胰岛素对脑缺血再灌注后bFGF表达的影响

目的 研究胰岛素对脑缺血再灌注后碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)蛋白表达的影响。方法 用线栓法制成大鼠大脑中动脉闭塞再灌注模型，外周应用胰岛素保持血糖水平正常，免疫组化观察单纯缺血再灌注后bFGF表达及胰岛素对它们的影响。结果胰岛素组bFGF表达明显强于未用药组。结论 胰岛素增强缺血再灌注后bFGF的表达可能是其具有脑保护作用的机制之一。     

大鼠脑缺血再灌流后海马区一氧化氮合酶活性的变化

目的：观察鼠全脑缺血再灌流后海马区ＮＯＳ活性的变化。方法：采用大鼠４血管关闭方法制作全脑缺血再灌流模型。实验动物分为假手术组、缺血１０ｍｉｎ组、再灌注１、２、３ｄ组。测定脑缺血再灌流后海马区ＮＯＳ活性的变化。结果：全脑缺血曹澡注后海马组织ＮＯＳ活性被激活上调。结论：ＮＯ可能参与了海马ＣＡ１区迟发性神经元死亡（ＤＮＤ）的发生。     

实验性脑缺血及再灌注大鼠脑组织bFGF表达的研究

目的　探讨大鼠脑缺血２ ｈ 后不同时间再灌注脑组织碱性成纤维细胞生长因子（ｂＦＧＦ）的表达程度。方法　采用线栓法栓堵一侧大鼠大脑中动脉,建立脑缺血及再灌注模型。用免疫组化的方法,对缺血脑组织ｂＦＧＦ的表达进行观察。用统计学分析ｂＦＧＦ阳性细胞的数据。结果　正常脑组织中只有微量ｂＦＧＦ的表达;脑缺血２ ｈ 后再灌注０．５ ｈ 起,ｂＦＧＦ少量表达,为神经元表达;脑缺血２ ｈ 后再灌注２２ ｈ,ｂＦＧＦ表达达到高峰,神经元及神经胶质细胞均有表达。脑缺血２ ｈ 后再灌注１６６ ｈ,ｂＦＧＦ仍有持续表达。结论　ｂＦＧＦ参与缺血脑组织的修复过程     

脑缺血再灌注后血管内皮细胞凋亡及其与Bcl—2表达的关系

目的 探讨大鼠局灶性脑缺血再灌注损伤后血管内皮细胞凋亡及其与Bcl-2蛋白表达的关系。方法 采用原位末端标记法和免疫组化法分别观察脑缺血再灌注2h、6h、12h、24h、2d、3d、7d、14d和21d等时间 点血管内皮细胞凋亡和Bcl-2蛋白的表达。结果 （1）脑缺血再灌注2h在缺血周围区即有凋亡内皮细胞出现,12－24h达高峰,之后逐渐下降,至21d与假手术组已无显著性差异。（2）脑缺血再灌注后2h在缺血周围区内皮细胞Bcl-2开始表达,12－24h达高峰,之后逐渐下降,至14d接近假手术组水平。（3）Bcl-2蛋白表达时相变化与内皮细胞凋亡基本一致。结论 脑缺血再灌注损伤中凋亡是血管内皮细胞的死亡形式之一,Bcl-2蛋白具有抑制缺血再灌注后血管内皮细胞凋亡的作用。     

bFGF对脑缺血再灌注大鼠ICAM-1表达及脑组织含水量的影响

目的探讨bFGF对局灶性缺血再灌注大鼠脑组织含水量及脑组织ICAM-1水平的影响。方法SD大鼠48只,随机分为假手术组（n=16）、缺血再灌注组（n=16）和bFGF组（n=16）。应用线栓法制作大鼠局灶性脑缺血再灌注模型,大脑中动脉阻塞1h再灌注损伤24h,bFGF组伤后即刻一次性经腹腔注射bFGF（10g／kg）,假手术组和损伤组以相同方法给予0．9％的生理盐水。采用干湿法检测各组大鼠脑组织含水量,采用伊文思蓝（evansblue,EB）法检测脑毛细血管通透性,采用免疫组化法检测大鼠脑组织ICAM-1水平。结果与假手术组比较,缺血再灌注组脑含水量、脑皮质EB含量及ICAM-1表达显著增加（P〈0．05）,与缺血再灌注组比较,bFGF组脑含水量、脑皮质EB含量及ICAM-1表达较模型组显著性降低（P〈0．05）。结论ICMA-1表达增加是脑缺血再灌注后脑水肿形成和缺血性损伤的重要原因之一,减少ICAM-1表达和脑组织含水量推测是bFGF脑保护作用机制之一。     

