胀亡-持续性局灶脑缺血星形胶质细胞的死亡方式

目的动态观察大鼠持续性局灶脑缺血后星形胶质细胞的形态学变化,探讨星形胶质细胞的死亡方式.方法将48只SD大鼠随机分为免疫组化组、免疫组化对照组、电镜实验组和电镜实验对照组.采用颈内动脉线栓并环扎的方法建立持续性局灶脑缺血模型.免疫组化组和电镜实验组大鼠按照缺血时间（3h、6h、12h、24h、48h）平均随机分为5个亚组.对照组为术后24h取脑.免疫组化标本采用HE染色及TUNEL-GFAP双染.电镜标本在中心区、边缘区分别取材、染色后,透射电镜观察.结果随着时间的延长,脑缺血中心区及边缘区星形胶质细胞逐渐出现核肿胀、染色质分散、边聚、空泡变,核膜破溃,染色质溢出.随着缺血时间延长,中心区GFAP阳性细胞数逐渐减少,直至基本消失.缺血边缘区则可见到GFAP阳性细胞数量逐渐增多.TUNEL-GFAP双染未见阳性细胞.结论持续局灶脑缺血后,星形胶质细胞未见凋亡,推测胀亡是星形胶质细胞主要的死亡方式.     

局灶脑缺血神经细胞和星形胶质细胞可能不同死亡途径探讨

目的本研究采用电镜和免疫组化的方法观察局灶脑缺血中心区和边缘区细胞死亡形态学变化特征,探讨神经细胞和星形胶质细胞可能存在的不同死亡途径。方法 78只SPF级雄性SD大鼠,随机分为:(1)假手术组6只;(2)电镜对照组2只;(3)免疫组化组30只;(4)电镜实验组10只。3、4组大鼠分别于缺血3h、6h、12h、24h、48h取脑,假手术组和对照组为术后24h取脑。HE染色,GFAP和TUNEL染色,GFAP、TUNEL双标免疫组化染色,图像分析观察上述指标表达情况。结果随缺血时间延长,电镜下可见缺血中心区星形胶质细胞明显肿胀,缺血12h星形胶质细胞核膜破溃,染色质漏出。而神经元电子密度增高,细胞核变形、固缩。缺血24h可见凋亡小体。缺血边缘区各时间点神经细胞的损伤程度呈明显的不一致性。免疫组化显示缺血3h中心区及边缘区均可见TUNEL阳性细胞,以边缘区为主,随缺血时间延长边缘区阳性细胞渐增多,中心区TUNEL阳性细胞递减,缺血24h后中心区罕见阳性细胞。缺血6h中心区GFAP阳性细胞明显减少,缺血12h中心区罕见阳性细胞,缺血24h后边缘区可见大量GFAP阳性细胞与中心区形成明显的阴阳分界线。GFAP和TUN...     

海风藤提取物对脑缺血保护作用的实验研究

目的:探讨血小板活化因子(PAF)受体拮抗剂海风藤提取物对鼠脑缺血半暗带神经细胞凋亡的影响,并与传统的PAF受体拮抗剂银杏苦内酯相比较。方法:采用流式细胞分析和TUNEL方法,观察各实验组鼠脑缺血半暗带神经细胞的凋亡,并结合电镜观察缺血神经细胞超微结构的改变。结果:假手术组仅有极少量神经细胞凋亡;缺血90min再灌注12、24h缺血半暗带神经细胞凋亡明显增多;海风藤提取物、银杏苦内酯治疗组于相同时限内细胞凋亡较缺血/再灌组显著减少。结论:海风藤提取物与传统PAF受体拮抗剂银杏苦内酯均能明显减少缺血半暗带神经细胞的凋亡数量,减缓缺血区神经元损害,具有显著的脑保护作用。     

