尼膜同对大鼠脑缺血再灌注后血-脑屏障通透性和脑梗死体积的影响

目的　研究尼膜同对大鼠脑缺血再灌注后血 脑屏障 (BBB)通透性和脑梗死体积的影响。方法采用插线法制作脑缺血再灌注的大鼠模型 ,缺血 2h后再灌注。实验分尼膜同组和生理盐水对照组 ,每组分再灌注 6h、12h、2 4h、4 8h、72h 5个时段 ,再灌注后立即分别腹腔注射尼膜同 2mg/kg或等量的生理盐水 ,每12h注射 1次。用荧光法及透射电镜观察不同时段BBB通透性破坏的情况 ,TTC染色后计算梗死体积百分比。结果　脑缺血再灌注后随时间延长 ,BBB通透性和梗死体积百分比逐渐增加 ,且BBB通透性的增加呈现两个高峰 ,分别为再灌注后 12h和 4 8h ;尼膜同组BBB通透性及脑梗死体积百分比明显高于生理盐水对照组 ,差异有显著性 (P <0 0 5 )。结论　脑缺血再灌注增加BBB的通透性和脑梗死体积百分比 ,再灌注后给予尼膜同可加重这些病理变化。     

乌司他丁对脑缺血再灌注损伤大鼠血脑屏障通透性和MMP-9活性的影响

目的 观察乌司他丁对大鼠局灶脑缺血再灌注损伤后血脑屏障(BBB)通透性和基质金属蛋白酶-9(MMP-9)活性的影响.方法 采用栓线法制备大鼠局灶性脑缺血再灌注损伤模型,腹腔注射乌司他丁,于脑缺血再灌注后6h、24h、48h、72h处死大鼠.通过测定损伤侧脑组织中伊文思蓝(EB)含鼍来观察BBB通透性的改变,用明胶酶谱法检测同侧脑部MMP-9活性变化.结果 脑缺血再灌注损伤后,大鼠EB含量增加,24h最明显;MMP-9活性明显升高,48h达高峰.乌司他丁处理组EB含量及MMP-9活性水平明显低于脑缺血再灌注组(P<0.05).结论 乌司他丁可抑制脑缺血再灌注后大鼠MMP-9的活性,减轻BBB通透性的破坏.     

拜阿司匹灵预处理对高血糖SD大鼠局部脑缺血再灌注损伤中ET-1的表达

目的 采用高血糖条件下SD大鼠局灶性脑缺血再灌注损伤模型,通过测量大鼠脑梗死体积及内皮素-1(Endothelin-1,ET-1)的表达情况,探讨预防性应用拜阿司匹灵对高血糖条件下SD大鼠局灶性脑缺血再灌注损伤的脑保护作用.方法 随机分为对照组与拜阿司匹灵组,2组按缺血90 min再灌注3 h、6 h、12 h再分为3个亚组.2组均建立高血糖模型及SD大鼠右侧大脑中动脉缺血再灌注模型.病理图像分析仪测量脑梗死体积,免疫组化方法测定ET-1的表达情况.结果 拜阿司匹灵组与对照组相同再灌注时间点相比较:梗死体积减小(P均<0.01);缺血区表达ET-1减少(P均<0.05).结论 预防性应用拜阿司匹灵能减轻高血糖条件下的局灶性脑缺血再灌注损伤,缩小梗死体积,使损伤脑区ET-1表达减少.     

BDNF及其受体TrkB mRNA在脑缺血后适应大鼠模型中的表达变化

目的检测脑源性性神经营养因子(BDNF)及其受体酪氨酸激酶B(TrkB)在脑缺血后适应大鼠模型再灌注不同时间窗的表达,探讨BDNF/TrkB在脑缺血后适应中的作用。方法 Wistar大鼠随机分成对照组、缺血-再灌注组(IR)和缺血后适应组(IP),后两组根据再灌注时间的不同各分为6h、12h、24h、48h、72h 5个亚组。线栓法建立局灶性脑缺血-再灌注模型。TTC染色测定脑梗死体积,原位杂交法检测BDNF/TrkB mRNA的表达。结果 IP组大鼠梗死体积较IR组明显减小(P0.05)。IP组各时间点BDNF mRNA及TrkB mRNA表达较IR组均明显升高(P0.05)。结论脑缺血后适应能增加脑缺血-再灌注后BDNF及TrkB的表达,减轻脑梗死体积,BDNF/TrkB在脑缺血后适应后脑缺血-再灌注损伤中发挥了重要保护作用。     

