高压氧治疗对家兔实验性大脑中动脉闭塞后梗死灶周围巢蛋白表达的影响

目的 探讨高压氧(HBO)治疗对兔大脑中动脉闭塞(MCAO)模型梗死灶周围巢蛋白(nestin)表达的影响.方法 制备兔右侧MCAO模型.将动物分为3组,即MCAO+HBO治疗组(30只):MCAO后立即行HBO治疗,每天1次,连续20 d;MCAO对照组(30只):MCAO后不行HBO治疗;假手术组(10只):仅开颅不闭塞血管.分别于MCAO后10d、20 d观察其行为学、梗死体积变化.并用免疫组化法检测距梗死灶中心3 mm内皮层脑组织内nestin的表达.结果 MCAO后.MCAO+HBO治疗组行为学评分高于MCAO对照组,差异有统计学意义(P<0.05);MCAO+HBO治疗组脑梗死体积小于MCAO对照组,差异有统计学意义(P<0.05);MACO后10 d、20 dMCAO+HBO治疗组nestin免疫阳性细胞数05.88±1.2、20.03±1.6)高于MCAO对照组(6.63±1.6、6.82±0.8),差异有统计学意义(P<0.05).结论 早期、连续20 d HBO治疗对兔MCAO后的神经行为学、梗死体积有明显的治疗效果,并促进兔MCAO后梗死灶周围脑组织内nestin的表达.     

诱导缺血耐受的缺血预处理动物模型的建立

目的 :建立能诱导脑缺血耐受的缺血预处理SD大鼠模型。方法 :SD大鼠分别给予生理盐水右侧颈内动脉灌注 (SI)、双侧颈总动脉夹闭 (BCAO)和双侧颈总动脉夹闭并生理盐水右侧颈内动脉灌注 (BCAO +SI)预处理 ,每次持续 3min ,间隔 7min ,反复 3次 ,2 4h后作线栓大脑中动脉栓塞 (MCAO)。观察处理对MCAO缺血对侧肢体活动、脑组织含水量和梗死体积的影响。结果 :MCAO后 2 4h和 48hBCAO +SI预处理组神经损害体征和脑含水量较SI和BCAO两组轻 ;MCAO 72hBCAO +SI组脑梗死体积也低于其他两组。结论 :BCAO +SI预处理能诱导脑组织明显缺血耐受 ,是研究缺血耐受机制比较理想的缺血预处理模型     

单次9小时高压氧超早期治疗对大鼠脑梗死体积的影响

目的 本研究主要观察高压氧（HBO）单次9 h超早期治疗对永久性大脑中动脉阻塞（MCAO）大鼠脑梗死体积的影响。方法 制作SD大鼠永久性MCAO模型,随机分为对照组、HBO组,HBO组大鼠于模型制备成功后3 h予单次9 h HBO治疗,压力0.2 MPa。模型成功后13 h、5 d,分别将大鼠脑组织进行2,3,5苯四氮唑（TTC）染色测定梗死体积,免疫组织化学染色测定脑组织中血管内皮生长因子（VEGF）的表达情况。结果 （1）13 h时,两组大鼠脑梗死体积相差不大（P >0.05）;5 d时,对照组大鼠脑梗死体积较13 h时增大（P <0.05）,而HBO组变化不大（P >0.05）,组间比较,HBO组较对照组脑梗死体积缩小（P <0.05）。（2）13 h时,对照组和HBO组VEGF均有表达,两组间差异无统计学意义（P >0.05）;5 d时,对照组VEGF表达较13 h时明显减少（P <0.01）,而HBO组VEGF表达明显高于13 h,而且显著高于对照组5 d水平（P <0.01）。结论 单次9 h HBO超早期治疗可缩小大鼠脑梗死体积,其机制可能与HBO提高内源性VEGF表达有关。     

