丙泊酚对大鼠局灶性脑缺血-再灌注低氧诱导因子-1和热休克蛋白70的影响

目的 观察丙泊酚对大鼠局灶性脑缺血-再灌注后低氧诱导因子(HIF-1)和热休克蛋白70(HSP70)的影响,探讨丙泊酚脑保护作用机制.方法 32只雄性sD大鼠,随机均分为四组,采用可逆性大脑中动脉内线栓法建立局灶性脑缺血-再灌注模型,缺血2 h再灌注24 h后断头取脑,采用免疫组化法检测HIF-1和HSP70.HE染色,光镜观察细胞形态学改变.结果 大鼠局灶性脑缺血-再灌注后大脑皮质和海马区出现神经细胞的坏死和凋亡改变,HIF-1和HSP70的表达均增加,给丙泊酚后神经细胞的肿胀、坏死、凋亡明显减少,HIF-1和HSP70蛋白的表达受到明显抑制.结论 丙泊酚对大鼠局灶性脑缺血-再灌注损伤的保护机制与减少HIFll、HSP70的表达有关.     

星状神经节阻滞对全脑缺血再灌注损伤家兔海马及颞叶皮质热休克蛋白70表达的影响

目的 观察星状神经节阻滞(SGB)对全脑缺血再灌注损伤家兔海马及颞叶皮质热休克蛋白70(HSP70)表达的影响,探讨SGB对全脑缺血再灌注损伤的处理效应及可能机制。方法 健康日本大耳白兔28只,随机分成四组(n=7):SGB组(E组)、生理盐水对照组(P组)、空白对照组(C组)和假手术组(S组)。采用星状神经节旁置管法制作SGB模型及六血管阻断法制作全脑缺血再灌注损伤模型。缺血10 min再灌注30 h(E、P、C组)或观察相应时间(S组)后取脑组织,使用免疫组化技术检测双侧海马CAl区及颞叶皮质HSP70的表达。结果 与P、C组比较,E组双侧海马和颞叶皮质HSP70的表达均有不同程度下降(P<0.05),且双侧之间改变无明显差异(P>0.05)。结论持续左侧SGB,可降低全脑缺血再灌注损伤家兔神经细胞HSP70的过度表达,单侧SGB的效应对于双侧脑组织损伤后的影响差异无显著性。     

全脑缺血-再灌注鼠STAT3基因的表达

目的 研究鼠海马组织中信号转导与转录激活子-3(STAT3)mRNA在短暂性全脑缺血-再灌注过程中的表达变化.方法 将健康雄性SD大鼠25只,随机均分为全脑缺血-再灌注4、24、48、72 h组和假手术组.以"双侧颈总动脉阻断加全身低血压法"建立大鼠短暂性全脑缺血模型,采用实时荧光定量PCR技术观察大鼠缺血性脑损伤海马组织中STAT3 mRNA的变化.结果 短暂性全脑缺血后海马组织STAT3 mRNA的表达增强,再灌注24 h达高峰.结论 短暂性全脑缺血-再灌注后STAT3 mRNA的活化及超量表达可能介导了缺血神经细胞信号传导过程,并参与了脑神经细胞损伤的病理生理过程.     

