异氟醚对大鼠局灶性脑缺血/再灌注损伤的保护作用

目的 探讨异氟醚对大鼠局灶性脑缺血/再灌注损伤的脑保护作用。方法 32只雄性SD大鼠,280～320 g,随机分为四组,假手术组:仅分离血管,不留置线拴;脑缺血组:缺血前吸入纯氧30min行2h大脑中动脉栓塞(MCAO);0.9％和1.5％异氟醚组:分别在MCA0前吸入0.9％和1.5％异氟醚30 min。监测缺血/再灌注期间鼓膜温度变化,测定再灌注22 h和70 h时脑梗死体积及再灌注22h时光、电镜的病理改变。结果 缺血侧鼓膜温度较非缺血侧明显降低,最大温差达0.78℃±0.35℃。异氟醚轻度缩小再灌注22 h和70 h时的脑梗死体积,且1.5％异氟醚对再灌注70 h时梗死体积百分比减小的效果优于0.9％异氟醚。光、电镜结果提示异氟醚能减轻局灶性脑缺血/再灌注损伤对神经元、线粒体和内皮细胞的损害。结论缺血前吸入0.9％和1.5％异氟醚对大鼠局灶性脑缺血,再灌注损伤,可产生一定程度的保护作用。     

再灌注期吸入异氟醚对不同程度大鼠脑缺血再灌注损伤的影响

目的 探讨再灌注期吸入异氟醚对不同程度全脑缺血再灌注损伤的保护效应及其机制。方法 将42只雄性 SD 大鼠随机分为假手术组(n=6)、复苏组(n=18)及对照组(n=18)，后两组又分为缺血10min、15min、20min 三个时间点，每个时间点6只大鼠，建立大鼠清醒全脑缺血模型。复苏组于再灌注开始后立即吸入1.4%异氟醚30min 进行复苏。收集清醒、缺血及再灌注后微透析标本，测定谷氨酸递质浓度。并进行运动功能双盲评定。双盲记数海马 CA1区核完整的锥体细胞及凋亡细胞的百分率。结果 与对照组相比，复苏组缺血再灌注早期海马组织谷氨酸递质浓度降低(P<0.05)；全脑缺血15min 复苏组的运动功能评分升高(P<0.05)；全脑缺血10、15、20min 对照组和复苏组海马神经细胞凋亡率均低于假手术组(P<0.05)；全脑缺血10、15min 复苏组海马 CA1区神经细胞凋亡率降低(P<0.05)。结论 再灌注早期吸入异氟醚具有脑保护作用，其机制与促进脑缺血期间过度释放的谷氨酸递质于再灌注期的吸收有关。     

七氟醚后处理对局灶性脑缺血-再灌注损伤的保护作用

目的评价在缺血后期及再灌注早期吸入不同浓度的七氟醚行后处理对大鼠局灶性脑缺血-再灌注损伤的保护作用及其剂量依赖性。方法雄性SD大鼠50只,随机分为空白对照组、吸氧组和0.5、1.0、1.5MAC七氟醚后处理组,每组10只。采用大脑中动脉线栓法阻闭(middle cerebral artery occlusion,MCAO)120min后再灌注72h制备局灶性脑缺血模型。各七氟醚后处理组于再灌注即刻的前20min和后10min给予不同浓度七氟醚吸入。再灌注后的24、48和72h行神经功能评分(NDS),并于最后一次评分后测定脑梗死容积比。结果0.5、1.0和1.5MAC组的脑梗死容积比分别为0.39±0.03,0.31±0.03和0.24±0.03(P<0.05),明显小于对照组0.53±0.05(P<0.05)。吸氧组为0.51±0.05,与对照组比差异无统计学意义。各个时间点七氟醚后处理组NDS明显优于对照组和吸氧组。结论在局灶性脑缺血-再灌注的缺血后期和再灌注早期吸入0.5、1.0和1.5MAC七氟醚行后处理均具有脑保护作用,并呈现剂量依赖性。     