局部脑缺血预处理对大鼠脑梗死的影响和HSP70的表达及mRNA的变化

目的建立局灶性可重复性大鼠脑缺血动物模型,研究短暂性局部脑缺血后再灌注不同时间对大脑中动脉阻塞(MCAO)的影响。方法应用改进的Longa's法,建立阻断左侧中动脉的局部脑缺血预处理模型。各组大鼠均经两次处理预处理(PC)组大鼠20min短暂脑缺血,分别在再灌注12h、1d、3d、5d、7d、14d后,造成MCAO;脑梗死组大鼠只在第二次处理造成大脑中动脉闭塞;短暂缺血组只在第一次处理时缺血20min,各组大鼠均在第二次处理后24h断头处死,检测以下指标神经功能缺失评分;TTC染色测量梗死范围HE染色观察组织结构变化;免疫印迹(原位杂交)和免疫组织化学染色观察HSP70的表达。结果PC后1d、2d、3d、5d、7d组与脑梗死组相比较,脑梗死范围,梗死周边区脑组织的缺血性损伤明显减轻了;短暂性脑缺血引起了轻微的神经细胞结构的改变并使缺血区HSP70的表达增加,MCAO后24hHSP70蛋白在缺血周边区出现了广泛表达。结论短暂局部缺血预处理可以诱导脑梗死后脑组织产生缺血耐受性,其保护作用出现再灌注后l~7d;缺血预处理引起HSP70的变化与缺血耐受的产生有一定联系。     

颅内动脉瘤手术中暂时阻断载瘤动脉的动物实验研究

目的探讨采用不同的颅内动脉瘤载瘤动脉阻断方法对神经功能的影响。方法82只蒙古沙土鼠,雌雄各半,随机分为正常对照组(10只)、假手术组(8只)和缺血-再灌注损伤组(实验组)。根据术中动脉阻断时间及再灌注时间的不同,实验组动物再分为8个亚组,每组8只,共64只。手术后收集脑组织间液,应用微透析仪分析其中葡萄糖、乳酸、丙酮酸、甘油水平以及乳酸/丙酮酸比值的变化,并依照Longa等的5分评分方法评定沙土鼠神经功能损伤程度,以观察缺血-再灌注损伤对脑组织间液中生化物质水平,以及各种不同阻断方式对神经功能的影响。结果实验组沙土鼠组织间液中的葡萄糖、乳酸、甘油水平及乳酸/丙酮酸比值的变化与对照组相比,差异有显著性意义(P<0.01);实验组各亚组间比较,葡萄糖、乳酸、甘油水平及乳酸/丙酮酸比值的变化差异亦有显著性意义(P<0.01);而丙酮酸水平的变化差异无显著性意义(P>0.05)。手术后72h,对各组沙土鼠的自主活动能力进行评价显示,假手术组、实验组第8、4亚组鼠神经功能受损较轻,实验组第1、2、3亚组受损较重。结论在灌注时间充足时,分次阻断载瘤动脉比一次长时间阻断对神经功能的损伤轻;在灌注时间不足时,分次阻断载瘤动脉所导致的神经功能损伤程度与一次长时间阻断相比无明显差异。故而在动脉瘤切除手术     

兔大脑中动脉梗死模型的建立

目的 :建立一种简单、实用的兔大脑中动脉阻塞 (MCAO)模型。方法 :2 0只新西兰大白兔 ,随机分为A、B两组 ,A组为电凝阻断右侧大脑中动脉形成局灶性脑梗死模型 ,B组为结扎右侧大脑中动脉形成局灶性脑梗死模型。利用MRI、TTC染色和光镜评价MCA闭塞效果。A、B两组动物模型制成后 10小时进行SE序列冠状位检查 :T1WI和T2 WI。结果 :A、B两组动物MCAO后 10小时MRI、TTC染色和光镜检查均证实脑梗死存在。MCAO后 10小时脑MRI均显示MCA供血区脑组织呈长T2 信号。A组方法制备兔MCAO操作简单易学 ,手术时间短 ,1h ;B组方法操作复杂 ,手术时间长 ,2h。结论 :用电凝阻断法制备兔大脑中动脉阻塞模型是一种较理想的方法     

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.     

兔大脑中动脉梗死模型的建立

目的：建立一种简单、实用的兔大脑中动脉阻塞（MCAO）模型。方法：20只新西兰大白兔，随机分为A、B两组，A组为电凝阻断右侧大脑中动脉形成局灶性脑梗死模型，B组为结扎右侧大脑中动脉形成局灶性脑梗死模型。利用MRI、TTC染色和光镜评价MCA闭塞效果。A、B两组动物模型制成后10小时进行SE序列冠状位检查：T1WI和T2WI。结果：A、B两组动物MCAO后10小时MRI、TTC染色和光镜检查均证实脑梗死存在。MCAO后10小时脑MRI均显著MCA供血区脑组织呈长T2信号。A组方法制备兔MCAO操作简单易学，手术时间短，1h；B组方法操作复杂，手术时间长，2h。结论：用电凝阻断法制备兔大脑中动脉阻塞模型是一种较理想的方法。     

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.     

