缺血再灌注蛋白激酶C同工酶表达与神经元凋亡关系的研究

目的 研究局灶脑缺血／再灌注大鼠蛋白激酶C（PKC）同工酶表达在缺血性脑损害中可能的作用机制。方法 采用线栓法制备大鼠局灶脑缺血／再灌注模型。于缺血1．5h再灌注4h、24h、72h观察PKCγ、δ表达及神经元坏死、凋亡的变化规律。结果 再灌注4h PKCγ、δ及神经元凋亡明显升高,PKCγ在24h达高峰,72h开始下降（P＜0．05）;PKCδ在再灌注24h、72h仍保持一高水平（P＞0．05）,神经元凋亡的变化规律同PKCγ（P〈0.05);神经元坏死在再灌注各时相点无显著性差异（P＞0．05）。结论 PKCγ、δ的异常表达与神经元坏死、凋亡有密切的联系。     

灯盏花对脑缺血再灌注损伤保护作用的实验研究

目的 探讨去势大鼠局灶脑缺血再灌注后灯盏花的保护作用及其可能机制。方法 采用线栓法制备去势大鼠大脑中动脉缺血再灌注模型。通过腹腔注射灯盏花,观察组织病理学,ＮＯ含量,ＩＬ－１及ＴＮＦ活性的变化;免疫组化方法检测雌激素受体（ＥＲ）的表达情况。结果 与对照组相比,灯盏花组的脑梗死体积比脑水肿体积,血液中ＮＯ含量,ＩＬ－１及ＴＮＦ活性明显降低（Ｐ〈０．０１）。结论 脑缺血后灯盏花具有明显的脑保护作用。其     

蛋白激酶C抑制剂对缺血/再灌注海马CAl区迟发性神经元死亡的作用研究

目的:蛋白激酶C与脑组织缺血性损害有密切关系,且证明可调节一氧化氮合成酶的活性。作为PKC抑制剂,灯盏花素可抑制蛋白激酶C的活性,但其对大鼠海马CAl区缺血/再灌注损害的作用和机制需深入研究。方法:四血管闭塞复制大鼠前脑缺血／再灌注模型,观察PKC抑制剂灯盏花素对海马CAl区NO浓度、局部脑血流量及CAl区锥体细胞密度变化的影响。结果:PKC抑制剂灯盏花素对大鼠海马CAl区缺血／再灌注脑组织的作用为降低CAl区局部NO的产生、明显改善脑组织的rCBF和显著降低该区锥体细胞的脱失。结论:PKC抑制剂对大鼠前脑缺血／再灌注所致海马CAl区迟发性神经元死亡的保护作用与其降低局部NO的产生及增加局部脑血流量有密切关系。     

三七总皂甙对大鼠海马缺血再灌注损伤的保护作用

目的 观察三七总皂甙（panax notoginseng saponins,PNS）对脑缺血-再灌注大鼠海马区脑组织凋亡诱 导因子（apoptosis inducing factor,AIF）表达的影响,探讨PNS神经保护作用机制。 方法 68只雄性Wistar大鼠分为假手术组、生理盐水对照组（对照组）和PNS干预组（干预组）,再按照 干预时间点将对照组与干预组分为缺血-再灌注O h、2 h、4 h、6 h亚组。改良线栓法制备大鼠大脑中动 脉闭塞模型（middle cerebral artery occlusion,MCAO）,2 h后拔出栓线,造成缺血-再灌注。依次于再灌注 后0 h、2 h、4 h、6 h分别对干预组大鼠腹腔内注射小剂量PNS（50 mg/kg）、中剂量PNS（100 mg/kg）和 大剂量PNS（150 mg/kg）,对照组注射等体积生理盐水。采用免疫组化法检测大鼠脑缺血-再灌注缺 血侧海马区脑组织AIF的表达并对比各组的情况。 结果 假手术组大鼠海马区脑组织AIF阳性细胞表达数显著少于对照组和PNS干预组各亚组（均 P <0.01）;PNS干预组相同干预时间点的不同剂量组脑组织AIF阳性细胞表达数均明显少于生理盐水 对照组（均P <0.01）,与PNS小剂量组和中剂量组相比,PNS大剂量组AIF阳性细胞数表达显著减少。 结论 P NS可使缺血-再灌注大鼠缺血侧海马区脑组织AIF表达减少,可能通过抑制AIF表达而起到神 经保护作用。     

