桃红四物汤对大鼠脑缺血再灌注损伤后大脑皮质神经元Caspase-3与p53表达的影响

目的:探讨桃红四物汤对脑缺血再灌注损伤大鼠大脑皮质神经元Caspase-3与p53表达的影响。方法:120只雄性SD大鼠随机分为正常组、假手术组、模型组、桃红四物汤低、中、高剂量组(0.7 g/kg、1.4 g/kg、2.1g/kg)共6组。采用改良后的Longa线栓法制备大脑中动脉阻塞再灌注模型,缺血90分钟再灌注24小时后,桃红四物汤各剂量组分别以桃红四物汤低、中、高剂量灌胃绐药量为1 ml/100 g,正常组和假手术组以等容量生理盐水灌胃。至第8天时将各组大鼠处死并取脑。通过2,3,5-氯化三苯四氮唑(TTC)染色法观察各组大鼠脑梗死体积及梗死体积率;TUNEL染色法显示大脑皮质凋亡神经元的形态和数量,免疫组织化学染色法观察半胱氨酸蛋白酶3(Caspase-3)与p53的表达情况。结果:与模型组比较,桃红四物汤各剂量组均能降低大鼠脑梗死体积与梗死体积率(P0.01);减少大脑皮质顶叶区凋亡神经元(P0.01),降低大脑皮质顶叶区神经元Caspase-3与p53的表达(P0.01);并且其治疗效果随桃红四物汤给药剂量的增加而增强(P0.01)。结论:桃红四物汤能够抑制脑缺血再灌注损伤后大鼠大脑皮质神经元Caspase-3与p53的表达。     

当归补血汤对大鼠局灶性脑缺血再灌注血-脑屏障和大脑皮质神经元的影响

目的:探讨当归补血汤对大鼠局灶性脑缺血再灌注后大脑皮质神经元的治疗作用。方法:将90只雄性SD大鼠随机分为正常对照组、模型组、当归补血汤(高、中、低剂量)组。观察各组大鼠行为学缺陷、从股静脉注入伊文斯蓝溶液观察血-脑屏障通透性变化、用Nissl染色法观察大脑皮质神经元的形态和数量。结果:与模型组相比较,当归补血汤治疗组各剂量均能改善大鼠神经功能(P<0.05)、减少脑组织中伊文斯蓝含量(P<0.05)、增加大脑皮质神经元数量(P<0.05),并以中剂量组效果最好。结论:当归补血汤对缺血再灌注引发的大脑皮质神经元死亡有保护作用,这可能与其降低血-脑屏障通透性有关。     

UCF-101对大鼠脑缺血再灌注损伤的神经保护作用

目的观察UCF-101对大鼠脑缺血再灌注损伤后神经元凋亡及Caspase-9蛋白表达的影响,探讨UCF-101对缺血性脑损伤的神经保护作用。方法随机将大鼠分为假手术组、缺血再灌注组及UCF-101处理组。采用线栓法建立Wistar大鼠大脑中动脉闭塞(MCAO)2h再灌注模型,于再灌注后24h取脑,采用TTC法测梗死体积,TUNEL法检测神经元凋亡,免疫组化法观察脑组织神经元Caspase-9蛋白的表达。结果假手术组未见梗死现象,与假手术组比较,缺血再灌注组脑组织凋亡细胞数和Caspase-9的表达均明显升高(P0.05)。与缺血再灌注组相比,UCF-101处理组梗死体积明显缩小(P0.05),UCF-101处理组脑组织凋亡细胞数和Caspase-9的表达均明显减少(P0.05)。结论 UCF-101可能通过下调脑组织神经元Caspase-9蛋白的表达,抑制神经元的凋亡而发挥神经保护作用。     