三七三醇皂苷对脑缺血再灌注大鼠的保护作用

目的 通过对局灶性脑缺血大鼠不同再灌注时段的动态观察．探讨三七三醇皂苷(PTS)对大鼠局灶性脑缺血／再灌注动物模型的神经行为学和脑梗死体积的保护作用。方法 采用改良的线栓法制备大脑中动脉阻塞(MACO)2h、再灌注不同时间段(3h、6h、12h、24h、48h、72h、7d)的大鼠短暂局灶性脑缺血模型。动物随机分假手术组、生理盐水对照组、三七三醇皂苷(PTS)组。用Zea Longa5分制评分和TTC染色法评价神经行为学和脑梗死体积。结果 神经行为学评分除72h组有明显改善外．其余各组与生理盐水对照组比较无显著性差异。脑梗死体积除再灌注3h、6h外．其余各组与生理盐水组比较差异均有显著性意义。结论 三七三醇皂苷对大鼠局灶性脑缺血及再灌注损伤有一定的保护作用。     

大鼠脑缺血/再灌注后血脑屏障通透性的改变及转移生长因子β_1的表达

目的　探讨大鼠脑缺血再灌注后血脑屏障 (BBB)通透性的改变以及转移生长因子 β1(TGF β1 )在脑组织中的表达。方法　采用线栓法制备大鼠局灶性脑缺血再灌注模型 ,通过测定脑组织中伊文氏蓝 (EB)含量及免疫组化法来观察TGF β1 的表达。结果　缺血 2h再灌注 3h ,BBB通透性开始增加 ,2 4h达高峰 ,72h后明显减弱。同时 ,TGF β1 在缺血再灌注 3h开始表达 ,2 4h达高峰 ,持续至 72h ,72h后逐渐减弱。结论　脑缺血后BBB的破坏与TGF β1 的表达密切相关 ,提示TGF β1 参与了BBB内皮细胞破坏的修复过程     

大鼠脑缺血再灌注半暗带β淀粉样前蛋白mRNA表达与梗死体积的关系

为了探讨大鼠局灶性脑缺血再灌注缺血半暗带β淀粉样前蛋白(APP)转录水平与缺血时间及梗死体积的相互关系,用插线法建立大鼠局灶性脑缺血再灌注模型,剥取缺血半暗带皮质组织,采用半定量逆转录-聚合酶链式反应(RT-PCR),测定永久性缺血48 h和不同缺血时间再灌注48 h后,APPmRNA水平的变化.结果显示,梗死体积随再灌注前缺血时间的延长而增大,皮质半暗带缺血30 min再灌注48 h APPmRNA表达升高;缺血60min和缺血120 min再灌注48 h APPmRNA升高明显;缺血180 min再灌注48 h和永久性缺血48 h APPmRNA达到高峰.提示缺血半暗带APPmRNA的表达随再灌注前缺血时间延长而增加并与梗死体积有一定的相关性,早期再灌注可减少其表达.((GFDAl))     

大鼠脑缺血/再灌注后血脑屏障通透性的改变及转移生长因子β1的表达

目的：探讨大鼠脑缺血再灌注后血脑屏障（BBB）通透性的改变以及转移生长因子β1（TGF－β1）在脑组织中的表达。方法：采用线栓法制备大鼠局灶性脑缺血再灌注模型，通过测定脑组织中伊文氏蓝（EB）含量及免疫组化法来观察TGF－β1的表达。结果：缺血2h再灌注3h,BBB 通透性开始增加，24h达高峰，72h后明显减弱。同时，TGF－β1在缺血再灌注3h开始表达，24h达高峰，持续至72h,72h后逐渐减弱。结论：脑缺血后BBB的破坏与TGF－β1的表达密切相关，提示TGF－β1参与了BBB内皮细胞破坏的修复过程。     