亚低温对大鼠脑缺血再灌注损伤的保护研究

目的观察亚低温对大鼠全脑缺血再灌注后海马CAI区神经元凋亡的影响,探讨亚低温对缺血再灌注脑损伤的保护作用。方法SD大鼠30只随机分为对照组（n=10）,常温缺血组（n=10）,亚低温组（n=10）,采用改良的Pulsinelli-Brierley4血管法建立全脑缺血再灌注动物模型,缺血30min后再灌注72h,尼氏体染色观察海马区存活锥体细胞数,TUNEL法检测缺血后海马CAI区神经元凋亡情况,电镜下观察神经细胞形态学改变。结果与对照组比较,常温缺血组的海马CAI区存活的锥体细胞数目减少（P〈0.01）;与常温缺血组比较,亚低温组海马CAI存活的锥体细胞数目明显增多（P〈0.01）。对照组、亚低温组的海马CAI区神经元凋亡数目和凋亡指数明显低于常温缺血组。在电镜下观察亚低温能明显减轻缺血后脑组织病理形态学的损害程度。结论亚低温可以抑制脑缺血再灌注后的神经细胞凋亡,对神经细胞有保护作用。     

灯盏花对脑缺血神经元凋亡的防治作用

目的探讨蛋白激酶C抑制剂灯盏花注射液对神经元凋亡的防治作用。方法采用大鼠全脑缺血模型，观察脑缺血／再灌流后蛋白激酶C活性、神经元凋亡的变化及灯盏花对上述的影响。结果脑缺血／再灌流可以导致蛋白激酶C的移位激活、神经元凋亡的增加。灯盏花可以阻止脑缺血／再灌流导致的上述变化。结论灯盏花注射液对脑缺血／再灌流导致神经元凋亡有防治作用。     

神经节苷脂对大鼠脑缺血再灌注损伤的脑保护作用

目的探讨神经节苷脂对大鼠脑缺血再灌注损伤的脑保护作用。方法采用线栓法制作缺血再灌注大鼠模型,分别用神经节苷脂(治疗组)和生理盐水(对照组)腹腔注射。观察两组大鼠缺血90min、缺血90min再灌注24h的脑梗死面积、神经功能缺损程度、细胞凋亡数、细胞凋亡率。结果治疗组大鼠于相同时间点脑梗死面积较对照组明显减小,仅表现轻度的神经功能缺损,且神经细胞的凋亡数较对照组显著减少(均P<0.01)。结论神经节苷脂能明显减小大鼠实验性脑缺血的脑梗死面积,减轻脑缺血再灌注后神经功能缺损程度,显著减轻缺血区神经元损害,具有显著的脑保护作用。     

大剂量甲基强的松龙对缺血再灌注大鼠脑保护作用的研究

目的 探讨大剂量甲基强的松（MP）对缺血再灌注大鼠脑保护作用的机制。方法 采用大鼠全脑缺血再灌注模型,观察缺血前后应用大剂量MP对脑组织自由基和超氧化物歧化酶（SOD）含量的影响,同时做脑组织病理学观察。结果 MP治疗组脑组织丙二醛（MDA）水平较对照组（盐水组）明显降低（P＜0．01）,而SOD水平较对照组增高（P＜0．01）;脑组织超微结构观察发现MP可抑制再灌注中脑组织巨噬细胞浸润。结论 MP的脑保护作用与抑制作用自由基产生、减少抗氧化剂消耗以及抑制巨噬细胞浸润有关。     

bFGF对大鼠局灶性缺血再灌注脑组织的保护作用

目的探讨bFGF对大鼠脑缺血再灌注损伤后神经细胞凋亡和脑组织中SOD、MDA含量变化的影响。方法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,检测假手术组、缺血再灌注组和bFGF组的凋亡细胞数和脑组织中SOD、MDA的含量。结果假手术组偶见凋亡细胞,缺血再灌注组和bFGF组凋亡细胞数分别是26.35±5.67和18.65±5.91,与缺血再灌注组相比,bFGF组缺血区皮质凋亡神经元明显减少(P<0.05)。SOD,MDA测定结果显示三组间比较,具有显著性差异(P<0.01和P<0.05)。结论抗氧化作用可能是bFGF减少大鼠脑缺血再灌注损伤后细胞凋亡的分子机制之一。     

