局灶性脑缺血后脑内髓过氧化物酶活性观察

目的　探讨局灶性脑缺血后脑组织髓过氧化物酶（ＭＰＯ） 活性的测定方法,以及与缺血性损害的关系。方法　采用新型小鼠大脑中动脉线栓模型,检测不同缺血时间组梗塞体积及ＭＰＯ活性。结果　缺血１ ｈ 后再灌注２３ ｈ 组（ｔＭＣＡＯ）缺血灶体积明显小于缺血２４ ｈ 组（ｐＭＣＡＯ）;ＭＰＯ活性在各缺血组缺血侧明显高于对照侧和对照组（ Ｐ＜ ０－０５）,ｐＭＣＡＯ 组缺血侧基底节区ＭＰＯ 活性显著高于ｔＭＣＡＯ 组（ Ｐ＜ ０－０５） ,而两组缺血皮质区ＭＰＯ 活性则无显著差异。结论　本研究建立了局灶性脑缺血的ＭＰＯ活性测定方法,证明ＭＰＯ活性与缺血损伤间具有一定关系。     

兔MCAO后脑组织NOS活性的变化

一氧化氮（ＮＯ）与脑缺血关系密切，对缺血性脑损害可能有直接的影响，一氧化氮的合成酶（ＮＯＳ）是ＮＯ生物合成的限速酶，本文在建立兔ＭＣＡＯ局灶脑缺血模型基础上，测定缺血后不同时间缺血区和正常脑组织的ＮＯＳ活性。结果证实缺血后早期（ＭＣＡＯ后１ｈ内）ＮＯＳ活性突然升高。     

SHR在MCAO后脑组织NOS活性的变化

一氧化氮（ＮＯ）在脑缺血中起重要作用，一氧化氮合成酶（ＮＯＳ）作为ＮＯ合成的关键酶，其活性变化直接调节ＮＯ的生成量及生物学效应。本文在建立ＳＨＲＭＣＡＯ局灶脑缺血模型基础上，测定脑缺血后不同时间和正常脑组织的ＮＯＳ活性，结果显示脑缺血早期（１、４ｈ），晚期（２４、４８ｈ）ＮＯＳ活性明显升高，提示脑缺血后缺血组织ＮＯ含量增加。     

大鼠局灶性脑缺血细胞因子介导的中性粒细胞化学吸附剂的动？…

目的：探索细胞因子介导的中性粒细胞化学吸附剂（ＣＩＮＣ）在脑缺血损伤中的作用。方法：用线栓法制备大鼠局灶性脑缺模型,观察不同脑缺血时程血浆（ｓｅｒａ）和脑组织内ＣＩＮＣ浓度与髓质过氧化物酶（ＭＰＯ）活性。结果：缺血组,血浆中ＣＩＮＣ浓度的高峰在缺血６小时,脑组织内ＣＩＮＣ浓度和髓质过氧化物酶（ＭＰＯ）活性均低水平,其中ＣＩＮＣ浓度高峰在缺血１２小时,与对照组比较,差异均有极显著性意义（Ｐ〈０．０１     

NO代谢变化对缺血性脑组织内皮素产生的影响

在兔大脑中动脉阻断（ＭＣＡｏ）型局灶脑缺血前后分别应用外源性一氧化氮合成酶（ＮＯＳ）抑制剂Ｌ－ＮＮＡ和ＮＯ合成底物Ｌ－ａｒｇｉｎｉｎｅ，观察缺血４小时后脑组织内皮素（ＥＴ）含量的变化。结果发现Ｌ－ＮＮＡ组较缺血对照组脑组织ＥＴ含量明显增多（１２６２．９±３８７．６ｖｓ７８９．３±１８８．４ｐｇ／ｍｇ·ｐｒｏ，Ｐ值＜０．０１），脑水肿显著；而Ｌ－ａｒｇｉｎｉｎｅ用药组脑组织ＥＴ含量较缺血对照组明显减少（Ｐ值＜０．０５），且脑水肿减轻。本研究提示ＮＯ能抑制缺血脑组织ＥＴ的产生。ＮＯ对脑缺血影响可能与此途径有关。     