糖尿病大鼠及局灶缺血再灌注模型的探讨

目的探讨一种比较简易的糖尿病大鼠局灶性脑缺血/再灌注模型制备方法并比较分析影响模型制备成功的因素。方法70只体质量为180~220g的雄性SD大鼠禁食12h后,于腹腔内一次性注射链脲霉素60mg/kg,选择体质量为280~320g血糖水平16.7~25.6mmol/L的成模实验性慢性糖尿病大鼠制作脑缺血再灌注模型;另选择55只体质量为280~320g的同种同月龄雄性大鼠制作单纯脑缺血再灌注模型作为对照;采用ZeaLonga线栓改进法,从rCBF、神经功能缺陷评分以及梗死灶体积等三个方面进行对比研究。比较2组大鼠模型制备成功率并分析2组大鼠模型制备失败及死亡原因。结果脑缺血再灌注模型制备:单纯脑缺血再灌注组大鼠神经功能评分低于糖尿病脑缺血再灌注组(P<0.01),2组模型制备成功后,大鼠脑组织的血流量在6h后进行性降低,可能与再灌注后的48h内脑组织水肿进行性加重有关。糖尿病组脑梗死灶体积在24、48h时明显比正常组大鼠严重(P<0.05)。结论此项研究为探索糖尿病与脑血管病变的关联提供了一种较为理想的动物模型。     

Kallikrein基因转导对脑缺血再灌注后局部血流灌注恢复的作用

目的 探讨Kallikrein基因对脑缺血再灌注后梗死灶周围血管增生与局部脑血流灌注恢复的作用.方法 建立大鼠脑缺血再灌注模型,术后将90只大鼠按照随机数字表法分为3组.每组30只,分别是空白对照组、注射生理盐水、注射pAdCMV-人组织激肽释放酶(HTK)组.各组大鼠又分为治疗后12 h、24 h及72 h组,每组各10只.治疗前后行大鼠神经功能缺损评分.TTC染色方法测定脑梗死面积的变化,用免疫组化检测外源性HTK的表达以及局部血管内皮生长因子(VEGF)的表达,并通过14C-iodoantipyrine微示踪技术检测局部脑血流灌注(rCBF)情况.结果 与其他两组相比,pAdCMV-HTK组大鼠脑梗死面积在治疗后24h已有明显减小,72h后这种变化更明显,差异有统计学意义(P<0.05);在治疗后24 h,pAdCMV-HTK组大鼠神经功能缺损评分明显低于生理盐水组及空白对照组,治疗后72h差异更明显,差异有统计学意义(P<0.05).vEGF阳性细胞主要分布于脑梗死灶周边皮质与部分白质;pAdCMV-HTK组VEGF表达在治疗后12h、24h、72h均明显高于生理盐水组及空白对照组,差异有统计学意义(P<0.05).各组缺血再灌注后脑梗死灶周围白质与皮质rCBF均较对侧稍减少:pAdCMV-HTK组治疗后12h,梗死灶周围白质与皮质rCBF较空白对照组与生理盐水组有增高.但不明显,差异无统计学意义(P>0.05),而在治疗24h、72 h后rCBF则明显增高,差异有统计学意义(P<0.05).结论 在脑缺血再灌注后,Kallikrein基因转导可增加梗死灶周围脑组织的血管增生,改善rCBF,减小梗死面积,从而达到保护缺血神经细胞功能的作用.     

Hyperlipidemia affects neuronal nitric oxide synthase expression in brains of focal cerebral ischemia rat model★