丙泊酚对大鼠局灶性脑缺血-再灌注时脑组织热休克蛋白70基因和蛋白表达的影响

目的观察丙泊酚对大鼠局灶性脑缺血-再灌注时脑组织热休克蛋白(HSP)70 mRNA和HSP70蛋白表达的影响,以探讨其脑保护的机制。方法采用大脑中动脉线栓法建立大鼠局灶性脑缺血-再灌注模型。60只雄性Wistar大鼠,随机分为假手术组(Sham组)、缺血-再灌注组(I-R组)和丙泊酚组(P组),每组20只。大鼠脑缺血2 h,然后进行再灌注。在再灌注3、6、24、72 h断头取脑组织,采用原位杂交法和免疫组织化学染色检测大鼠脑组织HSP70 mRNA和HSP70蛋白的表达。结果局灶性脑缺血-再灌注后,HSP70 mRNA和HSP70蛋白的表达增加(P<0.01),但HSP70 mRNA表达较早,分布范围较广泛,而HSP70蛋白表达以半暗带区为主。应用丙泊酚能显著地促进脑缺血-再灌注后脑组织中HSP70 mRNA和HSP70蛋白的表达(P<0.01),与脑缺血-再灌注组相比较,HSP70 mRNA和HSP70蛋白不仅表达增多、范围增加,而且还能延缓下降(P<0.05)。结论丙泊酚能促进大鼠局灶性脑缺血-再灌注时HSP70的表达,这可能是其脑保护作用的部分机制。     

氯胺酮对全脑缺血大鼠的脑保护作用

目的探讨氯胺酮对全脑缺血大鼠的脑保护作用。方法健康成年SD大鼠30只,随机均分为缺血加氯胺酮组(A组)、缺血组(B组)、假手术组(C组)。以Pulsinelli-Brierley方法为标准建立四动脉阻断法全脑缺血模型,A、B组行全脑缺血15min后再灌注,其中A组于全脑缺血5min时腹腔给氯胺酮100mg/kg,B组相同时间腹腔内注射同体积生理盐水,C组分离椎动脉及颈总动脉后不行全脑缺血。再灌注3d后经心脏灌注固定后取脑制作石蜡切片,分别行HE染色观察海马CA1区神经元存活数目和TUNEL法检测海马CA1区神经元凋亡。结果C组大鼠海马CA1区神经元大部分存活,少量神经元凋亡;B组神经元很少存活,大量凋亡,细胞计数明显少于C组(P<0.01);A组神经元存活数目明显少于C组,但多于B组(P<0.01),凋亡数目明显多于C组,但少于B组(P<0.01)。结论氯胺酮对脑缺血大鼠具有一定的脑保护作用。     

丙泊酚对脑缺血-再灌注后海马组织热休克蛋白70和c-fos基因表达的影响

目的观察丙泊酚对脑缺血一再灌注后海马组织热休克蛋白70(HSP70)与c-fos基因表达的影响。方法雄性Wistar大鼠40只,随机分为假手术组、缺血一再灌注对照组和缺血一再灌注丙泊酚处理组,后者按丙泊酚用量又分为50、100和150mg／kg三个亚组。采用大鼠全脑缺血一再灌注损伤模型。全脑缺血10min再灌注60min时,断头取脑,采用免疫组织化学和半定量RT-PCR方法,对脑内HSP70与c-fos蛋白及其mRNA在海马组织的表达水平进行检测。结果缺血一再灌注后皮层、海马、纹状体及边缘区等脑区均有大量的HSP70和c-fos阳性蛋白表达,海马组织HSP70及c-fos基因mRNA的表达水平明显增高,其中以缺血一再灌注对照组表达最为显著;假手术组仅有少量阳性蛋白的表达,海马组织mRNA的表达水平极低;麻醉相关剂量的丙泊酚可显著抑制HSP70与c-fos蛋白在各脑区的表达,尤以海马CA1区最为显著,亦可明显下调HSP70和c-fos mRNA在海马组织的表达水平。结论缺血一再灌注损伤可明显诱导HSP70与c-fos基因的表达,丙泊酚的脑保护作用可能与其下调HSP70与c-fos基因的异常表达有关。     