线粒体分裂抑制剂在大鼠脑缺血再灌注损伤中的保护作用及其机制

目的 探讨线粒体分裂抑制剂(Mdivi-1)在大鼠脑缺血再灌注损伤线粒体凋亡过程中的保护作用及其机制. 方法 按随机数字表法将成年健康雄性Wistar大鼠60只分为假手术组、模型组和Mdivi-1预处理组,每组各20只,其中模型组和Mdivi-1预处理组大鼠采用线栓法经左侧颈外-颈内动脉插线建立脑缺血再灌注损伤模型,并于脑缺血前15 min预先尾静脉给予等容量二甲基亚砜和Mdivi-1(1.2 mg/kg).再灌注24 h后应用TUNEL法观察各组大鼠脑组织神经细胞凋亡情况,SABC免疫组化染色检测细胞色素C(CytC)阳性细胞表达,Western blotting检测CytC蛋白表达,RT-PCR检测CytC mRNA表达. 结果 与假手术组比较,模型组神经细胞凋亡率、Cyt C阳性细胞率、Cyt C蛋白及mRNA表达水平(4.16％±0.25％vs 45.49％±0.77％;4.22％±0.20％vs55.12％±1.47％;0.395±0.002 vs 0.932±0.001;0.467±0.003 vs 0.789±0.009)显著升高,差异有统计学意义(P＜0.05).应用Mdivi-1预处理后神经细胞凋亡率、CytC阳性细胞率、CytC蛋白及mRNA表达水平(30.76％±0.51％; 35.07％± 1.42％; 0.594±0.002;0.523±0.004)较模型组明显降低,差异有统计学意义(P＜0.05). 结论 Mdivi-1通过阻断线粒体-Cyt C途径从而抑制细胞凋亡,减轻脑缺血再灌注损伤.     

Protein kinase C activity in permanent focal cerebral ischemia

Protein kinase C (PKC) activity was investigated in a model of focal stroke in the rat. Following 6 h of left middle cerebral artery occlusion, rat brains were frozenin situ. In the peripheral ischemic zone, total PKC activity declined by close to two-thirds (1.07±0.35 vs 2.77±0.12 nmol/min/mg protein;p<0.05,n=4), and the proportion of total activity associated with the particulate fraction decreased from 33.3±1.5% to 16.2±1.4% (p<0.01,n=4). Thus, overall particulate PKC activity in the ischemic zone was <20% of control. The cerebral energy metabolite profile of tissue from the ipsilateral hemisphere, corresponding to the region where samples were obtained for PKC activity assay, suggests that this tissue may have been part of the ischemic penumbra before further deterioration.     

头孢曲松钠对大鼠局灶性脑缺血损害保护作用机制研究

目的 探讨大鼠局灶性脑缺血模型中头孢曲松钠保护作用机制.方法 制备Wistar大鼠局灶性脑缺血模型,随机分为假手术组(S组)、脑缺血组(M组)、头孢曲松钠组(C组),C组为缺血90min时给予头孢曲松钠200mg/kg;在缺血后24h测定谷氨酸转运体-l(GLT-1) mRNA表达、超氧化物歧化酶(SOD)活性、丙二醛(MAD)含量以及钙神经素(calcineurin,CaN)和钙激活中性蛋白酶(calpain)活性.结果 M组、C组较S组GLT-1 mRNA表达相对量减少,SOD活性降低,MAD含量增加,CaN和calpain活性升高;C组较M组大鼠GLT-1 mRNA表达量明显增加,SOD活性升高,MAD含量减少,CaN和calpain活性降低(P＜0.01).结论 头孢曲松钠通过增加GLT-1表达、减轻氧自由基损伤作用以及降低钙超载激活的蛋白水解酶CaN、calpain活性等多种机制保护缺血脑组织,发挥神经保护作用.     

