17-β雌二醇对大鼠脑缺血再灌注损伤细胞凋亡影响的实验研究

目的观察雌二醇对大鼠脑缺血再灌注损伤脑细胞凋亡的影响。方法72只大鼠随机分为假手术组（n=8）、实验对照组及雌二醇治疗组，后两组又进一步分为3h、6h、12h、24h4个时间点，每时间点8只。线栓法建立大鼠局灶性脑缺血再灌注损伤模型，石蜡切片HE染色及免疫组化染色检测脑组织的细胞凋亡情况及凋亡调控基因Bcl-2、Caspase-3的表达。结果雌二醇治疗组的脑组织缺血半暗带区细胞凋亡较实验对照组明显减少；随着再灌注时间的延长，治疗组半暗带区Bcl一2的表达上调而Caspase-3的表达上调减弱。结论17-β雌二醇具有减少脑缺血再灌注损伤细胞凋亡的作用，而凋亡抑制基因Bcl-2的表达升高及凋亡执行蛋白Caspase-3的表达减弱可能其是重要机制之一。     

针刺对缺血再灌注大鼠海马脑源性神经营养因子mRNA的影响

目的 探讨针刺对缺血再灌注大鼠海马内脑源性神经营养因子（BONF）基因表达的影响，推测针刺改善缺血再灌注的可能机制。方法 采用4-血管阴断法制备大鼠全脑缺血再灌注模型，电针刺激百会、肾俞、足三里穴后，利用RT-PCR检测BDNF mRNA。结果 正常组大鼠海马BDNF mRNA表达极低，缺血再灌注组大鼠海马BDNF mRNA表达明显增高，治疗15d的针刺1、2组大鼠海马BDNF mRNA表达较缺血再灌注组更高，及早治疗且治疗时间为20d的针刺3组大鼠海马BDNF mRNA表达较降低。结论 缺血再灌注大鼠海马BDNF水平增高有利于损伤的神经元存活、恢复；针刺促进脑内细胞分泌内源性BDNF可能是针刺有效治疗缺血再灌注的机制之一。     

乌司他丁对脑缺血-再灌注大鼠脑组织细胞色素C、凋亡诱导因子表达及凋亡细胞数的影响

目的探讨乌司他丁对脑缺血-再灌注大鼠脑组织细胞色素C、凋亡诱导因子(AIF)表达及凋亡细胞数的影响。方法 54只SD大鼠随机分成假手术组、脑缺血-再灌注组(对照组)、脑缺血-再灌注+乌司他丁治疗组(治疗组)。采用大脑中动脉线栓法制作大鼠局灶性脑缺血-再灌注损伤模型。治疗组再灌注时,腹腔注射乌司他丁2万U/kg。采用免疫组化法检测大鼠脑组织细胞色素C表达,采用逆转录(RT)-PCR法检测大鼠脑组织AIF表达,采用原位末端标记法检测大鼠脑组织凋亡细胞数。结果对照组和治疗组大鼠脑组织皮质区细胞色素C、AIF的表达及凋亡细胞数均明显高于假手术组(均P<0.05),但治疗组大鼠脑组织皮质区细胞色素C、AIF的表达及凋亡细胞数明显低于对照组(均P<0.05)。结论乌司他丁抑制细胞凋亡可能与下调脑缺血-再灌注大鼠脑组织细胞色素C、AIF的表达,减轻线粒体损伤,抑制线粒体通路的凋亡途径有关。     