p38丝裂原活化蛋白激酶在全脑缺血再灌注损伤大鼠海马神经元DNA修复中的作用

目的 探讨p38丝裂原活化蛋白激酶(p38 MAPK)在全脑缺血再灌注损伤大鼠海马神经元DNA修复中的作用.方法 清洁级雄性SD大鼠108只,采用四血管阻断法建立大鼠全脑缺血再灌注模型,随机分为3组(n=36):假手术组(S组)仅暴露双侧颈总动脉和椎动脉;缺血再灌注组(IR组)侧脑室注射1%DMSO溶液5μl,30 min后行全脑缺血再灌注;p38 MAPK抑制剂SB203580干预组(SB组)侧脑室注射SB203580溶液5 μl(溶于1%DMSO溶液),30 min后行全脑缺血再灌注.分别于再灌注2、6、12、24、48和72 h时各组处死6只大鼠,提取海马组织观察神经元病理学结果,计算神经元凋亡指数(AI),测定磷酸化的p38 MAPK蛋白及Ku70蛋白表达水平.结果 与S组比较,IR组和SB组各时点AI升高,p-p38 MAPK蛋白表达上调,p-Ku70蛋白表达下调(P(0.05或0.01),病理损伤明显;与IR组比较,SB组各时点AI降低,p-p38 MAPK蛋白表达下调,p-Ku70蛋白表达上调(P<0.01),病理损伤程度减轻.结论 p38 MAPK可能通过下调DNA修复酶Ku70蛋白的表达,使海马神经元DNA修复功能受损,导致神经元凋亡,参与全脑缺血再灌注损伤.     

鼻咽腔降温对大鼠全脑缺血-再灌注损伤的保护作用

目的 探讨鼻咽腔降温对大鼠全脑缺血-再灌注损伤的保护作用.方法 健康雄性Wistar大鼠18只,随机均分为三组:全身降温组(A组)、鼻咽腔降温组(B组)、常温组(C组).采用Pulsinelli四血管阻断法建立大鼠伞脑缺血-再灌注损伤模璎.A、B组海马温度降至靶温度33℃.阻断双侧颈总动脉20 min再灌注,低温维持1 h后复温.C组保持大鼠直肠和海马温度均为(37±0.5)℃,阻断双侧颈总动脉20 min再灌注.利用微透析技术收集大鼠海马CA1区微透析液并测其谷氨酸(Glu)含量.再灌注8 h后断头取脑,用免疫组化法观察海马CA1区Bcl-2和Bax的表达.结果 A组海马温度从37℃降到33℃所需时间为B组的4.8倍;缺血10、20 min、再灌注后10、20、30 min时A、B组Glu含量明显低于C组(P＜0.05);A、B、C组海马CA1区Glu含量恢复至缺血前水平所需时间分别为(19.92±1.30)、(20.17±1.34)、(39.67±1.49)min.与C组比较,A、B组的Bax免疫阳性细胞数显著减少(P±0.05);A、B组的Bcl-2免疫阳性细胞数显著增多(P＜0.05).结论 鼻咽腔降温对大鼠全脑缺血-再灌注损伤具有保护作用,且鼻咽腔降温法降低海马温度的速度明显快于全身降温法.     

七氟醚预处理对局灶性脑缺血再灌注损伤大鼠海马TREK-1表达的影响

目的 探讨七氟醚预处理对局灶性脑缺血再灌注损伤大鼠海马机械敏感性钾通道TREK-1表达的影响.方法 健康雄性SD大鼠36只,体重240～280 g,随机分为3组(n=12):假手术组(S组)、局灶性脑缺血再灌注组(l/R组)和七氟醚预处理组(Sevo组).结扎右侧颈总动脉、颈外动脉,采用线栓法阻断颈内动脉2 h,再灌注24 h制备大鼠局灶性脑缺血再灌注损伤模型;Sevo组于缺血前1 h经半密闭的吸入箱持续吸入含2.5%七氟醚的02;S组仅分离并结扎右侧颈总动脉、颈外动脉,不置入线栓.各组于再灌注24 h时行神经功能缺陷评分后断头取脑,TIC染色后测定脑梗死体积,采用RT-PCR法测定海马TREK-1 mRNA的表达.结果 与S组相比,I/R组和Sevo组神经功能缺陷评分和脑梗死体积比升高(P<0.01);与I/R组相比,Sevo组神经功能缺陷评分和脑梗死体积比降低,海马TREK-1 mRNA表达上调(P<0.05).结论 七氟醚预处理可通过激活海马TREK-1减轻大鼠局灶性脑缺血再灌注损伤.     

