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。     

AKT信号通路通过亚低温对大鼠局脑缺血再灌注损伤神经元的保护作用

目的 通过检测AKT及Bcl-2蛋白的表达,探讨亚低温对局脑缺血再灌注后神经元存活的影响.方法 用线拴法制作大鼠大脑中动脉闭塞(MCAO)局脑缺血再灌注模型,将36只SD大鼠随机分成假手术组、常温缺血再灌注组和亚低温缺血再灌注组,缺血组分别缺血6h再灌注4h、24h、72h、1w(n=4)后处死,亚低温组于缺血后13~14min实施病灶侧亚低温持续4h.免疫组织化学法检测AKT、Bcl-2蛋白的表达,电镜检测自噬小体.结果 不同缺血时间再灌注4h,亚低温组比常温组缺血侧半暗带AKT表达水平显著增高(P<0.05),Bcl-2表达明显降低(P<0.01);亚低温组自噬小体明显减少.结论 病灶侧亚低温通过促进缺血半暗带脑组织AKT表达,抑制Bcl-2表达,从而抑制神经元凋亡,抑制自噬的产生,从而对神经元起保护作用,促进脑缺血后神经功能恢复.     

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。     

亚低温对沙土鼠海马CA1区缺血后细胞凋亡的影响

目的 探讨亚低温对沙土鼠短暂性脑缺血后海马CA1区细胞凋亡的影响。方法 阻断沙土鼠双侧颈总动脉15分钟造成前脑缺血模型。实验动物随机分为假手术组、缺血再灌注组、亚低温治疗组。用光镜观察海马CA1区的神经元死亡过程．采用原位末端标记(TUNEL)法检测凋亡的神经元。结果 脑缺血后．海马CA1区锥体神经元于再灌注后2～7天死亡,再灌注第3天神经元开始凋亡．第5天达高峰。亚低温治疗抑制了缺血后海马CA1区神经元的死亡及细胞凋亡。结论 亚低温治疗对脑缺血后的神经元具有保护作用．并可抑制神经细胞凋亡的发生。     

二氮嗪预处理对幼龄大鼠深低温脑缺血/再灌注损伤的影响

目的 探讨二氮嗪预处理对幼龄大鼠深低温脑缺血/再灌注损伤脑保护作用.方法 将3周龄SD大鼠90只随机分为假手术组、模型组及二氮嗪组,缺血/再灌注后1、6、24、72 h和7 d,建立深低温脑缺血/再灌注模型,采用免疫组织化学检测不同时点脑组织细胞色素C的蛋白表达,并观察脑组织病理变化.结果 与假手术组比较,模型组于再灌注后6和24 h显示明显的病理变化,其脑组织胞浆细胞色素C于灌注后6 h后即明显升高(P＜0.05),24 h达到高峰(P＜0.01).二氮嗪组病理改变较轻,细胞色素C含量于再灌注后24和72 h显著低于模型组(P＜0.05). 结论 二氮嗪预处理可抑制线粒体细胞色素C的释放,对幼龄大鼠深低温脑缺血/再灌注损伤具有一定脑保护作用.     

局部亚低温对大鼠全脑缺血再灌注后血清S100B蛋白的影响

目的探讨局部亚低温对大鼠全脑缺血再灌注后血清S100B蛋白的影响。方法 24只SD雄性大鼠随机分为3组：假手术组（S组）、缺血再灌注组（IR组）、亚低温组（H组）,每组8只。采用双侧颈总动脉夹闭＋基底动脉丝线提拉法制备全脑缺血再灌注损伤模型,全脑缺血10min再灌注6h。实验过程中监测大鼠脑血流图并测定动脉血气。H组再灌注前即刻经股静脉缓慢注射10℃0.9%氯化钠溶液3.5ml,冰块包绕头部,60W白炽灯照射身体。控制鼓膜温度在32～34℃,直肠温度同时降低,20min左右升至并维持在37.5～38.3℃。低温维持3h,3h后60W白炽灯照射身体缓慢复温。实验结束后测定大鼠血清S100B蛋白浓度;用干（110℃24h烘干）、湿重法计算左侧大脑半球脑水含量。结果与S组比较,IR组S100B蛋白浓度、脑含水量升高（P〈0.05）;与IR组比较,H组S100B蛋白浓度、脑含水量降低（P〈0.05）。结论局部亚低温降低大鼠全脑缺血再灌注后血清S100B蛋白的表达量,对全脑缺血再灌注损伤大鼠有保护作用。     