异氟醚、七氟醚和地氟醚预处理对脑缺血再灌注损伤大鼠海马CBS/H2S、iNOS/NO和HO-1/CO的影响

目的 研究异氟醚、七氟醚和地氟醚预处理对脑缺血再灌注损伤大鼠海马CBS／H，S、iNOS／NO和HO-1／CO的影响，探讨吸入麻醉药脑保护作用的机制。方法30只Wistar大鼠随机分为5组（n=6）：对照组（C组）、脑缺血再灌注组（I／R组）、异氟醚组（I组）、七氟醚组（S组）和地氟醚组（D组）。采用四动脉阻断法建立大鼠全脑缺血再灌注模型。Ⅰ组、S组和D组夹闭两侧颈总动脉前分别吸入氧气＋0．65MAC的异氟醚、七氟醚和地氟醚30min，C组和I／R组吸入氧气。缺血20min，再灌注12h后处死大鼠，取海马，测定大鼠海马组织中HS、NO、CO、cAMP和cGMP含量和CBS，iNOS和HO活性以及CBS—mRNA、iNOS，mRNA和HO—1-mRNA的表达水平；电镜下观察海马线粒体的变化。结果与C组相比，I／R组海马组织CO、H2S、NO、cAMP、cGMP含量和HO、CBS、iNOS活性升高，CBS—mRNA、iNOS-mRNA和HO-1-mRNA表达升高，海马神经细胞线粒体变性率升高（P〈0．01）；与I／R组相比，Ⅰ组、D组和S组CO含量和HO活性升高，H2S、NO、cAMP含量和CBS、iNOS活性降低，CBS—mRNA和iNOS-mRNA表达降低而HO-1-mRNA表达升高，线粒体变性率降低（P〈0．05或0．01）。结论 异氟醚、七氟醚和地氟醚预处理可通过抑制CBS／142S、iNOS／NO，激活HO-1／CO，减轻了大鼠脑缺血再灌注损伤。     

七氟醚预处理对大鼠局灶性脑缺血-再灌注损伤的保护作用

目的观察七氟醚预处理对大鼠局灶性脑缺血一再灌注损伤的保护作用。方法32只雄性SD大鼠随机均分为四组,假手术组：仅分离血管,不留置线栓;Sevol、Sevo2和对照组：分别在缺血前吸入2％、3％七氟醚和纯氧30min。用左颈内动脉尼龙线线栓法使大脑中动脉阻闭120min,拔出尼龙线恢复再灌注。观察再灌注24h后神经功能损害改变并评分,然后处死动物取大脑行2,3,5-氯化三苯基四氮唑（TTC）染色以测量脑梗死体积。结果缺血-再灌注损伤后对照组大鼠神经功能损害较Sevol和Sevo2组更明显（P〈0．05或P〈0．01）。缺血-再灌注损伤24h后Sevo1组和Sevo2组脑梗死体积和梗死体积百分比,较对照组减小（P〈0．01）。结论缺血前吸入2％、3％七氟醚对大鼠局灶性脑缺血-再灌注损伤可产生保护作用。     

异氟醚对大鼠肺缺血再灌注损伤的保护作用

目的 探讨异氟醚对大鼠肺缺血再灌注损伤的保护作用。方法 120只SD雄性大鼠，随机分成4组（n=30）：假手术组（S组）、缺血再灌注组（IR组）、异氟醚-缺血再灌注组（ISO-IR组）和异氟醚组（ISO-S组）。IR组、ISO-IR组建立肺缺血再灌注模型，ISO-IR组吸入1MAC异氟醚30min时行肺缺血再灌注，ISO-S组吸入1MAC异氟醚，不进行肺缺血再灌注。分别在缺血45min、再灌注30、60、120min处死6只大鼠，测定肺组织湿干比（W／D）、髓过氧化物酶（MPO）活性、中性粒细胞（PMN）膜表面CD18和肺组织ICAM-1mRNA表达、支气管肺泡灌洗液（BALF）中自细胞计数、沉渣白细胞分类和总蛋白（TP）浓度，并进行肺组织病理学检查。结果 再灌注期间IR组肺组织W／D、MPO活性、CDl8和ICAM-1mRNA表达、BALF中PMN百分比、TP浓度及PMN膜表面CD18表达均升高。而异氟醚预先给药减弱了缺血再灌注诱导的上述指标的升高。肺组织病理学检查显示异氟醚预先给药减轻了肺缺血再灌注损伤。结论 通过抑制PMN浸润和肺组织ICAM-1mRNA及CD18表达上调，缺血前吸入异氟醚对肺缺血再灌注损伤有一定的保护作用。     