高热对大鼠局部脑缺血再灌流损伤的影响

目的 研究短暂高热（脑温40℃）在脑缺血再灌流不同时间对脑损伤的影响。方法 采用自制的大鼠脑温调控装置,分别于大鼠局部脑缺血1b,再灌流2h,24h,48h,对大鼠进行短暂的高热或常温处理,高热或常温处理后24h对大鼠进行神经功能缺损评分。72h后测脑梗死体积。结果 大鼠脑缺血再灌流2h时,40℃高热可导致脑梗死体积显著增大,神经功能显著恶化,而再灌流24h或48h后高热对脑损伤的作用不明显。结论 脑缺血后,短暂高热仅在再灌流早期对缺血性脑损伤有加重作用。高热加重缺血性脑损伤的时间窗可能仅限于脑缺血再灌流后24h内。     

大鼠局灶性脑缺血再灌流后HSP70表达及其mRNA变化

目的 探讨热休克蛋白７０（ＨＳＰ７０）在局灶脑缺血再灌流后的变化和作用。方法 采用线栓法制备大脑中动脉缺国知再灌流模型。应用免疫组化方法观察ＨＳＰ７０的组织学分布,利用ＲＴ－ＰＣＲ方法检测缺血皮层与基底节区脑组织ＨＳＰ７０ｍＲＮＡ相对含量。结果 基底节区ＨＳＰ７０阳性细胞较少,持续时间短,眼层区ＨＳＰ７０阳性细胞较多,持续时间长。ＲＴ－ＰＣＲ结果表明ＨＳＰ７０ｍＲＮＡ相对含量与免疫组化结果相一致。     

大鼠局灶脑缺血再灌注后GM1的保护作用及其对FGFR1表达的影响

目的 探讨大鼠局灶脑缺血再灌注后神经节苷脂（ＧＭ１）的保护作用及其对碱性纤维母细胞生长因子的特异性受体（ＦＧＦＲ１）表达的影响。方法 采用检线法备大脑中动脉缺血再灌注模型。通过腹腔注射给予ＧＭ１,利用免疫组化方法检测ＦＧＦＲ１表达情况,并对病理学改变进行观察研究。结果 与对照组相比,缺血再灌组ＦＧＦＲ１表达明显增多（Ｐ〈０．０１）,而ＧＭ１用药组与缺血再灌组相比,ＦＧＦＲ１表达也明显增长（Ｐ〈０．     

阿魏酸钠对大鼠脑缺血—再灌流后氧化性DNA损伤的保护作用

为研究脑缺血 再灌流后氧化性DNA损伤及阿魏酸钠的保护作用 ,采用线栓法制成大鼠大脑中动脉阻塞及再通模型。大脑中动脉再通时静脉注射阿魏酸钠 (15mg/kg) ,用免疫组织化学方法检测脑缺血 2h ,再灌流 4 8h后缺血再灌流组、阿魏酸钠组及对照组脑组织再灌流后氧化性DNA损伤产物 8 羟基脱氧鸟苷(8 OHdG)的表达。结果发现对照组脑区仅见少数散在微弱的 8 OHdG阳性表达 ;缺血再灌流组大脑中动脉阻塞侧额顶叶上部皮质和内侧尾壳核脑区有大量的 8 OHdG阳性表达 ,较对照组显著增加 (P <0 .0 1) ;阿魏酸钠组 8 OHdG阳性表达在脑区分布与缺血再灌流组相似 ,但较缺血再灌流组显著减少 (P <0 .0 1)。上述结果表明脑缺血—再灌流所致的氧化性DNA损伤主要存在于缺血半暗带 ,阿魏酸钠对氧化性DNA损伤具有保护作用。     

孕酮对大鼠脑缺血再灌注损伤后TASK3蛋白表达的影响

目的观察孕酮对大脑中动脉栓塞(MCAO)大鼠脑组织TASK3蛋白表达的影响,探讨孕酮对脑缺血再灌注损伤大鼠的脑保护作用及机制。方法雄性SD大鼠随机分为正常对照组、假手术组、缺血再灌注组(I/R组)和孕酮+I/R组,后3组按缺血再灌注后不同时间随机分为0 h、6 h、12 h、24 h、48 h、72 h、96 h和120 h 8个亚组。线栓法建立大鼠右侧MCAO模型,缺血2 h再灌注24 h进行脑损伤评估,检测各组大鼠死亡率、神经功能缺陷评分以及2,3,5-氯化三苯基四氮唑(TTC)染色测定脑梗死体积;采用免疫印迹法检测各组大鼠脑组织缺血2 h再灌注后不同时间点TASK3蛋白的表达。结果孕酮+I/R组大鼠死亡率(18.18%)明显低于I/R组(40.66%),该组动物脑梗死体积(21.85%±3.53%)也显著低于I/R组(37.21%±3.50%)(P<0.01),且该组神经功能缺陷评分(2.00±0.74)显著低于I/R组(2.67±0.49)(P<0.05)。与正常对照组相比,假手术组各时间点脑组织TASK3蛋白的表达无明显变化,而I/R组各时间点脑组织TASK3蛋白的表达均显著降低(P<0.05);与I/R组相比,孕酮+I/R组各时间点脑组织TASK3蛋白的表达显著升高(P<0.05)。结论孕酮对脑缺血再灌注损伤的大鼠具有脑保护作用,其机制可能与上调TASK3通道蛋白的表达有关。     