不同脑温对缺血脑组织细胞坏死和凋亡的影响

目的研究脑缺血后不同脑温对细胞坏死和凋亡的影响,探讨亚低温脑保护作用的机制。方法 36只雄性远交系(sprague dawley,SD)大鼠,随机分为脑缺血常温(37～38℃)、亚低温(31～32℃)、高温(41～42℃)和对照组,每组9只。脑缺血动物模型采用改良四动脉阻断法,制作大鼠全脑缺血再灌注模型(Pulsinelli法)。凋亡细胞的检测采用原位末端脱氧核糖核酸酶介导的地高辛标记的脱氧三磷酸腺苷(dUTP)缺口末端标记(TUNEL)法。结果常温脑缺血再灌注海马CA1区神经细胞变性坏死,锥体细胞密度下降;亚低温组较常温组脑缺血CA1区锥体细胞密度明显增加(P<0.01);脑缺血后高温组则使锥体细胞密度进一步下降(P<0.01)。常温脑缺血再灌注后48～72h,大脑皮质和海马可见到凋亡细胞,亚低温组CA1区锥体细胞凋亡的密度明显减少,高温则使锥体细胞凋亡密度增加。结论脑缺血后即时开始亚低温可减少神经细胞的坏死和凋亡,是亚低温脑保护作用的机制之一;脑缺血后高温则加剧脑缺血损伤。     

咪唑酮类化合物ZLJ-6对大鼠脑缺血再灌注损伤的保护作用及其机制研究

目的:考察化合物ZLJ-6对大鼠局灶性脑缺血再灌注损伤的保护作用,并探讨其可能的作用机制.方法:将50只健康雄性大鼠,随机分为假手术组、缺血-再灌注模型组、阿司匹林(10 nag·kg-1)阳性对照组、ZLI-6(20 mg·kg-1)高剂量组和ZLJ-6(10 mg·kg-1)低剂量组.以线栓法制作大鼠大脑中动脉缺血再灌注模型.造模后24小时,进行神经功能评分,并断头取脑制备组织匀浆,测定丙二醛和谷氨酸的含量以及超氧化物歧化酶、髓过氧化物酶、一氧化氮合酶和诱导型一氧化氮合酶的活性.结果:与模型组比较,阳性对照组和ZLJ-6高剂量组大鼠的神经功能评分均明显改善(P<0.05),ZLJ-6高、低剂量组大鼠脑中髓过氧化物酶活性均显著降低(P<0.01),ZLJ-6高剂量组大鼠脑中一氧化氮合酶活性降低(P<0.05),ZLJ-6低剂量组大鼠脑中诱导型一氧化氮合酶活性和丙二醛含量显著降低(P<0.01和JP<0.05);ZLJ-6对大鼠脑中超氧化物歧化酶活性和谷氨酸含量无明显影响.结论:化合物ZLJ-6对大鼠脑缺血再灌注损伤具有一定的保护作用,其作用机制可能与抑制缺血再灌注时中性粒细胞向脑组织浸润和抑制一氧化氮合酶活性有关.     

