组织型激肽释放酶对脑缺血再灌注大鼠缺血脑组织缓激肽及其受体表达的影响

目的 探讨组织型激肽释放酶(tissue kallikrein,TK)对脑缺血再灌注大鼠缺血脑组织缓激肽、缓激肽B1受体(bradykinin B1 rgceptor,B1R)和缓激肽B2受体(bradykinin B2 receptor,B2R)表达的影响.方法 54只SD大鼠随机分为3组,每组18只.3组分别为假手术组;生理盐水(normal saline,NS)处理组(Ns组):NS 2 ml/(kg·d),连用3 d;TK(处理组(TK组):TK 17.5×10-3U/(kg·d),连用3 d.3 d后分别进行神经功能缺损评分、脑梗死体积测定.酶联免疫吸附法检测缺血区缓激肽含量;采用逆转录聚合酶链反应和Western印迹法分别检测缺血脑组织B1R、B2R mRNA和蛋白表达.结果 与NS组比较,TK组神经功能缺损显著减轻[(6.17±1.17)分对(8.17 4±1.33)分,t=2.000,P=0.004],脑梗死体积明显缩小[(29.67±3.78)%对(37.50±6.72)%,t=0.078,P=0.005];缺血脑组织缓激肽含量升高[(9.25 4±1.13)对(15.53±1.68),t=6.283,P:0.000];B2RmRNA表达显著上调[(1.21±0.17)对(2.15±0.20),t=0.943,P=0.000),而B1R mRNA表达上调不明显[(0.51±0.05)对(0.57±0.06),t=0.058,P=0.141)];B2R蛋白表达显著上调[(1.15±0.16)对(1.88 4±0.21),t=0.737,P=0.0001,B1R蛋白表达上调不明显[(0.50±0.04)对(0.53±0.05),t=1.326,P=0.214].结论 TK 对脑缺血再灌注大鼠具有保护作用,能使缺血脑组织缓激肽含量增高,B2R表达上调,而对B1R表达影响不大.由此推测,B2R在TK保护缺血脑组织中发挥着主要作用.     

黄体酮对大鼠局灶性脑缺血再灌注损伤后脑组织神经生长因子表达的影响

目的 观察黄体酮对大鼠局灶性脑缺血-再灌注损伤后缺血区皮层神经生长因子(NGF)和脑源性神经营养因子(BDNF)在mRNA与蛋白质水平表达的影响,探讨黄体酮在脑缺血-再灌注损伤中的脑保护作用机制. 方法 采用SD雄性大鼠局灶性脑缺血-再灌注损伤模型.将96只大鼠随机分为4组:假手术组、缺血再灌注组、溶剂组和黄体酮组各24只.应用Real time-PCR和Western blot技术分别对缺血区皮层NGF和BDNF mRNA与蛋白表达情况进行测定. 结果 在缺血区皮层,缺血2h再灌注6h后,缺血再灌注组NGF和BDNF的mRNA及蛋白质表达达高峰,再灌注24 h后,回复到假手术组水平;缺血2h再灌注12 h后,黄体酮组NGF和BDNF mRNA及蛋白表达达高峰,再灌注24 h后,表达仍高(P＜0.05). 结论 黄体酮可以使脑缺血-再灌注损伤后NGF和BDNF的mRNA表达上调,促进脑内NGF和BDNF蛋白的合成,从而发挥脑保护作用.     

大鼠脑缺血再灌注损伤后iNOS的表达变化

目的 观察脑缺血再灌注后iNOS表达变化的规律.方法 利用缺血再灌注损伤的动物模型,通过蛋白质印迹法检测缺血再灌注不同时期iNOS在脑内的表达.结果 在缺血再灌注12、24、72 h与正常组比较表达明显增加,并且随着缺血再灌注时间的延长iNOS表达呈逐渐增加的趋势.结论 iNOS可能是脑缺血迟发性损伤的重要因素之一。     