大鼠脑缺血再灌流后HSP70的表达和bFGF对其影响

目的研究脑缺血再灌流后热休克蛋白７０（ＨＳＰ７０）表达的意义及外源性碱性成纤维细胞生长因子（ｂＦＧＦ）对其影响。方法应用免疫组化的方法观察大鼠局灶性脑缺血再灌流后脑组织ＨＳＰ７０的表达以及在侧脑室注射外源性ｂＦＧＦ对其影响。结果缺血２小时再灌流０小时即可见ＨＳＰ７０表达,至２４小时达高峰。ｂＦＧＦ组与生理盐水组相比于６～４８小时各组可见ＨＳＰ７０表达增高（Ｐ〈０．０５）。结论脑缺血诱导ＨＳＰ７０的     

The time course of glucose metabolism in rat cerebral ischemia with middle cerebral artery occlusion-reperfusion model and the effect of MK-801

Abstract

Following cerebral ischemiai, the extracellular concentration of excitatory amino acids increases, and the excitatory cell death may play an important role contributing to ischemic neuronal damage. Although sequential metabolic changes in permanent local cerebral ischemia have been reported\ the effect of reperfusion in local cerebral ischemia on glucose metabolism is less clear. In order to investigate the time course change of glucose metabolism in a middle cerebral artery occlusion-reperfusion model and the effect of dizocilpin (MK-801) on glucose metabolism, the 4C-Deoxyglucose method was used. Hypermetabolism occurred at 30 min after the middle cerebral artery (MCA) occlusioni, and reached a peak at 60 min after ischemia in both ischemic core and penumbra. The shift from hyper- to hypometabolism was observed after the ischemia. The reperfusion facilitated the decrease of cerebral glucose metabolism in the ischemic region following 2 h of MCA occlusion. The pretreatment of MK-801 (0.4 mg kg~ 7J inhibited both increased glucose metabolism during ischemia and decreased glucose metabolism during reperfusion. These findings support the hypothesis that excitation-induced hypermetabolism plays a major role in the ischemic insult following focal cerebral vascular occlusion. [Neurol Res 1996; 18: 505-508]     

MK-801 reduced cerebral ischemic injury by inducing hypothermia

The non-competitive N-methyl-D-aspartate (NMDA) antagonist, MK-801, has been reported to prevent or attenuate ischemic brain damage in various animal models. In halothane-anesthetized gerbils it was found that an optimal dose of MK-801 (3.0 mg/kg) for providing cerebral protection also produced hypothermia (31.1 +/- 0.62 degrees C) relative to control animals (34.2 +/- 0.77 degrees C, P less than 0.01). This degree of hypothermia alone was sufficient to provide complete histological and functional protection (spatial memory) against 5 min of carotid artery occlusion. In gerbils made ischemic, but maintained at normal body temperature, a dose of 3.0 mg/kg of MK-801 provided no protection against hippocampal cell loss or spatial memory impairment. These data suggest that the protective actions of MK-801 may be due entirely to drug-induced hypothermia.     

NMDA receptor antagonist MK-801 infused into the insular cortex prevents the attenuation of gustatory neophobia in rats

Gustatory neophobia dissipates with repeated exposures to an initially novel taste solution. The aim of the present study was to determine whether NMDA receptors in the insular cortex are involved in this experience-dependent process. Results showed that acute microinfusion of MK-801 into the insular cortex prevented the attenuation of gustatory neophobia indicating that this process is an NMDA receptor-dependent phenomenon.     

