光化学诱导的血栓形成性脑缺血及其代谢改变

本文用光化学法激发大鼠局部脑血栓形成，以组织病理学、局部脑血流量、皮层水含量、三磷酸腺苷、二磷酸腺苷，一磷酸腺苷、能量负荷、肌酸及乳酸为指标，探讨局部脑血栓形成后５天ｒＣＢＦ明显增高的可能机理。结果表明，血栓形成后局部脑组织ＡＴＰ水平进行性减少（Ｐ＜０．０１）、ＡＤＰ／ＡＴＰ及ＡＭＰ／ＡＴＰ比值明显升高（Ｐ均＜０．０１），ＬＡ及脑水含量显著增加（Ｐ＜０．０１）。这些因素既是能量衰竭、无氧酵解的结果     

盐酸水苏碱对实验性急性脑梗死大鼠的治疗作用

目的:观察盐酸水苏碱对实验性急性脑梗死大鼠的治疗效果,并探讨其可能作用机制。方法:将75只大鼠随机分为5组:假手术组、脑梗死组及不同剂量盐酸水苏碱治疗组,每组各15只。盐酸水苏碱治疗组大鼠在造模完成后分别给予盐酸水苏碱10 mg/kg、20 mg/kg和40 mg/kg灌胃,每天1次,连续给药14 d。给药完成后,对各组大鼠进行神经功能缺损评分,计算脑梗塞体积,干湿重法检测脑含水量,Western blot法检测脑组织中β-catenin、cyclin D1、糖原合成酶激酶3β(GSK-3β)和p-GSK-3β的蛋白水平。结果:与脑梗死组相比,盐酸水苏碱治疗后大鼠的神经功能缺损评分明显降低,脑梗死体积与脑含水量明显降低,β-catenin、cyclin D1和p-GSK-3β的蛋白水平明显升高。结论:盐酸水苏碱对实验性大鼠急性脑梗死具有一定的疗效,其机制可能与激活了Wnt/β-catenin信号通路有关。     

大鼠局灶性脑缺血/再灌注后缺血脑区缓激肽含量的变化

目的研究大鼠局灶性脑缺血/再灌注后缺血脑区缓激肽含量的变化。方法用线栓法制作SD大鼠大脑中动脉阻塞的脑缺血/再灌注动物模型,用免疫细胞化学法结合图像分析技术,检测缺血脑区缓激肽样免疫反应阳性物的平均光密度(A)值作为缓激肽的相对含量,比较局灶性脑缺血3h组、假手术对照组、正常对照组和再灌注30min、2h、4h、16h组缓激肽的相对含量。结果缺血脑区缓激肽样免疫反应阳性物的A值于脑缺血3h/再灌注2h后明显增高(P<0.05),随后下降至增高前水平。结论大鼠局灶性脑缺血/再灌注后,缺血脑区缓激肽含量于再灌注2h后明显增高,其可能在脑缺血后脑水肿的发生中起着重要作用。     

蛛网膜下隙出血后脑动脉痉挛形态学研究

采用大鼠蛛网膜下隙出血模型，经光镜和Ｖｉｄａｓ图像分析的方法，对不同时间段的脑动脉平滑肌的横断面积（Ｓ１），内膜的横断面积（Ｓ２），脑动脉壁横断面积（Ｓ３），脑动脉腔横断面积（Ｓ４），Ｖ１，平滑肌的体密度（Ｓ１／Ｓ３）；Ｖ２；内的体密度（Ｓ２／Ｓ３）；Ｄ１；蛛网膜下隙面脑动脉壁厚度；Ｄ２：脑面及动脉壁厚度进行了观察测定发现蛛网膜下隙出血后脑血管痉挛具有双相性，管腔缩窄，管壁增厚，急性脑血管痉挛比迟     

大鼠局灶性短暂脑缺血后前脑室下带的神经发生

目的：观察大鼠短暂性局灶性脑缺血后前脑室下带(SVZ)神经发生的增殖规律。方法：将SD大鼠随机分为正常对照组、假手术组和缺血实验组,缺血实验组再分为缺血后1、4、7、10、14d组。线栓法制作局灶性脑缺血模型;BrdU标记S期细胞并用免疫组织化学方法检测含BrdU的阳性细胞;测量SVZ区域BrdU阳性细胞核的总面积。结果：在缺血侧,缺血后4d BrdU阳性细胞核的总面积明显增加,7d时达到峰值,随后开始下降,在14d时明显下降,但仍高于正常对照组;在缺血对侧,该区域也表现出同样的表达规律,在缺血后10d达到峰值,但增幅较小。结论：短暂性局灶性脑缺血可促进前脑室下带的神经发生,提示成年脑有潜在的自我修复能力。     

Inhibition of nitric oxide synthesis does not reduce infarct volume in a rat model of focal cerebral ischaemia.

