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1.
目的 观察大鼠脑缺血再灌流时胶质源性神经营养因子(GDNF)在脑组织的分布特点,及其在缺血性脑损伤中的作用。方法 阻断大鼠大脑中动脉(MCA)血流2小时,再灌流0.5-48小时制成局灶性脑缺血模型,HE染色评价缺血性脑损伤的组织学特点,免疫组化法观察GDNF在脑组织的分布特点。结果 再灌流0.5小时组有灶性缺血区,24小时组面积最大,包括视前区、纹状体和皮质。再灌注6小时组开始出现神经元不可逆变性,24小时组梗死形成。再灌注0.5小时组,缺血区皮质神经元GDNF弱阳性,缺血周边区中等阳性;再灌流3-48小时组,缺血区神经元GDNF阴性。再灌流48小时组视前区的梗死周边区巨噬细胞GDNF呈强阳性。GDNF阳性细胞计数显示缺血区各实验组与正常组相比均减少(均P<0.01);24小时和48小时组分别与0.5小时组和3小时组相比,GDNF阳性细胞数减少(分别P<0.01)。结论 缺血性脑损伤时,变性死亡的神经元GDNF不表达,存活的神经元和活化的小胶质细胞或巨噬细胞的GDNF表达增加。  相似文献   

2.
目的 研究胶质源性神经营养因子GDNF基因转导的细胞侧脑室内移植治疗局灶性缺血性脑损伤大鼠的可行性,并探讨GDNF的神经保护作用机制.方法 体外培养SH-SY5Y细胞株,并用分子克隆技术转导入GFP-GDNF基因,使其可持续分泌绿色荧光蛋白GFP和GDNF.取75只体重150~180 g的健康雄性大鼠,分为移植缺血组、注射缺血组、缺血对照组和正常组等.在立体定向仪介导下向移植缺血组大鼠侧脑室注入转导GDNF基因的SY5Y细胞,向注射缺血组大鼠侧脑室内注射入5U/10μL的GDNF,24 h后采用线栓法对移植缺血组、注射缺血组和缺血对照组动物进行手术,建立局灶性脑缺血损伤模型(即大脑中动脉阻断,MCAO),在缺血后2 d时用Longa五分法评测行为学改变,TTC染色判断梗塞体积大小,用Western-blot法检测凋亡相关蛋白Bcl-2/Bax的表达水平.结果 在缺血损伤两天后,移植缺血组动物的肢体功能恢复效果优于缺血对照组,TTC染色亦提示移植缺血组脑梗死体积小于缺血对照组和注射缺血组(P<0.01).缺血灶周围脑组织凋亡相关蛋白Bcl-2和Bax含量均明显增高,移植缺血组Bcl-2/Bax的比值高于缺血对照组和注射缺血组.结论 GD-NF对缺血性脑损伤大鼠有神经保护作用,用GDNF基因转导的细胞移植治疗是一种可行的途径,效果优于经侧脑室直接给药.GDNF可调节凋亡相关蛋白Bcl-2/Bax的表达,这可能为其神经保护作用的机制之一.  相似文献   

3.
目的探讨缺血性脑损伤大鼠对轻度束缚应激的反应性。方法通过阻断大脑中动脉(MCAO)建立缺血性脑损伤大鼠模型,术后第5周开始行2周束缚应激,应激结束后处死大鼠,脑组织HE染色明确缺血灶,免疫组化法检测大鼠脑内Fos和促肾上腺皮质激素释放因子(CRF)蛋白表达水平。结果单纯MCAO组(M)和MCAO+应激组(MR)大鼠可见明确缺血灶,损伤侧大脑半球萎缩和脑室扩大,光镜观察缺血区大量核固缩,坏死灶周边神经胶质细胞增生;MR组大鼠下丘脑室旁核、杏仁核中央亚核及终纹床核Fos和CRF阳性神经元明显多于其他组,差异有统计学意义(P〈0.05)。结论缺血性脑损伤后大鼠脑内Fos和CRF蛋白表达对应激的反应性增强,CRF通过前反馈机制持续激活下丘脑-垂体-肾上腺轴并导致抑郁可能是脑卒中后抑郁发生的主要机制之一。  相似文献   