眼针对急性脑缺血再灌注损伤大鼠脑组织ICAM-1表达的影响

目的观察眼针对急性脑缺血再灌注损伤模型大鼠脑组织细胞间黏附因子(ICAM-1)表达的影响。方法 64只SD大鼠随机分为4组:正常组(未处理)、假手术组(同模型组,仅鱼线插入深度1 cm)、模型组(应用线栓法复制脑缺血再灌注损伤大鼠模型,鱼线插入深度1.8～2 cm)和眼针组(模型成功后取肝区、上焦区、下焦区、肾区进行眼针治疗20 min,每日2次),每组16只。于再灌注后3 h进行神经功能缺损评分,采用免疫组化、Western印迹、实时荧光定量聚合酶链反应(RQ-PCR)方法测定脑组织ICAM-1蛋白及mRNA表达的变化。结果眼针治疗后可使大鼠神经功能缺损评分明显下降,并显著降低脑组织ICAM-1蛋白及mRNA表达(P<0.01)。结论眼针具有明显地改善大鼠脑缺血再灌注损伤的作用;其机制与下调脑组织ICAM-1表达有关。     

活血开窍法对脑缺血再灌注损伤大鼠脑组织兴奋性氨基酸的影响

目的观察活血开窍法对大鼠脑缺血再灌注损伤脑组织兴奋性氨基酸(EAA)的影响。方法以大鼠局灶性脑缺血再灌注模型为研究对象,于缺血2h再灌注48h,取脑组织应用高效液相色谱法测定谷氨酸(Glu)、天门冬氨酸(Asp)的含量。结果缺血2h再灌注48h后,模型组、药物组与正常组大鼠比较,脑组织G1u及Asp含量升高(P0.01);与模型组大鼠比较,醒脑通脉大、小剂量组脑组织中Glu、Asp含量显著降低(P0.01)。结论活血开窍法抗缺血性脑损伤的作用机制可能与其对抗脑缺血再灌注后EAA的升高有关。     

雌激素对沙土鼠脑缺血再灌注损伤的影响

近年来 ,一些研究提示老年期雌激素水平的变化与缺血性脑血管病的发病及病程有一定联系 ,但雌激素对脑缺血的影响机制还不十分清楚 ,为此 ,我们利用沙土鼠脑缺血再灌注模型 ,观察雌激素对海马区神经细胞凋亡 ,脑组织匀浆中超氧化物歧化酶(ＳＯＤ)、谷氨酸 (Ｇｌｕ)含量的影响。     

脑缺血-再灌注损伤对大鼠脑组织髓磷脂相关糖蛋白表达的影响

目的 探讨脑缺血-再灌注损伤对大鼠脑组织髓磷脂相关糖蛋白（MAG）表达的影响.方法 应用线检法制作大鼠脑缺血-再灌注损伤模型;采用免疫荧光化学和免疫印迹法研究大鼠脑缺血-再灌汴损伤后MAG表达的定位和定量的变化.结果 脑缺血-再灌注后4 h和24 h大鼠皮质区MAG的表达有增高趋势,但是差异无统计学意义;基底核区MAG的表达4h即开始升高,但差异亦无统计学意义.缺血绀基底核区MAG 24 h的表达与无缺血组比较,差异有统计学意义,（P〈0.05）.免疫荧光实验显示,阳性表达在基底核的白质区域,与细胞核的复染发现,主要表达在细胞间.结论 大鼠脑缺血再灌注后MAG的表达在皮质区有增加趋势,在基底核区的表达明显增高,24 h缺血组显著高于无缺而组.提示脑缺血-再灌注损伤不仅损伤神经元,其白质也存在损伤,干预白质损伤可能是脑缺血-一再灌注损伤新的治疗靶点.     