iASPP在大鼠脑缺血再灌注中的表达及其意义

目的 观察p53凋亡刺激蛋白（apoptosis stimulating protein of p53,ASPP）家族的抑制因子（inhibitorymember of the ASPP family,iASPP）在大鼠脑缺血再灌注后的表达及其意义。方法 48只清洁级、成年健康雄性SD大鼠随机分为假手术组（8只）和脑缺血再灌注组（40只）。脑缺血再灌注组又分为缺血2h再灌注4h、12h、24h、48h和72h 5个时间点,其中每个时间点8只大鼠。苏木素-伊红染色测定脑梗死体积;原位末端转移酶标记技术检测半暗带细胞凋亡情况;免疫印迹法测定半暗带iASPP的表达变化。结果 脑缺血再灌注4h组和24h组的凋亡细胞阳性率与假手术组存在统计学差异（P <0.01）。脑缺血再灌注组的脑梗死体积百分比与假手术组相比具有统计学意义（P <0.05）。与假手术组相比,在脑缺血再灌注12h时iASPP表达开始下降（P <0.01）,再灌注24h降至最低（P <0.01）,再灌注48h开始回升（P <0.01）。结论 在脑缺血再灌注后,缺血半暗带凋亡细胞显著增多,iASPP表达下降,提示在脑缺血再灌注中iASPP的表达下降可能在细胞凋亡的发生中发挥重要作用,其表达上调可能具有神经保护作用。     

大鼠局灶性脑缺血/再灌注损伤后Caspase-1的表达

目的研究Caspase-1在大鼠脑缺血／再灌注损伤中的作用。方法用Longa法制备大鼠大脑中动脉缺血（2h）／再灌注模型，HE染色观察梗死灶的形成，分别用TUNEL染色及免疫组化技术检测鼠脑缺血中心区及半暗带凋亡细胞与Caspase-1的表达。结果在缺血中心区Caspase-1及凋亡细胞主要见于缺血再灌注损伤早期；在缺血半暗带凋亡细胞与Caspase-1于缺血再灌注损伤早期表达不明显，于缺血再灌注24-48h则明显表达。结论细胞凋亡机制参与了缺血后迟发性神经元死亡，Caspase-1参与了其损伤过程。     

大鼠局灶性脑缺血半暗带葡萄糖转运子3 mRNA的表达

目的 研究大鼠局灶性脑缺血不同缺血时间皮质半暗带和中心区葡萄糖转运子3（GLUT3）转录水平的表达规律。方法 用插线法建立大鼠局灶性脑缺血模型，剥取缺血半暗带及中心区皮质组织，采用逆转录-聚合酶链反应（RT-PCR），测定GLUT3mRNA水平的变化。结果 缺血半暗带GLUT3mRNA在缺血3小时升高，24小时达到高峰，96小时后基本恢复正常。缺血中心区GLUT3mRNA在缺血后3小时有一短暂的升高，随后迅速下降呈低水平表达。结论 GLUT3在缺血半暗带的表达上调，有可能是机体对缺血损伤的保护性反应。     

大鼠局灶性脑缺血β淀粉样前体蛋白mRNA在缺血半暗带的表达变化

目的 :研究大鼠局灶性脑缺血不同缺血时间皮质半暗带和中心区淀粉样前体蛋白 (APP)在转录水平表达规律。方法 :用线栓法建立大鼠局灶性脑缺血模型 ,剥取缺血半暗带及中心区皮质组织 ,采用半定量逆转录 聚合酶链式反应 (RT PCR) ,测定APPmRNA水平的变化。结果 :半暗带APPmRNA在缺血后 48h升高 ,缺血 72h达到高峰 ,缺血 1周后仍高于正常。缺血中心区APPmRNA在缺血后 72h和 96h高于正常水平。结论 :APPmRNA在缺血半暗带的表达上调 ,有可能加重缺血损伤。     

