Protective roles of heat stress on the neurons in hippocampal CA1 region of mice

The effects of heat stress on the neurons in hippocampal CA1 region of brain ischemia/reperfusion were explored. The mice were pretreated with heat stress followed by ischemia/reperfusion by clipping bilateral cervical common arteries for 7 min. Mice were divided randomly into four groups as follows: (1) normal control group; (2) heat stress pretreated subsequent to ischemia/reperfusion group (HS/IR); (3) ischemia/reperfusion group (IR); and (4) heat stress group (HS). Animals in the last three groups were subdivided into three subgroups: 1 d, 4 d, 14 d respectively. The Morris water maze was used to test the ability of learning and memorizing, Nissl staining was used to count the average number of survived neurons in hippocampal CA1 region, and immunohistochemistry combined with image analysis system to detect the changes of Microtubule associated protein 2 (MAP-2) expression. The results showed that mice in IR group exhibited increased escape latency when compared with that of normal, HS and HS/IR groups (P < 0.01), and the mice in IR group adopted an inefficient search strategy, major in circling and restricted searching manners. Nissl staining results showed a significant reduction in the number of pyramidal neurons in hippocampal CA1 regions in HS/IR and IR groups, with a decrease in IR group (P < 0.01). Compared with normal group, the expression of MAP-2 in hippocampal CA1 region obviously decreased in IR group (P < 0.05). The present results indicate that heat stress pretreatment can improve the spatial learning and memorizing function through protection to hippocampal neurons. __________ Translated from Chinese Journal of Neuroanatomy, 2006, 22(3): 328–332 [译自: 神经解剖学杂志]     

亚低温对沙土鼠前脑缺血/再灌注海马CA1区神经元凋亡及Bcl-2、Caspase-3表达的影响

目的通过动态观察亚低温(33℃,4h)对沙土鼠前脑缺血/再灌注后不同时间点海马CA1区Bcl-2、Caspase-3的表达及凋亡细胞的影响,探讨亚低温脑保护的可能机制。方法采用沙土鼠双侧颈总动脉阻断5min前脑缺血/再灌注损伤模型,随机分为假手术组,常温再灌注组,低温假手术组,低温再灌注组,每组根据再灌注的不同时间点(2h、4h、1d、3d、5d)又分为5个对应的亚组(n=6)。在预定时间点行开阔法迷宫检查,TUNEL法检测海马CA1区的凋亡细胞,HE染色检测海马存活细胞,免疫组化检测Bcl-2、Caspase-3在海马各区的动态变化。结果4h亚低温可减少缺血沙土鼠1、3、5d的探索活动及CA1区的凋亡细胞,增加存活细胞,明显抑制脑缺血后海马CA1区Caspase-3早期的表达(2、4h),但对Bcl-2的表达没有影响。结论4h亚低温对沙土鼠5min前脑缺血有确切的保护作用,对Bcl-2的表达没有影响,抑制海马CA1区缺血/再灌注早期Caspase-3的激活可能是其减少海马细胞凋亡,产生脑保护作用的机制之一。     