茅莓总皂苷对局灶性脑缺血再灌注大鼠兴奋性氨基酸含量的影响

目的:研究茅莓总皂苷对局灶性脑缺血再灌注大鼠兴奋性氨基酸(EAA)含量的影响。方法:将大鼠随机分为茅莓总皂苷5,10,20mg.kg-1组及尼莫地平10mg.kg-1组、模型组和假手术组。灌胃给药3d,采用线栓法制备大鼠大脑中动脉缺血再灌注模型,相应时间断头取脑。采用高效液相法测定大鼠脑组织中天冬氨酸(Asp)、谷氨酸(Glu)的含量。结果:缺血对照组天冬氨酸、谷氨酸含量明显高于治疗组。结论:茅莓总皂苷对脑缺血再灌注损伤有保护作用。其可能的机制为:干扰脑缺血再灌注损伤中EAA代谢而发挥脑保护作用。     

亚低温对颅内巨大动脉瘤夹闭术瞬间阻断及缺血再灌注期的脑保护作用

目的：研究亚低温对颅内巨大动脉瘤夹闭术瞬间阻断其供血动脉时缺血再灌注期的脑保护作用。方法：对颅内巨大动脉瘤行夹闭术27例，13例于动脉瘤夹闭瞬间阻断及缺血再灌注期行亚低温处理。直肠温度（RT）控制在31．0℃～36．0℃，脑组织温度（BT）为32．0℃～35．0℃。同时，监测患者的生命体征、BT和失血量。常温组14例，RT控制在36．0℃～37．2℃。2组患者均于术后3个月时根据GOS评估法判定疗效。结果：术中2组生命体征差异无统计学意义。亚低温组与常温组相比．手术完成比较顺利，无严重并发症，病死率较低，运动神经功能良好率较高，预后显著改善。结论：亚低温可明显降低颅内巨大动脉瘤夹闭术患者的病死率，提高患者生命质量，对脑缺血及再灌注性损伤具有良好的脑保护作用。     

丹参酮对脊髓缺血再灌注损伤大鼠模型脊髓、血清谷氨酸含量的影响

目的观察丹参酮对脊髓缺血再灌注大鼠脊髓、血清谷氨酸水平探讨丹参酮保护脊髓的作用机制。方法选用SD大鼠88只,采用结扎腹主动脉的方法制作脊髓缺血再灌注模型。按随机数字表法将动物分为假手术组（n=8）、模型组（n=40）和丹参酮组（n=40）。A组在全麻下充分暴露脊髓,B组及C组采用Zivin法改进方法复制模型,随机在脊髓缺血再灌注30min、1h、4h、8h、12h的相应时间点切取脊髓,抽取下腔静脉血,检测缺血再灌注后脊髓谷氨酸、血清谷氨酸含量及对缺血再灌注4h、8h、12h,采用改良Tarlov评分标准进行神经功能评分。结果丹参酮组及模型组大鼠脊髓、血清谷氨酸含量均于脊髓缺血再灌注损伤后30min开始上升,缺血再灌注损伤4h后含量达到高峰,其后含量逐渐下降,12h后基本恢复正常。丹参酮组各观测点脊髓、血清谷氨酸含量均低于模型组。结论丹参酮能降低脊髓缺血再灌注大鼠脊髓谷氨酸含量,对大鼠脊髓缺血再灌注损伤具有保护作用。     

L-arginine protects from pringle manoeuvere of ischemia-reperfusion induced liver injury

Pringle described a new technique to reduce blood loss during liver surgery. Adult Wistar rats were subjected to 1 h of partial liver ischemia and followed by 3 h reperfusion. Eighteen Wistar rats were divided into sham-operated control group (I) (n=6), ischemia and reperfusion (I/R) group (II) (n=6), L-arginine treated group (100 mg/kg body weight/daily by oral route for 7 d before induced ischemia reperfusion maneuver) (III) (n=6). Ischemic and reperfusion hepatocellular injury occurred as indicated by increased-alanine transaminase (ALT), aspartate transaminase (AST). Pre-treatment with L-arginine significantly decreased serum-ALT, AST after 1 h ischemia followed by 3 h of reperfusion. Nitric oxide production, in hepatocytes was increased 2 fold and MDA levels significantly decreased by L-arginine treatment as compared to I/R rat. Histopathology and TEM studies showed markedly diminished hepatocellular injury in L-arginine pretreated rats during the hepatic I/R, which reached a level comparable to saline-treated rat of sham operated group. Thus, findings it may be concluded that L-arginine afforded significant protection from hepatobiliary function from I/R injury by nitric oxide production.     