人脑梗死后星形胶质细胞活性与凋亡相关蛋白Bcl-2的相关性研究

目的 探讨人脑梗死后星形胶质细胞活性与凋亡的关系。方法 应用10例脑梗死后的尸检全脑标本，用HE和免疫组化方法检测胶质纤维酸性蛋白(GFAP)、凋亡相关蛋白(Bcl-2)，进行定性和定量分析。结果 人脑梗死后以梗死灶为中心，按照组织损伤程度由内到外分为4个区(0-3区)，其中2区为半暗带区，40％以上的神经元和星形胶质细胞形态基本正常，随缺血时间延长，星形胶质细胞增生明显，形态正常神经元的数量减少；3区神经元形态及数量正常，星形胶质细胞反应性增生。GFAP在0区和1区表达很少，2区随缺血时间延长阳性细胞数增多，3区早期即有星形胶质细胞的簇样增生。Bcl-2在0区无表达，1区表达较少，2区于缺血后8h开始出现，23h达高峰，之后开始下降。结论人脑梗死后在半暗带区23h前GFAP和Bcl-2表达呈正相关；23h后呈负相关。2区是临床需要积极抢救的区域，并可应用干预因素上调Bcl-2表达，缩小梗死面积。     

大鼠脑缺血再灌注后胰岛素样生长因子－1的表达及意义

目的 观察胰岛素样生长因子-1（IGF-1）在大鼠脑缺血再灌注后在缺血不同部位的表达及组织病理学改变，探讨其对神经元的保护作用。方法 72只清洁级、成年健康雄性SD大鼠随机等分为假手术对照（sham）组和脑缺血再灌注（CIR）组，CIR组缺血3 h后，按再灌注时间的长短不同分为0、6、24、48、72 h和7 d 6个亚组，每亚组均为6只大鼠。于各相应时间点以Longa法、Berderson法和平衡木法分别进行行为学评分后处死动物，制做脑组织病理切片，苏木精-伊红染色后观察组织病理学改变，采用免疫组织化学方法测定IGF-1的动态表达变化。结果 （1）大鼠在大脑中动脉阻断后手术对侧肢体存在不同程度瘫痪，24 h后行为学评分结果逐渐趋于稳定,根据观察大鼠病变对侧肢体出现不同程度的瘫痪，其功能异常程度与病变严重程度一致；（2）除假手术对照（sham）组外，其余各组在脑梗死后6 h局部可见少量散在炎性细胞浸润，梗死后48 h炎性细胞浸润明显增多，并持续到7 d；（3）IGF-1在sham组神经元中呈弱阳性表达（灰度值127±6）；CIR组各缺血时段IGF-1表达分别为147±5（0 h）、153±6（6 h）、170±7（24 h）、169±5（48 h）、150±6（72 h）和147±5（7 d）。其中，缺血3 h及缺血3 h再灌注6 h组中心区、半影区阳性细胞数均增多，表达增强；随再灌注时间延长，中心区表达接近正常水平，半影区阳性细胞数增多，表达呈持续升高趋势，再灌注24 h和48 h达高峰，72 h表达有所下降，但仍表达高水平。结论 高表达的IGF-1参与了脑缺血再灌注后内源性神经保护过程，IGF-1在缺血半影区与中心区的演变病理生理中起重要作用，说明IGF-1对缺血半影区的保护作用。     

大鼠短暂性脑缺血后葡萄糖转运子3表达变化

目的 研究大鼠短暂性脑缺血葡萄糖转运子3（GLUT3）转录水平表达规律。方法 用插线法建立大鼠短暂性脑缺血模型。剥取缺血半暗带及中心区皮质组织,采用半定量逆转录-聚合酶链式反应（RT-PCR）,测定不同再灌注时间GLUT3mRNA水平的变化。结果 再灌注3h缺血半暗区GLUT3mRNA3h升高,48h达到高峰,再灌注1周后仍高于正常。结论 再灌注后,缺血半暗带GLUT3的表达明显上调,有可能是机体抗损伤性反应。     