脂氧素A4后处理对大鼠全脑缺血再灌注时细胞凋亡的影响

目的 评价脂氧素A4时处理对大鼠全脑缺血再灌注时细胞凋亡的影响.方法 雄性成年SD大鼠180只,体重200 ～ 250 g,采用随机数字表法,将其分为3组:假手术组(S组)、缺血再灌注组(I/R组)和脂氧素A4后处理组(L组).I/R组和L组采用四血管阻塞法建立大鼠全脑缺血再灌注损伤模型.L组于再灌注即刻侧脑室注射脂氧素A4 100 ng(用生理盐水稀释至5ul),S组和I/R组侧脑室注射生理盐水5ul.分别于再灌注2、6、12、24和72 h时,处死6只大鼠,取脑组织,行HE染色,光镜下观察病理学结果,采用免疫组化法测定海马CA1区caspase-3表达.分别于再灌注2、6、12、24和72 h时,处死6只大鼠,取海马组织,采用流式细胞仪检测细胞凋亡率.结果 与S组比较,I/R组和L组再灌注各时点海马CA1区caspase-3表达上调,海马组织细胞凋亡率升高(P＜0.01);与I/R组比较,L组再灌注各时点海马CA1区caspase-3表达下调,海马组织细胞凋亡率降低(P＜0.01),病理学损伤减轻.结论脂氧素A4后处理减轻大鼠全脑缺血再灌注损伤的机制与下调caspase-3表达,减少细胞凋亡有关.     

姜黄素预先给药对大鼠全脑缺血再灌注诱导内质网应激的影响

目的 探讨姜黄素预先给药对大鼠全脑缺血再灌注诱导内质网应激的影响.方法 雄性SD大鼠144只,体重200～250 g,月龄2～3月,采用随机数字表法,将大鼠随机分为4组(n=36):假手术组(S组)仅分离双侧颈总动脉;缺血再灌注组(I/R组)采用四血管阻断法制备大鼠全脑缺血再灌注模型;姜黄素组(Cur组)于缺血前1 h腹腔注射姜黄素200 mg/kg;溶媒对照组(VC组)给予等容量姜黄素溶媒--0.5%羧甲基纤维素钠.于再灌注12 h、1、3.7 d时取9只大鼠,取脑,分离海马,采用TUNEL法标记凋亡神经元,计算凋亡指数;采用Western blot法检测海马神经元葡萄糖调节蛋白78(GRP78)、生长停止和DNA损伤诱导基因153(GADDl53)和半胱氨酸天冬氨酸酶-12(caspase-12)的表达水平.结果 与S组比较,I/R组和VC组凋亡指数升高,GRP78和caspase-12表达上调(P<0.05);与I/R组比较,Cur组凋亡指数降低,GRP78表达上调,caspase-12表达下调(P<0.05).I/R组、VC组和Cur组间GADD153表达差异无统计学意义(P>0.05).结论 姜黄素预先给药可通过抑制内质网应激途径介导的细胞凋亡减轻大鼠全脑缺血再灌注损伤,其机制与海马GRP78表达上调和caspase-12表达下调有关.