中枢吗啡预处理对心脏缺血后大鼠海马CaM、血浆CGRP以及下丘脑室旁核和心肌P物质表达的影响

目的探讨侧脑室内注射吗啡预处理对在体大鼠心肌缺血/再灌注损伤的影响及可能的信号机制。方法建立模型大鼠,随机分为两个部分:①分为4组,每组6只:对照组(CON组),在缺血/再灌注前30 min内,侧脑室内微量泵注射0.9%生理盐水5 min,停止注射5 min,重复3次;预处理组(MPC组),在缺血/再灌注前30 min内,侧脑室内注射吗啡(1μg.kg-1)5 min,停止5 min,重复3次;钙调蛋白抑制剂三氟拉嗪(trifluoperazine,TFP)+预处理组(TFP+MPC组),在吗啡预处理前10 min一次侧脑室内给予TFP(浓度为20 g.L-1)5μl;另设TFP自身对照组(TFP组)。②分为3组,每组6只:假手术组(Sham组),CON组和MPC组均同第一部分。观察指标包括:平均动脉压(MAP)、心率(HR),计算平均动脉压和心率乘积(RPP);心肌缺血危险区(AAR)、梗死区(IS)的体积、心肌梗死面积以IS/AAR表示;检测血浆降钙素基因相关肽(calcitonin gene related peptide,CGRP);测定海马组织钙调蛋白;测定下丘脑室旁核、心肌缺血区和非缺血区P物质的表达。结果与CON组相比,MPC组的IS和IS/AAR均明显下降(P<0.01),TFP+MPC组分别与TFP组和CON组相比差异无显著性(P>0.05),而均明显高于MPC组(P<0.01);CON组分别与Sham组和MPC组相比,其下丘脑室旁核、心肌缺血区和非缺血区P物质表达均明显增高(P<0.01,P<0.05);MPC组血浆降钙素基因相关肽CGRP水平与海马钙调蛋白的表达均明显高于其它各组(P<0.01)。结论侧脑室内注射吗啡预处理对在体大鼠心肌缺血/再灌注损伤具有保护作用,其机制可能与钙调蛋白介导释放CGRP和痛觉的干预有关。     

依达拉奉对大鼠XRCC1和细胞凋亡的影响

目的研究大鼠全脑缺血/再灌注不同时点海马CA1区神经元细胞凋亡与DNA修复蛋白XRCC1的变化及相互关系,探讨依达拉奉对神经元细胞凋亡与DNA修复蛋白表达的影响。方法 SD大鼠108只,随机平均分为假手术组(SH组)、缺血再灌注组(IR组)和依达拉奉干预组(ED组)。采用四血管阻塞法建立大鼠全脑缺血再灌注模型,干预组经腹腔注射依达拉奉。分别于再灌注后2、6、12、24、48、72 h处死大鼠,提取脑海马部组织。原位末端标记法(TUNEL)检测细胞凋亡;免疫组织化学方法检测DNA修复蛋白XRCC1的表达。结果 TUNEL法:SH组凋亡率较低,IR组凋亡率于缺血再灌注6 h开始明显增多,48 h凋亡率达到最高。IR组与SH组凋亡率比较,差异有统计学意义(P<0.01)。ED组在6 h后各时点凋亡率较IR组降低(P<0.01)。免疫组化方法:SH组XRCC1在各时点表达较为明显;IR组XRCC1表达在缺血再灌注2 h开始下降,6 h后下降明显,持续到72 h,与SH组比较差异有统计学意义(P<0.01);ED组XRCC1表达量降低不明显,各时点与IR组比较差异有统计学意义(P<0.01)。结论依达拉奉通过减缓XRCC1表达的下降,促进DNA损伤修复,从而阻止锥体细胞凋亡,进而起到脑保护作用。     

原花青素对大鼠局灶性脑缺血再灌注损伤后海马线粒体CytC的释放和Caspase-9的影响研究

目的:研究原花青素对大鼠局灶性脑缺血再灌注所致线粒体损伤的保护作用机制。方法:48只Wistar大鼠随机分为假手术组,缺血再灌注模型组,原花青素高、低剂量(400、40mg.kg-1)组,各组灌胃给予相应试药后30d,采用线栓法阻塞大鼠大脑中动脉(MCA)制作脑缺血再灌注损伤模型,24h后处死取脑。利用免疫荧光方法测定各组小鼠细胞色素C(CytC)的表达,以逆转录聚合酶链反应(RT-PCR)技术检测半胱氨酸蛋白酶(caspase)-9mRNA的表达。结果:与模型组比较,原花青素组CytC阳性细胞明显增多,而caspase-9mRNA表达减弱(P<0.05)。结论:原花青素可以抑制海马CA1区神经元CytC的释放,并减弱cas-pase-9mRNA的表达,对脑缺血再灌注损伤产生保护作用。     