养血清脑颗粒对蒙古沙鼠全脑缺血再灌注后的神经保护作用

目的 探讨养血清脑颗粒对蒙古沙鼠全脑缺血再灌注后的神经保护作用.方法 用两血管阻塞法(2-VO)结扎30 min再灌注损伤模型,将蒙古沙鼠随机分为假手术组、模型组和手术前90min灌胃法给药预防组.用Nissl染色法观察蒙古沙鼠海马CA1区细胞的变化;用免疫组织化学方法观察海马CA1区表达谷氨酸盐合成酶(G1 Syn)和Caspase-3阳性细胞数量的变化;TUNEL法检测细胞凋亡.结果 蒙古沙鼠全脑缺血再灌注1d及2d预防给药组Nissl染色结果显示,海马CA1区存活细胞数量比模型组明显增多(分别为P＜0.01,P＜0.05);再灌注5d预防给药组海马CA1区存活细胞数量与模型组相比无显著性差异(P＞0.05).再灌注1d及2d预防给药组海马CA1区表达谷氨酸盐合成酶(G1 Syn)的阳性细胞量较模型组明显减少(分别为P＜0.01,P＜0.05);再灌注5d预防给药组海马CA1区免疫阳性细胞数量与模型组相比无显著性差异(P＞0.05);Caspase-3的表达在再灌注1d时预防给药组免疫阳性细胞数量与模型组比较有显著性升高(P＜0.05),但是再灌注2d及5d时预防给药组免疫阳性细胞数较模型组无显著降低(P＞0.05).TUNEL结果显示预防给药组凋亡细胞相应减少.结论 养血清脑颗粒能通过谷氨酸盐合成酶选择性抑制兴奋性氨基酸谷氨酸的神经毒性作用,减少神经细胞的凋亡,从而发挥神经保护作用.     

小檗碱对局部脑缺血组织中HIF-1α表达的影响

目的 研究大鼠局部性脑缺血再灌注损伤时,小檗碱(BE)对缺氧诱导因子-1α(HIF-1α)表达及脑神经元凋亡的影响.方法 雄性SD大鼠随机分为假手术组、大脑中动脉阻塞再灌注组(MCAO/R组)、假性治疗组(DMSO组)、小檗碱10mg/kg治疗组(BE10组)、小檗碱20mg/kg治疗组(BE20组)、小檗碱40mg/kg治疗组(BE40组).治疗组在术前48h、24h及术后6h腹腔注射相应剂量药物,观察各组大鼠神经行为学缺陷;再灌注7d,TTC染色观察脑梗死体积变化;再灌注24h,制备脑组织切片分别作Nissl染色、免疫组织化学染色、TUNEL标记及免疫荧光双标记.结果 BE20、BE40组神经功能较MCAO/R组有明显改善(P＜0.05),但BE10组神经学评分与MCAO/R组比较,差异无统计学意义(P＞0.05).不同剂量BE治疗均可以减小梗死灶体积(P＜0.05),且呈现剂量依赖性.Nissl染色可见BE治疗组皮质神经元结构较清晰,胞体肿胀、核固缩、核溶解程度较模型组及假性治疗组明显减轻,淡染区域减小;免疫组织化学法观察到,BE组HIF-1α、Caspase-3、BNIP3、VEGF及TUNEL标记的阳性细胞数减少;免疫荧光双标记显示HIF-1α与BNIP3、Caspase-3及TUNEL阳性颗粒共表达于细胞中.结论 BE可能通过降低HIF-1α水平并下调其下游的BNIP3和VEGF的表达,从而减少凋亡因子Caspase-3的作用而发挥神经元保护作用.     

