山茱萸环烯醚萜苷对局灶性脑缺血模型大鼠BDNF及其受体TrkB表达的影响

我们的系列研究发现,在局灶性脑缺血/再灌注大鼠模型上,山茱萸环烯醚萜苷(cornel iridoid glycoside,CIG)具有良好的缺血保护作用,能够明显改善模型大鼠的神经功能,减小脑梗死体积,其作用机制与抗氧自由基、抑制炎性反应、促进血管内皮生长因子及其受体的表达、促进神经发生和血管新生等有关[1～5].为了进一步探讨脑缺血后CIG神经保护的作用机制,本研究观察了CIG对局灶性脑缺血大鼠大脑皮质脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)及其受体TrkB表达的影响,旨在为将CIG开发成治疗缺血性脑损伤的新药提供实验依据.     

西洛他唑对小鼠慢性缺血性脑损伤的保护作用及机制

目的：观察西洛他唑对小鼠慢性缺血性脑损伤的保护作用,探讨其与促血管生成的关系。方法：以大脑中动脉栓塞方法诱导小鼠局灶性脑缺血,缺血后1、4、7h和术后1～14d腹腔注射西洛他唑（10mg／kg）,每天一次,观察缺血后35d西洛他唑对神经症状评分、斜板角度、脑梗死体积、神经元密度和缺血侧血管内皮生长因子（VEGF）、血管内皮生长因子受体2（Flk-1）表达的作用。结果：西洛他唑能降低缺血后神经症状评分,提高斜板角度,减少脑梗死体积,增加存活神经元密度和VEGF、Flk-1表达的数目。结论：西洛他唑对小鼠慢性局灶性脑缺血具有保护作用,其作用机制可能与诱导缺血侧VEGF、Flk-1表达,促进血管生成有关。     

冰片配伍三七对局灶性脑缺血大鼠的神经保护作用

目的:研究冰片配伍三七对局灶性脑缺血大鼠的神经保护作用。方法:SD大鼠随机分为假手术组、模型组、冰片组、三七组、冰片配伍三七组和尼莫地平组6组，连续灌胃给药7 d后复制大脑中动脉脑缺血(MCAO)模型，术后24 h进行神经功能缺损测定，检测血清中的超氧化物歧化酶(SOD)活性及一氧化氮(NO)、丙二醛(MDA)含量，观察脑组织病理形态，检测脑组织中B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关X蛋白(Bax)的蛋白表达及血管内皮生长因子(VEGF)、脑源性神经营养因子(BDNF)、基质金属蛋白酶2(MMP-2)的mRNA表达。结果:冰片配伍三七组能降低MCAO大鼠的神经功能评分(P<0.01),改善脑组织病理形态，升高血清中SOD活性并降低NO、MDA含量(P<0.05),降低脑组织中Bax蛋白表达和MMP-2的mRNA表达(P<0.01),升高Bcl-2蛋白表达，以及BDNF、VEGF的mRNA表达(P<0.01)。结论:冰片配伍三七对局灶性脑缺血大鼠具有神经保护作用，其机制可能是提高了MCAO大鼠血清中SOD活性并降低了MDA、NO含量，降低脑组织中Ba...     

重组粒细胞集落刺激因子对大鼠急性缺血性脑梗死后损伤修复的研究

目的观察人重组粒细胞集落刺激因子(rhG-CSF)对大鼠急性局灶性脑梗死轴突、血管再生的影响。方法健康雄性Wistar大鼠建立局灶性脑缺血模型,随机分为脑缺血组及相应时间点的假手术组、药物组。免疫组织化学法检测脑内血管内皮细胞生长因子(VEGF)变化及反转录-聚合酶链反应(RT-PCR)法检测神经生长相关蛋白(GAP)-43表达。结果①缺血组及药物组1～10d GAP-43均呈增高趋势,2组各时间表达量有区别;②缺血组VEGF表达1～10d内缓慢增高;药物组上调VEGF表达,1～4d迅速增高,4d时达到高峰,4～10d有降低趋势,10d与假手术组相比仍有差别。结论G-CSF可促进轴突再生、血管增殖,延长缺血治疗窗,发挥脑保护作用。     