4.
大鼠弥漫性脑损伤阻滞ERK通路下调脑组织MMP-9 mRNA的表达   总被引:1,自引:0,他引:1  
目的探讨大鼠弥漫性脑损伤后磷酸化ERK1/2和基质金属蛋白酶-9(MMP-9)的变化规律及相互作用关系,从而进一步理解ERK1/2在弥漫件脑损伤中的作用及其对脑的保护机制。方法按Mamarou方法制作大鼠重型弥漫性脑损伤模型,尾静脉沣射ERK通路阻滞剂U0126;Western blot法检测磷酸化ERK1/2;RT—PCR检测MMP-9 mRNA;干湿重法测脑组织含水量。结果弥漫性脑损伤后磷酸化ERK1/2表达迅速增高,持续高水平表达至72h。MMP-9 mRNA在损伤后3h开始上升,24h达高峰,可维持较高水平直至7d。注射U0126后,磷酸化ERK1/2表达明显下降(P〈0.01),MMP-9 mRNA表达亦明显下降(P〈0.05),脑组织含水量减少(P〈0.05)。结论大鼠重型弥漫性脑损伤后ERK1/2被过度激活。MMP-9 mRNA表达增高,通过阻滞ERK通路可以下调MMP-9 mRNA的表达.保护受损脑组织。  相似文献   

5.
bFGF对脑缺血再灌注大鼠ICAM-1表达及脑组织含水量的影响   总被引:1,自引:0,他引:1  
目的探讨bFGF对局灶性缺血再灌注大鼠脑组织含水量及脑组织ICAM-1水平的影响。方法SD大鼠48只,随机分为假手术组(n=16)、缺血再灌注组(n=16)和bFGF组(n=16)。应用线栓法制作大鼠局灶性脑缺血再灌注模型,大脑中动脉阻塞1h再灌注损伤24h,bFGF组伤后即刻一次性经腹腔注射bFGF(10g/kg),假手术组和损伤组以相同方法给予0.9%的生理盐水。采用干湿法检测各组大鼠脑组织含水量,采用伊文思蓝(evansblue,EB)法检测脑毛细血管通透性,采用免疫组化法检测大鼠脑组织ICAM-1水平。结果与假手术组比较,缺血再灌注组脑含水量、脑皮质EB含量及ICAM-1表达显著增加(P〈0.05),与缺血再灌注组比较,bFGF组脑含水量、脑皮质EB含量及ICAM-1表达较模型组显著性降低(P〈0.05)。结论ICMA-1表达增加是脑缺血再灌注后脑水肿形成和缺血性损伤的重要原因之一,减少ICAM-1表达和脑组织含水量推测是bFGF脑保护作用机制之一。  相似文献   

6.
目的 探讨氯沙坦对大鼠脑缺血再灌注后血浆、脑组织中血管紧张素Ⅱ(angiotensin Ⅱ,ANGⅡ)、脑组织中血管加压素(vasopressin,AVP)的影响和脑保护作用及两者的相互关系。方法 制作大鼠大脑中动脉栓塞模型(middle cerebral artery occlusion,MCA0),用Longa法评分,测定神经功能;干湿法测定脑水肿;TUNEL法凋亡染色。观察脑梗死灶半暗带区凋亡细胞的变化;用放免法测定血浆、脑匀浆ANGⅡ及脑匀浆AVP,并作统计分析。结果 结果显示实验组的神经功能缺损、脑水肿、半暗带区细胞凋亡程度均明显轻于缺血未治疗组(P〈0.05,P〈0.01,P〈0.01),血浆中的ANG Ⅱ水平则显著高于缺血未治疗组(P〈0.01),但脑局部ANGⅡ实验组与缺血未治疗组间无显著差异(P〉0.05)。实验组脑组织中的AVP明显低于缺血未治疗组(P〈0.01)。结论 氯沙坦可通过影响大鼠缺血再灌注脑局部ANGⅡ和AVP发挥一定的脑保护作用。  相似文献   