头孢曲松钠对大鼠脑缺血损伤的保护作用及其机制

目的 探讨在大鼠局灶性脑缺血模型中应用头孢曲松钠对脑缺血损伤的保护作用及其相关机制.方法 制备Wistar大鼠局灶性脑缺血模型,并按随机数字表法分为单纯缺血组(MCAO组)、头孢曲松钠治疗组(MCAO+CTX组)和盐水对照组,其中MCAO+CTX组为缺血90min时给予头孢曲松钠200 mg/kg.缺血后24 h、48 h、7 d时对各组大鼠进行神经行为学评分和脑水肿程度测定,同时比较各组大鼠皮层和海马谷氨酸转运体功能的差异.结果 随着缺血时间延长,各组大鼠神经行为学评分逐渐提高;脑水肿在缺血后24 h、48 h时逐渐加重,至7 d时已逐渐消退.与MCAO组比较,各时间点MCAO+CTX组大鼠神经行为学评分明显提高,脑水肿程度明显减轻,伤侧皮层及海马谷氨酸转运体功能明显增强,差异均有统计学意义(P＜0.05).结论 头孢曲松钠对大鼠局灶性脑缺血损伤具有保护作用,其机制可能与增强谷氨酸转运体功能从而减轻谷氨酸神经毒性作用有关.

Abstract：

Objective To explore the neuroprotective effect of ceftriaxone on cerebral ischemia injury in rats with focal cerebral ischemia and its possible mechanism. Methods Focal cerebral ischemic models were established in Wistar rats and randomly divided into ischemic group (performed middle cerebral artery occlusion [MCAO]), ceftriaxone (CTX) therapy group (given CTX at a dosage of 200 mg/kg 90 min after MCAO) and control group (given physiological saline only). Twenty-four and 48 h, and 7 d after MCAO, neurological behaviors and cerebral edema level were evaluated in these 3 groups;glutamate transporter function in the cortex and hippocampus of rats was compared between each 2 groups. Results With time extended, neurological behaviors scores were obviously elevated in every group;and cerebral edema became worse at 24 and 48 h and decreased 7 d after MCAO. As compared with that in the ischemic group, glutamate transporter function, level of edema and neurological behaviors scores in cortex and hippocampus of rats in the CTX therapy group were statistically increased at different ischemic time points (P<0.05). Conclusion Ceftriaxone has a neuroprotective effect against focal cerebral ischemia in rats, which may relate to increased glutamate transporter function and reduced glutamate neurotoxicity.     

Calpain inhibitor A-558693 in experimental focal cerebral ischemia in rats

OBJECTIVES: Calpains are intracellular proteases, which are activated in various cerebral injuries. We studied the expression of mu-calpain in a model of focal cerebral ischemia/reperfusion and the efficacy of the calpain inhibitor A-558693. METHODS: A transient occlusion of the middle cerebral artery was produced in male Wistar rats by using the suture model with 3 hours of ischemia and 24 hours of reperfusion. Six animals were given the calpain inhibitor and six animals were treated with placebo. The infarct size was determined by the loss of the calpain substrate microtubule-associated protein-2 (MAP-2) immunohistochemistry using volumetry in serial slices of the brains. Furthermore mu-calpain positive-stained cells were detected by immunohistochemistry and western blotting. RESULTS: In placebo-treated animals the mu-calpain expression was significantly increased in the ischemic hemisphere compared with the contralateral non-ischemic hemisphere (88.6 versus 10.5% in the basal ganglia, 60.7 versus 10.7% in the cortex, p < 0.001, respectively) with a subsequent loss its substrate MAP-2. However, the use of the calpain inhibitor A-558693 did not significantly change the mu-calpain expression, nor significantly reduce the infarct volume. DISCUSSION: The present data indicate that mu-calpain proteolysis plays an important role in the chain of events following cerebral ischemia. However, the calpain inhibitor A-558693 failed to prevent these changes.     