氟美松对成年大鼠持续性局灶脑缺血后细胞凋亡和Fas基因表达的作用

目的 研究氟美松对成年人局灶性脑缺血后细胞凋亡及相关Ｆａｓ基因表达的作用。方法 健康雄性ＳＤ大鼠随机分成１４组（每组５只）。１～７组为对照组，８～１４组为实验组。用右侧近端大脑中动脉电凝术建立大鼠持续性局灶性脑缺血模型。缺血后１ｈ，实验组动物尾静脉射氟美松（５ｍｇ／ｋｇ），对照组注射生理盐水。分别在缺血后３、６、１２、２４、４８、７２和１２０ｈ取材，用原位末端标记（ＴＵＮＥＬ法）、原位ＲＴ－ＰＣＲ法分别检测缺血后细胞凋亡和Ｆａｓ ｍＲＮＡ表达并进行了半定量分析。结果 氟美松可导致缺血后细胞凋亡提前发生，促进大鼠局灶性脑缺血后Ｆａｓ ｍＲＮＡ的表达，使其表达开始时间提前、表达持续时间延长、表达细胞增多及表达信号增强。结论 氟美松可促缺血后细胞凋亡相关基因Ｆａｓ ｍＲＮＡ的表达，可能是其加重成年大鼠缺血性脑损伤尤其     

小鼠大脑中动脉缺血再灌注后缺血区及周边区星形胶质细胞的变化

目的 探讨小鼠大脑中动脉缺血再灌注后脑梗死体积、星形胶质细胞(AS)病理形态及其蛋白表达的变化.方法 选取69只成年健康雄性KM小鼠,将小鼠随机分为脑缺血2h再灌注1、4、10、24、48、72 h模型组(n=9)以及假手术组(n=6,仅结扎右侧颈总动脉)和正常组(n=9).采用线栓法制备小鼠大脑中动脉局灶性脑缺血再灌注模型.应用2,3,5-氯化三苯基四氮唑(TTC)染色法观察脑梗死的部位与体积;免疫组化法观察脑缺血中心区与周边区不同再灌注时间点胶质纤维酸性蛋白(GFAP)的表达.结果 缺血再灌注1h开始出现脑梗死灶,且再灌注24 h时梗死体积最大,之后逐渐缩小(F=745.534,P=0.000).小鼠脑缺血再灌注后缺血中心区AS肿胀、肥大进而较快发生凋亡,其GFAP表达水平低于周边区(P＜0.05);而缺血周边区GFAP阳性表达的AS出现反应性活化,进而发生形态学改变;缺血周边区及对侧相应脑组织区域GFAP的表达量均随再灌注时间的延长呈现增加趋势(P＜0.05).结论 AS反应性活化可能是一种缺血后的全脑保护性防御机制,尤其是在缺血周边区,其活化程度影响脑组织的存活与修复,提示在脑缺血再灌注过程中AS反应性活化可能在脑损伤后可塑性形态及功能改变中发挥重要作用.     

Immunoreactivity of astroglia in the hippocampus of the Mongolian gerbil during short survival following brief ischemia.

Mongolian gerbils subjected to 5-min cerebral ischemia by common carotid artery ligation were decapitated after 24, 48, 72 and 96 h of survival to investigate the immunoreactivity of astroglia in the hippocampus. The sections from formalin-fixed, paraffin-embedded brains were stained histologically and with ABC method (Hsu et al. 1981). Control animals (normal and shame-operated) presented positive GFAP immunostaining in corpus callosum, in subventricular regions, in temporal subcortical white matter, in fimbria hipocampi and perivascularly in stratum lacunosum-moleculare. Experimental animals, independently of postischemic survival time showed various individual GFAP reactivity. Differences concerning the number and localization of immunoreactive astrocytes in both cerebral hemispheres of the same animal stressed the asymmetry of the reaction. The authors did not observe any accumulation of reactive astrocytes in the area of synaptic terminals of glutaminergic fibers (mossy fibers, Schaffer's collaterals) or in the neighbourhood of CA1 and CA3 sectors. In particular, there was complete lack or only sporadic reactive astrocytes among pyramidal neurons of CA1 and among granular cells of dentate gyrus in all examined animals.     