7.
目的 观察局灶性脑缺血-再灌注后亚低温干预对大鼠脑源性神经营养因子表达及神经元凋亡的影响,并探讨脑源性神经营养因子在亚低温脑保护机制中的作用。方法 采用线栓法制备成年雄性SD大鼠左侧大脑中动脉闭塞局灶性脑缺血-再灌注改良模型,缺血时间2h。随机分为常温缺血组和亚低温缺血组。常温时大鼠脑温控制于36.5℃~37.5℃,肛温为35.9℃~36.9℃;亚低温时脑温维持于32.5℃~33.5℃,肛温为32.2℃~33.1℃。两组大鼠分别于脑缺血一再灌注及亚低温干预后2、6、24和72h进行神经功能缺损评分,并同时行三苯基氯化四唑(1TC)染色、HE染色、TUNEL染色、免疫组化染色及免疫组化与TUNEL双重染色,从而评估大鼠神经功能缺损状况;检测脑梗死体积及脑源性神经营养因子表达水平;观察组织病理学变化和神经元凋亡数量。结果 与常温缺血组相比,亚低温缺血组大鼠神经功能缺损评分低(P〈0.01),脑梗死体积小(P〈0.01),缺血灶周围脑皮质中的脑源性神经营养因子表达水平增高(P〈0.01),而且神经元凋亡数量少(P〈0.01)。在脑源性神经营养因子免疫组化染色呈阳性反应的神经元细胞核中,未发现TUNEL染色阳性者。结论 亚低温干预治疗可促进缺血灶周围的脑皮质对脑源性神经营养因子的表达,从而抑制神经元凋亡,减少大鼠脑梗死体积,改善神经功能缺损体征。  相似文献   

8.
阿托伐他汀钙对大鼠脑缺血再灌后NF-kBp56表达的影响   总被引:3,自引:3,他引:0  
目的探讨阿托伐他汀钙对大鼠脑缺血再灌后脑组织中NF-kBp56rnRNA及蛋白表达的影响。方法采用大脑中动脉线栓法制备局灶性脑缺血再灌注模型,参考Longa的5分制法在大鼠麻醉清醒后进行评分,应用原位杂交和免疫组化法检测NF-kBp56mRNA及蛋白表达。结果大鼠脑缺血再灌注后缺血脑组织中NF-kBp56mRNA和蛋白表达增加(P〈0.01),24h达高峰;给予阿托伐他汀钙干预后能减少缺血脑组织中NF-kBp56mRNA和蛋白表达(P〈0.05),降低神经功能缺损评分(P〈0.05)。结论阿托伐他汀钙能抑制大鼠脑缺血再灌注后脑组织中NF-kBp56mRNA及蛋白表达,减轻缺血再灌损伤。  相似文献   

9.
目的能量限制(CR)可产生脑缺血耐受作用,但详细机制尚不清楚。本研究主要探讨CR是否对脑外伤引起的脑损伤起到脑保护作用,及其作用是否与一氧化氮(NO)产生有关。方法SD大鼠分为两组:CR和自由饮食(AL)组,喂养4W后,行大鼠脑损伤模型,进行神经功能评分,并监测造模前后大鼠脑组织及血清中的内皮型一氧化氮合酶(eNOS)和NO的含量。结果①CR组脑组织和血清内eNOS表达和NO含量明显高于AL组(P〈0.05);②神经功能评分显示,CR组大鼠神经功能评分明显好于AL组(P〈0.05)。结论CR可通过上调eNOS表达和促进NO合成对脑外伤引起的脑损伤起到脑保护作用。  相似文献   