大鼠肝缺血再灌注后肺细胞凋亡及七氟醚对细胞凋亡及 NF-κBp65的影响

目的：探讨七氟醚预处理对大鼠肝缺血再灌注后肺细胞凋亡的影响。方法24只Wister大鼠随机分为3组（n＝8）：假手术组,缺血再灌注组,七氟醚组,阻断肝门30 min后建立大鼠70％肝缺血再灌注模型。假手术组（ S组）仅游离肝门,但不阻断;肝缺血再灌注组（ IR组）采用阻断肝门30 min,再灌注1 h的方法制备大鼠肝缺血再灌注损伤模型;七氟醚预处理组（ SP组）吸入2．1％七氟醚30 min,停止吸入10 min后制备肝缺血再灌注模型。于再灌注1 h时处死动物,留取肺组织,测定湿／干重比（ W／D比）,采用比色法检测超氧化物歧化酶（ SOD）活性及丙二醛（ MDA）含量,采用原位末端转移酶法（ TUNEL）检测细胞凋亡,计算细胞凋亡指数（ AI）,采用Western blot法测定核蛋白NF-κBp65表达,光镜下观察肺组织病理学结果。结果与S组比较,IR组和SP组再灌注各时点肺组织W／D比值、细胞凋亡指数（ AI）和NF-κB 活性水平及MDA含量均显著增高（均P＜0．05）;SOD活性显著降低（P＜0．05）;与IR组比较,SP组W／D比值、细胞凋亡指数（AI）、NF-κB表达水平与MDA含量显著降低（均P＜0．05）;而SOD活性显著增加（P＜0．05）;SP组肺组织损伤较IR组减轻。结论细胞凋亡可能在肝缺血再灌注肺损伤发生过程中具有重要意义;七氟醚对大鼠肝缺血再灌注后肺细胞凋亡具有抑制作用,其作用机制可能通过降低肺组织NF-κB的活性,从而清除自由基、抑制脂质过氧化有关。     

前脑缺血及再灌流损伤后大脑皮层内皮素、降钙素基因相关肽和神经元凋亡的研究

目的：探讨大脑皮层缺血及再灌流内皮素（ET）,降钙素基因相关肽（CGRP）与神经元凋亡的变化规律及关系。方法：以前脑缺血及再灌流不同时段的大鼠为模型。用放免法检测皮层ET和CGRP含量;TUNEL法检测原位细胞凋亡。结果：缺血后15分。ET低于正常和假手术组：再灌流后进一步降低。12小时达最低水平,6天后恢复,缺血后CGRP升高,再灌流后继续升高,12小时和1天达高峰后下降,6天时恢复正常,缺血后神经元凋亡增加,再灌流后继续增加,1天时达高峰后缓慢下降,8天时基本恢复正常,ET量与凋亡细胞呈负相关,CGRP量与凋亡细胞呈正相关。结论：缺血和再灌流均可导致神经元凋亡,CGRP在缺血及再灌注早期升高,其对神经元凋亡可能具有双重作用。     