天麻糖复合物对大鼠缺血/再灌注模型视网膜的影响

目的观察天麻糖复合物(polysaccharides from Gastro-d ia elata B lum e,GEP)对大鼠视网膜缺血/再灌注(retinal is-chem ia reperfusion,R IR)后视网膜超氧化物歧化酶(superox-ide d ismutase,SOD)、丙二醛(m alond ialdehyde,MDA)、一氧化氮(n itric oxide,NO)含量及视网膜形态的影响。方法采用前房灌注液体形成16 kPa高眼压而建立R IR模型。SD大鼠随机分为:GEP小剂量组、中剂量组、大剂量组、维生素E组、阴性对照组,缺血60 m in后恢复血流,分别于再灌注60 m in,24 h和72 h检测视网膜组织中MDA(比色法),SOD(比色法)、NO(硝酸还原酶法)含量及视网膜光学显微镜的组织学观察。结果GEP干预后,再灌注60 m in,24 h和72h后中、大剂量干预组视网膜中MDA含量均明显低于阴性对照组(P<0.05);SOD含量均明显高于阴性对照组(P<0.05);NO含量在再灌注24~72 h时间段内明显低于阴性对照组(P<0.05),GEP干预组视网膜组织形态学损害较阴性对照组明显减轻。结论GEP对缺血/再灌注的视网膜具有保护作用。     

Modulation of the oxidative stress and inflammatory response by PPAR-gamma agonists in the hippocampus of rats exposed to cerebral ischemia/reperfusion

Agonists of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) exert protective effects in several models of ischemia/reperfusion injury, but their role in stroke is less clear. The study investigates the effects of two PPAR-gamma agonists, rosiglitazone and pioglitazone, on oxidative stress and inflammatory response induced by ischemia/reperfusion in the rat hippocampus. Common carotid artery occlusion for 30 min followed by 1 h reperfusion resulted in a significant increase in the generation of reactive oxygen species, nitric oxide and the end products of lipid peroxidation as well as markedly reduced endogenous antioxidant glutathione levels and up-regulated superoxide dismutase activity. Western blot analysis showed that ischemia/reperfusion lead to an increase in cyclooxygenase-2 (COX-2) expression, as well activating p38 and p42/44 mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB). Pre-treatment with either rosiglitazone or pioglitazone significantly reduced oxidative stress, COX-2 protein expression and activation of MAPKs and NF-kappaB. Taken together, the results provide convincing evidence that PPAR-gamma agonists exert protective effects in a rat model of mild forebrain ischemia/reperfusion injury by inhibiting oxidative stress and excessive inflammatory response.     

局部亚低温治疗胆红素脑病仔兔中GLU的变化研究

目的:观察局部亚低温对胆红素脑病仔兔血清中GLU(谷氨酸)治疗前后的影响.方法:建立胆红素脑病模型,对治疗组予亚低温治疗,采用高效液相色谱仪测定胆红素脑病仔兔治疗前后血清中GLU含量.结果:胆红素脑病仔兔治疗前亚低温治疗组血清中GLU含量与常温组比较,无显著性差异,(P＞0.05).亚低温治疗48小时后与同时间点常温组比较血清中GLU明显降低,有显著性差异(P＜0.01).结论:贴敷式局部亚低温治疗可降低胆红素脑病仔兔血清中GLU含量,减轻胆红素神经毒性,对脑组织具有保护作用,有可能成为治疗胆红素脑病的一种有效措施.     