电针对脑缺血再灌注模型大鼠纹状体NMDA受体NR2亚基蛋白表达的影响

目的 观察脑缺血再灌注模型大鼠受损侧纹状体组织中NMDA受体调节亚单位NR2A和NR2B蛋白表达及其电针干预后的变化,探讨电针对缺血再灌注兴奋性氨基酸毒性的拮抗作用,进一步阐明电针治疗缺血性脑血管疾病的机制.方法 用数字随机表将15只SD大鼠随机分成3组:假手术组、模型组、电针组,每组各5只.采用改良Longa线栓法制作大脑中动脉短暂性缺血再灌注模型,电针组大鼠在再灌同时电针“百会”、“大椎”两穴(连续波,频率3 Hz,电流强度1～3 mA),30 min,深度均为10 mm.免疫组织化学法及图像处理系统检测分析大鼠受损侧纹状体NR2A、NR2B蛋白表达情况.结果 与假手术组相比,模型组大鼠纹状体组织中NR2A的表达量明显下降,而NR2B的表达量明显升高,给予电针“百会”、“大椎”穴后的大鼠纹状体组织NR2A表达细胞数及含量均明显高于模型组,表达NR2B的细胞数及含量均明显降低.结论 电针可能通过激活NR2A受体蛋白表达,抑制NR2B受体蛋白的过量表达,从而调节NMDA受体复合物的整体功能活性,减少NMDA受体介导的兴奋性氨基酸毒性反应,减轻脑缺血再灌注引起的局灶性脑损伤,发挥一定的脑神经保护作用.     

荭草苷对脑缺血再灌注大鼠脑组织线粒体自噬的影响

目的 探讨荭草苷对脑缺血再灌注大鼠脑组织线粒体自噬的影响。方法 采用改良线栓法制备大鼠局灶性大脑中动脉缺血(MCAO)模型,将模型制备成功的大鼠随机分为3组：模型组、荭草苷组、荭草苷合用雷帕霉素组,另取不插栓线的大鼠为假手术组,每组18只。荭草苷组和荭草苷合用雷帕霉素组于术后1 h和12 h分别腹腔注射6.48μmol/kg荭草苷溶液两次,荭草苷合用雷帕霉素组于术前24 h和30 min腹腔注射2.66 mg/ml雷帕霉素溶液2次。再灌注24 h后,采用ZeaLonge评分法对各组大鼠进行神经功能损伤评分,2′3′5-氯化三苯基四氮唑(TTC)法测定MCAO大鼠脑梗死体积,分光光度法测定MCAO大鼠缺血侧脑组织线粒体中超氧化物歧化酶(SOD)活性及丙二醛(MDA)和钙离子(Ca²⁺)含量,Western印迹法测定MCAO大鼠脑组织线粒体中微管相关蛋白轻链(LC)3和B细胞淋巴瘤-2基因(Bcl-2)/E1B-19K相互作用蛋白(BNIP)3表达情况。结果 与假手术组相比,模型组神经功能损伤评分和脑梗死体积均明显升高,线粒体中MDA和Ca²⁺含...     

肌苷对大鼠脑缺血再灌注后神经细胞干细胞因子mRNA表达的影响

目的：研究大鼠缺血再灌注后神经细胞干细胞因子(stem cell factor，SCF)mRNA表达的变化和肌苷对它的影响。方法：成年健康雌性SD大鼠68只，随机分为缺血再灌注组(n=64)和假手术组(n=4)，前者随机分为肌苷处理组(100mg／kg，腹腔注射；n=32)和对照组(n=32)，然后各组再随机分为缺血1．5h再灌注2h、6h、12h、24h、2d、3d、7d、14d组(每绀4只)。用线栓法制作大脑中动脉缺血再灌注模型，用原位杂交法检测脑组织SCF mRNA表达。结果：对照组缺血侧皮质除2h、6h、12h以外，纹状体除2h、6h以外，空旁区除2h、14d以外，各时间点SCF mRNA均显著高于假手术组(P＜0．05)，与对照组相比，肌苷处理组14d时皮质和纹状体SCF mRNA表达有所降低，3d和7d时皮质、纹状体和室旁区SCF mRNA表达均显著增高(P＜0．01)。结论：肌苷可增加大鼠脑缺血再灌注后SCF mRNA表达，可能在促进神经干细胞增殖方面起一定作用。     

Role of p38 and JNK in liver ischemia and reperfusion

Background/purpose

The signal transduction of mitogen-activated protein kinases (MAPKs) has appeared to be an important mediator of ischemic-related events. Because of this, we analyzed the participation of p38 and JNK in liver ischemia and reperfusion, as two individual members of the MAPK family of proteins.