The effect of the nitric oxide (NO) synthesis inhibitor Ng-nitro-L-arginine methylester (L-NAME) on ischaemic brain damage was determined in a rat model of focal cerebral ischaemia. Ischaemia was induced by permanent occlusion of the left middle cerebral artery (MCA) and infarction assessed 4 h post-occlusion by quantitative histopathology. L-NAME (30 mg/kg s.c.), administered 30 min pre- and 30 min post-MCA occlusion, did not significantly alter the volume of ischaemic damage in the cerebral hemisphere, neocortex or caudate nucleus compared with saline controls. This result provides no support for the view that NO generation is a key component in the post-ischaemic cascade leading to acute neuronal death.     

Hemin offers neuroprotection through inducing exogenous neuroglobin in focal cerebral hypoxic-ischemia in rats

Objective: To investigate the inducible effect of hemin on exogenous neuroglobin (Ngb) in focal cerebral hypoxic-ischemia in rats. Methods: 125 healthy SD rats were randomly divided into five groups: sham-operation control group, operation group, hemin treatment group, exogenous Ngb treatment group, and hemin and exogenous Ngb joint treatment group. Twenty-four hours after focal cerebral hypoxic-ischemia, Ngb expression was evaluated by immunocytochemistry, RT-PCR, and western blot analyses, while the brain water content and infarct volume were examined. Results: Immunocytochemistry, RT-PCR, and western blot analyses showed more pronounced Ngb expression in the hemin and exogenous Ngb joint operation group than in the hemin or exogenous Ngb individual treatment groups, thus producing significant differences in brain water content and infarct volume (p < 0.05). Conclusions: Hemin may be beneficial in protecting against focal cerebral hypoxic-ischemia through inducing the expression of exogenous Ngb.     

In vivo effects of phenytoin and phenobarbital on GABA receptors in rat cerebral cortex and cerebellum

The in vivo effects of anticonvulsants on specific binding of [3H]GABA in the rat brain were examined in male Wistar rats. Acute treatment with phenobarbital increased specific [3H]GABA binding in the cerebral cortex, whereas repeated treatment with phenobarbital failed to change [3H]GABA binding. [3H]GABA binding in the cerebellum was not influenced by phenobarbital administration. Acute treatment with phenytoin produced no change in [3H]GABA binding, whereas repeated treatment with phenytoin caused a significant increase in [3H]GABA binding in the cerebellum, but not in the cerebral cortex. The effects of these anticonvulsants may be due, at least in part, to GABA receptor-mediated mechanisms.     

Rapamycin alleviates brain edema after focal cerebral ischemia reperfusion in rats

Brain edema is a major consequence of cerebral ischemia reperfusion. However, few effective therapeutic options are available for retarding the brain edema progression after cerebral ischemia. Recently, rapamycin has been shown to produce neuroprotective effects in rats after cerebral ischemia reperfusion. Whether rapamycin could alleviate this brain edema injury is still unclear. In this study, the rat stroke model was induced by a 1-h left transient middle cerebral artery occlusion using an intraluminal filament, followed by 48?h of reperfusion. The effects of rapamycin (250?μg/kg body weight, intraperitoneal; i.p.) on brain edema progression were evaluated. The results showed that rapamycin treatment significantly reduced the infarct volume, the water content of the brain tissue and the Evans blue extravasation through the blood–brain barrier (BBB). Rapamycin treatment could improve histological appearance of the brain tissue, increased the capillary lumen space and maintain the integrity of BBB. Rapamycin also inhibited matrix metalloproteinase 9 (MMP9) and aquaporin 4 (AQP4) expression. These data imply that rapamycin could improve brain edema progression after reperfusion injury through maintaining BBB integrity and inhibiting MMP9 and AQP4 expression. The data of this study provide a new possible approach for improving brain edema after cerebral ischemia reperfusion by administration of rapamycin.     