亚硒酸钠对脑缺血再灌注损伤大鼠HIF-1α表达的影响

目的 研究亚硒酸钠对大鼠脑缺血再灌注损伤后海马神经细胞凋亡的保护作用及其对低氧诱导因子-1α(HIF-1α)表达的影响.方法 48只SD大鼠随机分为假手术组、缺血再灌注组(模型组)及亚硒酸钠治疗组,每组16只,采用线栓法建立脑缺血再灌注模型,治疗组于再灌注后给予亚硒酸钠0.625 mg/(kg·d)腹腔注射7 d.各组大鼠经组织处理后用亚甲兰尼氏体染色及TUNEL染色,分别观察大鼠海马CA1区神经元存活和凋亡情况,Western Blot实验测定缺血组织HIF-1α水平的表达.结果 脑缺血再灌注损伤大鼠海马神经元数目明显减少,凋亡细胞明显增加(P<0.001),亚硒酸钠治疗后海马神经细胞存活数目明显增多,凋亡细胞明显减少(P<0.01);与假手术组比较,模型组大鼠海马HIF-1α水平表达明显增加(P<0.01),而经亚硒酸钠治疗后大鼠海马HIF-1α水平表达较模型组明显降低(P＜0.05).结论 亚硒酸钠可减轻脑缺血再灌注损伤大鼠神经元凋亡,同时能抑制组织HIF-1α的过度表达.     

大鼠局灶性脑缺血再灌注后凋亡诱导因子的表达与神经元凋亡的关系

目的 探讨大鼠局灶性脑缺血再灌注后凋亡诱导因子(AIF)的表达变化及与细胞凋亡的关系.方法 将Wistar大鼠分为假手术组(6只)和模型组(30只).模型组大鼠采用线栓法建立大脑中动脉闭塞模型,假手术组大鼠插线较模型组浅,不造成大脑中动脉闭塞.观察假手术组及模型组缺血再灌注后6 h、24 h、48 h、72 h和7 d缺血半暗带AIF的表达,同时利用TUNEL法观察对应区域细胞凋亡的动态变化规律.结果模型组脑缺血再灌注6 h在缺血半暗带区AIF阳性细胞显著增加,再灌注48 h达到高峰[(130.47±11.32)个];各时相点均可见细胞凋亡,凋亡细胞数以再灌注48 h最多f(118.53±11.67)个];各组问比较差异均有统计学意义(JP<0.05).结论 局灶性脑缺血再灌注可致AIF表达增加.并引起细胞凋亡.     

乌司他丁对脑缺血再灌注大鼠脑组织JNK及细胞凋亡的影响

目的探讨乌司他丁对脑缺血再灌注大鼠缺血侧脑组织c-Jun氨基末端激酶(JNK)蛋白表达及凋亡细胞数的影响。方法 36只雄性清洁SD大鼠按随机平均原则分成3组:假手术组(12只)、脑缺血再灌注组(对照组,12只)、脑缺血再灌注+乌司他丁治疗组(治疗组,12只)。大鼠局灶性脑缺血再灌注损伤模型采用大脑中动脉线栓法制作。采用RT-PCR法检测大鼠脑组织JNK的表达,采用TUNEL法检测大鼠脑组织凋亡细胞数。结果与假手术组相比,对照组和治疗组大鼠脑组织皮质区JNK的表达明显升高,凋亡细胞数均明显增加(P均0.05)。与对照组相比,治疗组大鼠脑组织JNK的表达明显下降,凋亡细胞数均明显减少(均P0.05)。结论乌司他丁可下调缺血再灌注大鼠脑组织JNK的表达并抑制其细胞凋亡,乌司他丁抑制细胞凋亡可能与抑制JNK传导通路相关。     

黄芪注射液对脑缺血再灌注后的神经细胞凋亡及相关基因表达的影响

目的观察黄芪注射液对大鼠脑缺血再灌注后神经细胞调亡及其相关基因Bc1-2、Bax蛋白表达的影响。方法SD大鼠36只,随机等分为假手术组、模型组、黄芪注射液组。分别采用TUNEL法及免疫组织化学与医学图像分析结合的方法检测各组大鼠脑组织神经细胞凋亡及Bc1-2、Bax蛋白的表达。结果与假手术组相比,模型组大鼠组织神经细胞凋亡数目及Bc1-2、Bax蛋白表达增多（P〈0.01）。与模型组相比,黄芪注射液组大鼠脑组织神经细胞凋亡数目及Bax蛋白表达减少,Bc1-2蛋白表达增强（P〈0.05）。结论黄芪注射液可通过抑制脑缺血再灌注后神经细胞发挥脑保护,其抗凋亡机制可能与上调Bc1-2蛋白表达同时下调Bax蛋白的表达有关。     