10.
目的 研究大鼠缺血性脑损伤后室旁区巢蛋白(nestin)和干细胞因子(SCF)基因表达的变化规律,探讨肌苷治疗中枢神经缺血性损伤的作用机制。方法 成年健康雌性SD大鼠68只,以线栓法建立大脑中动脉缺血再灌注模型,随机分为治疗组(注射肌苷注射液100mg/kg)和对照组(注射相同剂量的生理盐水),各32只,另外4只作假手术组(不插线)。应用原位杂交技术检测脑缺血再灌注后脑组织室旁区nestin和SCF的表达。结果 假手术组室旁区nestin和SCF表达很弱。对照组缺血侧nestin的表达除2h、6h、2d、14d以外各时间点均显著高于假手术组(P〈0.01)。治疗组nestin表达较对照组于各时间点均显著升高(P〈0.01)。对照组缺血侧SCF的表达除2h、2d、14d以外各时间点均显著高于假手术组(P〈0.01)。治疗组SCF表达较对照组于各时间点均显著升高(P〈0.01)。结论 肌苷可以促进大鼠脑缺血再灌注后nestin、SCF的表达,推测具有促进神经干细胞生成的作用。  相似文献   

11.
探讨脑缺血再灌流不同时程及不同程度缺血对海马及皮层胶质源性神经营养因子(glialcellline derived neurotrophic factor, GDNF)基因表达的影响,以及N甲基D天冬氨酸(Nm ethylDsapartate, NMDA)受体拮抗剂,钙离子通道阻断剂是否能调节缺血病态下GDNFm RNA的表达。参照Sm ith 等方法建立大鼠前脑缺血再灌流动物模型。用DIGOligonucleotide 3′end labeling Kit,标记51 m er的GDNF寡核苷酸探针在含有海马结构的冰冻组织切片上进行原位杂交检测GDNFm RNA的表达。10 m in 缺血再灌流2 h,齿状回GDNFm RNA表达上调。再灌流6 h,CA1,CA3 和皮层PAR区GDNFm RNA表达亦见增多,24 h 达高峰。Ketam ine 可使GDNF的基因表达在海马结构及皮层PAR区明显低于相应的缺血再灌流组,统计学差异显著(P< 005)。脑缺血再灌流时GDNF基因表达增加,对缺血神经元可能起保护作用。Ketam ine可阻断缺血后GDNFm RNA 的表达增加,提示NMDA谷氨酸受体很可能参与介导了缺  相似文献   

12.
In an attempt to elucidate whether glial cell line-derived neurotrophic factor (GDNF) receptors are induced after ischemic brain injury, possible expression of immunoreactive GDNF receptor-alpha1 (GFRalpha-1) and c-ret (RET) was examined at 3, 8, or 24 h after permanent middle cerebral artery occlusion (MCAO) in rats. Immunohistochemical study showed that both GFRalpha-1 and RET staining cells which were not detected in sham control brain, were present in the ipsilateral cortex and caudate at 3 to 8 h after permanent MCAO, and then decreased but remained to some extent at 24 h. Positive cells for both GDNF receptors were predominantly in cortical neurons of ischemic penumbral area. Western blot analysis confirmed the induction of those receptors after permanent MCAO. This rapid induction of GFRalpha-1 and RET, which correlates with the similar induction of GDNF under these conditions, may play a role in the early response to ischemic brain injury.  相似文献   

13.
BACKGROUND:Nuclear factor-κB (NF-κB), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in brain tissue can participate in inflammatory reactions after cerebral ischemia.Acupuncture treatment for acute cerebral ischemia produces abnormal protein expression.OBJECTIVE:To investigate the effects of acupuncture on NF-κB, ICAM-1, and VCAM-1 mRNA and protein expression in the brain tissue of rats with cerebral ischemia/reperfusion injury.DESIGN, TIME AND SETTING:Randomized...  相似文献   