小鼠局灶性脑缺血梗死灶的定量分析

目的:用小鼠持续性局灶性脑缺血模型,证明新建的透光法测定局灶性脑缺血梗死灶的实用性。方法:采用大脑中动脉阻塞法(MCAO)造成小鼠持续性局灶性脑缺血,于缺血后2 4h进行Bederson’s症状评分和爬板、悬挂试验,并以计算机图像分析技术测定和分析脑缺血梗死体积、脑半球面积、皮层及皮层下神经元密度;在大脑中动脉线栓手术前3d和术前1h分别腹腔注射Pranlukast 0 .1mg·kg-1或尼莫地平0 .4mg·kg-1,观察药物的神经保护作用。结果:透光测定的梗死体积与TTC染色测定的梗死体积、神经元密度密切相关,与神经症状综合评分具有等级相关。Pranlukast和尼莫地平能减少脑梗死体积和脑半球的缺血侧 非缺血侧比值,减轻神经症状和神经元死亡。结论:透光法结合神经症状综合评分法可用于小鼠局灶性脑缺血的定量分析和药物的神经保护作用评价。     

山麦冬总皂苷对局灶性脑缺血损伤的保护及抗凝血作用研究

目的:研究山麦冬总皂苷(TSL)对大鼠局灶性脑缺血损伤的保护及抗凝血作用。方法:采用三氯化铁局部涂抹损伤血管的方法复制大鼠大脑中动脉血栓模型,观察TSL对大鼠行为障碍、脑梗死范围、相关脑区组织病理变化、神经型一氧化氮合酶(nNOS)阳性细胞表达率等指标的影响;采用毛细管法及断尾法观察TSL对小鼠出、凝血时间的影响。结果:10、40mg.kg-1TSL可显著减少大鼠脑梗死范围,改善行为学障碍,降低nNOS阳性细胞表达率;20、60mg.kg-1TSL可使小鼠凝血时间及出血时间显著延长。结论:TSL对大脑中动脉血栓所致局灶性脑缺血损伤具有保护作用,并具有显著的抗凝血作用。     

雏菊叶龙胆酮对局灶性脑缺血损伤的保护作用及机制探讨

目的　研究雏菊叶龙胆酮 (Bellidifolin)对大鼠局灶性脑缺血损伤的保护作用,并探讨其可能的作用机制。方法　利用电凝法制作SD大鼠右侧大脑中动脉阻塞 (MCAO)模型,于MCAO缺血后 4h和 24h进行神经行为学评分, 24评分后断头取脑测量脑梗塞面积,应用HE染色和免疫组化法观察Bellidifolin干预后缺血区病理学改变和ICAM 1、Bcl2蛋白的变化。结果　Bellidifolin能改善MCAO缺血后神经功能障碍并缩小脑梗塞面积;减轻相关脑区神经元损伤程度;显著抑制大鼠局灶性脑缺血损伤ICAM 1表达,上调缺血周边区神经元Bcl 2抗凋亡蛋白的表达。结论　Bellidifoli口服给药对缺血性脑损伤有保护作用,其作用机制可能与抑制ICAM 1表达和促进Bcl 2表达有关。     

骨髓间充质干细胞移植对缺血性脑损伤大鼠的作用及其机制研究

目的观察骨髓间充质干细胞(MSCs)移植对大鼠缺血性脑损伤后神经功能恢复的作用并探讨其作用机制。方法体外培养MSCs;线栓法制作SD大鼠脑缺血2h再灌注模型,24h后将标记5-溴脱氧尿嘧啶(B rdu)的MSCs通过颈动脉移植入脑缺血大鼠体内;采用神经功能缺损评分检测大鼠神经系统功能;用苏木素-伊红(HE)染色以观察梗死灶的部位和范围;用免疫组化方法检测脑内MSCs的迁移及分泌营养因子的分泌情况;寡核苷酸末端脱氧核糖核酸介导的dUTP缺口末端标记法(TUNEL)原位检测缺血周边区皮质神经细胞凋亡的情况。结果动脉移植后,MSCs在脑内存活、迁移,同时分泌血管内皮细胞生长因子(VEGF)、脑源性神经营养因子(BDNF)等多种神经保护性因子;显著上调BDNF和VEGF的表达,延长其高表达时程;并减少了神经细胞的凋亡。与模型组和PBS组相比,MSCs移植组神经功能明显改善;脑组织病理变化明显减轻(P<0.05)。结论动脉移植MSCs治疗大鼠缺血性脑损伤具有较好的疗效。MSCs分泌多种神经保护性营养因子及减少缺血周边区神经细胞凋亡可能是其主要机制之一。     