CGRP、K_(ATP)通道和脊神经在鞘内注射吗啡预处理减轻大鼠心肌缺血后损伤中的作用

目的探讨降钙素基因相关肽(CGRP)、ATP敏感性钾离子通道(KATP通道)和脊神经在鞘内注射吗啡预处理对在体大鼠心肌缺血/再灌注损伤中的保护作用。方法♂SD大鼠60只,建立鞘内置管和心肌缺血/再灌注损伤模型,随机分为10组,每组6只:对照组(CON,生理盐水)、二甲亚砜组(DMSO,GLI的溶剂)、CGRP8-37组(CGRP受体阻滞剂,3nmol.kg-1)、格列苯脲组(GLI,KATP通道阻滞剂,0.3 mg.kg-1)、利多卡因组(LID,1%盐酸利多卡因10μl)、鞘内注射吗啡预处理组(MPC,3×1μg.kg-1)、CGRP8-37+MPC组、GLI+MPC组、LID+MPC组、GLI+LID组。观察指标包括:平均动脉压(MAP)、心率(HR),计算平均动脉压和心率乘积(RPP);心肌缺血危险区(AAR)、梗死区(IS)的体积、心肌梗死面积以IS/AAR表示。结果与CON组比较,MPC组、LID组、LID+MPC组和GLI+LID组的IS和IS/AAR均明显下降(P<0.05,P<0.01);与MPC组比较,CGRP8-37+MPC组、GLI+MPC组和LID+MPC组的IS和IS/AAR均明显增加(P<0.01)。结论外周CGRP的释放、KATP通道和脊神经可能参与了鞘内注射吗啡预处理减轻大鼠心肌缺血后损伤的作用。     

缺血预适应对大鼠小肠缺血再灌注损伤的保护作用(英文)

观察预适应对大鼠小肠缺血再灌的保护作用及对内源性神经递质降钙素基因相关肽 (CGRP)释放的影响 .选用雄性 Wistar大鼠 40只 (2 75- 32 5g) ,实验分在体和离体两部分 .(1 )在体部分 :30 min的小肠缺血和 60 min的再灌流可引起小肠湿重干重比值 (WW/DW)增高 ,血中乳酸脱氢酶 (LDH)活性 ,丙二醛 (MDA)含量显著增加 .3次 8min缺血及1 0 min再灌流预适应可降低前述缺血再灌引起的WW/DW,LDH活性及 MDA含量增高 ,但各组血液中 CGRP水平未见明显变化 .(2 )离体部分 :肠系膜上动脉插管连接灌流装置 .肠系膜上静脉插管收集流出液 .小肠灌流 1 0 min后 ,反复 3次 8min阻断灌流及 1 0 min再灌流预适应模型可使流出液中的 CGRP显著增加〔(1 .30± 0 .0 8) vs(0 .68±0 .0 5) μg· L-1,P<0 .0 1〕.结果提示 :缺血预适应对小肠缺血再灌损伤具有显著保护作用 ,CGRP可能是预适应的一种内源性神经介质     

黄芪提取物对大鼠海马神经元迟发性死亡的影响

目的探讨黄芪提取物(Extractofastragalus,EA)对全脑缺血再灌注7d引起的大鼠海马神经元迟发性死亡的作用。方法用四动脉阻断法造模,观察背侧海马神经元的超微结构;CA1区神经元结构、正常神经元计数;免疫组化法检测胶质纤维酸性蛋白(GFAP)的表达。结果与缺血再灌(I/R)组比较,EA能改善背侧海马神经元超微结构;抑制CA1区正常神经元数目的减少,I/R组为38±11.5,EA(20、40mg·kg-1)分别为63±12.8(P<0.05)和77±16(P<0.01);降低GFAP的表达,I/R组GFAP阳性细胞数为69±10.7,EA三个剂量组分别为53±5.6(P<0.05)、39±7.1(P<0.01)、46±7.6(P<0.05)。结论EA能抑制全脑缺血再灌注7d大鼠海马迟发性神经元死亡,可能与其抑制海马CA1区星形胶质细胞(AS)过度增生有关。     

Naloxone Postconditioning Alleviates Rat Myocardial Ischemia Reperfusion Injury by Inhibiting JNK Activity