地氟醚、七氟醚和异氟醚预处理对兔心肌缺血/再灌注损伤的保护作用

目的 研究地氟醚，七氟醚和异氟醚预处理对兔心肌缺血／再灌注损害的影响。方法 35只大白兔，阻断左冠状动脉前降支缺血50min，开放再灌注120min，随机分为5组。3个预处理组分别吸入1.5MAC地氟醚，七氟醚和异氟醚20min，继之10min，药物排出；C＋地氟醚组于地氟醚预处理前10min静注KATP通道阻断剂Glybenclamide 2mg/kg；对照组无任何处理。实验中监测血流动力学变化，实验结束用氯化硝基四氮唑蓝光法测定心肌梗死范围。结果 缺血和再灌注早期，HR，MAP，CO，LVSP，LVEDP和RPP各组间无统计学差异；再灌后期，对照组LVEDP明显高于各项处理组。与对照组比，地氟醚，七氟醚，异氟醚和G＋地氟醚各组，分别缩小心肌梗死范围41．3％，47．2％，31．7％和17．8％，G＋地氟醚组心肌梗范围明显高于地氟醚组。结论 地氟醚，七氟醚和异氟醚预处理不同程度缩小兔心肌梗死范围，KATP通道部分介导了其心肌保护。     

异氟醚预处理兔缺血再灌注心肌蛋白质组双向凝胶电泳分析

目的研究异氟醚预处理对缺血再灌注心肌保护的相关蛋白的变化。方法将8只新西兰大白兔随机分为心肌缺血再灌注对照组(C组)和异氟醚预处理组(I组),每组4只。两组均接受左冠状动脉前降支阻断40 m in,开放再灌注120 m in。I组在缺血前24 h前吸入1MAC异氟醚2 h。分别取各组缺血区心肌进行二维凝胶电泳,利用Im ageM aster 2D软件分析实验结果。结果与C组对比,I组有13个蛋白表达发生了显著变化,其中表达明显增强的有10个蛋白,表达明显降低的有3个蛋白。结论差异表达的蛋白可能在异氟醚对心肌缺血再灌注损伤的保护中发挥作用。     

异氟醚对大鼠全脑缺血再灌注时海马ICAM-1 mRNA和外周血中性粒细胞表面CD11b/CD18表达的影响

目的 探讨异氟醚对大鼠全脑缺血再灌注时海马组织ICAM-1 mRNA和外周血中性粒细胞表面CD11b/CD18表达的影响.方法 Wistar大鼠63只,随机分为3组(n=21):假手术组(S组)、缺血再灌注组(I/R组)和异氟醚组(Iso组).采用四血管阻断法制备全脑缺血再灌注模型.Iso组在四血管阻断过程中及再灌注早期吸入1.4%异氟醚.于再灌注6、24、72 h时,采集外周静脉血,采用流式细胞仪测定中性粒细胞表面CD11b/CD18和CD18的表达;RT-PCR法测定海马组织细胞间粘附分子-1(ICAM-1)mRNA和核因子κB(NF-κB)mRNA的表达.结果 与S组比较,I/R组再灌注6 h时CD11b/CD18和CD11b表达上调,再灌注24、72 h时ICAM-1 mRNA表达上调,I/R组和Iso组再灌注24 h时NF-κB mRNA表达上调(P＜0.05或0.01);与I/R组比较,Iso组再灌注6 h时CD11b表达下调,再灌注24 h时ICAM-1 mRNA表达下调(P＜0.05).结论 异氟醚可减轻大鼠全脑缺血再灌注损伤,可能与其抑制海马ICAM-1 mRNA及外周血中性粒细胞表面CD11b/CD18的表达有关.     