重组人促红细胞生成素对大鼠急性脑缺血脑组织中肿瘤坏死因子-α基质金属蛋白酶-9和血管生成素-2表达的影响

目的探讨重组人促红细胞生成素(rhEPO)对大鼠急性局灶性脑缺血损伤的神经保护作用及其机制。方法健康雄性SD大鼠54只随机分为假手术组、模型组和rhEPO治疗组。采用线栓法制作大鼠永久性局灶性脑缺血(pMCAO)模型。rhEPO治疗组在缺血2h后腹腔注射rhEPO4000U/kg,模型组和假手术组在等时间点给予等量的生理盐水。缺血24h后断头取脑分别用干湿质量法计算脑组织含水量,2,3,5-氯化三苯基四氮唑(TTC)法测量脑梗死体积,免疫组织化学方法测定肿瘤坏死因子-α(TNF-α)、基质金属蛋白酶-9(MMP-9)、血管生成素-2(Ang-2)的表达。结果 rhEPO治疗组与模型组相比,脑组织含水量减少,脑梗死体积减小,TNF-α和MMP-9的表达降低,而Ang-2的表达较模型组升高(P<0.05)。结论 rhEPO对大鼠急性脑缺血有一定的神经保护作用,其机制可能是通过降低TNF-α、MMP-9的活性和促进Ang-2的表达来实现的。     

康脑液对脑缺血再灌注动物血管新生的影响

目的：观察康脑液对大鼠局灶脑缺血再灌注损伤后血管新生的影响。方法将雄性SD大鼠随机分为假手术组、模型组、尼莫地平组（1 mg· kg-1· d-1）及高、中、低剂量（24,12,6 g · kg-1· d-1） 康脑液组,线栓法制备大鼠脑缺血再灌注模型。于缺血后2 h再灌注0.5,3,7 d后,处死大鼠,用免疫组织化学法观察脑缺血区微血管密度（MVD）的变化及脑组织血管内皮生长因子（VECF）和肝细胞生长因子（HGF）的表达情况;同时分别于再灌注后2,24,48 h评价动物神经功能。结果与模型组相比,各剂量康脑液组与尼莫地平组的神经功能均明显改善,MVD显著升高,VEGF和HGF蛋白表达明显上调（ P＜0.05或P＜0.01） ,其中以中剂量康脑液组最为显著。结论康脑液增强大鼠局灶性脑缺血后VEGF及HGF的表达,是其抗脑缺血的可能作用机制之一。     

半胱氨酰白三烯受体拮抗剂pranlukast对小鼠局灶性脑缺血的治疗作用

目的　观察半胱氨酰白三烯受体拮抗剂pranlukast(ONO 10 78)在小鼠局灶性脑缺血后的治疗作用。方法　采用大脑中动脉阻塞造成小鼠持续性局灶性脑缺血 ,缺血后1、6、2 4h分别给小鼠腹腔注射 pranlukast或依达拉奉 ,观察药物对缺血 2 4、4 8h后的神经功能缺损症状 ,4 8h后的脑梗死体积、两侧大脑半球比值、神经元密度的影响。结果　Pranlukast 0 1、0 2mg·kg-1及依达拉奉 3、10mg·kg-1均能减轻神经症状、减小脑梗死体积、降低缺血侧 /非缺血侧大脑半球比值、减轻海马CA1区、皮层和纹状体的神经元密度降低。结论　Pranlukast脑缺血后给药对脑损伤有治疗作用 ,提示有治疗缺血性脑卒中的临床前景。     

Pranlukast reduces neutrophil but not macrophage/microglial accumulation in brain after focal cerebral ischemia in mice

AIM: To determine whether pranlukast, a cysteinyl leukotriene receptor-1 antagonist, exerts an anti-inflammatory effect on focal cerebral ischemia in mice. METHODS: Focal cerebral ischemia in mice was induced by permanent middle cerebral artery occlusion (MCAO). In addition to neurological deficits, infarct volume, degenerated neurons and endogenous IgG exudation, we detected accumulation of neutrophils and macrophage/microglia in the ischemic brain tissue 72 h after MCAO. Pranlukast was ip injected 30 min before and after MCAO. RESULTS: Pranlukast significantly attenuated neurological deficits, infarct volume, neuron degeneration and IgG exudation. Importantly, pranlukast (0.01 and 0.1 mg/kg) inhibited myeloperoxidase-positive neutrophil, but not CD11b-positive macrophage/microglial accumulation in the ischemic cortical tissue. CONCLUSION: Pranlukast exerts an anti-inflammatory effect on focal cerebral ischemia in the subacute phase that is limited to neutrophil recruitment through the disrupted blood-brain barrier.     