To investigate the alteration of c-Jun N-terminal kinase (JNK) activity after myocardial ischemia reperfusion injury (MIRI) and further explore the effect of naloxone postconditioning on MIRI. Forty male Sprague Dawley rats were randomly divided into five groups: sham operation (sham, n=8); ischemia reperfusion (IR, n=8); IR+naloxone 0.5 mg/kg (Nal L, n=8); IR+naloxone 1.0 mg/kg (Nal M, n=8); IR+naloxone 2.0 mg/kg (Nal H, n=8). Pathological changes of myocardial tissue were visualized by HE staining. The expression of p-JNK, and the apoptosis of cardiomyocytes were investigated with Western blotting and the TUNEL assay, respectively. Irregular arrangement and aberrant structure of myocardial fibers, cardiomyocytes with granular or vacuolar degeneration, and inflammatory cells infiltrating the myocardial interstitial regions characterized MIRI in the IR group. Signs of myocardial injury and inflammatory infiltration were less prominent in the Nal-treated groups. The expression of p-JNK in the sham group and in all Nal-treated groups was significantly lower than that in the IR group (p<0.01). The apoptosis index of cardiomyocytes in the IR group was significantly higher than in the sham group (p< 0.01). The apoptosis indices of cardiomyocytes in all Nal-treated groups were significantly reduced to 55.4%, 26.2%, and 27.6%, respectively, of the IR group (p< 0.01). This study revealed that Naloxone postconditioning before reperfusion inhibits p-JNK expression and decreases cell apoptosis, thus alleviating MIRI.     

原花青素对大鼠局灶性脑缺血再灌注损伤后海马线粒体CyfC的释放和Caspase-9的影响研究

目的：研究原花青素对大鼠局灶性脑缺血再灌注所致线粒体损伤的保护作用机制。方法：48只Wistar大鼠随机分为假手术组，缺血再灌注模型组，原花青素高、低剂量（400、40mg·kg^-1）组，各组灌胃给予相应试药后30d，采用线栓法阻塞大鼠大脑中动脉（MCA）制作脑缺血再灌注损伤模型，24h后处死取脑。利用免疫荧光方法测定各组小鼠细胞色素C（CytC）的表达，以逆转录聚合酶链反应（RT—PCR）技术检测半胱氨酸蛋白酶（caspase）-9mRNA的表达。结果：与模型组比较，原花青素组CytC阳性细胞明显增多，而caspase-9mRNA表达减弱（P〈0．05）。结论：原花青素可以抑制海马CAl区神经元CytC的释放，并减弱caspase-9mRNA的表达．对脑缺血再灌注损伤产生保护作用。     

褪黑素对肠缺血再灌注损伤保护作用的临床研究

目的 研究褪黑素对肠缺血再灌注损伤(IIRI)的保护作用.方法 研究对象随机分为缺血再灌注A组,生理盐水处理B组,地塞米松治疗C组,褪黑素治疗D组,每组20例.手术解除肠缺血前后10min分别静脉注射生理盐水10ml、地塞米松20mg和褪黑素20μg,手术结束后1h内采外周静脉血,用MDA、SOD试剂盒测定血浆MDA浓度和SOD活性.用NO试剂盒和酶学分光光度法测定血浆NO2-/NO3-水平和血浆D-乳酸水平.观察处理后各组肠管颜色完全恢复时间和术后肛门排气时间.结果 褪黑素治疗组与生理盐水处理组和地塞米松治疗组比较,血浆SOD活性明显上升(P＜0.01),MDA浓度降低(P＜0.05),血浆中NO2-/NO3-浓度上升(P＜0.05),D-乳酸明显降低(P＜0.01),各组肠管颜色完全恢复时间和术后肛门排气时间均有缩短(P＜0.05).结论 褪黑素对肠缺血再灌注损伤有较好保护作用,其机制可能是通过清除氧自由基,防止脂质过氧化和保护肠黏膜机械屏障.     

