Neuroprotective effect of morroniside on focal cerebral ischemia in rats

Cornus officinalis Sieb. et Zucc., known as Shan-zhu-yu in Chinese, has been used to treat cerebrovascular disease and diabetes in Traditional Chinese Medicine for a long time and morroniside is the main component of Shan-zhu-yu. In this study, we examined whether morroniside could protect ischemia/reperfusion-induced brain injury by minimizing oxidative stress and anti-apoptosis. Morroniside was intragastrically administered to rats in doses of 30, 90 and 270 mg/kg/day, starting 3 h after the onset of middle cerebral artery occlusion. The behavioral test was performed by using the Zea-Longa scores, Prehensile Traction score and Ludmila Belayer score. Rats were sacrificed 3 days after ischemia occurred. The infarction volume of brain was assessed in the brain slices stained with 2,3,5-triphenyl tetrazolium chloride. Cortex tissues were also used for determination of malondialdehyde levels, glutathione levels and superoxide dismutase. The treatment with morroniside significantly improved Zea-Longa scores and Prehensile Traction score at the doses of 30, 90 and 270 mg/kg, increased Ludmila Belayer score and reduced the infarction volume at the doses of 90 and 270 mg/kg. Morroniside (30, 90 and 270 mg/kg) treatment significantly decreased the level of malondialdehyde and caspase-3 activity by colorimetric analysis in ischemic cortex tissues. Morroniside (270 mg/kg) treatment significantly increased the content of glutathione, enhanced the activity of superoxide dismutase, but decreased the caspase-3 expression by Western-blot analysis in ischemic cortex tissues. These findings demonstrated that morroniside could notably protect the brain from damage induced by focal cerebral ischemia which might be related to morroniside antioxidant and anti-apoptotic properties in the brain.     

硫酸镁在大鼠局灶脑缺血中的保护作用

目的 研究非竞争性谷氨酸受体拮抗剂－－硫酸镁在大鼠局灶脑缺血中的作用。方法 采用线栓法建立大鼠右侧大脑中动脉区永久脑缺血模型,分别于缺血前半小时,、缺血后第１、３、６、１２小时静滴１０％硫酸镁溶液,滴速１．５ｍｌ／ｈ,通过神经功能评分、梗死体积及含水量的改变、病理学检查,探讨硫酸镁对脑缺血的保护作用及治疗时间窗。结果 缺血６小时内应用硫酸镁能改善运动功能,减轻脑水肿,缩经体积。结论 硫酸镁具有明显     

Neuroprotective effects of daidzein on focal cerebral ischemia injury in rats

Daidzein, a plant extract, has antioxidant activity. It is hypothesized, in this study, that daidzein exhibits neuroprotective effects on cerebral ischemia. Rat models of middle cerebral artery occlusion were intraperitoneally administered daidzein. Biochemical and immunohistochemical tests showed that superoxide dismutase and nuclear respiratory factor 1 expression levels in the brain tissue decreased after ischemia and they increased obviously after daidzein administration; malondialdehyde level and apoptosis-related cysteine peptidase caspase-3 and caspase-9 immunoreactivity in the brain tissue increased after ischemia and they decreased obviously after daidzein administration. Hematoxylin-eosin staining and luxol fast blue staining results showed that intraperitoneal administration of daidzein markedly alleviated neuronal damage in the ischemic brain tissue. These findings suggest that daidzein exhibits neuroprotective effects on ischemic brain tissue by decreasing oxygen free radical production, which validates the aforementioned hypothesis.     

银杏叶提取物后处理对大鼠局灶性脑缺血再灌注损伤保护作用的研究

目的 探讨银杏叶提取物EGb761对大鼠局灶性脑缺血再灌注损伤的保护作用及其机制.方法 制作大鼠右侧大脑中动脉闭塞再灌注模型.将30只清洁级雄性SD大鼠随机分为3组,即假手术组（n-10）：给予5 ml生理盐水腹腔注射;对照组（n-10）：缺血90 min,再灌注24 h,5 ml生理盐水腹腔注射;实验组（n-10）：缺血90 min,再灌注24 h,在再灌注即刻20 mg/kg银杏叶提取物生理盐水稀释成5 ml腹腔注射.再灌注24 h后采用四分法测定大鼠的神经功能障碍评分（NDS）;实验结束后断头取脑采用TTC染色法测定脑梗死面积（以其同侧大脑半球体积的百分比表示）;采用western blot测定脑组织微管相关蛋白2（MAP2）的表达水平.结果 与假手术组比较,对照组、实验组小鼠NDS评分均显著升高,分别为（2.49±0.85）分和（1.58±0.62）分,3组间比较差异均明显（P＜0.05）;对照组、实验组脑梗死面积均显著增大（P＜0.05）,实验组脑梗死面积较对照组显著减小（P＜0.05）;与假手术组比较,与假手术组比较,对照组、实验组缺血侧MAP2蛋白的表达水平均显著降低（P＜0.05）,实验组缺血侧MAP2蛋白的表达水平较对照组显著升高（P＜0.05）.结论 银杏提取物EGb761对大鼠局灶性脑缺血再灌注损伤具有显著的保护效应,其效应与MAP2蛋白表达水平升高有关.     

