑缺血再灌注损伤模型,大脑中动脉阻塞2小时,再灌注损伤10小时,用逆转录聚合酶链反应（RT－PCR）技术、免疫组织化学法和原位缺口末端标记（TUNEL）法分别检测假手术组、对照组和亚低温组HSP70mRNA、HSP70表达水平和凋亡细胞百分率。结果 亚低温组HSP70mRNA、HSP70表达水平较对照组显著升高（P＜0．05）,而凋亡细胞百分率明显低于对照组（P＜0．05）。结论 亚低温上调大鼠脑缺血再灌注损伤后HSP70mRNA、HSP70表达水平可能与其抗损伤神经细胞凋亡作用有关。     

升压联合亚低温治疗对局灶性脑缺血再灌注的脑保护作用

目的　观察升压联合亚低温治疗对大鼠局灶性脑缺血再灌注的脑保护作用。方法　 32只大鼠随机分为对照组、升压组、亚低温组、升压 亚低温组 ,采用大鼠局灶性脑缺血再灌注模型 ,观察各组神经功能缺损评分和脑梗死体积。结果　升压组、亚低温组及升压 亚低温组神经功能缺损评分 (P <0 .0 5 )、脑梗死体积 (P <0 .0 1)均明显低于对照组 ;升压 亚低温组脑梗死体积明显低于升压组和亚低温组 (P <0 .0 5 )。结论　升压、亚低温对局灶性脑缺血再灌注损伤有明显脑保护作用 ,升压联合亚低温应用效果更佳     

补阳还五汤对老龄大鼠脑缺血再灌注海马齿状回细胞增殖分化的影响

BACKGROUND： The mobilization of endogenous stem cells is an effective way to promote repair following ischemic brain damage. Buyang Huanwu decoction （BHD） can effectively improve cerebral blood flow and protect against cerebral ischemia/reperfusion damage. OBJECTIVE： To study the effects of BHD on cell proliferation and differentiation in the hippocampal dentate gyrus of rats following cerebral infarction, to investigate the protective effects of BHD against cerebral infarction, and to analyze the dose-effect relationship. DESIGN, TIME AND SETTING： This randomized, controlled, animal study was performed at the Laboratory of Department of Physiology, Henan College of Traditional Chinese Medicine, China from June 2007 to February 2008. MATERIALS： A total of 36 male, Sprague Dawley rats, aged 20-21 months, were equally and randomly assigned to the following groups： sham operation, model control, and nimodipine, as well as high-dose, moderate-dose, and low-dose BHD. BHD was composed of milkvetch root, Chinese angelica, red peony root, earthworm, peach seed, safflower, and Szechwan Iovage rhizome, which were provided by the Outpatient Department, Henan College of Traditional Chinese Medicine, China. METHODS： The Chinese medicinal ingredients described above were decocted. The external carotid artery was ligated in rats from the sham operation group. Rat models of focal cerebral infarction were established by middle cerebral artery occlusion in the model control and nimodipine groups, as well as the high-dose, moderate-dose, and low-dose BHD groups. The drugs were administered by gavage 5 days, as well as 2 hours, prior to model induction. Rats in the nimodipine group were daily administered a 6 mg/kg nimodipine suspension by gavage. Rats in the high-dose, moderate-dose, and low-dose BHD groups were administered daily 26, 13, and 6.5 g/kg BHD, respectively. Rats in the sham operation and model control groups were treated with an equal volume of saline. MAIN OUTCOME MEASURES： The effects of BHD on neurological dysfunction score, brain water content, cell proliferation and differentiation in the hippocampal dentate gyrus, and pathological changes in the ischemic brain hemisphere were measured in cerebral infarction rats. RESULTS： Compared with the sham operation group, the neurological dysfunction score, brain water content, number of BrdU-positive cells, BrdU/NeuN-positive cells, and BrdU/GFAP-positive cells in the hippocampal dentate gyrus significantly increased in the model control group （P 〈 0.01 ）. Compared with the model control group, neurological dysfunction score and brain water content were significantly decreased （P 〈 0.01 or 0.05）, as were the number of BrdU-positive and BrdU/NeuN-positive cells （P 〈 0.01 or 0.05）. The number of BrdU/GFAP-positive cells was significantly reduced （P 〈 0.05） in the nimodipine group, high-dose, moderate-dose, and low-dose BHD groups. Compared with the nimodipine group, the neurological dysfunction score was significantly reduced in the moderate-dose BHD group （P 〈 0.05）. However, the number of BrdU-positive cells was significantly increased in the rat hippocampal dentate gyrus in the high-dose and moderate-dose BHD groups （P 〈 0.01 or 0.05）. The following was determined by microscopy： slightly disarranged neural cells, mild vascular dilatation, inflammatory cell infiltration, and light tissue edema were observed in the nimodipine group; inflammatory celt infiltration was reduced in the low-dose BHD group; cerebral edema and inflammatory cell infiltration were significantly reduced in the high-dose and in the moderate-dose BHD group. Electron microscopy revealed lipofuscin, slightly swollen mitochondria, and normal rough endoplasmic reticulum in the high-dose and moderate-dose BHD groups. Improvement was best in the moderate-dose BHD group. CONCLUSION： Cerebral ischemia activated proliferation of neural stem cells in the rat hippocampal dentate gyrus. The actions of BHD against cerebral ischemia/reperfusion damage correlated with proliferation and differentiation of neural stem cells in the hippocampal dentate gyrus. A moderate-dose of BHD resulted in the most effective outcome.     