Shh/Gli1信号通路在异氟醚后处理减轻大鼠脑缺血-再灌注损伤中的作用

目的评价Shh/Gli1信号通路在异氟醚后处理减轻大鼠脑缺血-再灌注损伤中的作用。方法清洁级健康雄性SD大鼠44只,6~8周龄,体重220~280 g,采用随机数字表法将其分为四组:假手术组(S组)、缺血-再灌注组(IR组)、缺血-再灌注+异氟醚后处理组(ISO组)和环巴胺+缺血-再灌注+异氟醚后处理组(CYC组),每组11只。采用线栓法栓塞大脑中动脉90 min、再灌注24 h制备脑缺血-再灌注损伤模型。ISO组大鼠在再灌注即刻吸入1.5%异氟醚。CYC组大鼠在缺血前30 min腹腔注射Shh/Gli1信号通路特异性抑制剂环巴胺10 mg/kg。再灌注24 h后,所有大鼠进行神经行为学评分,采用TTC法测定脑梗死体积,HE染色和尼氏染色观察病理学改变,TUNEL染色观察海马CA1区细胞凋亡,免疫荧光和Western blot法测定Shh和Gli1蛋白含量。结果与S组比较,IR组、ISO组和CYC组大鼠神经行为学评分明显升高,脑梗死体积明显增大,坏死和凋亡细胞明显增多,组织病理学损伤严重,Shh和Gli1蛋白含量明显增加(P<0.05)。与IR组比较,ISO组神经行为学评分和脑梗死体积明显降低,坏死和凋亡明显减少,组织病理学损伤明显减轻,Shh和Gli1蛋白含量明显增加(P<0.05)。与ISO组比较,CYC组神经行为学评分明显升高,脑梗死体积明显增大,坏死和凋亡细胞明显增多,组织病理学损伤明显加重,Shh和Gli1蛋白含量明显减少(P<0.05)。结论 Shh/Gli1信号通路激活参与了异氟醚后处理减轻大鼠脑缺血-再灌注损伤的过程。     

The dose-dependent effects of isoflurane on outcome from severe forebrain ischemia in the rat

Isoflurane improves outcome against cerebral ischemia in the rat. However, the optimal neuroprotective concentration has not been defined. We examined the effects of different isoflurane concentrations on outcome from severe forebrain ischemia in the rat. Fasted rats were subjected to 0.5, 1.0, 1.5, 2.0, or 2.5 minimum alveolar concentration (MAC) isoflurane during 10 min bilateral carotid occlusion plus systemic hypotension. Each isoflurane concentration was administered only before ischemia. Arterial blood pressure was not pharmacologically manipulated. After ischemia, the anesthetic regimen was changed to fentanyl/nitrous oxide and maintained for 2 h. Pericranial temperature was maintained normothermic during the experiment. Neuromotor score, % dead hippocampal CA1 neurons, and cortical injury were measured 5 days postischemia. Preischemic arterial blood pressure decreased as MAC was increased. Animals administered >1.0 MAC frequently exhibited postischemic seizures resulting in increased mortality. There was no difference among MAC conditions for % dead CA1 neurons (93 approximately 95%). In the cortex, neuronal necrosis was less severe with 0.5 MAC and 1.0 MAC isoflurane relative to >1.0 MAC values. The neuromotor score in the 1.0 MAC isoflurane group was superior to the 2.5 MAC group. Dose-dependent effects of preischemic administration of isoflurane on histologic and behavioral outcome after severe forebrain ischemia were observed. Isoflurane MAC values <1.5 provided superior overall outcome relative to larger isoflurane concentrations.     

茶氨酸在大鼠脑缺血/再灌注过程中对大鼠海马c-Jun氨基末端激酶和P38信号通路的作用

目的 探讨茶氨酸在大鼠脑缺血/再灌注(ischemia/reperfusion,I/R)过程中对大鼠海马c-Jun氨基末端激酶(c-Jun N-terminal kinases,JNK)和P38信号通路所发挥的作用.方法 雄性SD大鼠108只,体重290~310 g,采用随机数字表法分成假手术组(SH组)、I/R组、茶氨酸组(TH组),每组36只.每组根据再灌注时间分为2、6、12、24、48、72 h 6个亚组,每亚组6只.采用4-VO法建立SD大鼠全脑缺血模型,在预定时间点行灌注、固定、取脑、石蜡包埋切片,免疫组化检测磷酸化JNK(phosphorylate JNK,p-JNK)和磷酸化P38(phosphorylate P38,p-P38)的表达变化,光镜下计数CA1区存活细胞,TUNEL法检测CA1区凋亡细胞.结果 与SH组比较,I/R组海马CA1区各时点p-JNK和p-P38表达明显增加(P<0.01),于再灌注2 h时即明显升高[灰度值分别为(163.5±3.8)和(163.0±1.9)],24 h到高峰[灰度值分别为(132.3±4.9)和(141.0±5.7)].TH组p-JNK和p-P38的表达则无明显增高,各时点与I/R组比较差异均有统计学意义(P<0.05).海马CA1区神经元存活数目TH组明显高于I/R组(P<0.01),凋亡细胞数显著低于I/R组(P<0.01).结论 在大鼠全脑I/R损伤过程中,茶氨酸通过抑制JNK和P38信号通路的激活可对脑I/R损伤导致的细胞损伤起到保护作用,对临床脑缺血的治疗有一定的指导意义.     