甘氨酸受体激动剂对大鼠局灶性脑缺血再灌注损伤的神经保护作用

目的 观察5种甘氨酸受体激动剂对大鼠局灶性脑缺血再灌注损伤的神经保护作用,从中筛选出作用最佳的氨基酸.方法 大鼠70只,随机分为假手术组、对照组、牛磺酸组、L-丝氨酸组、甘氨酸组、β-丙氨酸组、L-α-丙氨酸组,每组10只.用大脑中动脉线栓法制作大鼠缺血再灌注模型,再灌注时各组分别腹腔注射相应的药物,对照组注射等剂量生理盐水,12 h后各组重复注射1次.所有动物于再灌注后24 h进行神经行为学评分,各组中6只采用TTC法测量脑梗死体积,剩余4只用尼氏染色观察脑组织病理学改变.结果 5种甘氨酸受体激动剂中,牛磺酸组、L-丝氨酸组与对照组相比,可明显改善大鼠神经功能缺损(均P＜0.01),减少脑梗死体积(均P＜0.05),同时逆转脑缺血损伤侧顶叶皮质神经元的变性坏死与丢失;而其余氨基酸的神经保护作用不明显.结论 5种甘氨酸受体激动剂中,L-丝氨酸、牛磺酸的抗脑缺血损伤效果最佳.     

步长脑心通胶囊对大鼠脑缺血再灌注损伤的神经保护作用

目的研究步长脑心通胶囊对脑缺血再灌注(IR)损伤的神经保护作用。方法采用Longas法制备大鼠脑IR模型,分为IR组、步长脑心通组;再灌注后2h开始给药,依照IR的持续时间不同又分为1d、3d、7d、10d及15d共5组。各时相点取材,用HE染色和电镜观察脑部组织学改变,用干湿重法进行脑含水量测定;免疫组化染色检测脑组织血管内皮生长因子(VEGF)的表达,并使用多媒体彩色病理图像分析系统进行定量分析。结果与IR组比较,步长脑心通组脑组织中皱缩或肿胀神经元数目少,胞浆肿胀较轻,胶质细胞肿胀不明显,血管周围间隙水肿和渗出较轻;脑含水量及VEGF的表达差异具有显著性(均P<0.05)。结论步长脑心通胶囊可减少IR后脑含水量并增强VEGF表达,从而起到神经保护作用。     

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。     

Protective effects of cilostazol against transient focal cerebral ischemia and chronic cerebral hypoperfusion injury

Cilostazol increases intracellular cyclic adenosine monophosphate (cyclic AMP) levels by inhibiting type III phosphodiesterase. It was approved by the Food and Drug Administration for the treatment of intermittent claudication. Its principal actions include inhibition of platelet aggregation, antithrombotic action in cerebral ischemia, and vasodilation, mediated by increased cyclic AMP levels. In a multicenter, randomized, placebo-controlled, double-blind clinical trial, cilostazol has been shown to protect patients from recurrent cerebral infarction. It has been recently suggested that cilastozol could be useful in the treatment of transient focal cerebral ischemic injury. Beneficial effects of cilostazol in cerebral ischemic infarction and edema formation has been confirmed in rats by the magnetic resonance imaging (MRI). The preventive effect was ascribed to cAMP-dependent protein kinase (PKA)-coupled maxi-K channel activation with additional antioxidant and poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitory actions. Most recently, cilostazol has been shown to prevent vacuolation and rarefaction in the white matter of the rats subjected to chronic cerebral hypoperfusion in association with suppression of astrocyte and microglial activation. Taken together, recent experimental studies with cilostazol showed promising results in cerebral ischemia and chronic cerebral hypoperfusion.     

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.     