Abstract：

Objective To investigate the effect of curcumin pretreatment on endoplasmic reticulum stress induced by global cerebral ischemia-reperfusion (I/R) in rats. Methods One hundred forty-four male SD rats weighing 200-250 g were randomly divided into 4 groups (n = 36 each): sham operation group (group S) ; I/Rgroup; curcumin group (group Cur) and vehicle control group (group VC). Global cerebral I/R was produced by four-vessel occlusion technique in S, I/R, Cur, VC groups. Bilateral vertebral arteries were cauterized. Bilateral common carotid arteries were occluded by clipping for 15 min. Curcumin 200 mg/kg was injected intraperitoneally (IP) at 1 h before cerebral ischemia. Global cerebral ischemia was confirmed by unconsciousness and disappearance of papillary and righting reflex. Animals were sacrificed at 12 h, 1,3 and 7 d of reperfusion. Neuronal apoptosis in hippocampal CA1 region was detected by TUNEL assay. Apoptosis index (AI) was calculated. The expression of glucose regulated protein 78 (GRP78) ,growth arrest and DNA damage inducible gene 153 (GADD153) and caspase-12 protein in hippocampal region was assessed by Western blot analysis. Results Cerebral I/R significantly increased AI and GRP78 and caspase-12 protein expression in hippocampus as compared with group S( P <0.05) . Curcumin pretreatment significantly decreased AI, increased GRP78 protein expression and decreased caspase-12 protein expression as compared with group I/R ( P < 0.05) . There was no significant difference in the GADD153 protein expression among Cur, VC and I/R groups ( P > 0.05) . Conclusion Curcumin pretreatment can significantly reduce global cerebral I/R-induced neuronal apoptosis in hippocampus by increasing GRP78 expression and decreasing easpase-12 expression in hippocampus.     

姜黄素预先给药对大鼠全脑缺血再灌注诱导内质网应激的影响

目的 探讨姜黄素预先给药对大鼠全脑缺血再灌注诱导内质网应激的影响.方法 雄性SD大鼠144只,体重200～250 g,月龄2～3月,采用随机数字表法,将大鼠随机分为4组(n=36):假手术组(S组)仅分离双侧颈总动脉;缺血再灌注组(I/R组)采用四血管阻断法制备大鼠全脑缺血再灌注模型;姜黄素组(Cur组)于缺血前1 h腹腔注射姜黄素200 mg/kg;溶媒对照组(VC组)给予等容量姜黄素溶媒--0.5%羧甲基纤维素钠.于再灌注12 h、1、3.7 d时取9只大鼠,取脑,分离海马,采用TUNEL法标记凋亡神经元,计算凋亡指数;采用Western blot法检测海马神经元葡萄糖调节蛋白78(GRP78)、生长停止和DNA损伤诱导基因153(GADDl53)和半胱氨酸天冬氨酸酶-12(caspase-12)的表达水平.结果 与S组比较,I/R组和VC组凋亡指数升高,GRP78和caspase-12表达上调(P<0.05);与I/R组比较,Cur组凋亡指数降低,GRP78表达上调,caspase-12表达下调(P<0.05).I/R组、VC组和Cur组间GADD153表达差异无统计学意义(P>0.05).结论 姜黄素预先给药可通过抑制内质网应激途径介导的细胞凋亡减轻大鼠全脑缺血再灌注损伤,其机制与海马GRP78表达上调和caspase-12表达下调有关.     

姜黄素预先给药对大鼠全脑缺血再灌注诱导内质网应激的影响

目的 探讨姜黄素预先给药对大鼠全脑缺血再灌注诱导内质网应激的影响.方法 雄性SD大鼠144只,体重200～250 g,月龄2～3月,采用随机数字表法,将大鼠随机分为4组(n=36):假手术组(S组)仅分离双侧颈总动脉;缺血再灌注组(I/R组)采用四血管阻断法制备大鼠全脑缺血再灌注模型;姜黄素组(Cur组)于缺血前1 h腹腔注射姜黄素200 mg/kg;溶媒对照组(VC组)给予等容量姜黄素溶媒--0.5%羧甲基纤维素钠.于再灌注12 h、1、3.7 d时取9只大鼠,取脑,分离海马,采用TUNEL法标记凋亡神经元,计算凋亡指数;采用Western blot法检测海马神经元葡萄糖调节蛋白78(GRP78)、生长停止和DNA损伤诱导基因153(GADDl53)和半胱氨酸天冬氨酸酶-12(caspase-12)的表达水平.结果 与S组比较,I/R组和VC组凋亡指数升高,GRP78和caspase-12表达上调(P<0.05);与I/R组比较,Cur组凋亡指数降低,GRP78表达上调,caspase-12表达下调(P<0.05).I/R组、VC组和Cur组间GADD153表达差异无统计学意义(P>0.05).结论 姜黄素预先给药可通过抑制内质网应激途径介导的细胞凋亡减轻大鼠全脑缺血再灌注损伤,其机制与海马GRP78表达上调和caspase-12表达下调有关.     