Pyrrolidine dithiocarbamate reduces renal dysfunction and injury caused by ischemia/reperfusion of the rat kidney

Dithiocarbamates can modulate the expression of genes associated with inflammation or development of ischemia/reperfusion injury. Here, we investigate the effects of pyrrolidine dithiocarbamate, an inhibitor of nuclear factor (NF)-kappaB activation, on the renal dysfunction and injury caused by ischemia/reperfusion of the rat kidney. Bilateral clamping of renal pedicles (45 min) followed by reperfusion (6 h) caused significant renal dysfunction and marked renal injury. Pyrrolidine dithiocarbamate (100 mg/kg, administered i.v.) significantly reduced biochemical and histological evidence of renal dysfunction and injury caused by ischemia/reperfusion of the rat kidney. Furthermore, pyrrolidine dithiocarbamate markedly reduced the expression of inducible nitric oxide synthase (iNOS) protein and significantly reduced serum levels of nitric oxide. Finally, pyrrolidine dithiocarbamate inhibited the activation of NF-kappaB by preventing its translocation from the cytoplasm into the nuclei of renal cells. These results demonstrate that pyrrolidine dithiocarbamate reduces renal ischemia/reperfusion injury and that dithiocarbamates may provide beneficial actions against ischemic acute renal failure.     

后适应对大鼠脑缺血神经细胞凋亡和内皮型一氧化氮合酶与诱导型一氧化氮合酶的影响

目的：研究缺血耐受（后适应和预适应）对脑缺血再灌注神经细胞凋亡及内皮型一氧化氮合酶（eNOS）和诱导型一氧化氮合酶（iNOS）蛋白表达的影响。方法：50只雄性SD大鼠随机分为假手术组（sham）、脑缺血再灌注模型组（MCAO）、预适应组（MCAO＋preconditioning）、后适应组（MCAO＋postconditioning）和尼莫地平组（MCAO＋nimodipine），每组10只大鼠。预适应组大鼠在MCAO前24h，双侧颈总动脉夹闭2min，再灌注20min，循环两次。后适应组大鼠在脑缺血再灌注开始时，再灌注20s，栓塞20s，循环3次。大鼠大脑中动脉阻断1．5h，再灌注24h。用TUNEL法和免疫组化染色法分别检测缺血半暗带凋亡细胞和iNOS、eNOS蛋白表达。结果：与MCAO组比较，后适应组大鼠脑缺血半暗带的凋亡细胞显著减少，eNOS蛋白表达显著增加，iNOS蛋白表达显著减少，差异有统计学意义（P〈0．05）。结论：缺血后适应能诱导脑缺血耐受，对脑缺血／再灌注损伤产生保护作用，其保护作用与促进eNOS蛋白的表达，抑制iNOS蛋白的表达有关。     

Resveratrol, a polyphenol found in wine, reduces ischemia reperfusion injury in rat kidneys

Reactive oxygen species have been implicated in the pathophysiology of renal ischemia reperfusion injury. Antioxidants including polyphenolics have been found to protect renal cells from the cellular injury induced by ischemia and reperfusion. Resveratrol, a stilbene polyphenol found in grapes and red wine, has recently been found to protect isolated rat heart from ischemia reperfusion injury. This study was sought to determine if resveratrol could also protect renal cells from ischemic injury. Male Wistar rats were treated with control, resveratrol (0.23 microg/kg), vehicle used to solubilize resveratrol, and resveratrol plus L-NAME (15 mg/kg body wt), a nitric oxide blocker. Our results demonstrated that resveratrol administration reduced the mortality of ischemic rats from 50% to 10% and renal damage was reduced as indicated by histologic examination and serum creatinine level. The short-term administration of resveratrol also inhibited renal lipid peroxidation induced by ischemia and reperfusion both in cortex and in medulla. Electron paramagnetic resonance detected an increased formation of nitric oxide in the resveratrol-treated kidney that was reduced to the baseline value after treating the rats with L-NAME in addition to resveratrol. The results suggest that resveratrol reduced the renal ischemia reperfusion injury through a nitric oxide-dependent mechanism.