L-THP对脑缺血大鼠脑组织NO含量变化影响的研究

目的：通过检测局灶性脑缺血大鼠脑组织中ＮＯ含量的变化及左旋四氢巴马汀（Ｌ－ｔｅｔｒａｂｙｄｒｏｐａｌｍａｔｉｎｅ,Ｌ－ＴＨＰ）的影响．从而探讨Ｌ－ＴＨＰ的脑保护作用机制。方法：采用线栓法制备大鼠右侧大脑中动脉阻断（ＭＣＡＯ）模型。 应用硝酸还原酶法检测缺血３ｈ及４８ｈ脑组织 ＮＯ含量的变化及Ｌ－ＴＨＰ对ＮＯ含量的影响。结果：缺血３ｈ及４８ｈ脑组 织 ＮＯ含量明显升高,且４８ｈ缺血组ＮＯ含量高于３ｈ缺血组。缺血前３０ｍｉｎ应用Ｌ－ＴＨＰ２０ｍｇ／ｋｇ可明显降低３ｈ及 ４８ｈ脑缺血组织中ＮＯ含量。结论：Ｌ－ＴＨＰ可降低局灶性脑缺血脑组织中ＮＯ的含量。其脑保护作用是通过抑制ＮＯ介 导的神经毒性作用实现的。     

大鼠急性局灶性脑缺血再灌注脑组织NO含量和NOS活性的变化

目的探讨一氧化氮（ＮＯ）和神经元型ＮＯ合酶（ｎＮＯＳ）是否参与急性局灶性脑缺血再灌注的发病机理。方法采用栓红法建立大鼠大脑中动脉阻塞（ＭＣＡＯ）模型,观察脑组织ＮＯ含量和一氧化氮合酶（ＮＯＳ）活性的变化及ｎＮＯＳ抑制剂７－硝基吲唑（７－ＮＩ）对再灌注期两者的影响。结果缺血３０分种ＮＯ含量和ＮＯＳ活性显著升高,缺血３小进两者下降;再灌注３０分种ＮＯＴ和ＮＯＳ再次升高,而再灌注３小时两者又下降。７－Ｎ     

NO对实验性局灶脑缺血再灌流神经细胞凋亡影响的定量研究

目的 研究ＮＯ在局灶性脑缺血再灌流过程中对神经细胞的作用机制，特别是ＮＯ与细胞凋亡的关系。方法 利用流式细胞仪检测法，测定Ｎ－硝基－左旋－精氨酸（ＮＮＬＡ）干预后局灶性脑缺血鼠脑组织中神经细胞的凋情况。结果 在缺血再灌流期间过多或过少的ＮＯ均对缺血区凋亡峰有明显影响，小剂量ＮＮＬＡ减少神经细胞凋亡的发生率，大剂量ＮＮＬＡ增加神经细胞凋亡的发生率。结论 局灶性脑缺血的不同区域，包括正常及病变组织中的     

兔局灶脑缺血后内源性阿片肽含量变化

应用兔大脑中动脉阻断（ＭＣＡＯ）局灶脑缺血模型，放免法测定脑组织和血浆中内源性阿片肽（β－内啡肽、强啡肽Ａ１－１３）的含量。结果发现脑缺血后这两种肽含量均显著增加，且随缺血时间的延长而递增，与脑组织Ｈ２Ｏ、Ｎａ含量之间呈一定的正相关关系，该结果提示内源性阿片肽可能参与局灶脑缺血脑水肿的发生发展。     

大剂量甲基强的松龙对大鼠局灶性缺血再灌注脑损伤的影响

目的 探讨大剂量甲基强的松龙（ＭＰ）对局灶性缺血再灌注大鼠脑保护作用的机理。方法采用大鼠局灶性脑缺血再灌注模型,观察缺血前后应用大剂量ＭＰ对大鼠大脑中动脉闭塞侧梗死体积的影响以及脑含水量的变化,同时观察脑组织病理学改变。结果 缺血前后ＭＰ治疗组大脑中动脉供血区脑梗死体积较盐水对照组明显减小（均Ｐ〈０．０１）;缺血性前后ＭＰ治疗组与盐水对照组脑含水量比较无明显差别（均Ｐ〉０．０５）。病理学发现盐水对照组织血管周围可见巨噬细胞浸润,而ＭＰ治疗组无此病理改变。结论 大剂量ＭＰ可改善缺血性脑损伤,其机理与减小缺血区梗死体积、抑制脑组织巨噬细胞浸润有关。     