不同强度电针刺激对脑缺血再灌注大鼠脑能量代谢的影响

目的 探讨不同强度电针刺激对脑缺血再灌注大鼠脑能量代谢的影响.方法清洁级雄性SD大鼠40只,体重200～230 g,采用随机数字表法,将大鼠随机分为5组(n=8):假手术组(S组)、脑缺血再灌注组(I/R组)、脑缺血再灌注+5 mA电针组(I/R+E1组)、脑缺血再灌注+3 mA电针组(I/R+E2组)和脑缺血再灌注+1 mA电针组(I/R+E3组).采用四血管阻断法制备脑缺血再灌注模型.I/R+E1组、I/R+E2组和I/R+E3组分别于模型制备后1、12 h实施电针刺激,20 min/次,电流强度分别为5、3和1 mA.再灌注24 h时,测定脑组织琥珀酸脱氢酶(SDH)、LDH和Na+-K+-ATP酶的活性.结果 与S组比较,I/R组脑组织LDH活性升高,Na+-K+-ATP酶活性降低(P＜0.05),SDH活性差异无统计学意义(P＞0.05),I/R+E1组SDH活性升高(P＜0.05);与I/R组比较,I/R+E1组脑组织LDH活性降低,SDH和Na+-K+-ATP酶活性升高,I/R+E2组和I/R+E3组LDH活性降低(P＜0.05或0.01),SDH和Na+-K+-ATP酶活性差异无统计学意义(P＞0.05);与I/R+E1组比较,I/R+E3组脑组织SDH活性降低(P＜0.05),I/R+E2组差异无统计学意义(P＞0.05);与I/R+E2组比较,I/R+E3组脑组织SDH活性降低(P＜0.05).结论 电针刺激可改善大鼠脑缺血再灌注时的脑能量代谢,且与刺激强度有关,该作用可能是其减轻脑缺血再灌注损伤的机制.

Abstract：

Objective To investigate the effects of electroacupuncture (EA) of different intensities on cerebral energy metabolism in a rat model of global cerebral ischemia-reperfusion (I/R) . Methods Forty male SD rats weighing 200-230 g were randomized into 5 groups ( n = 8 each) : group A sham operation; group B global cerebral I/R and C, D, E groups cerebral I/R+ 5, 3, 1 mA EA. Global cerebral I/R was induced by 4-vessel occlusion technique. Bilateral vertebral arteries were permanently occluded by cauterization.Bilateral common carotid arteries were clamped. When the bilateral pupils were completely dilated, the arteries were unclamped. Baihui,Mingmen and Zusanli were electrically stimulated with 5,3,1 mA (30-50 Hz) for 20 min at 1 h of reperfusion in C, D, E groups. The EA was repeated at 12 h of reperfusion. The animals were sacrificed at 24 h of reperfusion.The activities of Na+ -K+ -ATPase, succinodehydrogenase (SDH) and lactic dehydrogenase(LDH) in brain tissue were measured.Results Cerebral I/R significantly increased LDH activity and decreased Na+ -K+ -ATPase activity in group B as compared with group A. EA with 5 mA significantly decreased LDH activity and increased SDH and Na+ -K+ -ATPase activities in group C compared with group B. Conclusion EA can improve the cerebral energy metabolism in a rat model of global cerebral I/R and it is related to the intensity, which may be the mechanism by which EA reduces the global cerebral I/R injury.     