BACKGROUND: Hyperlipidemia, a risk factor for ischemic cerebrovascular disease, may mediate production of neuronal nitric oxide synthase (nNOS) to induce increased nitric oxide levels, resulting in brain neuronal injury. OBJECTIVE: To investigate effects of hyperlipidemia on brain nNOS expression, and to verify changes in infarct volume and pathology during reperfusion, as well as neuronal injury following ischemia/reperfusion in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING: Complete, randomized grouping experiment was performed at the Laboratory of Physiology, Shanxi Medical University from March 2005 to March 2006. MATERIALS: A total of 144 eight-week-old, male, Wistar rats, weighing 160-180 g, were selected. A rat model of middle cerebral artery occlusion was established by suture method after 4 weeks of formulated diet. Nitric oxide kit and rabbit anti-rat nNOS kit were respectively purchased from Nanjing Jiancheng Bioengineering Institute, China and Wuhan Boster Biological Technology, Ltd., China. METHODS: The rats were equally and randomly divided into high-fat diet and a normal diet groups. Rats in the high-fat diet group were fed a high-fat diet, consisting of 10% egg yolk powder, 5% pork fat, and 0.5% pig bile salt combined with standard chow to create hyperlipidemia. Rats in the normal diet group were fed a standard rat chow. A total of 72 rats in both groups were randomly divided into 6 subgroups: sham-operated, 4-hour ischemia, 4-hour ischemia/2-hour reperfusion, 4-hour ischemia/4-hour reperfusion, 4-hour ischemia/6-hour reperfusion, and 4-hour ischemia/12-hour reperfusion, with 12 rats in each subgroup. MAIN OUTCOME MEASURES: nNOS expression was measured by immunohistochemistry, and pathomorphology changes were detected by hematoxylin-eosin staining. Infarct volume and nitric oxide levels were respectively measured using 2, 3, 5-triphenyltetrazolium chloride (TTC) and immunohistochemistry. RESULTS: In the ischemic region, pathology changes were significant in the 4-hour ischemia/4-hour, 4-hour ischemia/6-hour reperfusion, and 4-hour ischemia/12-hour reperfusion subgroups fed on a high-fat diet compared to the same groups fed on a normal diet. In each ischemia subgroup, nNOS expression in brain tissues was higher than in the sham-operated subgroups fed on either the high-fat diet or normal diet (P < 0.01). At each ischemia/reperfusion time point, rats fed on a high-fat diet expressed higher levels of nNOS compared to rats fed on the normal diet (P < 0.05). When tissue was stained with TTC, a white infarction area was detected in the ischemic hemisphere, demonstrating that the infarct volume gradually increased with prolonged reperfusion time in each ischemia subgroup. At each ischemia/reperfusion time point, the infarct volume was larger in rats fed on a high-fat diet compared to those fed on a normal diet. CONCLUSION: nNOS expression was greater in hyperlipidemia rats following ischemia/reperfusion. Cerebral ischemia/reperfusion injury is aggravated with prolonged reperfusion time. Key Words: focal cerebral ischemia; hyperlipidemia; ischemia/reperfusion injury; neuronal nitric oxide synthase     

Hyperlipidemia affects neuronal nitric oxide synthase expression in brains of focal cerebral ischemia rat model★

BACKGROUND: Hyperlipidemia, a risk factor for ischemic cerebrovascular disease, may mediate production of neuronal nitric oxide synthase (nNOS) to induce increased nitric oxide levels, resulting in brain neuronal injury. OBJECTIVE: To investigate effects of hyperlipidemia on brain nNOS expression, and to verify changes in infarct volume and pathology during reperfusion, as well as neuronal injury following ischemia/reperfusion in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING: Complete, randomized grouping experiment was performed at the Laboratory of Physiology, Shanxi Medical University from March 2005 to March 2006. MATERIALS: A total of 144 eight-week-old, male, Wistar rats, weighing 160-180 g, were selected. A rat model of middle cerebral artery occlusion was established by suture method after 4 weeks of formulated diet. Nitric oxide kit and rabbit anti-rat nNOS kit were respectively purchased from Nanjing Jiancheng Bioengineering Institute, China and Wuhan Boster Biological Technology, Ltd., China. METHODS: The rats were equally and randomly divided into high-fat diet and a normal diet groups. Rats in the high-fat diet group were fed a high-fat diet, consisting of 10% egg yolk powder, 5% pork fat, and 0.5% pig bile salt combined with standard chow to create hyperlipidemia. Rats in the normal diet group were fed a standard rat chow. A total of 72 rats in both groups were randomly divided into 6 subgroups: sham-operated, 4-hour ischemia, 4-hour ischemia/2-hour reperfusion, 4-hour ischemia/4-hour reperfusion, 4-hour ischemia/6-hour reperfusion, and 4-hour ischemia/12-hour reperfusion, with 12 rats in each subgroup. MAIN OUTCOME MEASURES: nNOS expression was measured by immunohistochemistry, and pathomorphology changes were detected by hematoxylin-eosin staining. Infarct volume and nitric oxide levels were respectively measured using 2, 3, 5-triphenyltetrazolium chloride (TTC) and immunohistochemistry. RESULTS: In the ischemic region, pathology changes were significant in the 4-hour ischemia/4-hour, 4-hour ischemia/6-hour reperfusion, and 4-hour ischemia/12-hour reperfusion subgroups fed on a high-fat diet compared to the same groups fed on a normal diet. In each ischemia subgroup, nNOS expression in brain tissues was higher than in the sham-operated subgroups fed on either the high-fat diet or normal diet (P< 0.01). At each ischemia/reperfusion time point, rats fed on a high-fat diet expressed higher levels of nNOS compared to rats fed on the normal diet (P<0.05). When tissue was stained with TTC, a white infarction area was detected in the ischemic hemisphere, demonstrating that the infarct volume gradually increased with prolonged reperfusion time in each ischemia subgroup. At each ischemia/reperfusion time point, the infarct volume was larger in rats fed on a high-fat diet compared to those fed on a normal diet. CONCLUSION: nNOS expression was greater in hyperlipidemia rats following ischemia/reperfusion. Cerebral ischemia/reperfusion injury is aggravated with prolonged reperfusion time.     