Methods

All papers referred to in PubMed for the past 15 years were analyzed to determine how and when these MAPKs were considered to be an intricate part of the ischemic event. References were cross-studied to ascertain whether other papers could be found in the literature.

Results

The role of p38 and JNK in liver ischemia was confirmed in the literature. The activation of these mediators was associated with the induction of apoptosis and necrosis. Inhibitors of p38 and JNK reduced the liver ischemia and reperfusion damage, probably through the mechanisms mentioned before.

Conclusions

The development of effective inhibitors of p38 and JNK protein mediators is important for minimizing the harmful effects associated with liver ischemia and reperfusion.     

姜黄素对大鼠脑缺血再灌注损伤的保护作用

目的探讨姜黄素对大鼠脑缺血再灌注损伤的保护作用。方法将32只SD大鼠均分为假手术组(sham组)、缺血再灌注组、姜黄素组和对照组各8只。用焦油紫染色法检测其大脑海马CA 1区的细胞数量,免疫印迹法分析c-Jun氨基端激酶(JNK)的激活情况。结果姜黄素组海马CA1区存活细胞数量显著高于缺血再灌注组及对照组(P<0.05),JNK磷酸化程度显著低于对照组(P<0.05)。结论姜黄素对大鼠脑缺血再灌注损伤具有保护作用,此作用可能与抑制JNK激活有关。     

Effects of glutamic acid on cardiac function and energy metabolism of rat heart during ischaemia and reperfusion

The effects of exogenous glutamate (20 mM) on myocardial energy metabolism and cardiac function during low-flow ischaemia and subsequent reperfusion were studied in isolated working rat hearts. Hearts were made severely ischaemic for 60 min by reducing the perfusion rate to 0.17 ml/min, and then reperfused for 30 min. Low-flow ischaemia resulted in a 50% reduction of myocardial ATP, a 70% reduction of both creatine phosphate (CP) and GTP, and a 250% rise in AMP. After reperfusion, CP was restored to normal levels but ATP and GTP remained significantly low. All hearts failed completely to recover cardiac pump function. The addition of glutamate to the perfusate during low-flow ischaemia had no significant effect on myocardial high-energy phosphates (HEP) but slightly increased succinate production. Subsequent reperfusion without added glutamate resulted in the recovery of 62% of pre-ischaemic aortic flow rate, as well as restoration of myocardial ATP and GTP to 70% of their control values and of creatine phosphate to supranormal levels. Reperfusion with added glutamate did not raise HEP levels any further but did increase recovery of cardiac function to 92% or more of pre-ischaemic values. Thus, by mechanism(s) which are not yet clear but which may include an increase in HEP via anaerobic succinate production, elevated levels of exogenous glutamate exert a highly beneficial effect on the post-ischaemic recovery of cardiac function.     

脑温变化对大鼠局灶脑缺血再灌注组织兴奋性氨基酸的影响

目的　研究轻度高温、亚低温对局灶脑缺血组织兴奋性氨基酸 (EAA)的影响。方法　建立大鼠大脑中动脉缺血再灌注线栓模型 ,诱导目标脑温 ,用HPLC荧光法检测脑组织谷氨酸 (Glu)、天冬氨酸 (Asp)、甘氨酸 (Gly)含量。结果　轻度高温组Glu、Asp、Gly明显增高 ;亚低温组则明显降低。结论　轻度高温促进EAA增高 ,在持续增加Glu“兴奋毒性”方面起重要作用 ;亚低温抑制EAA增高 ,在降低Glu“兴奋毒性”方面起重要作用。     