针刺对大鼠缺血再灌注后脑细胞内钙稳态的影响及脑保护的机制探讨

目的探讨针刺对抗脑缺血再灌注所致脑细胞凋亡的机制。方法采用线栓法制作SD大鼠脑缺血再灌注动物模型,于脑缺血30m in再灌注30m in时给予针刺干预,于再灌注72h处死动物取材,分别作脑细胞内游离钙、CGRP和脑细胞凋亡的检测。结果针刺干预组与单纯脑缺血再灌注组比较,脑细胞内游离钙明显降低(P<0.05),CGRP的表达明显增强(P<0.05),脑细胞凋亡数目明显减少(P<0.05)。结论针刺通过调节钙稳态及介导CGRP的分泌,减少脑缺血再灌注后脑细胞的凋亡,增强脑组织对脑缺血缺氧的耐受性。     

Bcl-2、Bax蛋白产物在脑缺血耐受中的表达及前列腺素E1的干预作用

目的探讨大鼠脑缺血时凋亡相关基因Bcl-2、Bax蛋白的表达与脑缺血耐受的关系及前列腺素E1 (PGE1)对脑缺血耐受的影响。方法采用大鼠全脑-局灶脑缺血耐受模型。观察预缺血组、PGE1组在大脑中动脉梗死2h再灌注(MCAO)24h后神经行为评分、脑梗死体积、Bcl-2、Bax蛋白表达和TUNEL、流式细胞仪检测神经细胞凋亡。结果MCAO后24h,PGE1组的神经行为评分、脑梗死体积、Bax蛋白表达更少,Bcl-2蛋白表达较高,神经细胞凋亡降低。结论预缺血及PGE1预处理后,使Bax蛋白表达减少,Bcl-2蛋白表达增高能够诱导脑缺血耐受,且PGE1的作用优于预缺血。     

亚低温对大鼠脑缺血再灌注神经细胞凋亡的影响

目的 观察亚低温对脑缺血再灌注后神经细胞凋亡的影响.方法 制作SD大鼠脑缺血再灌注损伤模型,分亚低温治疗组和对照组,组织原位凋亡检测法检测亚低温治疗期间第24、48、72小时,以及复温后第24、48、72、96和120小时的细胞凋亡情况,RT-PCR方法检测所有观察时间点促凋亡基因Caspase、Fas和凋亡抑制基因Bcl-2的mRNA表达水平.结果 亚低温治疗组脑组织的细胞凋亡数量在亚低温治疗期间的三个检测时间点均少于对照组(P＜0.05),复温以后逐渐增加,至复温后第72小时及以后细胞凋亡数量与对照组差异无统计学意义(P＞0.05);促凋亡基因Caspase、Fas和凋亡抑制基因Bcl-2的mRNA表达水平在亚低温治疗期间均低于对照组(P＜o.05),复温后出现mRNA表达的同向性升高,复温72 h及以后接近对照组(P＞0.05).结论 亚低温可明显减缓脑缺血再灌注后神经细胞的凋亡进程,但在其复温后凋亡速度迅速回升.因此,应积极争取亚低温治疗时间窗,同步进行神经细胞救治.     

Shallow needling on Neiguan and Gongsun acupoints in rats with brain ischemia Changes in apoptosis regulating genes and vasoactive substances

For the treatment of brain ischemia using acupuncture, the needle is predominantly inserted into muscular layers and deep tissue. However, few studies have investigated the outcomes of shallow needling. The present study established middle cerebral artery occlusion models in rats using the thrombosis method. Shallow needling and conventional needling at the bilateral Neiguan (PC 6) and Gongsun (SP 4) acupoints improved neurological function of middle cerebral artery occlusion rats, increased the expression ...     