Matrix metalloproteinase-9 expression and blood brain barrier permeability in the rat brain after cerebral ischemia/reperfusion injury

BACKGROUND: The integrity of the blood brain barrier (BBB) plays an important role in the patho-physiological process of cerebral ischemia/reperfusion injury. It has been recently observed that metalloproteinase-9 (MMP-9) is closely related to cerebral ischemia/reperfusion injuryOBJECTIVE: This study was designed to observe MMP-9 expression in the rat brain after cerebral ischemia/reperfusion injury and to investigate its correlation to BBB permeability.DESIGN, TIME AND SETTING: This study, a randomized controlled animal experiment, was performed at the Institute of Neurobiology, Central South University between September 2005 and March 2006.MATERIALS: Ninety healthy male SD rats, aged 3-4 months, weighing 200-280g, were used in the present study. Rabbit anti-rat MMP-9 polyclonal antibody (Boster, Wuhan, China) and Evans blue (Sigma, USA) were also used.METHODS: All rats were randomly divided into 9 groups with 10 rats in each group: normal control group, sham-operated group, and ischemia for 2 hours followed by reperfusion for 3,6,12 hours, 1,2,4 and 7 days groups. In the ischemia/reperfusion groups, rats were subjected to ischemia/reperfusion injury by suture occlusion of the right middle cerebral artery. In the sham-operated group, rats were merely subjected to vessel dissociation. In the normal control group, rats were not modeled.MAIN OUTCOME MEASURES: BBB permeability was assessed by determining the level of effusion of Evans blue. MMP-9 expression was detected by an immunohistochemical method.RESULTS: All 90 rats were included in the final analysis. BBB permeability alteration was closely correlated to ischemia/reperfusion time. BBB permeability began to increase at ischemia/reperfusion for 3 hours, then it gradually reached a peak level at ischemia/reperfusion for 1 day, and thereafter it gradually decreased. MMP-9 expression began to increase at ischemia/reperfusion for 3 hours, then gradually reached its peak level 2 days after perfusion, and thereafter it gradually decreased.CONCLUSION: MMP-9 expression increases in rat brain tissue after focal cerebral ischemia/reperfusion injury, which correlates with increased permeability of the BBB.     

米诺环素对脑缺血再灌注后明胶酶活性及血脑屏障影响的研究

目的 探讨米诺环素对大鼠局部脑缺血再灌后血脑屏障损伤的影响及其作用机制.方法 28只Wistar大鼠分为假手术组、缺血再灌注组、米诺环素组和生理盐水组.运用磁共振成像监测缺血再灌后血脑屏障损伤及梗死体积的变化,再灌注24h后进行神经功能缺陷评分和脑组织明胶酶活性测定.结果 缺血再灌后3.5h及24h,米诺环素组DWI、T2WI上异常高信号体积,T1WI增强扫描的信号强化范围、信号强度均明显低于缺血再灌注组和生理盐水组（P＜0.05）;与后两组相比,米诺环素组神经功能缺陷评分及脑组织明胶酶活性亦显著降低（P＜0.05）.结论 米诺环素能显著减轻缺血再灌注早期血脑屏障损伤,缩小梗死体积,促进神经功能恢复,其保护机制可能与米诺环素抑制脑组织明胶酶活性有关.     