Montelukast, a cysteinyl leukotriene receptor-1 antagonist, dose- and time-dependently protects against focal cerebral ischemia in mice

Our previous studies showed that cysteinyl leukotriene receptor-1 (CysLT1) antagonist pranlukast has a neuroprotective effect on cerebral ischemia in rats and mice. However, whether the neuroprotective effect of pranlukast is its special action or a common action of CysLT1 receptor antagonists remains to be clarified. This study was performed to determine whether montelukast, another CysLT1 receptor antagonist, has the neuroprotective effect on focal cerebral ischemia in mice, and to observe its dose- and time-dependent properties. Permanent focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO). Montelukast was injected intraperitoneally either as multiple doses (once a day for 3 days and 30 min before MCAO) or as a single dose (at 30 min before, 30 min after, or 1 h after MCAO), respectively, and pranlukast and edaravone were used as controls. The neurological deficits, infarct volumes, brain edema, neuron density, and Evans blue extravasation in the brain were determined 24 h after MCAO. Pretreatments with multiple doses or a single dose of montelukast (0.1 and 1.0 mg/kg) before MCAO significantly attenuated all the ischemic insults. Post-treatment with a single dose of montelukast (0.1 and 1.0 mg/kg) at 30 min after MCAO also significantly decreased brain edema and infarct volume, but not neurological deficits. However, post-treatment with a single dose of montelukast at 1 h after MCAO had no significant effect. Pranlukast showed the same effects as montelukast, but edaravone attenuated the ischemic insults only with multiple doses before MCAO. Thus, montelukast has a dose- and time-dependent neuroprotective effect on permanent focal cerebral ischemia in mice, with an effective dose range of 0.1-1.0 mg/kg and a therapeutic window of 30 min. These findings further support the therapeutic potential of CysLT1 receptor antagonists in the treatment of cerebral ischemia at earlier phases.     

Pretreatment with eplerenone reduces stroke volume in mouse middle cerebral artery occlusion model

Eplerenone, a mineralocorticoid receptor antagonist, is reported to be effective to prevent end-stage cardiovascular damage induced by aldosterone. However, the effect of eplerenone on brain damage is not fully understood. Here, we investigated whether pretreatment with eplerenone attenuates stroke size in mice subjected to middle cerebral artery occlusion. Middle cerebral artery occlusion with a microfilament technique induced focal ischemia, to approximately 25% of the total area in a coronal section of the brain. Treatment with eplerenone at a dose of 1.67 mg/g chow significantly reduced the ischemic area, ischemic volume, and neurological deficit, without a blood pressure-lowering effect. Laser-Doppler flowmetry analysis showed a decrease in surface cerebral blood flow in the peripheral region after 1 h of middle cerebral artery occlusion. This decrease was smaller in mice treated with eplerenone. Superoxide production evaluated by staining with dihydroethidium was attenuated in the ischemic area of the brain in eplerenone-treated mice. Taken together, our findings suggest that eplerenone has a protective effect on ischemic brain damage, at least partly due to improvement of cerebral blood flow in the penumbra and reduction of oxidative stress.     

盐酸埃他卡林对大鼠局灶性脑缺血后脑组织损伤和血液流变学的作用

目的研究盐酸埃他卡林(Ipt)对局灶性脑缺血后脑组织损伤保护作用及对血液流变学变化的影响。方法线栓法阻断SD大鼠大脑中动脉造成大鼠局灶性脑缺血。神经功能行为学评分参考Longa法,脑水肿形成检测采用Ellis公式,TTC染色法测定脑梗死范围。以DPH为荧光探针,采用荧光偏振法测定脑缺血6h后红细胞膜脂流动性,微粘度。结果脑缺血6h后,脑梗死范围达对侧脑半球的(24.75±6.66)%,预防性给予Ipt(1.0～4.0mg·kg-1,ip)可使脑梗死范围分别减少0.95%,6.6%(P<0.05),14.34%(P<0.01)。Ipt2.0和4.0mg·kg-1还可降低大鼠的神经功能行为评分及脑组织含水量。尼莫地平(Nim)0.3mg·kg-1也可减少脑梗死范围,降低脑组织含水量,降低神经功能行为评分。脑缺血6h后,红细胞变形能力下降,红细胞膜脂流动性降低,红细胞聚集程度及膜微粘度皆明显提高。预防性给予Ipt(2.0～4.0mg·kg-1,ip)及Nim0.3mg·kg-1可显著改善上述血液流变学指标。Ipt4.0mg·kg-1治疗作用的时间窗为3h,超过4h则治疗作用不显著。Nim0.3mg·kg-1治疗作用不明显。结论盐酸埃他卡林对局灶性脑缺血引起的脑损伤有一定的保护作用。     