轻度低温对脑缺血再灌注后细胞凋亡的影响

观察轻度低温对脑缺血再灌注后细胞凋亡的影响。方法：沙鼠４０只,随机分假手术组、缺血组和轻度低温（３２－３３℃）２ｈ组、６ｈ组、１２ｈ组共５组。夹闭双侧颈总动脉２０ｍｉｎ再灌注７２ｈ观察细胞凋亡。结果：ＦＣＭ显示缺血组海马区凋亡细胞９．３％,轻度低温２ｈ、６ｈ、１２ｈ组分别４．６％、２．６％、１．７％、。     

亚低温对脑缺血再灌注后缺血核心区皮质内MCP-1作用的实验研究

目的观察缺血过程中亚低温对大鼠脑缺血再灌注后缺血核心区皮质内单核细胞趋化蛋白(MCP)-1mRNA和蛋白质含量的影响。方法将60只雄性Wistar大鼠随机分为常温组(37℃)和亚低温组(32～33℃),以半定量逆转录PCR(RT-PCR)法测定MCP-1mRNA的表达,ELISA法测定缺血2 h再灌注不同时间缺血核心区脑皮质内MCP-1含量的变化,2,3,5三苯基四氮唑(TTC)染色法观察脑皮质梗死灶的变化并对大鼠进行神经病学评分。结果缺血2hMCP-1mRNA表达明显升高,再灌注后16h达高峰,此后仍维持较高水平的表达,直至再灌注后48 h;MCP-1含量于再灌注后6h开始升高,至48h逐渐达到高峰。亚低温能显著抑制再灌注后6h和16 hMCP-1mRNA的表达(P <0.05),但对再灌注后24h和48hMCP-1mRNA的表达无影响(P >0.05);亚低温能显著抑制再灌注后6h及48h脑皮质内MCP-1含量的升高(P <0.05)。亚低温组的脑梗死灶面积和神经病学评分较相应时间点的常温组明显减小。结论抑制缺血再灌注后脑皮质内MCP-1mRNA的表达和蛋白质分泌可能是亚低温发挥脑保护作用的重要途径之一。     