14.
目的探讨针刺对急性脑挫裂伤大鼠磷酸化的环磷酸腺苷反应元件结合蛋白(p-CREB)表达的影响。方法 48只雄性SD大鼠随机分为针刺治疗组、模型对照组、正常对照组,每组16只。模型对照组仅制备急性脑挫裂伤模型,针刺治疗组在建立模型后行针刺治疗,正常对照组不致伤。损伤后48 h、6 d取损伤或对应局部脑组织,采用免疫组化法观察p-CREB的表达变化,并进行统计学分析。结果伤后48 h、6 d,模型对照组损伤脑组织中p-CREB的表达较正常对照组升高(均P<0.05),针刺治疗组损伤脑组织中p-CREB表达较模型对照组显著升高(均P<0.05)。伤后6 d针刺治疗组p-CREB表达较伤后48 h降低(P<0.05)。结论针刺治疗对大鼠颅脑损伤后p-CREB的表达具有明显的促进作用,并呈一定规律性,提示p-CREB与颅脑损伤后脑组织的修复相关。  相似文献   

15.
Wei G  Wu G  Cao X 《Neuroreport》2000,11(6):1177-1183
The aim of this study was to understand the possible involvement of glial cell line-derived neurotrophic factor (GDNF) in rat brain ischemic injury by examining the expression and the cellular location of GDNF with molecular biological and morphological techniques. Expression of GDNF mRNA and protein was first increased as early as 2h after ischemia-reperfusion in peri-infarct cerebral cortex and striatum; it then declined, and showed a second increase at 72 h. Double staining confirmed that the earlier peak of GDNF expression was of neuronal origin and the later peak of glial origin. Considering the neurotrophic characteristics of GDNF, our findings suggest that elevated endogenous GDNF expression may have important roles in protection of ischemic injured neuronal cells.  相似文献   

16.
The present study established a model of brain ischemia in aged rats using four-vessel occlusion.We observed hippocampal CA1 neuronal apoptosis and apoptosis-mediated protease caspase-3 expression following preconditioning of electroacupuncture at Baihui(GV 20).Our results showed that the number of hippocampal CA1 normal neurons was decreased,and degenerated neurons were increased 12 hours to 3 days following cerebral ischemia/reperfusion.The number of hippocampal CA1 apoptotic neurons and caspase-3-positive neurons in rats with cerebral ischemia/reperfusion injury was significantly decreased following acupuncture preconditioning.Acupuncture preconditioning protects aged rats against ischemia/reperfusion injury by regulating caspase-3 protein expression.  相似文献   

17.
To examine a possible protective effect of exogenous glial cell line-derived neurotrophic factor (GDNF) gene expression against ischemic brain injury, a replication-defective adenoviral vector containing GDNF gene (Ad-GDNF) was directly injected into the cerebral cortex at 1 day before 90 minutes of transient middle cerebral artery occlusion (MCAO) in rats. 2,3,5-Triphenyltetrazolium chloride staining showed that infarct volume of the Ad-GDNF-injected group at 24 hours after the transient MCAO was significantly smaller than that of vehicle- or Ad-LacZ-treated group. Enzyme-linked immunosorbent assay (ELISA) for immunoreactive GDNF demonstrated that GDNF gene products in the Ad-GDNF-injected group were higher than those of vehicle-treated group at 24 hours after transient MCAO. Immunoreactive GDNF staining was obviously detected in the cortex around the needle track just before or 24 hours after MCAO in the Ad-GDNF group, whereas no or slight GDNF staining was detected in the vehicle group. The numbers of TUNEL, immunoreactive caspase-3, and cytochrome c-positive neurons induced in the ipsilateral cerebral cortex at 24 hours after transient MCAO were markedly reduced by the Ad-GDNF group. These results suggest that the successful exogenous GDNF gene transfer ameliorates ischemic brain injury after transient MCAO in association with the reduction of apoptotic signals.  相似文献   