Increased expression of cysteinyl leukotriene receptor-1 in the brain mediates neuronal damage and astrogliosis after focal cerebral ischemia in rats

Cysteinyl leukotrienes are potent pro-inflammatory mediators. Cysteinyl leukotriene receptor 1 is one of the two cysteinyl leukotriene receptors cloned. We recently reported that cysteinyl leukotriene receptor 1 antagonists protected against cerebral ischemic injury, and an inducible expression of cysteinyl leukotriene receptor 1 was found in neuron- and glial-appearing cells after traumatic injury in human brain. To determine the role of cysteinyl leukotriene receptor 1 in ischemic brain injury, we investigated the temporal and spatial profile of cysteinyl leukotriene receptor 1 expression in rat brain from 3 h to 14 days after 30 min of middle cerebral artery occlusion, and observed the effect of pranlukast, a cysteinyl leukotriene receptor 1 antagonist, on the ischemic injury. We found that cysteinyl leukotriene receptor 1 mRNA expression was up-regulated in the ischemic core both 3-12 h and 7-14 days, and in the boundary zone 7-14 days after reperfusion. In the ischemic core, cysteinyl leukotriene receptor 1 was primarily localized in neurons 24 h, and in macrophage/microglia 14 days after reperfusion; while in the boundary zone it was localized in proliferated astrocytes 14 days after reperfusion. Pranlukast attenuated neurological deficits, reduced infarct volume and ameliorated neuron loss in the ischemic core 24 h after reperfusion; it reduced infarct volume, ameliorated neuron loss and inhibited astrocyte proliferation in the boundary zone 14 days after reperfusion. Thus, we conclude that cysteinyl leukotriene receptor 1 mediates acute neuronal damage and subacute/chronic astrogliosis after focal cerebral ischemia.     

脑室和腹腔注射灯盏花素对大鼠脑缺血再灌注损伤的保护

目的探讨脑室直接灌注灯盏花素注射液，对大鼠脑缺血再灌注损伤的保护作用。方法采用线栓法制备大鼠大脑中动脉缺血再灌注模型，在再灌注后的不同时间点（3h、6h、24h）；通过脑室直接灌注、腹腔注射和脑室灌注＋腹腔注射的方式使用灯盏花素，观察用药后大鼠神经功能和组织病理学改变，计算脑梗死体积比、脑水肿体积和脑含水量。结果与对照组相比，灯盏花素组的脑梗死体积比、脑水肿体积和脑含水量均明显减轻，随着缺血时间的延长，这种保护作用逐渐降低，脑室灌注＋腹腔注射联合使用的保护效果明显优于单纯脑室灌注或腹腔注射给药。结论脑缺血再灌注后使用灯盏花素具有明显的神经功能保护作用，脑室灌注和腹腔注射给药的保护作用相似，但在损伤后的早期（〈6h）、超早期（〈3h）采用脑室灌注＋腹腔注射联合给药的方式效果最佳。     

大鼠脑血栓形成时心功能不全发生机制的探讨

以脑水含量、局部脑血液、全血血小板聚集、心输出量、每搏出量、心率、平均血压、外周总阻力及心、肝、脾。肾和肾上腺局部血流量为指标，探讨 光化学法诱导的实验性血栓形成性局部脑缺血时全血血小板功能改变对心功能的影响及其机理。结果表明，光化学反应后４小时，全血血小板聚集明显增强（Ｐ＜０．０１），ＣＯ、ＳＶ降低（Ｐ＜０．０５）；２４小时ｒＣＢＦ，ＣＯ，Ｓ及心肌ｒＢＦ均明显减少，ＴＰＲ及脑水含量明显增加（Ｐ＜     

The infarct‐limiting effect of cerebral ischaemic postconditioning in rats depends on the middle cerebral artery branching pattern

Cerebral ischaemic postconditioning (PostCon) is a recently discovered endogenous neuroprotective phenomenon that occurs after several brief bouts of reperfusion/ischaemia instituted immediately after prolonged cerebral ischaemia. Data on the extent of PostCon‐mediated infarct size limitation in models of focal cerebral ischaemia–reperfusion are controversial. In this study, we investigated the infarct‐limiting effect of PostCon in the rat model of focal cerebral ischaemia–reperfusion. The relationship between anatomic pattern of the middle cerebral artery (MCA) and infarct size was also studied. The protocol of PostCon consisting of five episodes each of 10‐s ischaemia and 10‐s reperfusion was protective in terms of infarct size limitation only in animals with the typical bifurcating MCA branching pattern. The anatomic pattern of the MCA should be considered as one of the important factors influencing the outcome of neuroprotection studies.     