大鼠脑缺血及再灌注损伤的亚低温治疗时间窗研究

目的研究大鼠脑缺血再灌注损伤的亚低温(32±1℃)治疗时间窗,探讨最长脑缺血时间和开始低温时间所能获得的有效脑保护作用.方法采用改良线栓法制备大鼠大脑中动脉缺血再灌注模型.将72只SD大鼠随机分为12组,缺血后常温组(分4个亚组)缺血4、6、8及10小时后再灌注亚组;缺血后亚低温组(缺血模型建立后开始亚低温并持续12小时,分4个亚组)缺血4、6、8及10小时后再灌注亚组;再灌注期亚低温组(再灌注后开始亚低温并持续12小时,分4个亚组)缺血4、6、8、及10小时后再灌注亚组.观察脑梗死体积、脑组织水分含量和病理改变.结果缺血后亚低温能显著减小脑梗死体积(与对照组比较,脑梗死体积减小92.2%～65.3%;再灌注期亚低温组除缺血10小时后再灌注亚组无统计学意义外,其它亚组脑梗死体积减小68.4%～36.79%.结论结果显示缺血后亚低温的脑保护作用非常显著,提示超早期诱导亚低温可能延长溶栓治疗时间窗;缺血4小时后开始诱导亚低温效果较好,缺血8小时后开始诱导亚低温仍有效.     

亚低温对大鼠局灶性脑缺血ICAM-1和TNF-α表达的影响

目的:脑缺血后ICAM-1和TNF-α的表达增加。降低ICAM-1和TNF-α的表达和亚低温对缺血性脑卒中具有神经保护作用。本研究的目的在于观察亚低温对大鼠局灶性脑缺血ICAM-1和TNF-α表达的影响,并探讨亚低温对脑缺血性损害的神经保护作用机制。方法:采用栓线法阻断大鼠一侧大脑中动脉制作局灶性脑缺血动物模型,设实验组和对照组,分别置于冰毯机上和常温操作台上,使其肛温分别保持在34℃±0.5℃和37℃±0.5℃。12h后断头取脑,采用免疫组化方法检测缺血区ICAM-1阳性血管数目和采用双抗夹心酶联免疫吸附法(ELISA)测定血清TNF-α水平。结果:实验组ICAM-1和TNF-α的表达较对照组下降。结论:亚低温可降低大鼠局灶性脑缺血的ICAM-1和TNF-α的表达,推测亚低温降低ICAM-1和TNF-α的表达为亚低温减轻脑缺血性损害的神经保护作用机制之一。     

亚低温在急性脑缺血中对氨基酸和自由基含量的影响

目的研究亚低温状态下,急性脑缺血时皮质内四种氨基酸和自由基含量的改变,探讨亚低温对缺血脑组织的保护机制。方法将63只Wistar大鼠随机分为9组,假手术组7只,缺血组(手术后将其颞厂讥温度控制在36．5+-0．5℃)-缺血3h组,缺血3h分别再灌注1h、2h、3h组各7只;亚低温组(手术后将其颞肌温度控制在32．5±0．5℃)-缺血3h,缺血3h分别再灌注1h、2h、3h组各7只。动物模型参照Zealonga的大脑中动脉线栓模型并加以改进。结果比较缺血组和低温组,可见低温组缺血皮质内的谷氨酸(Glu)、天门冬安酸(Asp)、丙醛(MDA)的产生明显减少,而超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)的生成和释放明显增加,γ-氨基丁酸(GABA)的含量亦增加。结论亚低温状态下4种氨基酸含量及自由基系统的改变是其保护缺血神经元的重要机制。     

电针可影响脑缺血再灌注大鼠抗氧化应激MAPK信号的转导

针刺脑缺血再灌流模型大鼠 “百会”和“大椎”穴后,可见脑皮质及纹状体组织ERK表达增加,血清谷胱甘肽还原酶、谷胱甘肽过氧化物酶活性与血清谷胱甘肽含量上调,脑缺血再灌流大鼠神经行为学评分改善,应用MAPK阻滞剂PD98059可拮抗上述作用。说明电针能逆转脑缺血再灌流所造成自由基连锁反应及氧应激损伤,产生脑神经元的保护作用,MAPK信号通路可能是电针抗氧应激及氧化还原敏感信号的重要转导途径之一。     