局灶脑缺血再灌注脑温对抑制性氮基酸的影响

目的 研究轻度、亚低温对局灶脑缺血抑制性氨基酸的影响。方法 建立大鼠大脑中动脉缺血再灌注模型,诱导目标脑温,用HPLC荧光法检测脑组织GABA含量。结果 轻度高温组GABA短暂增高后下降,亚低温组GABA持续增高。结论 轻度高温使脑内GABA水平下调,在加重缺血神经元损伤方面起着不容忽视的作用：亚低温使GABA水平持续上调,在保护缺血神经元方面起重要作用。     

腺苷A2受体激动剂对大鼠胰腺缺血再灌注损伤时氧自由基和细胞凋亡的影响

目的:研究腺苷A2受体激动剂对大鼠胰腺缺血再灌注损伤时的氧自由基和细胞凋亡的影响.方法:大鼠随机分成3组(n=18),即假手术组、对照组和实验组,对照组和实验组大鼠脾下动脉钳夹30 min,假手术组不进行缺血处理;三组再灌注前经阴茎背静脉分别注射生理盐水(2mL/kg)或A2受体激动剂CGS21680(300μg/kg);再灌注15 min、30 min和60 min分别检测胰腺组织中脂质过氧化物(lipoperoxides,LPO)、细胞凋亡的变化以及观察胰腺组织的形态学变化.结果:再灌注15、30和60 min后,对照组胰腺组织中LPO和细胞凋亡明显高于假手术组(LPO:8.25±1.15 vs 1.63±0.46,10.67±2.04 vs 1.85±0.62,15.31±3.02vs2.02±0.86,均P＜0.05:细胞凋亡:0.55±0.08vs0.18±0.04,1.21±0.15 vs 0.20±0.06.2.63±0.52 vs 0.23±0.06,均P<0.05或0.01)和实验组(LPO:8.25±1.15 vs 6.51±1.38.10.67±2.04 vs 6.84±1.74.15.31±3.02 vs 10.22±2.91.均P<0.05:细胞凋亡:0.55±0.08 vs 0.32±0.16,P<0.05;1.21±0.15 vs 0.44±0.20,2.63±0.52 vs 0.50±0.43,均P<0.05或0.01);.对照组中,再灌注30 min和60 min同15 min相比,前两者LPO、细胞凋亡增高明显,且差异有统计学意义(P<0.05 或P＜0.01).假手术组和实验组胰腺组织损伤不明显,而对照组胰腺组织随再灌注时间的延长损伤加重.结论:腺苷A2受体激动剂可减轻大鼠胰腺缺血再灌注损伤时氧自由基和细胞凋亡的发生,从而减轻胰腺缺血再灌注损伤.     

Protective effect of glutamic acid on cardiac function and metabolism during cardioplegia and reperfusion

The effect of glutamic acid added to cardioplegic solution containing 20 mM K+ on the cardiac function and metabolism was studied in isolated working rat hearts. 30-min cardiac arrest resulted in profound fall in creatine phosphate and ATP content, by four- and two-fold, respectively, as well as in four-fold rise in AMP content. Simultaneously, during cardioplegia a decline in tissue glutamate and aspartate content and an increase in tissue ammonia and alanine content were found. After reperfusion, an incomplete restoration of ATP, AMP, and creatine phosphate content were observed; the cardiac output recovered only to 39 percent of the initial value. An addition of glutamic acid to cardioplegic solution was associated with significantly less decline in the content of high-energy phosphates and less prominent rise in AMP content during cardioplegia. It also prevented the decline in tissue aspartate content and caused a lesser ammonia accumulation in myocardial tissue due to the activation of glutamine synthesis. In spite of this the tissue ammonia level remained elevated. Reperfusion with Krebs-Henseleit buffer resulted in the recovery of cardiac output to 75% of the initial value as well as better restoration of high-energy phosphate content. The addition of glutamic acid in the perfusate during reperfusion led to further improvement of ATP and creatine phosphate content. It is suggested that an addition of glutamic acid may have beneficial effect in open heart surgery.     