尤瑞克林对大鼠局灶性脑缺血再灌注损伤后炎性反应的影响

目的研究尤瑞克林对大鼠局灶性脑缺血再灌注损伤后炎性反应的影响。方法将90只SD大鼠随机分为3组:假手术组,对照组,治疗组。采用线栓法建立大鼠大脑中动脉闭塞再灌注模型,缺血2 h后,拔出线栓,恢复灌注24 h,观察大鼠神经功能缺损症状、脑梗死体积、脑组织中白细胞浸润、MPO活性、IL-1和ICAM-1的表达。结果 (1)假手术组大鼠在神经功能缺损评分、脑梗死体积均低于对照组,有显著的统计学差异(P<0.01);脑组织中白细胞浸润程度、髓过氧化物酶(MPO)活性、ICAM-1和IL-1的表达均较对照组低,统计学差异明显(P<0.01);(2)治疗组与对照组相比,大鼠的神经功能缺损评分低、脑梗死体积小,有显著统计学差异(P<0.01);白细胞浸润程度、MPO活性、ICAM-1和IL-1的表达均较对照组减少(P<0.01)。结论尤瑞克林可通过抑制大鼠脑缺血再灌注损伤后的炎性反应来实现其神经保护作用。     

3-Aminobenzamide reduces brain infarction and neutrophil infiltration after transient focal cerebral ischemia in mice

Poly(ADP-ribose) polymerase (PARP) was shown to be detrimental in cerebral ischemia but the mechanisms whereby PARP is deleterious have yet to be determined. They may include a role in neutrophil infiltration known to aggravate ischemic damage. In this context, we investigated the effect of 3-aminobenzamide (3-AB), a PARP inhibitor, on brain damage and neutrophil infiltration after transient focal cerebral ischemia in mice. Ischemia was induced in male Swiss mice, anaesthetized with chloral hydrate (400 mg/kg, i.p.), by a 15-min-occlusion of the left middle cerebral artery using an intraluminal suture. Treatments with 3-AB were first administered intraperitoneally 15 min before reperfusion and endpoints measured at 24 h. Among the range of dosages studied (20-320 mg/kg), 40 mg/kg gave the maximal neuroprotection with a 30% decrease in the infarct volume and tended to improve the neurological score evaluated by a grip test. The same dosage was, however, devoid of effect when injection was delayed 2 or 6 h after reperfusion. Myeloperoxidase (MPO) activity used as an index of neutrophil infiltration showed that infiltration peaked 48 h after reperfusion in our model. At this time point, 3-AB (40 mg/kg given 15 min before reperfusion) markedly reduced the neutrophil infiltration, as evidenced by a 72%-decrease in MPO activity, and was still neuroprotective. Our results confirm that 3-AB reduces brain damage. Moreover, for the first time, a quantitative study shows that 3-AB decreases neutrophil infiltration elicited by cerebral ischemia.     

Puerarin protects brain tissue against cerebral ischemia/reperfusion injury by inhibiting the inflammatory response

Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ischemia/reperfusion injury using the suture method. Puerarin(100 mg/kg) was administered intraperitoneally 30 minutes before middle cerebral artery occlusion and 8 hours after reperfusion. Twenty-four hours after reperfusion, we found that puerarin significantly improved neurological deficit, reduced infarct size and brain water content, and notably diminished the expression of Toll-like receptor-4, myeloid differentiation factor 88, nuclear factor kappa B and tumor necrosis factor-α in the ischemic region. These data indicate that puerarin exerts an anti-inflammatory protective effect on brain tissue with ischemia/reperfusion damage by downregulating the expression of multiple inflammatory factors.     

血管内皮生长因子和碱性成纤维细胞生长因子在缺血预处理大鼠局灶性脑缺血再灌注区域的表达

背景：脑缺血预处理可增加碱性成纤维细胞生长因子的表达,可能导致脑缺血耐受的产生。大鼠大脑中动脉缺血再灌注给予血管内皮生长因子能够起到神经保护作用。 目的：观察缺血预处理对缺血再灌注大鼠血管内皮生长因子和碱性成纤维细胞生长因子表达的影响。 方法：将SD大鼠随机分为缺血预处理组、模型组和假手术组。缺血预处理及模型组线栓法阻塞大脑中动脉制备脑缺血模型。预处理组在脑缺血-再灌注前3 d用插入尼龙线阻塞大脑中动脉,缺血2 h后再灌注22 h。模型组第一次手术将线栓前推5 mm,不阻断血流,其他同预处理组。假手术组仅插入尼龙线不阻塞大脑中动脉。用苏木精-伊红染色法观察3组间神经细胞变化。用抗生物素-生物素-过氧化物酶复合物法检测各组血管内皮生长因子和碱性成纤维细胞生长因子蛋白的表达。分别比较3组神经功能评分、光镜下脑缺血再灌注区神经细胞形态、血管内皮生长因子和碱性成纤维细胞生长因子的表达。 结果与结论：与模型组比较,预处理组神经功能评分明显低于模型组(P < 0.01)。光镜下观察结果显示,与模型组比较,预处理组缺血面积及缺血程度均减轻,血管内皮生长因子和碱性成纤维细胞生长因子表达均明显升高(P < 0.05)。结果提示缺血预处理可能通过增强血管内皮生长因子和碱性成纤维细胞生长因子而对缺血再灌注大鼠神经细胞起保护作用。     