亚低温对大鼠脑缺血再灌注损伤的保护研究

目的观察亚低温对大鼠全脑缺血再灌注后海马CAI区神经元凋亡的影响,探讨亚低温对缺血再灌注脑损伤的保护作用。方法SD大鼠30只随机分为对照组（n=10）,常温缺血组（n=10）,亚低温组（n=10）,采用改良的Pulsinelli-Brierley4血管法建立全脑缺血再灌注动物模型,缺血30min后再灌注72h,尼氏体染色观察海马区存活锥体细胞数,TUNEL法检测缺血后海马CAI区神经元凋亡情况,电镜下观察神经细胞形态学改变。结果与对照组比较,常温缺血组的海马CAI区存活的锥体细胞数目减少（P〈0.01）;与常温缺血组比较,亚低温组海马CAI存活的锥体细胞数目明显增多（P〈0.01）。对照组、亚低温组的海马CAI区神经元凋亡数目和凋亡指数明显低于常温缺血组。在电镜下观察亚低温能明显减轻缺血后脑组织病理形态学的损害程度。结论亚低温可以抑制脑缺血再灌注后的神经细胞凋亡,对神经细胞有保护作用。     

亚低温对缺血性神经元凋亡、细胞色素C释放的影响

通过大鼠短暂全脑缺血模型来探讨亚低温对大鼠脑缺血后细胞色素C(CytochromeC ,CytC)释放及缺血性神经元凋亡的影响 ,揭示亚低温的部分神经保护机制。用原位细胞凋亡检测法 (TUNEL染色 )检测及电镜观察脑缺血后大鼠脑海马CA1区神经元凋亡发生情况 ;免疫组织化学法测定脑缺血后大鼠脑海马区神经元中细胞色素C释放情况。结果显示 :①低温缺血组海马CA1区凋亡神经元数明显少于常温缺血组 (P <0 .0 1) ;②低温缺血3h组海马CA1区神经元CytC阳性表达低于常温缺血 3h组 (P <0 .0 1)。据此认为 ,全脑缺血后的迟发性神经元死亡很可能经由凋亡途径 ,而CytC激活、释放是缺血性神经元凋亡的一个关键事件。亚低温可抑制CytC的释放 ,推测经此途径减少缺血性神经元凋亡而发挥一定的神经保护作用。     

局部亚低温对大鼠脑缺血后凋亡细胞及谷氨酸转运体、亲代谢型谷氨酸受体表达的影响

目的 探讨亚低温对大鼠局灶性脑梗死后凋亡细胞及谷氨酸转运体(GLT-1)和亲代谢型谷氨酸受体(mGluR2/3)表达的影响.方法 88只大鼠随机分为亚低温组、常温组、对照组.制备一侧永久性大脑中动脉阻塞(pMCAO)模型.亚低温组应用贴敷式局部亚低温治疗仪将病灶侧脑部温度降至(33±0.5)℃并持续3 h,常温组保持全身温度在(37±0.5)℃.在脑缺血后3 h、6 h、12 h、24 h、3 d、7 d用Western印迹法检测各组病灶周围大脑皮质GLT-1和mGluR2/3表达;在脑缺血后6 h、24 h、3 d、7 d用末端标记(TUNEL)法检测凋亡细胞.结果 亚低温组在脑缺血后24 h、3 d,常温组在脑缺血后24 h、3 d、7 d脑梗死灶周围凋亡细胞与脑缺血后6 h比较差异有统计学意义(均P＜0.01).在脑缺血后24 h、3 d、7 d,亚低温组凋亡细胞明显少于常温组(均P＜0.01).与对照组相比,亚低温组大鼠脑缺血后3 h、6 h、12 h GLT-1表达增加,24 h、3 d、7 d减少;常温组大鼠脑缺血后3 h GLT-1表达增加,24 h、3 d、7 d减少(均P＜0.05).在脑缺血后6 h、12 h、7 d,亚低温组GLT-1表达显著高于常温组(均P＜0.05).与对照组相比,亚低温组和常温组在脑缺血后3 h、6 h、12 h、24 h、3 d mGluR2/3表达均明显增加(均P＜0.05).在脑缺血后3 h、6 h、24 h、3 d,亚低温组mGluR2/3表达显著高于常温组(均P＜0.05).结论 亚低温能促进脑缺血后星形胶质细胞mGluR2/3和GLT-1的表达,减少脑梗死后神经元凋亡.     