骨形态发生蛋白-7对大鼠脑缺血再灌注后Caspase-3表达的影响

目的 观察骨形态发生蛋白-7（BMP-7）对大鼠局灶性脑缺血再灌注损伤神经细胞凋亡的影响及其机制。方法 将40只SD雄性大鼠随机分为实验组、对照组和假手术组,采用改良线栓法制作大脑中动脉栓塞缺血再灌注（MCAO/R）模型,实验组在缺血2h再灌注后尾静脉注射BMP-7（0.1mg/kg）250μl,对照组和假手术组尾静脉注射等量生理盐水,运用Bederson评分法进行神经功能缺失评分。再灌注24h后将大鼠处死,采用2,3,5-氯化三苯基四氮唑（TTC）染色法观察梗死灶范围,并计算梗死灶体积占半球体积的百分比;HE染色观察脑组织病理变化,原位缺口末端标记法（TUNEL）计数神经元凋亡数量,免疫组织化学染色观察缺血脑组织内Caspase-3表达。结果 BMP-7组大鼠Bederson评分（1.7±0.5）比对照组（2.7±0.5）明显降低（t =4.66,P ＜0.01）,脑梗死体积百分比（7.6±1.4）比对照组（22.3±4.5）明显降低（t =6.98,P ＜0.01）。与对照组相比,HE染色显示BMP-7组大鼠缺血侧大脑皮质脑组织损伤明显减轻。BMP-7组缺血侧大脑皮质、纹状体及海马TUNEL阳性细胞数（分别为3.6±0.6、7.4 ±1.1、5.0±0.7）明显低于对照组同一区域（分别为13.4±1.1、17.8±1.5、15.4±1.1,P ＜0.01）。BMP-7组缺血侧大脑皮质、纹状体及海马Caspase-3阳性细胞数（分别为7.6±0.9、5.8±0.8、10.6±1.1）明显低于对照组同一区域（分别为15.4±0.6、14.0±1.2、17.2±0.8,P ＜0.01）。结论 BMP-7可通过下调Caspase-3表达而抑制大鼠脑缺血再灌注损伤引起的细胞凋亡,起到神经保护作用。     

养血清脑颗粒对蒙古沙鼠全脑缺血再灌注后海马CA1区神经元的治疗作用

目的 探讨蒙古沙鼠全脑缺血再灌注后养血清脑颗粒(Yangxueqingnaokeli,YXQNKL)的治疗作用.方法 采用蒙古沙鼠两侧颈总动脉结扎法,缺血30min再灌注5d模型(分为假手术组、缺血再灌注组、养血清脑颗粒治疗组).用Nissl染色法观察海马CA1区神经元的形态和数量,用免疫组织化学方法观察海马CA1区神经元神经钙离子感应蛋白1(NCS-1)、天冬氨酸特异性半胱氨酸蛋白酶3(caspase-3)和谷氨酸盐合成酶(Glusyn)的表达情况.结果 与缺血再灌注组比较,缺血再灌注 0.4g/kg养血清脑颗粒治疗组和缺血再灌注 0.8g/kg养血清脑颗粒治疗组Nissl染色显示海马CA1区神经元数量明显增加(P＜0.05);免疫组织化学法显示海马CA1区神经元细胞NCS-1、caspase-3和Glusyn的阳性细胞数明显减少(P＜0.05).结论 全脑缺血再灌注后,给予养血清脑颗粒能显著增加海马CA1区神经元数量,这与其减少海马CA1区神经元NCS-1、caspase-3和Glusyn的表达有密切的联系.     