The neuroprotective efficacy of MK-801 in focal cerebral ischemia varies with rat strain and vendor

The present study was designed to evaluate whether the neuroprotective efficacy of MK-801 in focal cerebral ischemia was dependent on strain and/or vendor differences. MK-801 (0.12 mg/kg i.v. bolus followed by 0.108 mg/kg/h infusion or 0.60 mg/kg i.v. bolus followed by 0.540 mg/kg/h infusion) or saline was administered just after intraluminal middle cerebral artery occlusion. Administration of 0.540 mg/kg/h MK-801 provided strain/line-dependent neuroprotection in the following rank order: Simonsen Laboratories Sprague-Dawley rats > Simonsen Laboratories Wistar rats > Taconic Laboratories Sprague-Dawley rats. After 0.108 mg/kg/h MK-801 treatment, Simonsen Laboratories Wistar rats were the only strain/line that were significantly neuroprotected. These results indicate that the neuroprotective effect of an experimental drug may be influenced by rat strain and vendor differences.     

观察乌司他丁在大鼠脑缺血再灌注损伤中的作用

目的 通过对大鼠脑组织及血清中IL-8、ICAM-1浓度的测定,观察乌司他丁在脑缺血再灌注损伤中的作用.方法 将健康雄性SD大鼠随机分为对照组(5只)、乌司他丁治疗组(25只,线栓3h后给药)、未用药组(25只)、结扎组(结扎右侧颈总动脉,25只),应用ELISA法检测对照组及后3组在4h(各5只)、12h(各5只)、24h(各5只)、48h(各5只)、72h(各5只)大鼠脑组织及血清中IL-8、ICAM-1的含量.结果 结扎组与空白组IL-8及ICAM-1的含量无统计学意义(P＞0.05);未用药组与结扎组相对应的时间点数据有明显差异,具有统计学意义(P＜0.05);乌司他丁治疗组与未用药组相应时间点数据具有明显差异(除72h外),具有统计学意义(P＜0.05).结论 乌司他丁能减轻大鼠脑缺血后的再灌注损伤、机制与抑制炎症反应有关.     

The effects of dizocilpine (MK-801), phencyclidine, and nimodipine on infarct size 48 h after middle cerebral artery occlusion in the rat

The effects of the calcium channel blocker nimodipine and the non-competitive NMDA-antagonists MK-801 and phencyclidine (PCP) on infarct size 48 h after occlusion of the middle cerebral artery (MCA-O) were evaluated in the rat. Nimodipine was given at a dose of 0.3 mg/kg s.c. 30 min prior and 8, 16, and 24 h after MCA-O. MK-801 (1 mg/kg i.p. or 10 mg/kg i.p.) or PCP (0.3, 1.0, 3.0, 10, or 30 mg/kg i.p.) were administered 30 min prior to ischemia. In additional experiments 30 mg/kg PCP was given 1, 3, or 5 h post ischemia. Nimodipine and 1 mg/kg MK-801 reduced cortical infarct volumes significantly by 50% and 55%, respectively, while cortical infarct size fell by 32% and total infarct volume was not altered significantly after administration of 10 mg/kg MK-801. Pretreatment with 10 or 30 mg/kg PCP reduced cortical infarction by 47-53% and total infarct volumes by 39-42%. Posttreatment with PCP was effective if started at 1 or 3 h post ischemia.     

Nicotine reduces the binding of [H]MK-801 to brain membranes, but not via the stimulation of high-affinity nicotinic receptors

Nicotine (10 and 100 μM) inhibited [³H]MK-801 binding to rat cerebral cortical membranes and this effect was not blocked by dihydro-β-erythroidine, (+)-tubocurarine or mecamylamine. Cytisine, muscarine, mecamylamine and (+)-tubocurarine also inhibited [³H]MK-801 binding. Neither raising the MK-801 concentration, nor the addition ofn-methyl-D-aspartate (NMDA) receptor agonists altered the effects of nicotine. Hence this response is not mediated via high-affinity nicotinic receptor stimulation, competition for MK-801 binding sites or require NMDA receptor activation.     

Sensitization to noise-mediated induction of seizure susceptibility by MK-801 and phencyclidine

The effect of single administrations of MK-801 (5-methyl-10,11-dihydro-5H-dibenzo[a,d]cylohepten-5,10-imine) or PCP (phencyclidine) on the induction of audiogenic seizure susceptibility by noise in immature rats was examined. Treatments with these non-competitiveN-methyl-D-aspartate (NMDA) receptor antogonist resulted in increases in noise exposure-dependent susceptibility. In neonatally drug-treated rats, seizures during adulthood were found to occur with significantly higher incidence and severity. Furthermore, drug treatments were found to lengthen what is normally a restricted developmental period within which susceptibility can be induced by noise exposure. The 801 exhibited predictable anticonvulsant effects. These data suggests acute PCP or MK-801 exposures may transiently exacerbate risks inherent in certain forms of trauma. The mechanism underlying these effects is unknown although certain inferences are possible and may reveal much about epileptogenesis in this model.