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.     

头孢曲松钠对脑缺血再灌注大鼠脑损伤和谷氨酸转运体-1表达的影响

目的 研究头抱曲松钠对脑缺血再灌注损伤大鼠的神经损害程度、脑组织水肿以及谷氨酸转运体-1(GLT-1)表达的影响.方法 线栓法阻塞大鼠大脑中动脉,并于缺血后2h进行再灌注,造成脑缺血再灌注损伤,大鼠分为假手术组(S组)、脑缺血再灌注组(M组)、头孢曲松钠组(C组)3组,C组于造模后6h给予头孢曲松钠200mg/(kg·d),共5d.脑缺血再灌注ld、3d、5d时进行大鼠神经行为学评分和脑组织含水量测定,RT-PCR检测GLT-1 mRNA表达.结果 M组、C组较S组大鼠神经行为学评分降低,脑组织含水量增加,GLT-1 mRNA表达相对量减少;M组上述改变在缺血再灌注3d时最明显,5d时有所减轻.在同一实验时间点,C组较M组大鼠神经行为学评分明显升高,脑组织含水量明显减少,GLT-1 mRNA表达量明显增加(P<0.01),且C组GLT-1 mRNA表达相对量随时间延长逐渐增加(P<0.05).结论 脑缺血再灌注损伤中,头孢曲松钠可能通过上调GLT-1 mRNA的表达来减轻脑缺血损伤和再灌注后脑水肿,从而发挥神经保护作用.     

头孢曲松钠对大鼠脑皮质神经元氧糖剥夺损伤的保护作用及其机制

目的研究头孢曲松钠对大鼠脑皮质神经元氧糖剥夺(OGD)损伤的保护作用及其可能的机制。方法体外培养大鼠脑皮质神经细胞,分为正常对照组、氧糖剥夺(OGD)组和头孢曲松钠(CTX)预处理组。OGD组和CTX预处理组建立OGD模型。并检测各组的细胞活性、细胞谷氨酸转运体-1(GLT-1)mRNA表达、脑源性神经营养因子(BDNF)和白介素(IL)-6含量。结果与正常对照组比较,OGD组及CTX预处理组神经细胞活性减低,GLT-1 mRNA表达显著下调,细胞培养上清液中BDNF及IL-6含量显著增加(P<0.05～0.01);与OGD组比较,CTX预处理组神经细胞活性明显增加,GLT-1 mRNA表达上调,细胞培养上清液中BDNF含量增加(均P<0.01),IL-6含量无明显改变。结论 CTX预处理通过上调GLT-1和BDNF表达保护皮质细胞OGD损伤。     

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     

头孢曲松钠对谷氨酸神经毒性的影响及其机制

目的研究头孢曲松钠对谷氨酸神经毒性的影响及其机制。方法培养大鼠脑皮层神经细胞,加入谷氨酸损伤和头孢曲松钠保护作用,光镜及电镜观察细胞损伤程度,短暂谷氨酸诱导细胞内钙超载后,激光共聚焦显微镜实时观测细胞内Ca2 荧光强度变化,免疫组化、逆转录-聚合酶链反应(RT-PCR)检测胶质细胞性谷氨酸转运体1(GLT1)蛋白及GLT1mRNA表达变化。结果头孢曲松钠预处理组较谷氨酸组神经细胞光镜形态更接近正常,电镜超微结构损伤明显减轻,短暂细胞内钙超载后细胞内Ca2 相对荧光强度上升缓慢但恢复迅速,GLT1蛋白及GLT1mRNA表达增加(P<0.01)。结论头孢曲松钠通过上调GLT1mRNA表达,能减轻谷氨酸引起的细胞损伤和细胞内钙超载作用,对神经细胞产生保护作用。     

塞来昔布对大鼠局灶性脑缺血再灌注的保护作用及机制研究

目的 探讨塞来昔布对大鼠局灶性脑缺血再灌注损伤的保护作用及可能机制.方法 采用线栓法制作Wistar大鼠大脑中动脉闭塞（MCAO）90min再灌注模型,分为假手术组、等渗盐水组塞来昔布12.5mg/kg治疗组及塞来昔布25mg/kg治疗组.缺血后30min灌胃给予等渗盐水或两种剂量（12.5mg/kg或25mg/kg）的塞来昔布,检测各分组大鼠缺血侧额顶部皮质在再灌注不同时点前列腺素代谢物、丙二醛（malondialdehyde,MDA）含量、超氧化物歧化酶（superoxide dismutase,SOD）活性的动态变化.结果 （1）塞来昔布12.5mg/kg治疗及塞来昔布25mg/kg治疗均可明显缩小脑I/R时脑损伤范围,减轻脑水肿程度;（2）塞来昔布12.5mg/kg治疗和塞来昔布25mg/kg治疗均能不同程度的降低前列腺素E2（Prostaglandin E2,PGE2）、血栓素B2（Thromboxane B2,TXB2）、6-酮-前列腺素F1α（6-ketto-prostaglandin F1α,6-K-PGF1α）在缺血侧额顶部皮质中聚集,同时使TXB2/6-K-PGF1α比值下降.也能不同程度的降低MDA含量,提高SOD活性.结论 COX-2抑制剂可能通过减少PGE2的集聚,改善TXB2/6-K-PGF1α比值,减少氧自由基的产生,提高SOD活性而发挥脑保护作用.     