Effect of preconditioning ischemia on reperfusion arrhythmias after coronary artery occlusion and reperfusion in the rat

Severe arrhythmias occur predictably on reperfusion after 5 minutes of coronary occlusion in the rat. There is little data available on whether ischemic preconditioning (PC) of hearts can reduce the incidence of such arrhythmias. The effect of PC (three cycles of 2 minutes of coronary occlusion and 5 minutes of reperfusion) on development of arrhythmias after a subsequent 5-minute coronary artery occlusion and reperfusion was studied. Rats (n = 16 each group) underwent 5-minute occlusion and reperfusion alone or preceded by PC; arrhythmias were monitored during ischemia and for 10 minutes of reperfusion, and biopsies were taken for creatine phosphate and adenosine triphosphate in ischemic and nonischemic zones of the left ventricle. PC reduced the incidence of ventricular tachycardia (VT) during occlusion (81% control versus 13% PC, p less than 0.001). On subsequent reperfusion, ventricular fibrillation (VF) developed in zero PC animals versus 13 (81%) of controls (p less than 0.001), and irreversible VF in zero of PC versus seven (44%) of controls (p = 0.007). VT occurred in four (25%) of PC versus all (100%) of controls (p less than 0.001). PC reduced mean duration of VT plus VF from 320 +/- 54 to 5 +/- 1 seconds (p less than 0.001) and delayed arrhythmia onset from 8 +/- 2 to 85 +/- 35 seconds after reperfusion. There was no difference in creatine phosphate levels in the ischemic zone at the end of reperfusion in PC animals compared with controls without irreversible VF (16.2 +/- 4.1 versus 15.5 +/- 3.9 nmol/mg protein, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

预处理对缺血再灌注时心肌电生理的影响

目的探讨缺血预适应（IPC）对缺血/再灌注心律失常的影响及其机制。方法12只犬随机分为对照组（n=6）和IPC组（n=6）,采用特制电极记录技术,观察和测量三层心肌单相动作电位（MAP）及有效不应期（ERP）,分析室性心律失常发生率、MAP时程（MAPD）、MAPD跨室壁离散（TDR）及ERP跨室壁离散（TDE）。结果对照组6只中有4只发生室速/室颤,而IPC组6只中仅1只发生室速/室颤。对照组缺血时MAPD同步缩短,而ERP延长且三层心肌延长的幅度不一致,再灌注时逐步恢复。IPC组缺血时MAPD缩短与ERP延长均不明显,与对照组相比,具有显著差异（P<0.05）。各组三层心肌之间的MAPD是一致的。对照组缺血/再灌注时ERP明显不一致,TDE增大,而IPC组TDE小,两者相比较具有显著差异（P<0.05或P<0.01）。结论IPC减少缺血/再灌时MAPD、ERP的变化及TDE,这可能是其抗心律失常的部分机制。     

尼可地尔对心肌缺血再灌注损害的作用

目的：观察KATP通道开放剂预处理对在体缺血再灌注（ischemia／reperfusion,I／R）心脏的影响。方法：建立在体大鼠心脏缺血再灌注模型。将60只大鼠随机分成4组：缺血再灌注（I／R）组,尼可地尔（NIC）组,KATP通道阻滞剂格列苯脲（GLI）＋NIC组,GLI组。测定各组心肌梗塞范围,血清肌酸激酶（CK）,乳酸脱氢酶（LDH）浓度,监测各组心电图,应用透射电镜观察超微结构的变化。结果：与I／R组比较,NIC组心肌梗塞范围显著减小[（52．9±14．2）％：（20．3±6．4）％。P〈0．005],血浆CK,LDH浓度显著减少（P〈0．05）,但并不能减少心律失常的发生;GLI＋NIC组和GLI组与I／R组相比,心肌梗塞范围、血清CK、LDH浓度无显著性差异。结论：非特异性KATP通道开放剂尼可地尔有部分心肌保护作用,推测在缺血再灌注中发挥作用的KATP通道可能是对心电生理影响较小的亚型。