亚低温对局灶脑缺血再灌注后脑血流、血脑屏障、神经细胞损伤作用的研究

目的对比研究不同时期亚低温（ＭＨＴ３２℃±０．２℃）对局灶脑缺血再灌注损伤的作用。方法６４只雄性ＳＤ鼠被随机分成常温（ＮＴ）、缺血期亚低温（ＭＨＴｉ）、再灌注期亚低温（ＭＨＴｒ）、缺血期加再灌注期亚低温（ＭＨＴｉ＋ｒ）四组,并用改良Ｋｏｉｚｕｍｉ＇ｓ局灶脑缺血模型,分别观察了动物缺血３小时再灌注３小时过程中,缺血周边和核心区局部脑血流（ｒＣＢＦ）改变,再灌注３小时后血脑屏障（ＢＢＢ）破坏及再灌注７２小时后缺血梗塞灶体积。结果ＭＨＴｉ＋ｒ及ＭＨＴｉ均有改善缺血周边区再灌注后急性高灌注和继发低灌流及核心区持续低灌流、减轻血脑屏障破坏、减少缺血梗塞灶体积的作用。该作用尤以ＭＨＴｉ＋ｒ为明显。ＭＨＴｒ作用有限。结论ＭＨＴｉ＋ｒ对皮层的保护作用较ＭＨＴｉ好。由此可推知,局灶脑缺血再灌注损伤是个持续的过程,亚低温治疗不但要考虑开始时间,其持续时间对疗效具有同样重要价值     

缺血再灌注对大鼠海马CA1及DG神经元内19S蛋白酶体影响的激光扫描共聚焦显微镜研究

目的探讨缺血再灌注对大鼠海马CA1及海马齿状核(DG)神经元内19S蛋白酶体的影响。方法采用20min全脑缺血的大鼠模型,20只大鼠分为5组,分别为假手术组及按照再灌注时间分为30min组,4h组,24h组,72h组,每组4只。采用含有4%多聚甲醛的PBS液体进行灌注,取出脑组织,放于多聚甲醛中固定24h后行冠状切片,应用免疫组织化学法标记抗19S蛋白酶体抗体,应用激光共聚焦显微镜对组织切片进行观察。结果大鼠海马区CA1神经元内19S蛋白酶体在缺血再灌注30min后开始减少,4h略增高,然后逐渐减少,直至72h细胞大部份死亡;DG神经元内的19S蛋白酶体也于再灌注30min后减少,4h略增高,然后逐渐减少,至24h程度最重,72h则有所恢复。结论全脑缺血再灌注后,海马CA1及DG神经元内19S蛋白酶体的变化影响了神经元内蛋白的降解,是导致缺血后神经元死亡的一个因素。     

亚低温对大鼠全脑缺血再灌注损伤后海马CA1区c-Jun蛋白表达的影响

目的研究亚低温对大鼠全脑缺血再灌注损伤后海马CA1区神经元的保护作用,并探讨其可能的机制。方法采用四血管阻断法建立大鼠全脑缺血模型。SD大鼠,随机分为假手术组(SH组)、常温组(IR组)和亚低温组(HIR组)。各组在全脑缺血15min后分别再灌注6h、12h、1d、3d,采用苏木素-伊红(HE)染色观察各时间点海马CA1区细胞形态学变化和TUNEL法检测海马CA1区神经元凋亡,免疫印迹检测c-Jun蛋白表达。结果(1)HE染色结果 IR组和HIR组于全脑缺血再灌注后6h,HE染色未见明显改变,IR组缺血再灌注1d时CA1区出现严重改变,3d时损伤最严重,出现细胞数目减少,细胞胞体缩小、胞核固缩深染,损伤严重,排列紊乱,核膜不清,核仁消失。而HIR组海马存活的锥体细胞数较之IR组12h、1d、3d时间点均明显增加(P<0.05)。(2)TUNEL标记IR组于缺血再灌注后6h在海马CA1区阳性细胞开始增多,缺血再灌注1 d时阳性细胞数最多。而HIR组各时间点阳性细胞数均较IR组明显减少(P<0.01)。(3)免疫印迹结果全脑缺血再灌注后6h c-Jun蛋白在IR组海马CA1区表达开始增加,12h达高峰,持续到3d;HIR组在各时间点的表达均弱于IR组(P<0.01)。结论亚低温通过减少海马CA1区c-Jun的表达,抑制海马CA1区神经元的凋亡,可能是亚低温脑保护作用的机制之一。     