胰岛素对大鼠局灶性脑缺血再灌注损伤的保护作用

目的 :研究胰岛素对脑缺血再灌注损伤的保护作用。方法 :用线栓法建立大鼠脑缺血再灌注模型 ,按胰岛素不同给药时间分为 4组 ,检测各组不同时限的血糖、神经功能缺陷评分以及梗死灶体积 ,并在电镜下对缺血边缘区进行超微结构观察。结果 :在 6h内给予胰岛素治疗 ,可使神经功能缺陷评分显著降低 ,梗死灶体积明显缩小 ,缺血边缘区超微结构损伤明显减轻。结论 :在有效治疗时窗内 (6h) ,胰岛素可明显减轻脑缺血再灌注损伤     

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〉     

高压氧预处理可对大鼠局灶性脑缺血再灌注损伤的保护作用

目的研究短期高压氧预处理后是否可减轻大鼠局灶性脑缺血再灌注损伤。方法选取成年雄性Wister大鼠,采用连续5d,每天1次,3.0ATA,100%O2高压氧(HBO)预处理,每次60min,末次预处理后24h,运用改良的经典线栓法制作MCAO模型,再灌注2h。将实验大鼠分为假手术组、MCAO组、HBO+MCAO组(n=5)。造模后24h观察各组动物的一般精神状态及体重变化情况、用Rogers DC and Hunter AJ描述的神经功能7分评分法对神经功能损伤进行评估,TTC染色测梗死面积,并对脑组织进行石蜡切片,行Nissl、TUNEL染色,利用显微镜对神经细胞进行计数。结果假手术组无神经功能缺失,TTC染色未见梗死灶,镜下观察未见坏死细胞。MCAO组和HBO+MCAO组均有不同程度的神经功能缺损,且HBO+MCAO组神经功能缺失较MCAO组轻;TTC染色MCAO组的梗死面积明显大于HBO+MCAO组;镜下观察,MCAO组梗死区内尼氏小体明显少于HBO+MCAO组。结论短期高压氧预处理后可减轻大鼠局灶性脑缺血再灌注损伤。     

KATP开放剂对大鼠局灶性脑缺血再灌注损伤的保护作用及其机制

目的观察ATP敏感性钾通道（KATP）开放剂尼可地尔（nicorandil）对大鼠脑缺血／再灌注（I／R）损伤的保护作用及其机制。方法将60只雄性Wistar大鼠随机分为4组：A组（假手术组）、B组（脑缺血再灌注组）、C组（脑缺血再灌注＋尼可地尔组）及D组（脑缺血再灌注＋尼可地尔＋5-HD组），采用线栓法建立大鼠大脑中动脉闭塞（MCAO）模型，各组于脑缺血2h后进行再灌注，再灌注22h后观察各组大鼠神经功能评分、脑梗死体积、线粒体标志酶活性和脂质过氧化降解产物丙二醛（malondialdehyde，MDA）的含量。结果（1）B、C、D组再灌注22h后神经功能评分显著低于A组，脑梗死体积、脂质过氧化物MDA含量均显著高于A组，线粒体标志酶活性SDH、CO表达显著低于A组（P〈0.01）；（2）与B、D组比较，C组神经功能评分明显升高，脑梗死体积、MDA含量明显减少，SDH、CO活性明显增高（P〈0.01）；（3）B组和D组各指标之间比较差异均无显著性（P〉0.05）。结论尼可地尔对大鼠脑缺血再灌注损伤具有保护作用，其机制可能与开放mitoKATP通道、维护线粒体功能、减少氧自由基产生有关。     