高压氧预处理对老龄大鼠全脑缺血再灌注损伤时脑皮质Nogo mRNA、Nogo-A及NgR蛋白表达的影响

目的 研究高压氧预处理对老龄大鼠全脑缺血再灌注损伤时Nogo mRNA、Nogo-A及NgR蛋白表达的影响,探讨其改善认知功能的可能机制.方法 雄性SD大鼠42只,月龄14月,随机分为4组:对照组(C组,n=6)、高压氧组(H组,n=12)、脑缺血再灌注损伤组(I/R组,n=12)和高压氧预处理组(HOP组,n=12).H组和HOP组每天置于高压氧舱内1h,氧压为0.2 MPa,连续5 d,最后1次高压氧处理后24 h时I/R组和HOP组采用改良Pulsinelli四血管闭塞法制备大鼠全脑缺血再灌注损伤模型,全脑缺血10 min.再灌注24 h时H组、I/R组和HOP组随机取6只大鼠断头取脑,分离大脑皮质,采用实时荧光定量PCR法检测Nogo mRNA的表达水平,Western blot法检测Nogo-A及NgR蛋白的表达水平.余大鼠自由喂养5 d后采用Morris水迷宫实验测定认知功能.结果 与C组比较,I/R组和HOP组认知功能降低,Nogo mRNA及Nogo-A蛋白表达上调(P＜0.05);与I/R组比较,H组和HOP组认知功能提高,Nogo mRNA及Nogo-A蛋白表达下调(P＜0.05).各组NgR蛋白表达比较差异无统计学意义(P＞0.05).结论 高压氧预处理通过抑制脑皮质Nogo mRNA及Nogo-A蛋白表达上调,改善老龄大鼠全脑缺血再灌注损伤时的认知功能.     

再灌注期间给予富氢液对大鼠全脑缺血再灌注损伤的影响

目的 评价再灌注期间给予富氢液对大鼠全脑缺血再灌注损伤的影响.方法 成年雄性SD大鼠72只,月龄2.0～2.5个月,体重260～300 g,采用随机数字表法,将其随机分为3组(n＝24):假手术组(S组)、脑缺血再灌注组(I/R组)和富氢液组(H组).I/R组和H组采用四血管阻塞法(缺血15 min)制备全脑缺血再灌注损伤模型.H组于再灌注6h时腹腔注射0.6 mmol/L富氢液5ml/kg,I/R组给予等容量生理盐水.再灌注24h时,每组处死18只大鼠,取海马组织,测定丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)含量、NF-κB活性、活化的caspase-3表达;再灌注72 h时,处死6只大鼠,取脑组织,HE染色,光镜下观察海马CA1区病理学结果,进行海马CA1区正常锥体细胞计数.结果 与S组比较,I/R组海马组织MDA、TNF-α、IL-6含量和NF-κB活性升高,活化caspase-3表达上调,正常锥体细胞计数减少(P<0.05);与I/R组比较,H组海马组织MDA、TNF-α、IL-6含量和NF-κB活性降低,活化caspase-3表达下调,正常锥体细胞计数增多(P<0.05).H组脑组织海马CA1区病理学损伤程度轻于I/R组.结论 再灌注期间给予富氢液可减轻大鼠全脑缺血再灌注损伤,其机制与抑制脂质过氧化反应、炎性反应和细胞凋亡有关.     

参附注射液预处理对大鼠脑缺血-再灌注损伤后HSP70和HSP90表达的影响

目的探讨参附注射液(SF)单次预处理对大鼠脑缺血-再灌注损伤的保护作用。方法30只雄性SD大鼠随机均分为单纯缺血-再灌注组(MCAO组)、SF预处理组(SF组,缺血前30 min经腹腔注射SF 10 ml/kg)和假手术组(Sham组)。MCAO组和SF组采用颈内动脉尼龙线线栓法致右侧大脑中动脉栓塞120 min。观察再灌注后24 h时脑组织病理学改变,检测热休克蛋白(HSP)70和HSP90表达。结果再灌注24 h后,SF组脑组织病理学损害轻于MCAO组。Sham组未见HSP70及HSP90表达。MCAO组可见到较多的HSP70免疫阳性细胞,明显高于Sham组(P<0.01);SF组HSP70免疫阳性细胞分布较MCAO组广泛,数量明显增多,胞浆及胞核都可见HSP70免疫阳性细胞[(1.341±0.464)vs.(0.856±0.574)](P<0.05),而SF组HSP90的表达与MCAO组相仿[(0.006±0.013)vs.(0.005±0.007)]。结论SF预处理可通过增加HSP70表达而对大鼠脑缺血-再灌注损伤起保护作用。     