Ultrastructural changes of rat cortical neurons following ligustrazine intervention for cerebral ischemia/reperfusion injury

BACKGROUND: Ligustrazine can reduce the production of free radicals and the content of malonaldehyde, and improve the enzymatic activity of adenosine-triphosphate in cerebral anoxia. It also can increase the expression of heat shock protein-70 and Bcl-2, thus alleviating brain tissue injury caused by cerebral ischemia/reperfusion. This study aimed to address the question of whether ligustrazine can protect the membrane structure of neurons.OBJECTIVE: To establish rat models of cerebral ischemia/reperfusion, observe the membrane structure and main organelles of neurons with electron microscope after ligustrazine intervention, and to analyze the dose-dependent effects of ligustrazine on neuronal changes.DESIGN: Arandomized controlled study.SETTING: Department of Anatomy Research and Electron Microscopy, Hebei North University. MATERIALS: Forty Wistar rats of SPS grade, weighing 180–250 g and equal proportion of female and male, were provided by Hebei Medical University Animal Center (No. 060126). The ligustrazine injection (40 g/L, No. 05012) was produced by Beijing Yongkang Yaoye. LKB4 Ultramicrotome was purchased from LKB Company in Sweden. JEM100CXII electron microscope was purchased from JEOL in Japan.METHODS: The experiment was performed in the Laboratory of the Department of Anatomy and Electron Microscopy, Hebei North University from June to August 2006. ① Wistar rats were allowed to adapt for 3 days, and were then randomly divided into four groups, according to the numeration table method: normal group, model group, low-dose ligustrazine group, and high-dose ligustrazine group. There were 10 rats in each group. ②Rats in the model group, low-dose ligustrazine group, and high-dose ligustrazine group un-derwent cerebral ischemia/reperfusion model, according to Bannister's method. The carotid artery was opened for reperfusion after 90 minutes of cerebral ischemia. Samples were collected from the cerebral cor-tex after 24 hours. Animals from the ligustrazine low-dose group and ligustrazine high-dose group received ligustrazine injections, 50 mg/kg and 100 mg/kg, respectively. Samples were collected at the same time as the model group.MAIN OUTCOME MEASURES: Alterations of the neuronal ultrastructure and main organelles were ob-served by electron microscopy.RESULTS: Forty Wistar rats were included in the final analysis. Plentiful ribosome and rough endoplasmic reticulum existed in the cytoplasm of cortical neurons in the normal group. Edema existed in the nucleus and cytoplasm of neurons in the model group. The cell membrane was damaged, resulting in the external erup-tion of certain cellular organelles. In the low-dose ligustrazine group, neuronal swelling was decreased in the cytoplasm, whereas cellular organelles were relatively increased. However, the mitochondria remained swollen. The double layer structure disappeared in parts of the mitochondrial membrane. The caryotheca was still broken, and neuronal damage was significantly decreased in the high-dose ligustrazine group. In ad-dition, cytoplasmic swelling was reduced andmost part of caryotheca was complete. Fragmentation of the cellular membrane was not detected. Mitochondrial cristae and the lysosome could also be detected. The number of rough endoplasmic reticulum and free ribosomes was increased, and the structure of great part of caryotheca was clear. In addition, the number of nuclear pore was increased. However, the nuclear hetero-chromatin was relatively reduced.CONCLUSION: In the rat, the protective effects of ligustrazine were significant on neuronal membrane structures and main organelles after cerebral ischemia/reperfusion. There was a dose-dependent effect be-tween neuronal changes and Ligustrazine.     