大鼠局灶性脑缺血损伤后星形胶质细胞和神经元的动态变化

目的探讨脑缺血损伤后星形胶质细胞和神经元在时间和空间上的动态变化。方法健康雄性Wistar大鼠48只．随机分为假手术组、缺血0．5～24h组，采用大脑中动脉线栓模型．结合组织学和SP免疫组化方法，动态观察缺血不同时间神经元和星形胶质细胞分布、形态．通过组织化学染色，观察星形胶质细胞的周长和积分光度值的改变。结果星形胶质细胞对缺血极为敏感；缺血灶周边区和对侧半球反应性星形胶质细胞增生明显；反应性星形胶质细胞分布区神经元损伤较轻。结论反应性星形胶质细胞参与脑保护及促进损伤神经元修复。     

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.     

大鼠局灶性脑缺血再灌注后磷酸化细胞外信号调节激酶表达的变化

目的研究细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)在局灶性脑缺血再灌注中的作用。方法制备大鼠局灶性脑缺血再灌注模型,据Longa's的5级标准评分法进行神经功能评分,用免疫组织化学方法检测磷酸化ERK的表达,TUNEL染色检测神经元凋亡。结果在假手术组未检测到磷酸化的ERK表达,再灌注1h开始检测到阳性表达,再灌注4h达到峰值,12h下降;假手术组高倍镜视野仅见个别凋亡细胞,阴性对照片未检出阳性细胞,再灌注1h阳性细胞增加不明显,4h开始有明显的阳性细胞增加,24h细胞凋亡达到高峰,48h下降;磷酸化ERK阳性细胞计数与凋亡细胞数的相关分析显示相关系数(r)为-0.036,P=0.863,无统计学意义。结论局灶性脑缺血再灌注后磷酸化ERK表达增加,但其表达可能与神经元凋亡无关。     

TRPC1沉默对脑缺血大鼠神经干细胞迁移的影响

目的探讨瞬时受体电位通道1(TRPC1)沉默对脑缺血大鼠内源性神经干细胞增殖、迁移和分化的影响。方法 SD大鼠分为假手术组、脑缺血组、TRPC1沉默组(脑缺血+TRPC1沉默)和阴性对照组,以脑室内注射siRNA沉默TRPC1,以线栓法制作大鼠大脑中动脉脑缺血(MCAO)模型,脑缺血模型制作成功后,腹腔内注射Brdu标记内源性神经干细胞,分别于48 h、4 w后处死大鼠,行Brdu免疫组化染色、免疫荧光双标染色(Brdu/GFAP、Brdu/Neun)观察NSC的增殖、迁移和分化情况。结果脑缺血后48 h,脑缺血组和TRPC1沉默组SVZ区Brdu阳性表达均较假手术组明显增多(P0.01),但TRPC1沉默组Brdu阳性细胞数较缺血组低(P0.01)。脑缺血4 w后,缺血组与假手术组相比,皮质区具有更多的Brdu阳性细胞(P0.01),同样TRPC1沉默组Brdu阳性细胞数多于假手术组,但明显低于脑缺血组(P0.01);免疫荧光双标染色发现,脑缺血各组Brdu/GFAP、Brdu/Neun双阳性细胞的数量均比假手术组明显增高,但TRPC沉默组双阳性细胞显著少于脑缺血组和阴性对照组(P0.01)。结论 TRPC1沉默显著影响脑缺血大鼠SVZ区NSC的增殖、向脑缺血区迁移及向成熟细胞的分化。     