乳化异氟醚预处理对大鼠局灶性脑缺血再灌注时脑组织突触后致密物质95活化的影响

目的 探讨乳化异氟醚预处理对大鼠局灶性脑缺血再灌注时脑组织突触后致密物质95(PSD95)活化的影响.方法 雄性清洁级SD大鼠32只,体重280 ～ 300 g,采用随机数字表法,将大鼠随机分为4组(n=8):假手术组(S组)、缺血再灌注组(I/R组)、乳化异氟醚组(EI组)和脂肪乳剂组(LE组).采用大脑中动脉阻塞法制备局灶性脑缺血再灌注模型.EI组和LE组分别腹腔注射8％乳化异氟醚10.5 ml/mg或30％脂肪乳10.5 ml/mg,24h后制备模型.再灌注6h时行神经功能缺陷评分,随机取4只大鼠,处死后取缺血侧海马和皮层组织,采用Western blot法检测磷酸化的PSD95( pPSD95)的表达水平.再灌注24 h时,随机取4只大鼠,处死后取脑组织,计算脑梗死体积百分比.结果 S组未见神经功能缺陷和脑梗死发生.与S组比较,I/R组、EI组和LE组神经功能缺陷评分、脑梗死体积百分比、海马和皮质pPSD95表达水平升高(P＜0.01);与I/R组比较,EI组神经功能缺陷评分、脑梗死体积百分比、海马和皮质pPSD95表达水平降低(P＜0.05),LE组差异无统计学意义(P＞0.05).结论乳化异氟醚可通过抑制脑组织PSD95的活化,减轻大鼠局灶性脑缺血再灌注损伤.     

姜黄素对自发性高血压大鼠脑缺血再灌注时海马神经元凋亡及c-Jun氨基末端激酶3和突触后密度蛋白95表达的影响

目的 探讨姜黄素对自发性高血压(SH)大鼠脑缺血再灌注时海马神经元凋亡及c-Jun 氨基末端激酶3(JNK3)和突触后密度蛋白95(PSD95)表达的影响.方法 与雄性WKY同源的SH大鼠135只和雄性WKY大鼠90只,清洁级,体重275～325 g,采用随机数字表法,将WKY大鼠随机分为2组(n=45):假手术组(W-S组)及脑缺血再灌注组(W-I/R组),将SH大鼠随机分为3组(n=45):假手术组(S-S组)和脑缺血再灌注组(S-I/R组)及姜黄素组(S-C组).采用四血管阻断法制备全脑缺血再灌注模型.W-S组和S-S组仅分离双侧颈总动脉,W-I/R组和S-I/R组于再灌注30 min时腹腔注射玉米油10 ml/kg,S-C组于再灌注30 min时腹腔注射姜黄素100 mg/kg.于再灌注2 h,6 h、1 d、3 d和7d时进行海马凋亡神经元计数,并测定海马JNK3和PSD95蛋白的表达水平.结果 与W-S组比较,S-S组海马凋亡神经元计数增加(P<0.05),JNK3蛋白表达差异无统计学意义(P>0.05);与S-S组比较,S-I/R组海马凋亡神经元计数增加,JNK3蛋白表达上调(P<0.05);与S-I/R组比较,S-C组海马凋亡神经元计数减少,JNK3蛋白表达下调(P<0.05).各组海马PSD95蛋白表达比较差异无统计学意义(P>0.05).结论 姜黄素可抑制SH大鼠脑缺血再灌注时神经元凋亡,其机制与下调海马JNK3蛋白表达有关,姜黄素下调海马JNK3蛋白表达可能与PSD95途径无关.     