黄芪注射液腹腔注射脑缺血再灌注模型大鼠海马组织神经元凋亡及半胱氨酸天冬氨酸蛋白酶3的表达*

背景：有研究表明黄芪注射液可抑制脑缺血再灌注大鼠海马神经元凋亡。 目的：观察黄芪注射液腹腔注射脑缺血再灌注大鼠海马神经元凋亡及半胱氨酸天冬氨酸蛋白酶3的表达。 方法：采用四血管阻断法制备全脑缺血再灌注大鼠模型,建模后给予质量浓度2,4,6,8和10 mL/kg的黄芪注射液腹腔注射,并设立假手术组。分别采用原位末端标记法染色和蛋白免疫印迹方法检测各组大鼠海马神经元凋亡及半胱氨酸天冬氨酸蛋白酶3蛋白表达。 结果与结论：模型组大鼠海马神经元凋亡指数及半胱氨酸天冬氨酸蛋白酶3蛋白表达明显增多(P < 0.05);与模型组相比,黄芪注射液4,6,8,10 mL/kg组海马神经元凋亡指数及半胱氨酸天冬氨酸蛋白酶3蛋白表达明显减少(P < 0.05);与黄芪注射液4 mL/kg组比,黄芪注射液6,8,10 mL/kg 组神经元凋亡指数及半胱氨酸天冬氨酸蛋白酶3蛋白表达减少(P < 0.05),且呈剂量依赖性。结果证实,黄芪注射液可抑制脑缺血再灌注大鼠海马神经元凋亡及半胱氨酸天冬氨酸蛋白酶3蛋白表达。关键词：黄芪注射液;脑缺血再灌注;不同剂量;半胱氨酸天冬氨酸蛋白酶3;细胞凋亡;中医药;组织构建 doi:10.3969/j.issn.1673-8225.2012.20.031     

毛蕊异黄酮通过调控细胞色素C/凋亡酶激活因子1凋亡信号通路减轻大鼠脑缺血/再灌注损伤

目的 探讨毛蕊异黄酮对脑缺血/再灌注损伤的影响及其作用机制.方法 将SPF级雄性SD大鼠40只随机分为假手术组(sham)、模型组(model)、毛蕊异黄酮组(calycosin,20 mg/kg)和尼莫地平组(nimodipine,0.7 mg/kg,阳性对照药组),采用改良线栓法建立大鼠大脑中动脉闭塞模型,在体模拟脑缺血/再灌注损伤环境.Zea Longa评分法检测脑缺血/再灌注大鼠神经功能缺损情况;盐酸2,3,5-三苯基四氮(TTC)染色检测脑梗死体积;HE染色检测神经细胞病理形态学改变;尼氏染色观察尼氏小体变化;TUNEL染色检测神经细胞凋亡情况;Western blotting检测凋亡关键蛋白细胞色素C(Cyt C)、凋亡酶激活因子1(Apaf-1)、Caspase-9和Caspase-3的表达.结果 与sham组相比,model组神经功能缺损症状明显(P＜0.05),脑梗死体积明显增大(P＜0.05),倒置光学显微镜下观察发现神经细胞出现胞体收缩,胞核深染、固缩,细胞生长状态较差,尼氏小体明显减少或消失(P＜0.05),凋亡神经细胞明显增多(P＜0.05),凋亡关键蛋白Cyt C、Apaf-1、Caspase-9和Caspase-3表达均明显升高(P＜0.05);与model组相比,calycosin组和nimodipine组大鼠神经功能缺损症状明显减轻(P＜0.05),脑梗死体积明显缩小(P＜0.05),光学显微镜下观察发现,神经细胞损伤明显减轻,尼氏小体表达明显增多(P＜0.05),凋亡神经细胞明显减少(P＜0.05),凋亡关键蛋白Cyt C、Apaf-1、Caspase-9和Caspase-3的表达明显降低(P＜0.05).结论 毛蕊异黄酮可明显抑制神经细胞凋亡,减轻脑缺血/再灌注损伤,其作用机制与毛蕊异黄酮有效调控Cyt C/Apaf-1凋亡信号通路相关.     