莱菔硫烷对大鼠局灶性脑缺血再灌注损伤的保护作用及机制研究

目的 探讨莱菔硫烷对大鼠局灶性脑缺血再灌注损伤的保护作用及机制.方法 采用线栓法制备大鼠大脑中动脉阻断局灶性脑缺血模型,分别于MCAO后1h腹腔注射莱菔硫烷2.5mg/kg、5mg/kg、10mg/kg.于缺血2h再灌注24h时进行神经行为缺损评分,TTC染色评价脑梗死体积,测定脑组织中超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量.免疫荧光组织化学染色法检测黄核蛋白NQ01和脂质过氧化酶Prx6的表达.结果 莱菔硫烷给药组与对照组相比均能改善大鼠脑缺血再灌注后神经行为缺损评分,减少脑梗死体积.其中5mg/kg组能显著改善大鼠脑缺血再灌注后神经行为缺损评分,减少脑梗死体积,增强SOD活性,降低MDA含量.免疫荧光组织化学染色法提示NQ01和Prx6的表达明显增强.结论 莱菔硫烷对大鼠局灶性脑缺血再灌注损伤有神经保护作用,其机制可能与上调内源性抗氧化蛋白NQ01和Prx6的表达有关.     

Multiple modes of action of tacrolimus (FK506) for neuroprotective action on ischemic damage after transient focal cerebral ischemia in rats

While the immunosuppressant tacrolimus (FK506) is known to be neuroprotective following cerebral ischemia, the mechanisms underlying its neuroprotective properties are not fully understood. To determine the mode of action by which tacrolimus ameliorates neurodegeneration after transient focal ischemia, we therefore evaluated the effect of tacrolimus on DNA damage, release of cytochrome c, activation of microglia and infiltration of neutrophils following a 60-min occlusion of the middle cerebral artery (MCA) in rats. In this model, cortical brain damage gradually expanded until 24 h after reperfusion, whereas brain damage in the caudate putamen was fully developed within 5 h. Tacrolimus (1 mg/kg) administered immediately after MCA occlusion significantly reduced ischemic damage in the cerebral cortex, but not in the caudate putamen. Tacrolimus decreased both apoptotic and necrotic cell death at 24 h and reduced the number of cytochrome c immunoreactive cells at 8 h after reperfusion in the ischemic penumbra in the cerebral cortex. In contrast, tacrolimus did not show significant neuroprotection for necrotic cell death and reduction of cytochrome c immunoreactive cells in the caudate putamen. Tacrolimus also significantly decreased microglial activation at 8 h and inflammatory markers (cytokine-induced neutrophil chemoattractant and myeloperoxidase [MPO] activity) at 24 h after reperfusion in the ischemic cortex but not in the caudate putamen. These results collectively suggest that tacrolimus ameliorates the gradually expanded brain damage by inhibiting both apoptotic and necrotic cell death, as well as suppressing inflammatory reactions.     

Neuroprotective effect of baicalin on focal cerebral ischemia in rats

Baicalin, a flavonoid compound from the root of the herb Scutellaria baicalensis Georgi, has been widely used to treat patients with inflammatory disease. The aim of this study was to assess the efficacy of baicalin in a rat model of focal cerebral ischemia. Adult male Sprague-Dawley rat models of cerebral artery occlusion were established and then randomly and equally divided into three groups: ischemia(cerebral ischemia and reperfusion), valproic acid(cerebral ischemia and reperfusion + three intraperitoneal injections of valproic acid; positive control), and baicalin(cerebral ischemia and reperfusion + intraperitoneal injection of baicalin for 21 days). Neurological deficits were assessed using the postural reflex test and forelimb placing test at 3, 7, 14, and 21 days after ischemia. Rat cerebral infarct volume was measured using 2,3,5-triphenyltetrazolium chloride(TTC) staining method. Pathological change of ischemic brain tissue was assessed using hematoxylin-eosin staining. In the baicalin group, rat neurological function was obviously improved, cerebral infarct volume was obviously reduced, and the pathological impairment of ischemic brain tissue was obviously alleviated compared to the ischemia group. Cerebral infarct volume was similar in the valproic acid and baicalin groups. These findings suggest that baicalin has a neuroprotective effect on cerebral ischemia.     