藻酸双酯钠对大鼠脑缺血再灌注后神经细胞保护作用的研究

目的探讨藻酸双酯钠(PSS)对脑缺血再灌注后神经细胞的保护作用。方法采用线栓法制作大脑中动脉阻断(MCAO)再灌注大鼠模型。PSS治疗组大鼠于再灌注即刻及再灌注24 h、48 h分别给予PSS(18.75 mg/kg)腹腔注射;对照组、假手术组和正常组均同时给予等量生理盐水腹腔注射。观察大鼠神经功能、脑梗死体积、组织学、超微结构和凋亡细胞数的改变。结果(1)PSS治疗组和对照组神经功能评分分别为(1.83±0.75)分和(2.83±0.75)分,脑梗死体积分别为(107.9±12.1)mm3和(150.3±30.5)mm3,两组比较差异有显著性(均P<0.05);(2)PSS治疗组大鼠脑组织缺血损伤改变明显轻于对照组,神经细胞的组织学和超微结构接近正常;(3)PSS治疗组细胞凋亡数于再灌注后1 h和3 h与对照组相比,差异均无显著性(均P>0.05),再灌注6 h、12 h、24 h、48 h及72 h凋亡细胞数明显少于对照组(P<0.05~0.01)。结论PSS能明显减轻大鼠脑缺血再灌注后的神经功能障碍和神经细胞损害,缩小脑梗死体积,抑制神经细胞凋亡,从而对神经细胞具有保护作用。     

抗白细胞药物在大鼠局灶性脑缺血中的保护作用

目的研究抗白细胞药物：环磷酰胺、氯化奎宁、秋水仙碱在大鼠局灶性脑缺血中的作用。方法用线栓法建立大鼠大脑中动脉区缺血再灌注模型，检测抗白细胞药物对大鼠局灶性脑缺血后外周血白细胞总数，梗塞区小胶质细胞数及对梗塞体积的影响。结果三种抗白细胞药物均能抑制外周血白细胞活化和梗塞区小胶质细胞的激活，缩小梗塞体积。结论抗白细胞药物对缺血性脑梗塞有保护作用，且联合用药优于单一用药     

促红细胞生成素及其衍生物在局灶性脑缺血中的神经保护作用

目的 探讨氨甲酰促红细胞生成素(CEPO)对缺血性脑损伤的保护作用及机制,并与促红细胞生成素(EPO)进行比较. 方法 用腔内线栓法制造小鼠脑缺血90min再灌注模型,根据颈动脉注射药物的不同分为对照组(注射生理盐水)、EPO 5 μg/kg组、EPO 50 μg/kg组、CEPO 50μg/kg组,每组6只,用脑血流激光多普勒监测脑缺血过程中脑血流的变化;用甲酚紫染色法显示脑梗死区并用imageJ软件计算梗死体积和脑水肿体积;用TUNEL法观察凋亡细胞;用免疫组织化学方法 观察脑缺血再灌注后诱导型一氧化氮合酶(iNOS)的改变. 结果与对照组比较,EPO 50μg/kg组和CEPO 50μg/kg组的脑梗死体积、脑水肿体积、神经功能缺损评分明显减少,差异均有统计学意义(P＜0.05).EPO 50μg/kg组、CEPO 50 μg/kg组缺血皮层iNOS阳性细胞数与对照组比较,差异均有统计学意义(P＜0.05).EPO 50μg/kg组的凋亡细胞[(43.6±10.1)个]、CEPO 50 μg/kg组的凋亡细胞[(40.5±9.8)个]与对照组[(94.2±15.2)个]比较,差异均有统计学意义(P＜0.05). 结论 低剂量的EPO(5μg/kg)无脑保护作用,CEPO 50 μg/kg与较高剂量EPO(50μg/kg)具有相似的增加脑缺血再灌注后的脑血流、减少神经功能缺损评分、减少梗死体积、缩小脑水肿体积和抗细胞凋亡作用,它们通过减少iNOS的表达而发挥神经保护作用.     

超负荷血糖对鼠局灶性脑缺血侧皮质内皮抑素表达的影响

目的观察超负荷血糖对鼠局灶性脑缺血侧皮质区内皮抑素(endostatin)表达的影响,进一步探讨超负荷血糖加重脑缺血损伤的分子机制。方法用SD大鼠腹腔内注射链脲佐菌素首先建立糖尿病高血糖大鼠模型,继而应用栓线法建立永久性局灶性脑缺血模型。随机分为3大组:假手术组、脑缺血组和糖尿病脑缺血组。于缺血24h时间点行神经功能评分、TTC染色测梗死面积、TUNEL法检测细胞凋亡数目、免疫组化及Western blot检测ES表达,并进行图像分析。结果糖尿病脑缺血组的神经功能评分为(4.73±0.35)、梗死面积为(50.12±3.54)、细胞凋亡数为(26.22±2.35)、免疫组化检测ES为(99.35±3.25)及Western blot检测ES为(1.193±0.045)。脑缺血组的神经功能评分为(3.18±0.65)、梗死面积为(39.98±2.02)、细胞凋亡数为(17.28±1.01)、免疫组化检测ES为(113.17±1.35)及Western blot检测ES为(1.033±0.032)。与脑缺血组相比,糖尿病脑缺血组的神经功能评分、梗死面积、细胞凋亡数、ES蛋白表达均明显增加(P<0.05)。结论血管再生可能参与了超负荷血糖加重脑缺血损伤的过程,上调ES表达可能是超负荷血糖加重脑缺血损伤的机制之一。     