Tumor necrosis factor alpha expression produces increased blood-brain barrier permeability following temporary focal cerebral ischemia in mice.

Alteration of blood-brain barrier (BBB) function occurs in both permanent and temporary cerebral ischemia. Studies in vivo and in vitro have shown that tumor necrosis factor-alpha (TNFalpha) is involved in changes of BBB permeability. However, the relationship between TNFalpha expression and BBB disruption during reperfusion is unclear. The aim of this study is to find the cell source of TNFalpha and to determine the relationship between TNFalpha expression and BBB disruption following temporary focal cerebral ischemia in mice. Adult CD-1 mice received 1 h middle cerebral artery occlusion (MCAO) followed by 2 h, 6 h, 12 h, 24 h, and 48 h of reperfusion. MCAO was achieved using an intraluminal suture technique and reperfusion was performed by the suture withdrawal. Neutralizing monoclonal anti-mouse TNFalpha antibody was administrated intraventricularly immediately after reperfusion. TNFalpha expression was determined by double labeling immunohistochemistry. BBB permeability was determined by albumin immunostaining. TNFalpha immunoreactivity (IR) was observed in the ipsilateral hemisphere from 1 h MCAO with 2 h reperfusion. TNFalpha positive cells included neurons, astrocytes, and ependymal cells. BBB disruption was detected beginning at 6 h reperfusion but was not present at 2 h of reperfusion. The areas of BBB disruption were significantly enlarged at 12 h reperfusion and plateaued at 24 h to 48 h reperfusion. BBB disruptions were significantly attenuated in the anti-TNFalpha antibody treated mice (p<0.05). Our results demonstrate that TNFalpha IR existed in neurons, astrocytes, and ependymal cells during reperfusion. TNFalpha IR following temporary focal cerebral ischemia precedes increased BBB permeability. Treatment with TNFalpha antibody reduces BBB disruption, suggesting TNFalpha may be an important mediator in altering BBB permeability during reperfusion.     

Brain edema and tumor necrosis factor-like weak inducer of apoptosis in rats with cerebral ischemia

BACKGROUND： Recent studies have demonstrated that tumor necrosis factor-like weak inducer of apoptosis （TWEAK） participates in brain edema. However, it is unclear whether blood-brain barrier （BBB） disruption is associated with TWEAK during the process of brain edema OBJECTIVE： To investigate the effects of TWEAK on BBB permeability in brain edema. DESIGN, TIME AND SETTING： An immunohistochemical observation, randomized, controlled animal experiment was performed at the Laboratory of Neurosurgical Anatomy, Xiangya Medical College, Central South University ＆ Central Laboratory, Third Xiangya Hospital, Central South University between January 2006 and December 2007. MATERIALS： A total of 48 adult Wistar rats were randomly divided into three groups： normal control （n = 8）, sham-operated （n = 8）, and ischemia/reperfusion （n = 32）. Rats from the ischemia/reperfusion group were randomly assigned to four subgroups according to different time points, i.e., 2 hours of ischemia followed by 6 hours （n = 8）, 12 hours （n = 8）, 1 day （n = 8）, or 12 days （n = 8） of reperfusion. METHODS： Focal cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion （MCAO） using the suture method in rats from the ischemia/reperfusion group. Thread was introduced at a depth of 17-19 mm. Rats in the sham-operated group were subjected to experimental procedures similar to the ischemia/reperfusion group; however, the introducing depth of thread was 10 mm. The normal control group was not given any intervention. MAIN OUTCOME MEASURES： TWEAK expression was examined by immunohistochemistry; brain water content on the ischemic side was calculated as the ratio of dry to wet tissue weight; BBB permeability was measured by Evans blue extravasation. RESULTS： A total of eight rats died prior to and after surgery and an additional eight rats were randomly entered into the study. Thus 48 rats were included in the final analysis. In the ischemia/reperfusion group, TWEAK-positiv     