中药对大脑中动脉闭塞模型大鼠脑血管发生的作用

目的研究中药复方复健片对大脑中动脉闭塞（MCAO）模型大鼠脑血管发生的影响，并探讨其治疗缺血性脑卒中的作用机制。方法采用Tamura等方法制造大鼠MCAO模型。将30只大鼠随机分为药物组、MCAO模型组、假手术组。药物组于造模成功后6d按体重10g／kg灌胃给予复健片水溶液。余二组分别灌胃给予同等量NS，1次／d，共2周。观察模型大鼠脑内血管内皮细胞生长因子（VEGF）、碱性成纤维细胞生长因子（bFGF）、血小板源性生长因子（PDGF）的表达以及微血管密度的变化。结果药物组大鼠脑内VEGF、bFGF、PDGF表达明显增强．微血管密度增高。结论复健片可显著增加MCAO模型大鼠脑内VEGF、bFGF、PDGF的表达．提示其促进血管发生是治疗缺血性脑卒中的作用机制之一。     

Melatonin combined with exercise cannot alleviate cerebral injury in a rat model of focal cerebral ischemia/reperfusion injury

Previous studies have demonstrated that melatonin combined with exercise can alleviate secondary damage after spinal cord injury in rats.Therefore,it is hypothesized that melatonin combined with exercise can also alleviate ischemic brain damage.In this study,adult rats were subjected to right middle cerebral artery occlusion after receiving 10 mg/kg melatonin or vehicle subcutaneously twice daily for 14 days.Forced exercise using an animal treadmill was performed at 20 m/min for 30 minutes per day for 6 days prior to middle cerebral artery occlusion.After middle cerebral artery occlusion,each rat received melatonin combined with exercise,melatonin or exercise alone equally for 7 days until sacrifice.Interestingly,rats receiving melatonin combined with exercise exhibited more severe neurological deficits than those receiving melatonin or exercise alone.Hypoxia-inducible factor 1α mRNA in the brain tissue was upregulated in rats receiving melatonin combined with exercise.Similarly,microtubule associated protein-2 mRNA expression was significantly upregulated in rats receiving melatonin alone.Chondroitin sulfate proteoglycan 4 (NG2) mRNA expression was significantly decreased in rats receiving melatonin combined with exercise as well as in rats receiving exercise alone.Furthermore,neural cell loss in the primary motor cortex was significantly reduced in rats receiving melatonin or exercise alone,but the change was not observed in rats receiving melatonin combined with exercise.These findings suggest that excessive intervention with melatonin,exercise or their combination may lead to negative effects on ischemia/reperfusion-induced brain damage.     

A standardisable model of focal cerebral ischaemia innormotensive rats

In this study various techniques with different periods of ischaemia have been used in order to describe a standardisable and reproducible model of reversible focal cerebral ischaemia in normotensive rats. Cerebral blood flow to the left hemisphere of the rats was temporarily interrupted by middle cerebral artery occlusion only in four rats of each group, by simultaneous middle cerebral artery and ipsilateral common carotid artery occlusion in six rats of each group, and by middle cerebral artery and bilateral common carotid artery occlusion in six rats of each group. Within each group temporary ischaemia lasted for 1, 2 or 3 h and animals survived for 24 h following reperfusion. An infarct of significant size with low standard deviation was observed after 3 h of distal middle cerebral artery and bilateral common carotid artery occlusion followed by 24 h of reperfusion. We have found that the ratio of the infarct volume to the supratentorial brain volume is a more reliable criterion (with less standard deviation) than infarct volume alone and could be used for comparison of results obtained in experimental studies.     