七氟烷后处理对大鼠离体心脏缺血/再灌注损伤心功能和线粒体的影响

目的探讨七氟烷后处理对大鼠离体心脏缺血/再灌注的保护作用。方法48只SD大鼠,随机分为4组(n=12):假手术组(Sham),缺血/再灌注组(I/R)缺血后处理组(Post),七氟烷后处理组(Sevo)。采用Langendroff离体心脏灌注模型。除Sham组其余各组均平衡灌注30min,全心缺血30min,再灌注90min,Post组在再灌注即刻给予4个循环复灌20s/缺血20s,Sevo组在再灌注开始给予含1.5MAC(2.57V/V)七氟烷的K-H液灌注5min,再用K-H液冲洗10min,纪录平衡灌注末,再灌注30min、60min、90min时左室舒张末压(LVEDP)、左室发展压(LVDP)、左室内压上升最大速率(+dp/dt)、左室内压下降最大速率(-dp/dt)、心率(HR)、冠脉血流量(CF),再灌注90min时,计算心肌梗死面积百分比,电子显微镜观察线粒体的损伤程度,Westernblot半定量测定胞质和线粒体、细胞色素C的水平。结果平衡灌注末各组间心功能指标(基础值)差异未见统计学意义(P>0.05)。七氟烷后处理组和缺血后处理组可改善再灌注损伤心功能的各项指标(P<0.05)。复灌90min,Sevo组和Post组心肌梗死面积显著低于I/R组(P<0.05)。与I/R组比较,Sevo组和Post组胞质细胞色素C的含量明显减少(P<0.05),同时伴随线粒体细胞色素C的含量明显增多(P<0.05)。电子显微镜观察线粒体形态,Sevo组和Post组的损伤程度比I/R组明显减轻。结论七氟烷后处理对大鼠离体心脏再灌注损伤有明显的保护作用,其保护强度与缺血后处理相当,机制可能与减轻线粒体的损伤,抑制细胞色素C的释放有关系。     

Leptin attenuates cerebral ischemia/reperfusion injury partially by CGRP expression

Ischemic stroke is a medical emergency triggered by a rapid reduction in blood supply to localized portions of the brain, usually because of thrombosis or embolism, which leads to neuronal dysfunction and death in the affected brain areas. Leptin is generally considered to be a strong and quick stress mediator after injuries. However, whether and how peripherally administered leptin performs neuroprotective potency in cerebral stroke has not been fully investigated. It has been reported that CGRP(8-37), an antagonist of the CGRP receptor, could reverse the protective effect of leptin on rats with CIP (caerulein-induced pancreatitis). However, the question remains: are leptin and CGRP associated in cerebral ischemia/reperfusion injury? The present study attempted to evaluate the relationship between CGRP expression and leptin neuroprotective effects (1mg/kg in 200 μL normal saline, i.p.) on focal cerebral ischemia/reperfusion injury in mice and the protective effect of leptin (500 μg/L) on neurons during hypoxia/reoxygenation injury. Peripheral administration of leptin alleviated injury-evoked brain damage by promoting CGRP expression, improving regional cerebral blood flow, and reducing local infarct volume and neurological deficits. Furthermore, leptin also promoted bcl-2 expression and suppressed caspase-3 in vivo and vitro after injury. Administration of CGRP(8-37) (4 × 10(-8)mol/L) partly abolished the beneficial effects of leptin, and restored the normal expression levels of bcl-2 and caspase-3 in neurons, which indicated that leptin-induced protection of neurons was correlated with release of CGRP. These results indicate that the neuroprotective effect of leptin against cerebral ischemia/reperfusion injury may be strongly relevant to the increase of CGRP expression.     