姜黄素对自发性高血压大鼠脑缺血再灌注时海马神经元凋亡及c-Jun氨基末端激酶3和突触后密度蛋白95表达的影响

目的 探讨姜黄素对自发性高血压(SH)大鼠脑缺血再灌注时海马神经元凋亡及c-Jun 氨基末端激酶3(JNK3)和突触后密度蛋白95(PSD95)表达的影响.方法 与雄性WKY同源的SH大鼠135只和雄性WKY大鼠90只,清洁级,体重275～325 g,采用随机数字表法,将WKY大鼠随机分为2组(n=45):假手术组(W-S组)及脑缺血再灌注组(W-I/R组),将SH大鼠随机分为3组(n=45):假手术组(S-S组)和脑缺血再灌注组(S-I/R组)及姜黄素组(S-C组).采用四血管阻断法制备全脑缺血再灌注模型.W-S组和S-S组仅分离双侧颈总动脉,W-I/R组和S-I/R组于再灌注30 min时腹腔注射玉米油10 ml/kg,S-C组于再灌注30 min时腹腔注射姜黄素100 mg/kg.于再灌注2 h,6 h、1 d、3 d和7d时进行海马凋亡神经元计数,并测定海马JNK3和PSD95蛋白的表达水平.结果 与W-S组比较,S-S组海马凋亡神经元计数增加(P<0.05),JNK3蛋白表达差异无统计学意义(P>0.05);与S-S组比较,S-I/R组海马凋亡神经元计数增加,JNK3蛋白表达上调(P<0.05);与S-I/R组比较,S-C组海马凋亡神经元计数减少,JNK3蛋白表达下调(P<0.05).各组海马PSD95蛋白表达比较差异无统计学意义(P>0.05).结论 姜黄素可抑制SH大鼠脑缺血再灌注时神经元凋亡,其机制与下调海马JNK3蛋白表达有关,姜黄素下调海马JNK3蛋白表达可能与PSD95途径无关.

Abstract：

Objective To investigate the effect of curcumin on apoptosis in hippocampal neurons and the expression of c-Jun N-terminal kinase 3 (JNK3) and postsynaptic density protein 95 (PSD95) in hippocampus during cerebral ischemia-reperfusion (I/R) in rats with spontaneous hypertension (SH) .Methods One hundred and thirty-five male rats (homologous with WKY) with SH and 90 male normotensive WKY rats, weighing 275-325 g,were used in this study. The WKY rats were randomized into 2 groups ( n = 45 each) : sham operation group (WS group) and cerebral I/R group (W-I/R group) . The rats with SH were randomly divided into 3 groups ( n = 45each) : sham operation group (S-S group), cerebral I/R group (S-I/R group) and curcumin group (S-C group) .Global cerebral ischemia was produced by 4 vessel-occlusion method. The bilateral common carotid arteries were only exposed but not ligated in W-S and S-S groups. Intraperitoneal corn oil 10 ml/kg was injected at 30 min of reperfusion in W-I/R and S-I/R groups. Intraperitoneal curcumin 100 mg/kg was injected at 30 min of reperfusion in S-C group. Three animals in each group were sacrificed at 2 h, 6 h, 1 d, 3 d and 7 d of reperfusion and their brains were harvested for determination of apoptosis in hippocampal neurons and the expression of JNK3 and PSD95in hippocampus. Results The number of apoptotic neurons was significantly increased in S-S group compared with W-S group ( P < 0.05) . The number of apoptotic neurons was significantly increased and the expression of JNK3was up-regulated in S-I/R group compared with S-S group ( P < 0.05) . The number of apoptotic neurons was significantly decreased and the expression of JNK3 was down-regulated in S-C group compared with S-I/R group (P <0.05) . There was no significant difference in the expression of PSD95 among all the groups ( P > 0.05) . Conclusion Curcumin can inhibit apoptosis in hippocampal neurons and the mechanism is related to down-regulation of the expression of JNK3 in hippocampus. The mechanism by which curcumin down-regulates the expression of JNK3in hippocampus may not be related to PSD95 pathway.     