局灶性脑缺血/再灌注损伤后大鼠脑组织tPA表达变化与细胞凋亡研究

目的　探讨大鼠脑缺血 /再灌注后脑组织内组织型纤溶酶原激活物 (t PA)表达变化及与细胞凋亡的关系和意义。方法　采用大鼠局灶性脑缺血 /再灌注模型 ,应用免疫组化染色及原位杂交技术检测脑组织 t PA表达变化 ,TU NEL 染色观察神经元的凋亡及其发生规律。结果　 t PA蛋白及 m RNA在缺血再灌注早期即开始表达 ,主要见于皮质损伤区周围及海马区 ,阳性着色的神经元表达明显 ,血管表达较弱。再灌注 4 8h神经元表达明显增强 ,缺血灶及其周边的微血管内皮表达也明显增强。再灌注 72 h表达有所下降。凋亡细胞主要出现于大脑皮质及尾壳核病变中心区的周围 ,再灌注 4 8～ 72 h达高峰。结论　脑缺血 /再灌注损伤可诱导神经元及血管内皮细胞 t PA表达增加 ,t PA可能通过促进细胞凋亡而介导再灌注损伤。     

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。     

Neuroprotective effect of tacrolimus (FK506) on ischemic brain damage following permanent focal cerebral ischemia in the rat

We investigated the neuroprotective effect of tacrolimus (FK506) on the ischemic cell death with respect to cytochrome c translocation and DNA fragmentation, which are pivotal events in the necrotic and apoptotic signaling pathway, using permanent focal cerebral ischemia in rats. Immunohistochemically, cytochrome c was observed in the cytoplasm as early as 1 h after middle cerebral artery (MCA) occlusion in the infarcted hemisphere. Cytosolic release of cytochrome c after MCA occlusion was also confirmed by Western blot analysis and enzyme immunoassay. Terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) showed DNA fragmentation evolving in the ipsilateral cortex and the caudate putamen after 3 and 6 h, respectively, following MCA occlusion. Tacrolimus (1 mg/kg, i.v.), administered immediately after MCA occlusion, significantly attenuated the release of cytochrome c in the ischemic region, the number of TUNEL-positive cells in the ischemic penumbra zone, and the size of cortical ischemic lesions. This study demonstrated that tacrolimus ameliorated the accumulation of cytochrome c in the cytosol and the increase of TUNEL-positive cells induced by cerebral ischemia, indicating that the neuroprotective action of tacrolimus on ischemic brain injury caused by permanent focal cerebral ischemia could partially be attributed to the attenuation of the activation of the apoptotic execution machinery.     

糖皮质激素受体阻断剂抑制成年雄性大鼠持续性局灶脑缺血后Caspase-3基因表达

目的研究糖皮质激素受体阻断剂RU38486对成年雄性大鼠持续性局灶脑缺血后Caspase-3基因表达和凋亡的影响.方法健康成年雄性大鼠72只随机分为空白组、对照组和RU38486组,脑缺血前1 h注射麻油和RU38486(20 mg/kg).利用左侧大脑中动脉电凝术建立持续性局灶脑缺血模型,分别用原位杂交、免疫组化SP法和TUNEL法标记Caspase-3 mRNA阳性细胞、Caspase-3蛋白阳性细胞和凋亡细胞.结果RU38486组与对照组比较,Caspase-3基因表达开始时间推迟到脑缺血12 h,12 h～5 d Caspase-3基因表达减少(P＜0.01),并且局限在缺血半暗带;凋亡细胞的变化时程与对照组相似,但凋亡细胞数量减少(P＜0.05).结论脑缺血前阻断糖皮质激素受体可下调Caspase-3基因表达和减少细胞凋亡,提示脑缺血后应激水平的糖皮质激素可能有加重脑缺血后凋亡的作用.     

雌激素对大鼠局灶性脑缺血的保护作用

目的：探讨雌激素对大鼠局灶性脑缺血的保护作用及其机制。方法：将６０只雌性ＳＤ大鼠随机分成３组,每组２０只,Ａ组：假手术组：Ｂ组;卵巢切除组（ＯＶＸ）;Ｃ组：卵巢切除后给予１７β－雌二醇（１７β－Ｅ２）治疗组。６０只大鼠均采用线栓法制备局灶性脑缺血再灌注模型。统计分析了三组大鼠的致死率、梗死体积比及大脑皮质局部血流（ｒＣＢＦ）变化。结果：Ｂ组与Ａ组、Ｃ组比较,运动累积致死率升高,梗死积极比增大（Ｐ〉