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。     

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。     

大鼠局灶脑缺血病灶周围新血管生成的相关实验研究

目的本研究主要探讨大鼠局灶脑缺血病灶周围新血管形成现象,探讨外周血CD34+细胞和脑组织AC133抗原在新血管形成中的作用。方法将成年SD雄性大鼠随机分为:1.正常组,2.假手术组,3.动物模型组。分别取缺血再灌注1h、3h、6h、12h、24h、48h、3d、4d、7d、14d、28d共11个观察点。取前10个观察点外周血标本,采用流式细胞术检测单个核CD34+细胞平均荧光强度。采用免疫组化染色法检测48h、3d、4d、7d脑组织AC133抗原表达。对28d组进行脑血管荧光分布面积的检测。每个观察点5只大鼠,共65只大鼠,根据神经功能计分纳入实验。结果1.脑缺血再灌注28d梗死半球半暗带区域的血管荧光总面积较非梗死半球相似区域增加24.79%。2.大鼠脑缺血/再灌注3d外周血单个核CD34+细胞平均荧光强度明显降低,直到7d。14d恢复到基线水平。3.AC133抗原在再灌注4d梗死半球半暗带区域的血管内皮细胞表达阳性,3d、7d组无阳性表达。结论本研究证实大鼠脑缺血28天梗死半球半暗带区域的血管面积较非梗死半球增大。研究提示循环CD34+干细胞和AC133+细胞可能参与脑缺血损伤的血管修复和新血管形成。     

Magnetoencephalography of focal cerebral ischemia in rats.

BACKGROUND AND PURPOSE: The purpose of this study was to use magnetoencephalography to record magnetic field changes in the brain during middle cerebral artery occlusion. METHODS: A direct-current electrocorticogram (two channels) and a direct-current magnetoencephalogram (seven channels) were simultaneously recorded from five rats subjected to middle cerebral artery occlusion for 1-2 hours. RESULTS: Direct-current electrocorticographic and direct-current magnetoencephalographic signal deflections were observed after the onset of middle cerebral artery occlusion and occurred repeatedly throughout the ischemic period, with a mean +/- SD time interval of 12 +/- 5 minutes. A one-to-one correspondence of the electrocorticographic and magnetoencephalographic signal deflections was demonstrated. CONCLUSIONS: Direct-current magnetoencephalography can provide a new noninvasive technique for studying depolarization and/or spreading depression in focal cerebral ischemia.     

Midkine在局灶性脑缺血中的表达及意义

目的 探讨Midkine(MK)在局灶性脑缺血中的表达及意义。方法 采用腔内线栓法制成大鼠局灶性脑缺血模型LMCAO。应用RT-PCR检测缺血后1d组，2d组，14d组及对照组的MK表达情况。结果 在局灶性脑缺血后1d即有MK的表达，14d无MK表达，对照组呈阴性，结论 MK是一种即时表达因子。参与脑缺血急性期的修复。     

Neuroprotective effect of baicalin on focal cerebral ischemia in rats

Baicalin, a flavonoid compound from the root of the herb Scutellaria baicalensis Georgi, has been widely used to treat patients with inflammatory disease. The aim of this study was to assess the efficacy of baicalin in a rat model of focal cerebral ischemia. Adult male Sprague-Dawley rat models of cerebral artery occlusion were established and then randomly and equally divided into three groups: ischemia(cerebral ischemia and reperfusion), valproic acid(cerebral ischemia and reperfusion + three intraperitoneal injections of valproic acid; positive control), and baicalin(cerebral ischemia and reperfusion + intraperitoneal injection of baicalin for 21 days). Neurological deficits were assessed using the postural reflex test and forelimb placing test at 3, 7, 14, and 21 days after ischemia. Rat cerebral infarct volume was measured using 2,3,5-triphenyltetrazolium chloride(TTC) staining method. Pathological change of ischemic brain tissue was assessed using hematoxylin-eosin staining. In the baicalin group, rat neurological function was obviously improved, cerebral infarct volume was obviously reduced, and the pathological impairment of ischemic brain tissue was obviously alleviated compared to the ischemia group. Cerebral infarct volume was similar in the valproic acid and baicalin groups. These findings suggest that baicalin has a neuroprotective effect on cerebral ischemia.     

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.     

香港远志提取物对局灶性脑缺血大鼠脑保护作用与作用机制

目的探讨香港远志提取物对局灶性脑缺血大鼠脑保护作用与机制。方法线栓法制备SD大鼠大脑中动脉闭塞(MCAO)模型,随机分4组:假手术组、模型组及治疗A、B组。治疗组按设定方式给药,假手术组、模型组给1%吐温溶液。观察术后24h神经功能缺损评分(NBDS)、脑梗死体积(IV)、血清神经元烯醇化酶(NSE)及神经元凋亡、Bcl-2、Bax表达。结果与假手术组比较,模型组和治疗组NBDS、IV、NSE、神经元凋亡及Bcl-2、Bax显著增高、Bcl-2/Bax显著降低(P<0.05)。与模型组比较,治疗组NBDS、IV、NSE及神经元凋亡、Bax显著降低、Bcl-2、Bcl-2/Bax显著增高(P<0.05),治疗组间数据亦有显著差异(P<0.05)。结论香港远志提取物预处理,对局灶性脑缺血大鼠脑神经有保护作用,机制可能是促进Bcl-2、抑制Bax表达,上调Bcl-2/Bax比值,阻止神经元凋亡。