缺氧诱导因子-1α抑制剂对大鼠局部脑缺血再灌注损伤的影响

目的研究大鼠局部脑缺血再灌注损伤时,缺氧诱导因子-1α(HIF-1α)抑制剂2-甲氧雌二醇(2ME2)对损伤脑组织的影响。方法雄性SD大鼠60只随机分为假手术组、大脑中动脉阻塞再灌注组(MCAO组)、假性治疗组(DMSO组)、2ME2治疗组(2ME2组)。治疗组在术后1h腹腔注射相应剂量药物。观察各组大鼠神经行为学缺陷;再灌注7d,TTC染色观察脑梗死体积变化;再灌注24h,Western blotting检测HIF-1α及其下游基因的表达变化;制备脑组织切片分别作Nissl染色、免疫组织化学染色及原位缺口末端标记(TUNEL)。结果2ME2组神经功能较MCAO及DMSO组有明显改善(P<0.05),同时,2ME2组梗死面积明显减小(P<0.05)。Western blotting结果显示,HIF-1α的表达经2ME2治疗后降低,其下游基因VEGF、BNIP3及Caspase-3的表达有同样的变化。Nissl染色可见2ME2治疗组皮质神经元结构较清晰,胞体肿胀、核固缩、核溶解程度较模型组及假性治疗组明显减轻,淡染区域减小;免疫组织化学法观察到2ME2组HIF-1α、Caspase-3、BNIP3、VEGF及TUNEL标记的阳性细胞数明显减少(P<0.05)。结论2ME2可能通过降低HIF-1α水平并下调其下游的BNIP3和VEGF的表达,降低血脑屏障的通透性并减少凋亡因子Caspase-3的作用,发挥神经元的保护作用。     

Innervation of the cerebral vasculature

With the development of specific antibodies to vasoactive peptides and application of immunohistochemistry and radioimmunoassay methods, knowledge of vascular innervation has grown rapidly. In the cerebral circulation, four possible neurotransmitters are present: norepinephrine, acetylcholine, vasoactive intestinal peptide (VIP), and substance P. There is a dense adrenergic innervation of cerebral arteries, but contractile responses to nerve stimulation or circulating catecholamines are relatively small both in vitro and in vivo. Recent studies using radioligand binding techniques indicate a lack of specific³H-prazosin binding in cerebral arteries, in contrast to other vascular beds. Thus a lack of α₁-adrenergic receptors in cerebral arteries may account for weak responsiveness to sympathetic stimulation. Both VIP and acetylcholine may be vasodilator neurotransmitters, but blockade of cholinergic responses does not alter neurogenic vasodilation. The lack of specific VIP antagonists hampers efferots to explore this system more fully. Substance P-containing nerves are affected by capsaicin, supporting the hypothesis that these are primary sensory afferents, perhaps mediating pain. Future work in this area may focus on defining the pathways of these nerves and exploring the role of co-transmitters and possible interactions between nerves. With this basic information, experiments can be designed to elucidate more clearly the functional roles these nerves play. Established Investigator of the American Heart Association with funds contributed in part by the Arizona Affiliate.     

On regeneration of the cerebral cortex

Summary In order to ascertain the possibility of structural regeneration in the cortical areas of the cerebral hemispheres, the cortex of the sigmoid convolution was extirpated in puppies aged 10 and 14 days. These animals were then sacrificed 2 and 7 months after the operation. Their brains were fixed in 10% formalin and sections of the material were stained with cresyl violet. The site of the defect was clearly visible macroscopically. However, its size was considerably less than at the time of the operation. Due to growth of the brain, the edges of the injured area moved over the defect, closing it over and joining each other. This was quite distinct microscopically. However, where the size of the injury was enlarged by hematoma and reached the lateral ventricle, no closing in of the tissue or juncture of the edges was observed. Thus, in the opinion of the author, there was no replacement of the brain matter by new matter, but there only occurred superposition and juncture of the adjacent areas, which created the appearance of tissue regeneration.Presented by Active Member of the Academy of Medical Sciences, USSR B. N. Klosovskii Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 57, No. 3, pp. 105–108, March, 1964     

Glial regulation of the cerebral microvasculature

The brain is a heterogeneous organ with regionally varied and constantly changing energetic needs. Blood vessels in the brain are equipped with control mechanisms that match oxygen and glucose delivery through blood flow with the local metabolic demands that are imposed by neural activity. However, the cellular bases of this mechanism have remained elusive. A major advance has been the demonstration that astrocytes, cells with extensive contacts with both synapses and cerebral blood vessels, participate in the increases in flow evoked by synaptic activity. Their organization in nonoverlapping spatial domains indicates that they are uniquely positioned to shape the spatial distribution of the vascular responses that are evoked by neural activity. Astrocytic calcium is an important determinant of microvascular function and may regulate flow independently of synaptic activity. The involvement of astrocytes in neurovascular coupling has broad implications for the interpretation of functional imaging signals and for the understanding of brain diseases that are associated with neurovascular dysfunction.     