血管内尼龙线栓塞大鼠大脑中动脉局灶性脑缺血模型的改进

目的 确立更规范统一的制作大鼠局灶性脑缺血模型方法，使脑梗死体积更加稳定。方法 对24只大鼠使用液态硅胶涂层尼龙线栓塞大脑中动脉，分别缺血l，2，6和24h后再灌注24h，监测缺血侧局部脑血流，测定脑梗死体积及脑水肿程度。结果 缺血后所有大鼠局部脑血流均降到缺血前基值的25％以下，TTC染色显示所有动物在缺血侧皮质和尾状核均有明显的梗死灶和缺血，缺血1h组梗死体积与缺血2h以上组有显性差异，缺血2h以上各组之间梗死体积无显性差异；各组脑水肿程度无显性差异。结论 应用硅胶涂层尼龙线结合局部脑血流监测，缺血2h以上同时予以血流监测，可制作梗死体积稳定的大鼠局灶性脑缺血模型。     

短时间诱导高血压对急性脑缺血再灌注大鼠梗死体积的影响

目的探讨在不同缺血时间诱导高血压对急性局部脑缺血再灌注大鼠梗死体积的影响。方法61只年龄30～40周的SD大鼠,随机分为假手术组、缺血组、缺血再灌注组和升压组。通过静脉滴注新福林对升压组动物进行诱导高血压治疗。结果(1)缺血再灌注组的梗死体积大于相应的缺血组。(2)升压组的梗死体积小于缺血再灌注组和缺血4h组。(3)在缺血4h再灌注2h升压组中,再灌注前15min升压组的梗死体积小于再灌注后30min升压组。结论(1)诱导高血压治疗能有效地减少急性脑缺血再灌注大鼠梗死体积。(2)再灌注前升压疗效优于再灌注后升压。     

大鼠局灶脑缺血病灶周围新血管生成的相关实验研究

目的本研究主要探讨大鼠局灶脑缺血病灶周围新血管形成现象,探讨外周血CD34+细胞和脑组织AC133抗原在新血管形成中的作用。方法将成年SD雄性大鼠随机分为:1.正常组,2.假手术组,3.动物模型组。分别取缺血再灌注1h、3h、6h、12h、24h、48h、3d、4d、7d、14d、28d共11个观察点。取前10个观察点外周血标本,采用流式细胞术检测单个核CD34+细胞平均荧光强度。采用免疫组化染色法检测48h、3d、4d、7d脑组织AC133抗原表达。对28d组进行脑血管荧光分布面积的检测。每个观察点5只大鼠,共65只大鼠,根据神经功能计分纳入实验。结果1.脑缺血再灌注28d梗死半球半暗带区域的血管荧光总面积较非梗死半球相似区域增加24.79%。2.大鼠脑缺血/再灌注3d外周血单个核CD34+细胞平均荧光强度明显降低,直到7d。14d恢复到基线水平。3.AC133抗原在再灌注4d梗死半球半暗带区域的血管内皮细胞表达阳性,3d、7d组无阳性表达。结论本研究证实大鼠脑缺血28天梗死半球半暗带区域的血管面积较非梗死半球增大。研究提示循环CD34+干细胞和AC133+细胞可能参与脑缺血损伤的血管修复和新血管形成。     

亚低温疗法联合依达拉奉对大鼠脑缺血再灌注损伤的保护作用

目的探讨亚低温疗法联合依达拉奉对大鼠脑缺血再灌注损伤后的保护作用。方法采用线栓法建立局灶性脑缺血再灌注模型,缺血6h后再灌注,并分为假手术组、模型组、依达拉奉组、亚低温联合依达拉奉组,再灌注24h后进行神经功能缺损评分,采用TTC染色测定脑梗死体积和用免疫组化的方法检测Bax和Bcl-2的阳性细胞数。结果与模型组比较,依达拉奉未能减少脑梗死体积,但能通过下调Bax及上调Bcl-2减少细胞的凋亡,对脑细胞有保护作用;与模型组、依达拉奉组比较,亚低温联合依达拉奉组能通过上调Bcl-2及下调Bax明显降低大鼠神经缺陷评分及减少脑梗死体积。结论亚低温疗法联合依达拉奉对大鼠脑缺血再灌注损伤具有很好的保护作用。