脑缺血再灌注损伤模型大鼠大脑皮质BDNF mRNA表达减少

目的制备局灶性脑缺血再灌注损伤大鼠模型,并观察大脑皮质脑源性神经营养因子(BDNF)mR-NA表达的变化。方法雄性SD大鼠,采用线栓法闭塞大脑中动脉2h后进行再灌注3d,制备局灶性脑缺血再灌注损伤模型。采用神经缺失评分观察大鼠的行为学表现;TTC染色检查脑组织梗死情况;HE染色观察大鼠脑组织形态结构;RT-PCR技术检测大鼠大脑皮质BDNF mRNA的表达。结果假手术组大鼠无神经功能障碍表现;脑组织未见梗死灶;脑组织神经细胞形态规则;大脑皮质BDNF mRNA的相对表达量,与正常组相比,未见明显变化。与假手术组相比,局灶性脑缺血再灌注损伤模型大鼠出现神经功能障碍;左侧半球可见梗死灶;梗死侧脑组织形态学观察显示神经细胞大量坏死脱落、胞质呈空泡变性、疏松、胞核浓缩深染;大脑皮质BDNF mRNA表达量明显减少。结论大脑中动脉闭塞2h后进行再灌注3d可造成脑缺血再灌注损伤,可能与大脑皮质BDNF mRNA的表达减少有关。     

电刺激治疗对脑梗死大鼠运动功能和脑组织微管相关蛋白-2及存活素表达的影响

目的探讨电刺激对脑梗死大鼠运动功能和脑组织微管相关蛋白-2(MAP-2)及存活素表达的影响。方法采用线栓法制作大鼠局灶性脑梗死模型。制模后24h起,分别给予大鼠瘫痪侧(单侧)或双侧肢体电刺激治疗3d、7d、14d和21d。电刺激前、后各时间点用平衡木试验(BWT)检测大鼠的肢体运动功能,用免疫组化染色检测梗死灶周围大脑皮质MAP-2和存活素的表达水平,并与脑梗死对照组和假手术组大鼠比较。结果治疗第7d起电刺激组大鼠瘫痪肢体的BWT评分明显高于对照组(均P<0.05),治疗14d起双侧电刺激组BWT评分明显高于单侧电刺激组(均P<0.05)。治疗第7d起,电刺激组梗死灶周围脑组织MAP-2表达水平明显高于对照组(均P<0.05);治疗14d起,双侧电刺激组MAP-2的表达水平明显高于单侧电刺激组(均P<0.05);治疗21d时与假手术组MAP-2表达水平比较差异无统计学意义。电刺激组治疗后各时间点梗死灶周围脑组织存活素表达水平明显高于假手术组(均P<0.05),治疗7d、14d存活素表达水平明显高于对照组(均P<0.05),达到高峰;而双侧电刺激组明显高于单侧电刺激组(均P<0.05);治疗21d时,电刺激组和...     

Asymmetry of sympathetic consequences of experimental stroke.

Asymmetries of sympathetic regulation at the level of the inferior cervical ganglia have long been recognized. Lateralization of autonomic representation may also occur in the brain, since inactivation of the left and right hemispheres by intracarotid amobarbital produces an increase and decrease in heart rate, respectively. However, this conclusion has remained tentative, since the differential effect of lateralized brain lesions on sympathetic activity has not been studied systematically. Forty-eight urethan-anesthetized Wistar rats were divided into three groups: a group given left middle cerebral artery occlusion, and a group given sham operation. Heart rate, mean arterial blood pressure, renal sympathetic nerve discharge, and electrocardiogram were monitored throughout the 4-hour experiments. Plasma epinephrine and norepinephrine levels were measured at baseline and 1 and 4 hours after occlusion or sham occlusion. The mean arterial pressure decreased in the group given sham operation and to lesser extent in the group given left middle cerebral artery occlusion. By contrast, mean arterial pressure did not fall in the group given right middle cerebral artery occlusion and at 4 hours was significantly higher than control values in the sham-occluded rats. Renal sympathetic nerve discharge was decreased in the sham-occluded group, increased significantly from 20 minutes to 2 hours in the group given left middle cerebral artery occlusion, and increased from about 20 minutes to the end of the experiment in the group given right middle cerebral artery occlusion. The plasma norepinephrine level was significantly elevated at 1 hour (93%) and 4 hours (44%) only in the group given right middle cerebral artery occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