缺血预处理对大鼠局灶性脑缺血的保护作用

目的 探讨缺血预处理对大鼠局灶性脑缺血的保护作用及其机制。方法 将30只雄性SD大鼠随机分为假手术组、缺血组和缺血预处理组,每组10只。使用改良线栓法制作大鼠局灶性脑缺血模型。采用Longa-Bederson（LB）评分法评估缺血预处理对大鼠局灶性脑缺血后神经功能的影响,采用TTC染色方法分析大鼠海马区梗死面积,采用TUNEL染色法分析大鼠海马区细胞凋亡,使用气相色谱方法分析缺血预处理后大鼠海马区域丙酮酸含量。结果 缺血预处理组大鼠LB评分[（1.67±0.21）分}明显优于缺血组[（3.17±0.31）分;P<0.05]。缺血预处理组大鼠海马区梗死面积[（154±8.1）mm2]明显少于缺血组[（221.20±5.86）mm2;P<0.05]。缺血预处理组大鼠海马区域丙酮酸含量[（3.70±0.20）μmol/g]明显高于缺血组[（2.58±0.17）μmol/g;P<0.05]。结论 缺血预处理对大鼠局灶性脑缺血具有显著神经保护作用,其机制可能与明显减少大鼠脑组织梗死、增加海马丙酮酸含量、减少细胞凋亡有关。     

Effect of cerebral ischemia on brain mast cells in rats

The purpose of this study was to investigate the effect of transient cerebral ischemia on brain mast cells in rats. The mast cells decreased significantly at 1 h, 2 h, 4 h and 7 days after ischemia. At 1 day following ischemia, the increase of the number of mast cells in the middle aspect of the thalamus (bregma -2.80 to -3.16 mm) was twice as that of other regions in the thalamus. In addition, histamine contents increased significantly in the thalamus and striatum after ischemia. These results indicate that brain mast cells participate in the pathological process after ischemia.     

槲皮素-3半乳糖苷对大鼠局灶性脑缺血/再灌注炎症损伤机制的影响

目的研究槲皮素-3-半乳糖苷(金丝桃苷)对缺血性脑血管病的神经保护作用。方法78只Wistar大鼠随机分为假手术组、缺血对照组、金丝桃苷缺血组(Hyp组),后2组又根据观察时间点不同分为脑缺血2h后再灌注,3h、6h、12h、48h六个亚组,每组各6只,线栓法建立大鼠缺血再灌注模型。SABC免疫组化染色法分别记录各组不同时间点的P-选择素和E-选择素阳性反应血管数。结果自3h起同时间点金丝桃苷苷组P-选择素、E-选择素水平均显著低于对照组(P<0.05)。结论金丝桃苷能有效抑制大鼠缺血/再灌注早期P、E-选择素的表达,有显著脑保护作用。     

金丝桃苷对大鼠局灶性脑缺血／再灌注损伤的脑保护作用

目的研究金丝桃苷(Hyp)在缺血性脑血管病中的神经保护作用。方法78只Wistar大鼠随机分为假手术组、缺血对照组、Hyp组,后2组又根据观察时间点不同分为脑缺血2h后再灌注1、3、6、12、24、48h 6个亚组,每组6只,线栓法建立大鼠缺血再灌注模型,固定取脑干,湿比重法测定脑组织含水量。结果自3h起同时间点对照组和Hyp组脑水含量均显著高于假手术组(P<0.05),其中Hyp组显著低于对照组(P<0.05)。结论Hyp能有效减轻大鼠缺血/再灌注早期脑水肿,有显著脑保护作用。     

The Direct Effect of Lithium and Carbamazepine on Protein Kinase C in Rat Brain

Abstract: The effect of carbamazepine on protein kinase C, which is believed to phosphorylate a number of proteins, was compared with that of lithium in vitro . Lithium did not significantly inhibit the protein kinase C activity in the rat cerebral cortex in vitro , and 0.01 mM of carbamazepine had no inhibitory effect on the enzyme activity. However, inhibition did begin to appear at 1 mM. The Lineweaver-Burk plot of carbamazepine was similar to the competitive inhibition pattern. The data suggest that lithium and carbamazepine as mood stabilizers have the same effect on the manic state, but their mechanism reducing mania may differ in the cell signal transduction pathways.