家兔急性不完全性脑缺血及重灌流的实验研究

采用低压低灌流方法造成家兔急性不完全性脑缺血60分钟,缺血后进行重灌流。检测了脑电图(EEG)、心输出量、平均动脉血压及脑静脉血乳酸脱氢酶(LDH)、磷酸肌酸激酶(CPK)活性以及大脑皮质水、钠、钾及环核苷酸含量,观察组织形态学改变。实验结果表明通过低压低灌流成功地复制了兔急性不完全性脑缺血模型。其特点为EEG严重抑制、大脑皮质水、钠含量升高、LDH及CPK活性显著升高。并见脑组织出现脑水肿改变。重灌流期间EEG先有所恢复后严重抑制,LDH及CPK活性仍显著升高。大脑皮质cAMP含量进一步升高,水肿程度加重。组织形态学呈现明显的缺血性损伤尤以亚微结构更为严重,表明重灌流后组织损伤加重。作者分析了上述改变发生的可能机制。     

Ghrelin对脑缺血再灌注大鼠脑水肿和水通道蛋白4表达的影响

 目的： 探讨ghrelin对脑缺血再灌注大鼠脑水肿、血脑屏障通透性及水通道蛋白4（AQP4）表达的影响。方法： 成年SD雄性大鼠随机分为3组:sham组、大脑中动脉阻塞（MCAO）组和ghrelin处理组。采用线栓法复制MCAO模型（缺血2 h,再灌注22 h）。Ghrelin组大鼠于再灌开始时经股静脉注射ghrelin 10 nmol/kg。TTC染色观察脑梗死体积,神经功能评分判断脑功能障碍程度,分别以体积计算和干湿重法检测脑肿胀程度和脑含水量的变化,收集脑血管外伊文思蓝(EB)来评估血脑屏障的破坏程度,免疫组化和Western blotting检测AQP4的表达变化。结果： 与MCAO组比较,ghrelin处理组的脑梗死体积较小（P<0.01）,神经功能评分较低（P<0.01）,脑组织中的EB渗出量较少（P<0.01）。Ghrelin处理组大鼠的脑肿胀体积、脑含水量和AQP4表达明显低于MCAO组（P<0.05）。结论： Ghrelin减轻大鼠脑缺血/再灌注损伤,减轻脑水肿和血脑屏障的破坏,抑制脑组织中AQP4的表达。AQP4在ghrelin的脑保护机制中可能发挥重要作用。     

Corticotropin-releasing factor: effect on cerebral blood flow in physiologic and ischaemic conditions

The expression of corticotrophin-releasing factor (CRF) receptors in cerebral arteries and arterioles suggests that CRF may modulate cerebral blood flow (CBF). In the present study, the effects of CRF, CRF-like peptides and the CRF broad spectrum antagonist DPhe-CRF on CBF have been investigated under normal physiologic conditions and in the margins of focal ischaemic insult. The experiments were carried out in anaesthetised and ventilated rats. Changes in CBF after subarachnoid microapplication of CRF and related peptides were assessed with a laser-Doppler flowmetry (LDF) probe. In the ischaemic animals, agents were injected approximately 60 minutes after permanent middle cerebral artery occlusion (MCAo). Microapplication of CRF and related peptides in normal rats into the subarachnoid space produced sustained concentration-dependent increases in CBF. This effect was attenuated by co-application with DPhe-CRF, which did not alter CBF itself. A second microapplication of CRF 30 min after the first failed to produce increases in CBF in normal animals. Microapplication of CRF in the subarachnoid space overlying the ischaemic cortex effected minor increases in CBF whereas D-Phe-CRF had no significant effect on CBF. Activation of the CRF peptidergic system increases CBF in the rat. Repeated activation of CRF receptors results in tachyphylaxis of the vasodilator response. CRF vasodilator response is still present after MCAo in the ischaemic penumbra, suggesting that the CRF peptidergic system may modulate CBF in ischaemic stroke.     