姜黄素对自发性高血压大鼠脑缺血再灌注时海马神经元凋亡及c-Jun氨基末端激酶3和突触后密度蛋白95表达的影响

目的 探讨姜黄素对自发性高血压(SH)大鼠脑缺血再灌注时海马神经元凋亡及c-Jun 氨基末端激酶3(JNK3)和突触后密度蛋白95(PSD95)表达的影响.方法 与雄性WKY同源的SH大鼠135只和雄性WKY大鼠90只,清洁级,体重275～325 g,采用随机数字表法,将WKY大鼠随机分为2组(n=45):假手术组(W-S组)及脑缺血再灌注组(W-I/R组),将SH大鼠随机分为3组(n=45):假手术组(S-S组)和脑缺血再灌注组(S-I/R组)及姜黄素组(S-C组).采用四血管阻断法制备全脑缺血再灌注模型.W-S组和S-S组仅分离双侧颈总动脉,W-I/R组和S-I/R组于再灌注30 min时腹腔注射玉米油10 ml/kg,S-C组于再灌注30 min时腹腔注射姜黄素100 mg/kg.于再灌注2 h,6 h、1 d、3 d和7d时进行海马凋亡神经元计数,并测定海马JNK3和PSD95蛋白的表达水平.结果 与W-S组比较,S-S组海马凋亡神经元计数增加(P<0.05),JNK3蛋白表达差异无统计学意义(P>0.05);与S-S组比较,S-I/R组海马凋亡神经元计数增加,JNK3蛋白表达上调(P<0.05);与S-I/R组比较,S-C组海马凋亡神经元计数减少,JNK3蛋白表达下调(P<0.05).各组海马PSD95蛋白表达比较差异无统计学意义(P>0.05).结论 姜黄素可抑制SH大鼠脑缺血再灌注时神经元凋亡,其机制与下调海马JNK3蛋白表达有关,姜黄素下调海马JNK3蛋白表达可能与PSD95途径无关.     

瑞芬太尼后处理对脑缺血再灌注大鼠海马神经元凋亡的影响

目的 探讨瑞芬太尼后处理对脑缺血再灌注大鼠海马神经元凋亡的影响.方法 健康成年雄性SD大鼠24只,体重250～300 g,随机分为4组(n=6):假手术组(S组)、缺血再灌注组(IR组)、瑞芬太尼0.6μg·kg-1·min-1组(R1组)和瑞芬太尼1.8μg·kg-1·min-1组(R2组).采用夹闭双侧颈总动脉联合低血压法制备大鼠全脑缺血再灌注模型.R1组和R2组分别于再灌注前5 min泵注瑞芬太尼0.6、1.8μg·kg-1·min-1,注射时间5 min.于再灌注第3天采用Morris水迷宫实验及跳台实验测定大鼠认知功能.水迷宫实验结束后,处死大鼠取脑分离海马,采用免疫组化法检测海马CA1区caspase-3蛋白的表达,TUNEL法检测神经元凋亡情况.结果 与S组相比,IR组、R1组和R2组大鼠认知功能减退,海马CA1区神经元凋亡数目升高,IR组caspase-3表达上调(P＜0.05);与IR组相比,R1组和R2组大鼠认知功能提高,海马CA1区caspase-3表达水平和凋亡神经元数目降低(P＜0.05).结论 瑞芬太尼后处理可通过下调caspase-3表达,抑制海马神经元凋亡,从而改善脑缺血再灌注大鼠的认知功能.     

Isoflurane protects renal function against ischemia and reperfusion through inhibition of protein kinases, JNK and ERK

Isoflurane has a pharmacological preconditioning effect against ischemia in the heart and brain, but whether this also occurs in the kidney is unclear. In this study, we investigated pharmacological preconditioning by isoflurane in the rat kidney. In the isoflurane preconditioning group (1.5% isoflurane for 20 min before renal ischemia) serum creatinine (1.2 +/- 0.7 and 1.1 +/- 0.2 mg/dL) and blood urea nitrogen (99 +/- 29 and 187 +/- 31 mg/dL) were significantly smaller at 24 and 48 h after reperfusion than in the nonpreconditioning group (creatinine; 2.4 +/- 1.2 and 2.9 +/- 0.9 mg/dL, urea; 62 +/- 19 and 79 +/- 20 mg/dL). We also investigated the intracellular signal transduction involved in isoflurane preconditioning in the kidney. The activities of the stress protein kinases, JNK and ERK but not p38, were significantly less in the kidneys of the preconditioning group than in those of the nonpreconditioning group (P < 0.05). We conclude that isoflurane has a preconditioning effect against renal ischemia/reperfusion injury when administered before ischemia. Inhibition of the protein kinases, JNK and ERK, might be involved in the mechanisms of isoflurane preconditioning.     