Protective effect of oxysophoridine on cerebral ischemia/reperfusion injury in mice

Oxysophoridine, a new alkaloid extracted from Sophora alopecuroides L., has been shown to have a protective effect against ischemic brain damage. In this study, a focal cerebral ischemia/reperfusion injury model was established using middle cerebral artery occlusion in mice. Both 62.5, 125, and 250 mg/kg oxysophoridine, via intraperitoneal injection, and 6 mg/kg nimodipine, via intragastric administration, were administered daily for 7 days before modeling. After 24 hours of reperfusion, mice were tested for neurological deficit, cerebral infarct size was assessed and brain tissue was collected. Results showed that oxysophoridine at 125, 250 mg/kg and 6 mg/kg nimodipine could reduce neurological deficit scores, cerebral infarct size and brain water content in mice. These results provided evidence that oxysophoridine plays a protective role in cerebral ischemia/reperfusion injury. In addition, oxysophoridine at 62.5, 125, and 250 mg/kg and 6 mg/kg nimodipine increased adenosine-triphosphate content, and decreased malondialdehyde and nitric oxide content. These compounds enhanced the activities of glutathione-peroxidase, superoxide dismutase, catalase, and lactate dehydrogenase, and decreased the activity of nitric oxide synthase. Protein and mRNA expression levels of N-methyl-D-aspartate receptor subunit NR1 were markedly inhibited in the presence of 250 mg/kg oxysophoridine and 6 mg/kg nimodipine. Our experimental findings indicated that oxysophoridine has a neuroprotective effect against cerebral ischemia/reperfusion injury in mice, and that the effect may be due to its ability to inhibit oxidative stress and expression of the N-methyl-D-aspartate receptor subunit NR1.     

PAF受体拮抗剂对缺血/再灌注脑损害的作用研究

目的血小板活化因子(platelet activating factor，PAF)与缺血／再灌注(ischemic reperfusion，IR)脑损害有密切关系，此研究拟用PAF受体拮抗剂WEB2086对PAF、炎性细胞浸润及一氧化氮(NO)在脑IR损害中的作用和机制进行探讨。方法采用线栓法制成大鼠大脑中动脉IR模型，对IR脑组织NO含量、局部脑血流量(rCBF)、中性白细胞髓过氧化物酶(MPO)及脑梗死体积进行测定。结果：PAF受体拮抗剂WEB2086对IR脑组织NO的产生有明显影响．且可明显改善IR脑组织的rCBF和显著降低MPO活性，最终减轻局部IR脑损害。结论PAF受体拮抗剂WEB2086对IR脑组织的保护作用与NO有关。     

Protective effect of biflavones from Araucaria bidwillii Hook in rat cerebral ischemia/reperfusion induced oxidative stress

Oxidative stress is implicated in the pathogenesis of ischemic brain injury. Flavonoids from various herbal extracts have been shown to be neuroprotective in experimental models of cerebral ischemia/reperfusion (I/R). The present study was designed to investigate the neuroprotective effect of the biflavone rich fraction from Araucaria bidwillii Hook (ABH) (Family: Araucariaceae) in I/R induced oxidative stress. The I/R was induced by occluding bilateral common carotid arteries (BCCAO) for 30 min, followed by 24 h reperfusion. BCCAO caused significant depletion in superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and significant increase in lipid peroxidation (LPO) in various brain regions. The neurological deficit and sensory motor function were also decreased significantly by BCCAO group as compared to sham group animals. All the alteration induced by cerebral ischemia was significantly attenuated by 7 days' pretreatment with biflavone fraction (BFR) at the dose of 100 and 200 mg/kg, comparable to that given by Vitamin E (200 mg/kg). Consistent with neurobehavioral deficits, pretreatment with biflavones at higher doses significantly reduced ischemia-induced neuronal loss of the brain. In conclusion the biflavone rich fraction from A. bidwillii was found to protect rat brain against I/R induced oxidative stress, and attributable to its antioxidant properties.