18.
目的 探讨粒细胞集落刺激因子(G-CSF)在缺血脑保护中的作用机制.方法 制作大鼠大脑中动脉栓塞模型,7 d后断头取脑做冰冻切片,用免疫荧光双标的方法观察缺血周边区与假手术组相同部位G-CSF受体、胶质细胞源性神经营养因子(GDNF)和微管相关蛋白2(MAP2)、神经胶质原酸性蛋白(GFAP)的共表达情况.结果 G-CSF受体和GDNF在正常大鼠脑内广泛表达于神经元,不表达于星形胶质细胞;但在缺血周边区,星形胶质细胞亦部分表达G-CSF受体和GDNF.在正常脑组织,大部分G-CSF受体阳性的细胞也表达GDNF.结论 脑缺血可诱导缺血周边区星形胶质细胞表达G-CSF受体和GDNF,推测缺血后的内源性神经保护作用可能与缺血周边区星形胶质细胞的G-CSF受体表达以及GDNF产生有关.  相似文献   

19.
Acupuncture at Baihui (GV20) and Dazhui (GV14) reduces neuronal loss and attenuates ultra- structural damage in cerebral ischemic rats. However, whether acupuncture can treat addiction and prevent readdiction through changes to brain cell ultrastructure remains unknown. In this study, cell apoptosis was observed in the hippocampus and frontal lobe of heroin readdicted rats by electron microscopy. Immunohistochemical staining displayed a reduction in Bcl-2 ex- pression and an increase in Bax expression in the hippocampus and frontal lobe. After rats were given acupuncture at Baihui and Dazhui, the pathological damage in the hippocampus and frontal lobe was significantly reduced, Bcl-2 expression was upregulated and Bax expression was downregulated. Acupuncture exerted a similar effect with methadone, a commonly used drug for clinical treatment of drug addiction. Experimental findings suggest that acupuncture at Dazhui and Baihui can prevent brain cell apoptosis in heroin readdicted rats.  相似文献   

20.
Glial cell line-derived neurotrophic factor (GDNF) is a transforming growth factor-beta which has shown beneficial effects in rats after acute focal cerebral ischemia (FCI). To study the effects of GDNF on chronic FCI injury in conscious rats, we used fibrin glue (GDNF-fibrin glue) and fibrin glue free (GDNF-only)-GDNF topically applied to the ischemic brain after right middle cerebral artery (MCA) ligation. Infarct brain volume and functional motor deficits were measured before and after FCI injury. After FCI injury induced by right MCA ligation, rats were randomly assigned to one of four treatment groups: (a) sham, (b) control, (c) topically applied GDNF (1 mug)-only, and (d) topically applied GDNF (1 mug)-fibrin glue. The degree of ischemic brain injury was estimated by infarct volume of right MCA territory at 4 weeks after occlusion. The functional motor deficits were quantified with rotarod test and grasping power test once a week. Topically applied GDNF-fibrin glue at infarct brain tissue after 4 weeks FCI injury significantly reduced the total infarct volume by 44.3% and 36%, respectively, compared to that of control group and GDNF-only group. The mean latencies for rats to stay on the rotarod were 55.0%, 50.3%, and 92.2% (P < 0.05 vs. control group and GDNF-only group) of baseline, respectively, in the control, GDNF-only, and GDNF-fibrin glue groups at the end of the 1st week after FCI injury but 75.3%, 67.3%, and 106.6% (P < 0.05 vs. control group and GDNF-only group) of baseline at the end of the 4th week after FCI injury. The mean values of grasping power were 78.7%, 71.7%, and 101.2% (P < 0.05 vs. control group and GDNF-only group) of baseline, respectively, in the control, GDNF-only, and GDNF-fibrin glue groups at the end of 1st week after FCI injury but 89.6%, 97.6%, and 120.7% (P < 0.05 vs. control group) of baseline at the end of 4th week after FCI injury. These results indicate that GDNF-fibrin glue not only reduced the total infarct volume after FCI injury but can also improve motor deficits after FCI injury. We concluded GDNF-fibrin glue could facilitate delivery of GDNF to the damaged brain tissue with subsequent reduction of ischemic brain injury accompanied by enhancing functional recovery in rats with chronic FCI injury.  相似文献   

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