亚低温对沙土鼠前脑缺血再灌注海马神经元凋亡及p38活性的影响

目的通过动态观察亚低温(33℃,4h)对沙土鼠前脑缺血再灌注后不同时间点海马神经元凋亡细胞及磷酸化p38表达的影响,探讨亚低温脑保护的可能机制。方法采用沙土鼠双侧颈总动脉阻断5min前脑缺血再灌注损伤模型,随机分为假手术组,常温再灌注组,低温假手术组,低温再灌注组。每组根据再灌注的不同时间点(2h、4h、d1、3、d5)又分为5个对应的亚组(n=6)。在预定时间点行开阔法迷宫检查,TUNEL法检测海马CA1/3区的凋亡细胞,免疫组化检测pp38在海马各区的动态变化。结果4h亚低温可显著减少缺血沙土鼠d1、d3、d5的探索活动及CA1/区的凋亡细胞,明显抑制脑缺血后海马CA1区pp38早期的表达(2h、4h)。结论4h亚低温治疗对沙土鼠5min前脑缺血有明确的保护作用,抑制海马CA1区缺血再灌注早期pp38的激活可能是其减少海马细胞凋亡、产生脑保护作用的机制之一。     

ERK和JNK通路在沙土鼠脑缺血预处理中的表达及作用

目的探讨ERK和JNK在沙土鼠脑缺血预处理中的表达及作用。方法采用沙土鼠前脑缺血再灌注损伤模型。随机分为假手术组(SH)、预处理对照组(IC)、预处理缺血组(IP)及脑缺血再灌注组(IR);各组根据再灌注15 m in、2 h、4h、6 h、1 d、3 d、5 d及7 d又分8个亚组。在预定时间点行开阔法行为学检查、TUNEL法海马CA1/3区凋亡细胞检测、免疫组织化学SP法测定p-ERK、p-JNK在海马区的变化。结果IP可减少沙土鼠探索活动及海马CA1区凋亡锥体细胞数量(vsIR,P<0.01)各组CA1区p-ERK无表达,IR组海马CA1区p-JNK表达较强,再灌后1d最为明显,IP可明显减弱CA1区p-JNK的表达(vsIR,P<0.01),明显增强CA3区p-ERK的表达(P<0.05,P<0.01)。结论脑缺血可导致ERK及JNK在海马各亚区的差异性表达。缺血预处理可能通过抑制CA1区JNK磷酸化、增强CA3区ERK活性而保护海马细胞。     

丹皮酚银杏叶提取物组合物对大鼠脑缺血再灌注损伤的保护作用研究

目的评价丹皮酚与银杏叶提取物1∶1组合物对大鼠脑缺血再灌注损伤的保护作用。方法尼莫地平(10.8 mg/kg)组、丹皮酚(37.5 mg/kg)组、银杏叶提取物(37.5 mg/kg)组以及丹皮酚银杏叶提取物1∶1组合物(75.0 mg/kg)组大鼠灌胃给予相应药物,给药容积10 m L/kg,ig给药6 d后大脑中动脉栓塞造模,脑缺血再灌注后4、24 h进行观察,计算行为学评分;动物取脑,测定脑梗死面积,计算脑梗死率;大鼠脑缺血再灌注后24 h后,测定血清中自由基超氧化物歧化酶(SOD)、丙二醛(MDA)、γ-氨基丁酸(GABA)、谷氨酸(Glu)水平和脑组织中基质金属蛋白酶-9(MMP-9)、GABA、Glu含量。结果与模型组比较,脑缺血再灌注22 h后,各组大鼠行为学评分均有降低趋势,其中组合物组的降低作用的差异具有显著性(P0.05);与模型组比较,脑缺血再灌注24 h后,银杏叶提取物、丹皮酚、组合物组大鼠脑梗死率均明显降低,差异具有显著性(P0.01);与模型组比较,组合物组大鼠血清中SOD水平、丹皮酚和组合物组血清中GABA水平显著升高(P0.05),银杏叶提取物、丹皮酚、组合物组大鼠血清中MDA水平、组合物组血清中Glu水平显著降低(P0.01、0.05);丹皮酚和组合物组大鼠脑组织中MMP-9、Glu含量显著降低(P0.01、0.05),组合物组脑组织中GABA含量显著升高(P0.01)。结论丹皮酚银杏叶提取物组合物对大鼠脑缺血再灌注损伤具有保护作用,其作用机制可能是通过抗氧化损伤、平衡兴奋性氨基酸与抑制性氨基酸浓度、调节MMP-9表达量有关。     