局灶性脑缺血大鼠脑内mdr1/P-glycoprotein表达的变化

目的观察大鼠局灶性脑缺血损害后脑内mdr1／P—glycoprotein的表达变化。方法大鼠大脑中动脉栓塞法(MCAO法)制作局灶性脑缺血模型,脑切片免疫组织化学染色检测mdr-1／P—glycoprotein在脑内的表达部位及表达时程的变化。结果 mdr-1／P—glycoprootein在缺血侧皮层和纹状体的血管内皮细胞表达增多,并出现在同侧损伤部位的神经元,其在损伤后2h开始出现,6h达到高峰,之后开始下降,到24h不能被检测到。结论大脑中动脉阻塞后可以诱导缺血损伤侧的血管内皮细胞P—glycoprotein过量表达,而同侧的神经元短暂表达P-glyco- protein．     

Temporal evolution of ischemic damage in rat brain measured by proton nuclear magnetic resonance imaging

We studied the effect of focal cerebral ischemia on the "state" of brain water using proton nuclear magnetic resonance imaging. Focal cerebral ischemia was induced in five halothane-anesthetized rats via tandem occlusion of the left common carotid artery and the left middle cerebral artery. The proton transverse relaxation time, the proton density, and the water diffusion coefficient were measured at various times from the same region of brain tissue from 1.5 to 168 hours after occlusion. Early measurements indicated significant changes in the transverse relaxation time (p = 0.004) and water diffusion coefficient (p = 0.002) of ischemic brain tissue compared with a homologous region from the contralateral hemisphere. However, the transverse relaxation time, proton density, and water diffusion coefficient in ischemic brain tissue showed different temporal evolutions over the study period. Diffusion coefficient weighting was superior to relaxation time and proton density weighting for the visualization of early cerebral ischemia. Our data suggest that nuclear magnetic resonance imaging is sensitive in detecting changes in proton-associated parameters during early cerebral ischemia and confirm significant changes (p less than or equal to 0.01) in the temporal evolution of transverse relaxation times, proton densities, and diffusion coefficients following middle cerebral artery occlusion.     

经鼻导入rhG-CSF对脑梗死大鼠皮层FasL和HO-1表达的影响

目的 探讨经鼻靶向中枢导入重组人粒细胞集落刺激因子(rhG-CSF)对脑梗死大鼠皮层Fas配体(FasL)和血红素氧合酶-1(HO-1)表达的影响. 方法将60只大鼠按随机数字表法分为正常组、假手术组、脑梗死组、脑梗死+皮下注射rhG-CSF组、脑梗死+经鼻导入生理盐水组、脑梗死+经鼻导入rhG-CSF组.线栓法制作大鼠可逆性大脑中动脉阻塞(MCAO)模型,2 h后再灌注.于MCAO模型制作成功后1 d、3 d制备脑组织冠状冰冻切片,用免疫荧光染色检测FasL和HO-1在缺血半暗带皮层的表达,激光共聚焦显微镜采集图像并计数阳性细胞数. 结果正常组和假手术组大鼠脑组织中见极少量FasL和HO-1阳性细胞,两组比较差异无统计学意义(P>0.05).脑梗死组大鼠FasL和HO-1阳性细胞数明显增加(1 d时较3 d时高),表达区域主要为缺血半暗带皮层,与脑梗死+经鼻导入生理盐水组比较差异无统计学意义(P>0.05).经鼻给予rhG-CSF治疗后脑梗死大鼠脑组织内FasL阳性细胞表达下降,HO-1阳性细胞表达进一步上调,与脑梗死+皮下注射rhG-CSF组大鼠比较差异有统计学意义(P<0.05). 结论经鼻靶向中枢导入rhG-CSF可以通过降低FasL、上调HO-1表达抑制脑梗死大鼠缺血半暗带皮层神经元凋亡,参与脑保护机制.