Diazoxide, as a postconditioning and delayed preconditioning trigger, increases HSP25 and HSP70 in the central nervous system following combined cerebral stroke and hemorrhagic shock

Combined hemorrhagic shock (Shock) and unilateral common carotid artery occlusion (Stroke) results in a decrease of oxygen availability to peripheral tissues and organs and the central nervous system (CNS). A variety of biochemical processes ensue, including organ failure, cellular apoptosis, and necrosis. The present study used male, Sprague-Dawley rats to assess the impact of cerebral insult. Using heat-shock protein 25 and 70 (HSP25, HSP70) as biomarkers, measured 24 h after injury, we tested the hypothesis that pharmacological induction of preconditioning can offer cytoprotection from combined Stroke and Shock. The compound, diazoxide (DZ), is known to induce preconditioning through its effect as a mitochondrial potassium ATP (mK(ATP)) channel opener and succinate dehydrogenase inhibitor. When administered 24 h prior to Stroke and Shock (delayed preconditioning), DZ increased cerebral cortical and hippocampal levels of HSP25 and HSP70. A more clinically relevant treatment paradigm was tested, where DZ was administered after the induction of Stroke and Shock (postconditioning). When administered 60 min (but not 10 min) after the induction of Stroke and Shock, DZ significantly increased HSP25 and HSP70 expression in the ipsilateral cerebral cortex and hippocampus. Taken together, these results suggest that DZ treatment may be efficacious for CNS injury resulting from blood loss and anoxia from combined cerebral ischemia and hemorrhagic shock. "Postconditioning" triggered by DZ, immediately before resuscitation, is a potentially effective treatment for ischemia-reperfusion injury from combined Stroke and Shock.     

Effects of propofol and halothane on long-term potentiation in the rat hippocampus after transient cerebral ischaemia

BACKGROUND: Propofol is reported to have protective effects on cerebral ischaemia-induced neuronal death. The aim of this study was to explore whether propofol and halothane can protect hippocampal neuronal function from ischaemic injury during general anaesthesia in rats. METHODS: Rats were divided into 2-vessel occlusion (incomplete cerebral ischaemia) and 4-vessel occlusion (complete cerebral ischaemia) groups consisting of three subgroups each (sham-operated, propofol and halothane groups). One hour after starting propofol 1 mg kg(-1) min(-1) with 30% O2 and N2 or halothane 0.8% in 30% O2 and N2 rats with or without bilateral vertebral artery occlusion had bilateral common carotid arteries occluded by vessel clips for 10 min. Anaesthesia was maintained for another 1 h. Seven days after ischaemia-reperfusion, hippocampal long-term potentiation in the perforant path-dentate gyrus synapse was determined as an index of cerebral outcome. RESULTS: In the propofol groups, the formation of long-term potentiation was significantly impaired in the 2-vessel and 4-vessel occlusion groups compared to the respective sham-operated groups (P < 0.01 and P < 0.05, respectively). Impaired formation of long-term potentiation in propofol groups was comparable to that in halothane groups. The formation of long-team potentiation in the propofol and halothane 2-vessel group was not significantly different from that in the awake 2-vessel group. CONCLUSIONS: Propofol and halothane administered during ischaemia do not possess protective effects against hippocampal neuronal dysfunction induced by cerebral ischaemia-reperfusion as evaluated by our transient ischaemic rat models.