Mild hypothermia effects on intercellular adhesion molecule-1 and serum interleukin-6 expression in brain tissues of a rat focal ischemia model

BACKGROUND： Previous studies have confirmed the neuroprotective effect of mild hypothermia on ischemic brain injury. OBJECTIVE： To investigate the effects of mild hypothermia on intercellular adhesion molecule-1 expression and serum interleukin-6 levels in ischemic brain tissues of focal brain ischemia rats, and to explore the neuroprotective effects of mild hypothermia on ischemic brain injury. DESIGN, TIME AND SETTING： A randomized, controlled, neurobiological experiment was performed at the Central Laboratory, First Affiliated Hospital, Xinxiang Medical College, China from February to July 2006. MATERIALS： Thirty healthy, adult, Sprague Dawley rats were used to establish middle cerebral artery occlusion models using the suture method, The immunohistochemistry （streptavidin-biotin-peroxidase complex method） kit was purchased from Boster, China. Interleukin-6 radioimmunoassay was supplied by Institute of Radioimmunity, Technology Development Center, General Hospital of Chinese PLA. METHODS： The rats were equally and randomly assigned into mild hypothermia and control groups, and middle cerebral artery occlusion models were established. The rectal temperature was maintained at （37 ±0.5）℃ in the control group. In the mild hypothermia group, the rectal temperature was maintained at （33±1）℃. MAIN OUTCOME MEASURES： At 12 hours after model establishment, the ischemic brain hemispheres were coronally sliced at the level of the optic chiasm. The number of intercellular adhesion molecule-1-positive vessels per high-power field was observed with an optical microscope. Serum interleukin-6 levels were measured by radioimmunoassay. RESULTS： Compared with the control group, intercellular adhesion molecule-1 and serum interleukin-6 expressions were significantly decreased in ischemic brain tissues of the mild hypothermia group （P 〈 0.01）. CONCLUSION： Mild hypothermia exhibits a neuroprotective effect by reducing serum interleukin-6 and intercellular adhesion molecule-1 expression followi     

Effects of fastigial nucleus electrical stimulation on lateral ventricle nestin expression after focal cerebral ischemia/reperfusion in adult rats**★

BACKGROUND： Previous studies have confirmed that fastigial nucleus electrical stimulation can induce endogenous neuroprotective mechanisms and produce wide and long-lasting neuroprotective effects. Nevertheless, the precise mechanisms remain poorly understood. OBJECTIVE： This study was designed to observe the effects of fastigial nucleus electrical stimulation on nestin-positive cell expression in adult rat lateral ventricle after focal cerebral ischemia/reperfusion, as well as neurological functional changes as a function of time. DESIGN： A randomized controlled animal experiment. SETTING： Department of Neurology, First Affiliated Hospital of Chongqing Medical University; Chongqing Key Laboratory of Neurology. MATERIALS： This study was performed in the Department of Neurology, First Affiliated Hospital of Chongqing Medical University and Chongqing Key Laboratory of Neurology from September 2004 to February 2006. A total of 180 healthy, adult, male Wistar rats, aged 8 weeks old, were provided by the Laboratory Animal Center of Chongqing Medical University. The main reagents and equipments were as follows： rabbit anti-rat nestin monoclonal antibody （Wuhan Boster Company, China）. METHODS： The included male Wistar rats were randomly divided into 5 groups： normal control, sham-operated, model, fastigial nucleus sham-stimulation （sham-stimulation for short）, and fastigial nucleus electrical stimulation （stimulation for short） groups. Six time points （1 hour of ischemia and 1, 3, 7, 14, 21, and 28 days of reperfusion, 6 rats per time point） were allotted to each group. Cerebral ischemia/reperfusion was performed by occlusion to the right middle cerebral artery with suture, followed by suture removal. In the stimulation group, subsequent to reperfusion, the rat left cerebellar fastigial nucleus was immediately subjected to 1 hour of stimulation. After anesthesia, the rat left cerebellar fastigial nucleus was stimulated for 1 hour using a square-wave electronic stimulator with a current in