缺氧诱导因子-1α及促红细胞生成素在脑缺血耐受大鼠中的表达

目的 探讨缺氧诱导因子-1α（HIF-lα）及其靶基因促红细胞生成素（EPO）在脑缺血预处理诱导的大鼠脑缺血耐受机制中的作用。方法 将84只Wistar大鼠随机分成假手术对照组（SS+SS,4只）、假手术＋再缺血组（SS+MCAO,40只）、预缺血＋再缺血组（IP+MCAO,40只）,后两组再随机分成5个亚组。线栓法阻塞大脑中动脉建立局灶性缺血预处理模型（预缺血10 min）,分别在预缺血后1 d、3 d、7 d、14 d、21 d进行再次缺血2 h再灌注22 h,然后取脑组织进行脑梗死体积测量和病理观察,免疫组化方法检测HIF-lα与EPO蛋白的表达。结果 ⑴IP+MCAO组中1 d、3 d、7 d亚组的梗死体积与SS+MCAO各对应亚组相比明显减小;⑵IP+MCAO组1 d、3 d、7 d亚组中HIF-lα蛋白表达与SS+MCAO各对应亚组相比明显增高;IP+MCAO组3 d、7 d亚组中EPO蛋白表达与SS+MCAO各对应亚组相比明显增高。结论 缺血预处理诱导了脑缺血耐受,预缺血诱导的内源性HIF-lα及EPO蛋白表达增加参与脑缺血耐受形成的机制。     

Effect of hyperbaric oxygen on striatal metabolites: a microdialysis study in awake freely moving rats after MCA occlusion

We have shown that hyperbaric oxygen (HBO) reduced cerebral infarction in rat middle cerebral artery occlusion model (MCAO). The present study was undertaken to evaluate the effect of HBO on ischemic striatal metabolites at different times after MCAO and reperfusion. A rat MCAO model was produced via the intraluminal filament method. After 2 h of occlusion the suture was removed and reperfusion was allowed. The rats were sacrificed at 24 h after reperfusion. HBO treatment was administered by putting rats in the HBO chamber at 3 atmospheres absolute (ATA) HBO for 1 h. Glucose, lactate, pyruvate, and glutamate in striatal extracellular fluid were collected and measured by a microdialysis system at 7, 10, and 24 h after reperfusion. Glucose, pyruvate and glutamate concentrations were increased after reperfusion. HBO treatment decreased glucose, pyruvate, and glutamate almost to the control level (preocclusion level). The lactate concentration remained unchanged after ischemic/reperfusion and after HBO treatment. This study suggested that altered brain energy metabolites and excitatory amino acids occurred during cerebral ischemia and and HBO regulated these striatal metabolites, which might contribute to the protective effect of HBO in cerebral ischemia.     

高压氧预处理可对大鼠局灶性脑缺血再灌注损伤的保护作用

目的研究短期高压氧预处理后是否可减轻大鼠局灶性脑缺血再灌注损伤。方法选取成年雄性Wister大鼠,采用连续5d,每天1次,3.0ATA,100%O2高压氧(HBO)预处理,每次60min,末次预处理后24h,运用改良的经典线栓法制作MCAO模型,再灌注2h。将实验大鼠分为假手术组、MCAO组、HBO+MCAO组(n=5)。造模后24h观察各组动物的一般精神状态及体重变化情况、用Rogers DC and Hunter AJ描述的神经功能7分评分法对神经功能损伤进行评估,TTC染色测梗死面积,并对脑组织进行石蜡切片,行Nissl、TUNEL染色,利用显微镜对神经细胞进行计数。结果假手术组无神经功能缺失,TTC染色未见梗死灶,镜下观察未见坏死细胞。MCAO组和HBO+MCAO组均有不同程度的神经功能缺损,且HBO+MCAO组神经功能缺失较MCAO组轻;TTC染色MCAO组的梗死面积明显大于HBO+MCAO组;镜下观察,MCAO组梗死区内尼氏小体明显少于HBO+MCAO组。结论短期高压氧预处理后可减轻大鼠局灶性脑缺血再灌注损伤。     