脑梗死相关蛋白与ACI患者脑血管狭窄程度的多因素分析

目的研究脑梗死相关蛋白在评估急性脑梗死（ACI）患者脑血管狭窄程度中的作用。方法选取2010—2012年在珠江医院因ACI住院的患者,选取脑动脉造影结果狭窄程度〉70％及闭塞者为试验组（n=29）,≤70％者及正常者为对照组（n=23）。检测所有患者外周血脑梗死相关蛋白含量。结果试验组患者超敏C反应蛋白（hs—CRP）、血栓前体蛋白（TpP）、脂蛋白α（Lpα）外周血中含量分别为（3．51±2．25）mg／L、（1797．08±162．35）μg／L、（363．81±218．34）mg／L,均较对照组明显升高,差异有统计学意义（P〈0．05）。D-二聚体（DDI）、纤维蛋白原（Fg）、血小板凝聚因子（vWF）的含量无明显变化。hs-CRP（P=0．029,OR=2．232）、TpP（P=0．032,OR=1．014）、Los（P=0．024,OR=1．009）与脑大动脉粥样硬化病变导致的脑血管狭窄程度相关,DDI（P=0．671）、Fg（P=O．248）、vWF（P=0．090）与脑血管的狭窄程度相关性不明显。高血压（P=0．029,OR=4．582）是脑血管狭窄的危险因素。结论hs—CRP、TpP、Lpα、高血压是脑大动脉粥样硬化病变导致的ACI患者脑血管重度狭窄的危险因素,血清中hs．CRP、TpP、Lpα含量升高同时伴有高血压的ACI患者脑血管重度狭窄的可能性增大。     

川芎嗪对大鼠脑缺血再灌注损伤后大脑皮质Bc1-2表达的影响

目的:研究川芎嗪对大鼠脑缺血再灌注损伤后Bcl-2表达的影响.方法:以线栓法制作大鼠大脑中动脉阻塞的局灶性脑缺血再灌注模型,采用免疫印迹、2, 3, 5-氯化三苯四氮唑(TTC)、 H-E染色和神经行为相结合的方法,观测缺血再灌注侧大脑皮质内Bcl-2的表达、脑梗塞体积、脑组织结构及神经功能的变化.结果:与缺血再灌注组(I 2h/R24h)比较,川芎嗪组的Bcl-2表达明显增高,脑梗塞体明显缩小,脑组织的病理损伤和神经异常行为明显减轻.结论:川芎嗪可通过上调Bcl-2的表达,缩小脑梗塞的体积和减轻脑缺血区组织结构的损伤以及明显改善神经症状,对脑缺血再灌注损伤有保护作用.     

The effects of TRH analogues on cerebral ischaemia produced by middle cerebral artery occlusion in the rat

Summary This study examined the effects of two stabilised analogues of TRH, RX 77368 and CG 3509, in a rat cerebral ischaemia model produced by unilateral occlusion of the middle cerebral artery. The analogues were given intraventricularly after artery occlusion. The extent of the cortical ischaemia was evaluated after 10 days by somatosensory evoked potential (SEP) recording, followed by tetrazolium staining of brain slices for NADH-diaphorase activity. RX 77368 (2×10 g; 15 min, 24 h) significantly improved the survival rate, protected the SEP and reduced the area of infarct. In contrast, neither a smaller dose of RX 77368 (2×3 g) nor a 4 h delay in the treatment had any significant beneficial effects. Although CG 3509 (2×10 g) resulted in an apparent improvement in survival, its overall effects were not statistically significant. The findings indicate that stabilised TRH analogues may have beneficial effects when given to animals with focal cerebral ischaemia.     

全反式维甲酸通过作用于JNK/P38 MAPK信号通路减轻大鼠脑缺血再灌注引起的血脑屏障损伤

目的:观察全反式维甲酸(all-trans retinoic acid,ATRA)对脑缺血再灌注(cerebral ischemia-reperfusion,CIR)损伤大鼠血脑屏障的影响,并探讨其可能的作用机制。方法:将SD雄性大鼠随机分组为假手术(sham)组、模型(CIR)组及CIR+ATRA(10、30和90 mg/kg)组。采用MCAO线栓法建立大鼠CIR损伤模型,缺血1. 5 h,再灌注24 h后,进行神经功能行为学评分及脑梗死体积、脑含水量和伊文思蓝含量的测定;明胶酶谱法检测基质金属蛋白酶9(MMP-9)的活性; Western blot法检测脑组织中紧密连接蛋白(claudin-5、occludin和ZO-1)、JNK、p-JNK、P38、p-P38和MMP-9的蛋白水平。结果:与CIR模型组相比,ATRA(30 mg/kg)可明显改善大鼠神经功能,减少脑梗死体积,降低脑含水量和伊文思蓝含量,降低缺血区紧密连接蛋白的降解(P 0. 01),降低缺血脑组织中MMP-9的活性及蛋白的表达(P 0. 01),抑制JNK/P38 MAPK通路中JNK和P38的磷酸化并减少p-JNK和p-P38的蛋白水平(P 0. 01)。结论:ATRA能够减轻CIR对大鼠脑组织的损伤和血脑屏障的破坏,其保护作用可能与抑制JNK/P38 MAPK信号通路和MMP-9的激活有关。