大鼠脑缺血再灌注后星形胶质细胞反应性变化差异与海马CA1区的迟发性神经元死亡

BACKGROUND： Blood supply to the hippocampus is not provided by the middle cerebral artery. However, previous studies have shown that delayed neuronal death in the hippocampus may occur following focal cerebral ischemia induced by middle cerebral artery occlusion.
OBJECTIVE： To observe the relationship between reactive changes in hippocampal astrocytes and delayed neuronal death in the hippocampal CA1 region following middle cerebral artery occlusion.
DESIGN, TIME AND SETTING： The immunohistochemical, randomized, controlled animal study was performed at the Laboratory of Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, from July to November 2007.
MATERIALS： Rabbit anti-glial fibrillary acidic protein （GFAP） （Neomarkers, USA）, goat anti-rabbit IgG （Sigma, USA） and ApoAlert apoptosis detection kit （Biosciences Clontech, USA） were used in this study. METHODS： A total of 42 healthy adult male Wistar rats, aged 3–5 months, were randomly divided into a sham operation group （n = 6） and a cerebral ischemia/reperfusion group （n = 36）. In the cerebral ischemia/reperfusion group, cerebral ischemia/reperfusion models were created by middle cerebral artery occlusion. In the sham operation group, the thread was only inserted into the initial region of the internal carotid artery, and middle cerebral artery occlusion was not induced. Rats in the cerebral ischemia/reperfusion group were assigned to a delayed neuronal death （＋） subgroup and a delayed neuronal death （–） subgroup, according to the occurrence of delayed neuronal death in the ischemic side of the hippocampal CA1 region following cerebral ischemia.
MAIN OUTCOME MEASURES： Delayed neuronal death in the hippocampal CA1 region was measured by Nissl staining. GFAP expression and delayed neuronal death changes were measured in the rat hippocampal CA1 region at the ischemic hemisphere by double staining for GFAP and TUNEL.
RESULTS： After 3 days of ischemia/reperfusion, astrocytes with abnormal morphology were detected in the rat hippocampal CA1 region in the delayed neuronal death （＋） subgroup. No significant difference in GFAP expression was found in the rat hippocampal CA1 region at the ischemic hemisphere in the sham operation group, delayed neuronal death （＋） subgroup and delayed neuronal death （–） subgroup （P 〉 0.05）. After 7 days of ischemia/reperfusion, many GFAP-positive cells, which possessed a large cell body and an increased number of processes, were activated in the rat hippocampal CA1 region at the ischemic hemisphere. GFAP expression in the hippocampal CA1 region was greater in the delayed neuronal death （＋） subgroup and delayed neuronal death （–） subgroup compared with the sham operation group （P 〈 0.01）. Moreover, GFAP expression was significantly greater in the delayed neuronal death （–） subgroup than in the delayed neuronal death （＋） subgroup （P 〈 0.01）. After 30 days of ischemia/reperfusion, GFAP-positive cells were present in scar-like structures in the rat hippocampal CA1 region at the ischemic hemisphere. GFAP expression was significantly greater in the delayed neuronal death （＋） subgroup and delayed neuronal death （–） subgroup compared with the sham operation group （P 〈 0.05）. GFAP expression was significantly lower in the delayed neuronal death （–） subgroup than in the delayed neuronal death （＋） subgroup （P 〈 0.05）. The delayed neuronal death rates were 42% （5/12）, 33% （4/12） and 33% （4/12） at 3, 7 and 30 days, respectively, followingischemia/reperfusion. No significant differences were detected at various time points （χ2 = 0.341, P 〉 0.05）.
CONCLUSION： The activation of astrocytes was poor in the hippocampal CA1 region during the early stages of ischemia, which is an important reason for delayed neuronal death. Glial scar formation aggravated delayed neuronal death during the advanced ischemic stage.     

柚皮苷对脑缺血再灌注损伤的保护作用

目的研究柚皮苷(Naringin,NRG)对大鼠局灶性脑缺血再灌注损伤的保护作用及星形胶质细胞是否参与其中。方法柚皮苷连续灌胃7 d后进行大脑中动脉栓塞(middle cerebral artery occlusion,MCAO),缺血2 h后拔出线栓进行再灌注。24 h后TUNEL染色观察凋亡细胞数量,苏木精-伊红(hematoxyli-eosin,HE)染色观察形态学改变,免疫荧光染色分别检测星形胶质细胞标记物胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和缝隙连接蛋白43(connexin43,Cx43)。结果同模型组相比,柚皮苷预干预后凋亡细胞数量显著减少(P0.05),细胞损伤明显减轻。免疫染色显示柚皮苷可以减轻星形胶质细胞的激活程度,同时Cx43的表达也有所降低(P0.05)。结论柚皮苷预干预可有效减轻脑缺血再灌注损伤,该保护作用同降低星形胶质细胞Cx43表达密切相关。