Prevention of ischemic brain injury by adenosine receptor activation

The abilities of the xanthine oxidase inhibitor, oxypurinol, and the adenosine deaminase inhibitor, deoxycoformycin, to alleviate cerebral ischemic damage were evaluated in gerbil and rat models. Cerebral ischaemia of 5 min duration was induced in unanesthetized Mongolian gerbils by bilateral occlusion of the carotid arteries. Cerebral damage was assessed behaviorally by the elevation of motor activity and by histological assesment of neuronal degeneration in the CA1 area of the hippocampus. Oxypurinol (40 mg/kg) administered either prior to or 30 min after and ischaemic episode significantly reduced both the hypermotility and hippocampal damage observed in saline-treated control ischemic gerbils. Deoxycoformycin (500 μg/kg) was effective only when administered prior to ischemia. Rats with a focal ischaemic lesion (unilateral occlusion of a middle cerebral artery combined with tandem occlusion of the ipsilateral common carotid artery) were used to model strokes. The degree of ischaemic damage was evaluated by measuring the contralateral neurological deficits at 24 and 48 h post infarction and by calculating the volume of infarcted tissue after brain slices had been stained with 2,3,5-triphenyl, 2H-tetrazolium chloride (TTC) solution. Oxypurinol (40 mg/kg) administered 30 min prior to or 1h after the onset of focal ischaemia significantly reduced the infarct size, brain swelling, and neurological deficits. Deoxycoformycin (500 μg/kg) was effective only when administered preischemia. These findings suggest that oxypurinol and deoxycoformycin may be useful for the prevention and treatment of ischaemic brain injuries. © 1993 Wiley-Liss, Inc.     

AMG-1对小鼠和大鼠缺血脑能量代谢及神经细胞损伤的影响

本文观察AMG-1对小鼠断头全脑缺血时能量代谢及大鼠大脑中动脉阻断(MCAO)后行为和病理改变影响。小鼠sc AMG-1 1～10mg/kg 30min后,能有效减少脑缺血后乳酸(LA)堆积,ATP和磷酸肌酸(PCr)的耗竭。sc AMG-1 5mg/kg和尼英地平0.5 mg/kg,可减轻大鼠MCAO后的神经症状和神经细胞缺血性损害。AMG-1的这一改善脑缺血作用与尼莫地平近似。     

银杏叶提取物(EGb)对大鼠局部脑缺血及颈动脉血栓形成的保护作用

应用大鼠大脑中动脉梗塞和血栓形成导致缺血性脑卒中的实验模型,观察银杏叶提取物(EGb)对脑缺血面积和由缺血造成的行为障碍的影响。结果表明预防或治疗性iv大剂量EGb(200mg·kg^-1)均能显著减少脑缺血面积,明显改善大鼠脑缺血造成的行为障碍,其预防作用似优于治疗作用。预防性iv小剂量EGb(100mg·kg^-1)也能明显减少血栓形成性脑缺血面积,改善梗塞和血栓形成性脑缺血所致的行为障碍,与阳性对照药尿激酶和尼莫地平作用相同。实验还发现EGb有抑制大鼠电刺激颈总动脉的血栓形成的作用,且其对抗血栓形成强度具剂量依赖性。提示EGb对缺血性脑卒中和血栓形成有预防和治疗作用。     

Restoration of middle cerebral artery thrombosis by novel glycoprotein IIb/IIIa antagonist FK419 in guinea pig

We compared the antithrombotic efficacy of FK419 [(S)-2-acetylamino-3-[(R)-[1-[3-(piperidin-4-yl)propionyl]piperidin-3-ylcarbonyl]amino] propionic acid trihydrate], a novel nonpeptide glycoprotein IIb/IIIa antagonist, with recombinant tissue plasminogen activator (rt-PA) and other antithrombotic agents (aspirin, ozagrel, argatroban and heparin). FK419 not only inhibited ADP- and collagen-induced guinea pig platelet aggregation, but also induced disaggregation for ADP-induced aggregated platelets in vitro. In the photochemically induced middle cerebral artery thrombosis model in guinea pigs, FK419 dose-dependently shortened the time to first reperfusion and the total middle cerebral artery occlusion time and reduced ischemic brain damage and ameliorated neurological deficits measured 24 h after middle cerebral artery occlusion. Rt-PA similarly improved the middle cerebral artery patency, brain damage and neurological deficits. Neither aspirin, ozagrel, argatroban nor heparin restored the middle cerebral artery blood flow and improved the brain damage or neurological deficits. These results demonstrated that novel glycoprotein IIb/IIIa antagonist FK419 could disperse thrombus and ameliorated ischemic brain damage, suggesting that FK419 would be an attractive intervention for stroke patients.