高压氧预处理减少局灶性脑缺血后泛素化蛋白聚集

目的探讨泛素-蛋白酶体系统在重复高压氧（HBO）预处理导致的脑缺血耐受中所起的作用。方法采用大脑中动脉阻闭（MCAO）制备大鼠局灶性脑缺血模型,将33只SD大鼠随机分为假手术组（Sham）组、MCAO组和HBO组,分别观察各组大鼠脑梗死灶的大小和神经功能学评分,并用免疫组织化学染色检测再灌注2h、24h时相点大鼠脑组织CA1区异常泛素化蛋白聚集的变化。结果 HBO组脑梗死容积小于MCAO组,差异有统计学意义（P〈0.05）,其神经功能学评分也明显优于MCAO组（P〈0.05）。再灌注各时相点,HBO组泛素化蛋白聚集明显少于MCAO组（P〈0.05）。结论高压氧预处理所诱导的脑缺血耐受的机制可能与泛素化蛋白聚集降低有关。     

Neuroprotective effect of high-dose hyperbaric oxygenation on rats with acute cerebral infarction in super-early stage

BACKGROUND: Previously, only single short-time low-dose hyperbaric oxygenation (HBO) protocol was administrated to treat acute ischemic stroke in early stage and the conflicting results were obtained. There are few studies to report the outcome of administering long-time (can cover all the natural pathologic progression period) high-dose HBO to treat the disease. OBJECTIVE: To evaluate the therapeutic effect between two kinds of high-dose hyperbaric oxygenation on super-early stage of acute permanent middle cerebral artery occlusion (MCAO) in rats. DESIGN: A randomized controlled experimental study. SETTING: Beijing Tiantan Hospital, Capital Medical University; Beijing Research Institute of Neurosurgery. MATERIALS: Seventy-four male SD rats, aged 2.5 months old, weighing （280±20）g, were provided by the Animal Institute, Chinese Academy of Medical Sciences. Hyperbaric oxygenation device was hyperbaric air cabin in which there was a self-made pure oxygen animal experimental cabin (made in China). METHODS: This experiment was carried out in the municipal laboratory of Beijing Tiantan Hospital affiliated to Capital Medical University and Beijing Research Institute of Neurosurgery. ① Experimental intervention: All the rats were developed into models of permanent MCAO by suture embolism. Then, they were randomly divided into two HBO groups (9 hours and 18 hours) and control group, with 24 rats in each as well as 3-hour ultrastructure control group, with 2 rats. After being modeled for 3 hours, rats in the two HBO groups stayed in the hyperbaric cabin for 9 hours and 18 hours, separately. Rats in the 9-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7 and 9, and hyperbaric air at hours 2, 4, 6 and 8. Rats in the 18-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7, 9, 11, 13, 15 and 17, and hyperbaric air at hours 2, 4, 6, 8, 10 12, 14, 16 and 18. After being created into models, rats in the control group and 3-hour ultrastructure control group breathed room air. ② Experimental evaluation: Neurologic functions of rat models in the 9-hour and 18-hour HBO groups as well as control group were scored by Bederson and Garica two neurological grading systems at hours 14 and 28 and on day 5; Infarct volume of rat models in the two HBO groups and control group was measured at hour 24 and on day 5 with NIH image processing software Image J; The pathological changes of brain tissue in the brain infarct region and its opposite region of rat models in the two HBO groups and 3-hour ultrastructure control group were observed with a Philips EM 208S transmission electron microscope. MAIN OUTCOME MEASURES: ① Neurobehavioral outcome. ② Rat brain infarct volume. ③ Ultrastructure of brain tissue in the ischemic penumbra of infarct models at the different time points RESULTS: ① Neurobehavioral outcome: After treatment, Garica score in the 9-hour and 18-hour HBO groups was significantly higher than that in the control group (P < 0.01). Bederson score on day 5 after modeling in the 9-hour and 18-hour HBO groups was significantly lower than that in the control group (P < 0.01). ② Cerebral infarct volume: Cerebral infarct volume in the 9-hour and 18-hour HBO groups was significantly smaller than that in the control group at hour 24 and on day 5 after modeling (P < 0.01). In the 18-hour HBO group, infarct volume on day 5 after modeling was significantly larger than that at hour 24 after modeling (P < 0.05). ③In the 3-hour ultrastructure control group, astrocyte edema and neuron damage around the capillary in the infarct cerebral tissue significantly relieved in the rats which were subjected to HBO. CONCLUSION: High dose of HBO is highly efficient in reducing infarct volume and improving neurobehavioral outcome of rats with acute cerebral infarction, and also has an important role in inhibiting the pathological progression of ischemic brain tissue after cerebral infarction.     