gamma-Aminobutyric acid-A receptors contribute to isoflurane neuroprotection in organotypic hippocampal cultures

The mechanisms by which anesthetics such as isoflurane reduce cell death in rodent models of cerebral ischemia remain incompletely defined. Reduction in glutamate excitotoxicity explains some but not all of isoflurane's neuroprotection. Because isoflurane potentiates gamma-aminobutyric acid (GABA) receptor-mediated ion fluxes and GABA(A) receptor agonists have neuroprotective effects, we hypothesized that GABA(A) receptors contribute to isoflurane neuroprotection. As a model of cerebral ischemia and recovery, we used rat hippocampal slice cultures. Survival of CA1, CA3, and dentate neurons was examined 2 and 3 days after 1-h combined oxygen-glucose deprivation (OGD) at 37 degrees C. To define the role of GABA(A) receptors in mediating protection, the effect of 1% isoflurane on cell survival was examined in the presence of the GABA(A) antagonist bicuculline during OGD. Cell death was measured with propidium iodide fluorescence. Isoflurane and the selective GABA(A) agonist muscimol (25 micro M) reduced cell death after OGD to values similar to slices not exposed to OGD, with the exception that muscimol did not reduce cell death in CA3 neurons 2 days after OGD. The GABA(A) antagonist bicuculline reduced the neuroprotective effects of isoflurane on hippocampal neurons 2 and 3 days after OGD. We conclude that GABA(A) receptors contribute to neuroprotection against OGD produced by isoflurane in the hippocampal slice model. Based on this and other studies, it is likely that neuroprotection produced by isoflurane is multifactorial and includes actions at both GABA(A) and glutamate receptors and possibly other mechanisms. IMPLICATIONS: Isoflurane is neuroprotective in rodent brain ischemia models, but the mechanisms for this effect remain incompletely defined. In organotypic cultures of rat hippocampus, we show that protection of CA1, CA3, and dentate neurons by 1% isoflurane from death caused by oxygen and glucose deprivation involves GABA(A) receptors.     

乳化异氟烷预处理对大鼠局灶性脑缺血再灌注损伤的影响

目的 评价8%乳化异氟烷预处理对大鼠局灶性脑缺血再灌注损伤的影响.方法 健康雄性成年SD大鼠56只,体重250～280 g,随机分为4组(n=14),假手术组(S组)仅分离血管,不留置线栓;脑缺血再灌注组(IR组)、乳化异氟烷预处理组(EIP组)和脂肪乳剂组预处理(FIP组)分别腹腔注射生理盐水、8%乳化异氟烷或30%脂肪乳剂7.5 ml/kg,24 h后制备局灶性脑缺血再灌注模型.于再灌注24 h各组取8只大鼠,进行神经功能缺陷评分,然后处死大鼠,取脑组织,测定脑梗死体积;各组处死6只大鼠,取脑组织,检测细胞凋亡情况,计算细胞凋亡率,并测定Bcl-2、Bax、caspase-3和Cyt C的蛋白表达水平.结果 与S组比较,IR组、EIP组和FIP组神经功能缺陷评分和细胞凋亡率升高,脑组织Bcl-2、Bax、caspase-3和Cyt C的蛋白表达上调(P＜0.01);与IR组和FIP组比较,EIP组神经功能缺陷评分和细胞凋亡率降低,脑梗死体积减小,脑组织Bcl-2蛋白表达上调,Bax、caspase-3和Cyt C 的蛋白表达下调(P＜0.05);IR组和FIP组各指标比较差异无统计学意义(P＞0.05).结论 8%乳化异氟烷预处理可减轻大鼠脑缺血再灌注损伤,其机制可能与上调Bcl-2蛋白表达,下调Bax蛋白表达,减少线粒体释放Cyt C,降低caspase-3活化,抑制神经元凋亡有关.