Effect of celecoxib and L-NAME on global ischemia-reperfusion injury in the rat hippocampus

Abstract

Transient global ischemia continues to be an important clinical problem with limited treatment options. The present study aimed to investigate the possible protective effects of celecoxib [a selective cyclooxygenase (COX-2) inhibitor] and N-omega-nitro-L-arginine methyl ester (L-NAME) [a nonselective nitric oxide synthase (NOS) inhibitor] against global ischemia-reperfusion (IR) induced biochemical and histological alterations in the rat hippocampus. Global ischemia was induced by bilateral clamping of the common carotid arteries for 60 minutes. Hippocampal cysteinyl aspartate-specific protease-3 (caspase-3) activity, nitrite/nitrate contents (NO_X), as well as COX-2 immunoreactivity in the hippocampal Cornu Ammonis 1 (CA1) subregion were dramatically increased 24 hours after global ischemia. After 72-hour of reperfusion, ischemia induced a selective, extensive neuronal loss in the hippocampus CA1 subregion. Celecoxib (3 and 5?mg/kg, intraperitoneally; i.p.), administered 30 minutes before ischemia and at 6, 12, and 22 hours of 24-hour reperfusion, caused significant reductions in hippocampal caspase-3 activity as well as the number of COX-2 immunoreactive (COX-2 ir) neurons in the CA1 subregion. Further, celecoxib (3 or 5?mg/kg, i.p.), administered 30 minutes before ischemia and at 6, 12, 22, and 48 hours of 72-hour reperfusion, provided a notable histological protection of hippocampal CA1 neurons. Meanwhile, L-NAME (3?mg/kg, i.p.), administered twice (immediately after ischemia and 45 minutes after starting the reperfusion period), effectively reduced the elevated NO_X level, decreased hippocampal caspase-3 activity and COX-2 immumoreactivity, and ameliorated ischemia-induced damage in the hippocampal CA1 subregion. The present study indicates that celecoxib and L-NAME might be neuroprotective agents of potential benefit in the treatment of cerebral ischemia.     

七氟烷对大鼠缺血再灌注后肺组织氧自由基的影响

目的通过建立在体大鼠肺缺血再灌注损伤模型,观察七氟烷对缺血再灌注后肺组织氧自由基(OFRs)表达的影响,探讨缺血再灌注后肺损伤和七氟烷肺保护的可能机制。方法选择96只雄性wistar大鼠,参照改良的Eppinger方法建立在体大鼠肺缺血再灌注损伤模型。共分4组,每组24只大鼠。C组:开胸游离左肺门,未行肺门阻断;IR组:阻断肺门45min后开放再灌注;Sev-C组:吸入1MAC七氟烷30min,游离肺门不阻断;Sev-IR组:吸入七氟烷30min后阻断左肺门45min,然后开放再灌注。每组包括3个时点:缺血阻断45min、再灌注60min、再灌注120min,每时点6只大鼠,另外再灌注120min时,各组另取6只大鼠行支气管灌洗。记录各时点MAP、SpO2,测定W/D、肺通透指数(LPI),生化法检测肺组织MDA、SOD和MPO含量。结果与C组和Sev-C组比较,IR组和Sev-IR组再灌注后W/D、LPI均上升(P<0.05),Sev-IR组W/D、LPI升高的程度低于IR组(P<0.05);IR组再灌注60min、120min肺组织MDA、MPO含量增加(P<0.05),SOD含量减少(P<0.05)。Sev-IR组MDA、MPO增加、SOD减少的程度都低于IR组(P<0.05)。结论肺缺血再灌注后血管通透性增加,再灌注后肺损伤的机制与OFRs产生过多有关,七氟烷预处理能抑制OFRs的生成,对再灌注后肺组织具有一定的保护作用。