微透析法观察蜕皮甾酮对家兔蛛网膜下腔出血的作用

目的通过微透析的方法,观察蛛网膜下腔出血(SAH)后家兔海马内能量物质和谷氨酸的含量变化,了解蜕皮甾酮(EDS)对其干预的效果。方法 30只家兔分为5组,即结扎右侧颈总动脉组(L组)、结扎后枕大池二次注血组(L-SAH组)、结扎后枕大池二次注血尼莫地平治疗组(Nim/SAH组)、结扎后枕大池二次注血蜕皮甾酮(1 mg/kg,4/d)治疗组(EDS/SAH 1 mg组)、结扎后枕大池二次注血蜕皮甾酮(3 mg/kg,4/d)治疗组(EDS/SAH 3 mg组)。比较观察微透析所测得的各组家兔海马SAH前后葡萄糖、丙酮酸、乳酸、谷氨酸的含量变化。结果乳酸/丙酮酸比值(L/P)在SAH后有上升趋势。SAH后3 d时EDS/SAH 3 mg组右侧海马组织间液中L/P较其它组低(P<0.05)。谷氨酸的含量在SAH后也明显增高,10 d时达高峰。Nim/SAH组1 d和3 d右侧海马组织间液谷氨酸含量较L-SAH组降低(P<0.05),在SAH后1 d和3 d EDS/SAH 3 mg组较L-SAH组和Nim/SAH组也明显降低(P<0.01)。结论蜕皮甾酮能减轻家兔SAH后海马组织能量代谢的紊乱和谷氨酸的堆积。     

Delayed and multiple hyperbaric oxygen treatments expand therapeutic window in rat focal cerebral ischemic model

Although the brain-protective effect of single, early applications of hyperbaric oxygen (HBO) has been reported in acute ischemic stroke models, few studies have reported the long-term effect—especially after multiple HBO applications. This study employed delayed, multiple HBO treatments and evaluated cerebral infarction and neurological functional recovery for 4 weeks after transient focal ischemia. Adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and were subsequently exposed to HBO (2.5 atmospheres absolute [ATA]) for 2 hours per day. HBO was administered at either 6 or 24 hours after MCAO/R and was repeated daily for 6 days. Rat behavior was scored to evaluate neurological deficits. The brains were removed for histological analysis of the infarct ratio at 1 and 4 weeks. Rats with HBO delayed for 6 or 24 hours following MCAO/R displayed a significant decrease of infarct ratio and amelioration of neurological deficits compared to the untreated group. This study suggests that delayed, but multiple, HBO treatments can improve neurological evaluation and reduce cerebral infarction.     

Reduced infarct volume and differential effects on glial cell activation after hyperbaric oxygen treatment in rat permanent focal cerebral ischaemia

Permanent middle cerebral artery occlusion (MCAO) causes neurodegeneration and a robust activation of glial cells primarily in sensorimotor brain regions of rats. It has been shown that hyperbaric oxygen (HBO) increases oxygen supply to ischaemic areas and reduces neuronal cell loss. The effects of HBO treatment on microgliosis and astrogliosis in permanent cerebral ischaemia have not been addressed so far, but might be critical for neurodegeneration and neuroprotection, respectively. Therefore, we used spontaneously hypertensive rats with permanent MCAO to investigate the time window to start HBO and to compare the effects of different HBO treatment frequencies on infarct volume and on differences with regard to microgliosis and astrogliosis. Seven days after MCAO the infarct volume was calculated from Nissl-stained brain sections by image analysis. HBO significantly decreased the infarct volume when used as early as 15, 90 or 180 min post-MCAO by 24%, 16% and 13%, respectively, in the single-treatment group. Repetitive HBO treatment (first HBO session 90 min after MCAO) was not effective. Microglial cells and astrocytes were detected by cytochemical fluorescent labelling and confocal laser scanning microscopy. In the single-treatment group we observed significantly higher astrocyte immunoreactivity but decreased microglial density in the peri-infarct region. These effects of HBO treatment on glial cells were not present in rats where HBO did not reduce the infarct volume (360 min after MCAO). Our data indicate that HBO-induced suppression of microgliosis and aggravated response of astrocytes might contribute to the reported beneficial effects of early HBO treatment in cerebral ischaemia.