Charge-related alterations of the cerebral endothelium

In a short-term rat brain perfusion model, the luminal surface of cerebral endothelium was exposed to the following solutions: (a) the polycation protamine sulfate (PS) in a dose of 50, 100, and 500 micrograms/ml for 1 or 2 minutes; (b) PS in a dose of 100 micrograms/ml (or 500 micrograms/ml) for 1 or 2 minutes followed by the polyanion heparin in an equivalent dose of 12 units/ml (or 60 units/ml) for 1 or 2 minutes; (c) heparin alone for 1 or 2 minutes, and (d) Krebs-Ringer-bicarbonate solution as control for 1, 2, or 4 minutes. We studied in the cerebral endothelium: (a) structural alterations by electron microscopy, (b) permeability changes to horseradish peroxidase (HRP) by light and electron microscopy, and (c) charge alterations of luminal surface visualized with colloidal iron at pH 1.8 by electron microscopy. We found that: (a) PS resulted in extravasation of HRP throughout the perfused hemispheres in a time- and dose-dependent fashion. In this experimental group, colloidal iron binding decreased on the luminal surface of the cerebral blood vessels; (b) heparin perfusion following PS reversed the colloidal iron staining but failed to prevent the blood barrier opening to HRP; (c) heparin perfused alone also induced extravasation of HRP in the treated brain hemispheres; (d) in Krebs-Ringer-bicarbonate-perfused control brains extravasation of HRP was encountered only in occasional vascular segments. In all brain hemispheres showing tracer extravasation, electron microscopy revealed HRP reaction product in compartments of endothelial tight junctions suggesting opening of interendothelial routes as the structural basis of blood-brain barrier opening. Endothelial cell death reflected by swelling and influx of HRP into endothelial cytoplasm in PS- and/or heparin-perfused hemispheres was probably an additional mechanism explaining tracer extravasation into the neuropil. Our results indicate a correlation between the effect of polycation PS and a decrease in the anionic sites of cerebral endothelium. The relationship between charge alteration and barrier opening in the short-term rat brain perfusion model is not clear.     

Correlation between cerebral blood volume and cerebral blood flow in the cat

Summary Blood flow and blood volume were measured simultaneously in the same cerebral region in anaesthetized cats with controlled respiration. The measurements were made with the same scintillation-detector, using the freely diffusible indicator ¹³³ Xenon for flow determinations and the intra-vascular indicator RISA (¹³¹I) for volume recordings. A very high correlation was found between volume and flow changes (r = .96, p < 0.001). This finding indicates that variations of regional cerebral blood volume are accompanied by proportional blood flow changes.Attaché de recherche au C.N.R.S., Laboratoire de Neurophysiologie, Hopital Henri Rouselle, Paris, France.     

Dehydroepiandrosterone and the cerebral functions

Of all steroidal hormones, dehydroepiandrosterone (DHEA) and its sulphate form, DHEAS, are synthesized by the adrenal glands in the biggest quantities. In this review the authors consider the ways of the synthesis of the neurosteroids, possible mechanisms of the regulation of these processes, and their dynamics under stressful conditions. The paper presents analysis of experimental and clinical data on the role of DHEAS in the manifestation of different cerebral functions. The authors pay special attention to the results of substitutive therapy with DHEA(S) in patients with such CNS functional disorders, as Alzheimer's disease, depression, age-relative memory and sleep disturbances, etc.