脑脉泰对大鼠局灶性脑缺血再灌注损伤NOS和氧自由基的影响

目的研究脑脉泰对大鼠局灶性脑缺血再灌注损伤NOS和氧自由基的影响。方法大脑中动脉线拴法（MCAO）制作大鼠局灶性脑缺血再灌注模型：60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）、脑脉泰大、中、小（2．24、1．12、0．56g／kg）剂量组和尼莫地平组（10mg‘kg）,每组10只大鼠。术后取梗死侧脑组织做成匀浆,检测脑组织中丙二醛（MDA）、乳酸（LA）、超氧化物歧化酶（SOD）和谷胱甘肽（GSH）含量。免疫组化染色检测缺血半暗带iNOS和eNOS蛋白表达。结果脑组织匀浆生化指标检测发现缺血脑脉泰能显著降低脑组织中MDA和IA含量;升高SOD和GSH含量,脑缺血半暗带的eNOS蛋白表达明显增加,iNOS表达显著减少,与MCAO模型组比较,有显著性差异（P〈0．05）。结论脑脉泰能减少脑缺血／再灌注损伤,其保护作用与增加脑组织的抗氧化能力和eNOS／iNOS有关。     

氨氯地平对高胆固醇大鼠心肌缺血再灌注时一氧化氮合酶的影响

目的 :探讨高胆固醇血症大鼠心肌缺血 再灌注损伤时氨氯地平对内皮型一氧化氮合酶 (eNOS)和诱导型一氧化氮合酶 (iNOS)在冠脉血管内皮表达的影响。方法 :雄性Wistar大鼠分 4组 :单纯高胆固醇血症组 ;氨氯地平组 ;氨氯地平 N 甲基亚硝基左旋精氨酸甲酯组 ;氨氯地平 假手术组。大鼠经高胆固醇喂养 6周后 ,开胸结扎左冠状动脉 ,缺血30min后 ,行再灌注 2 0min、2h。分别用免疫组织化学ABC法检测冠脉血管内皮eNOS和iNOS的表达水平。结果 :缺血前 ,氨氯地平可显著降低冠脉血管内皮iNOS表达 (P <0 .0 1)。缺血 30min ,高胆固醇血症组eNOS、iNOS表达明显减少 (P <0 .0 1) ,氨氯地平组eNOS表达上调 (P <0 .0 1) ,iNOS下调 ;再灌注 2 0min时 ,高胆固醇血症组冠脉血管内皮表达iNOS增多 ,氨氯地平组eNOS、iNOS表达明显下调 ;再灌注 2h时 ,氨氯地平组NO水平及eNOS、iNOS表达较高胆固醇血症组轻度降低。各时相点L NAME均可部分阻断氨氯地平对eNOS、iNOS的效应。结论 :在高胆固醇血症时、缺血期及再灌注早期 ,氨氯地平可调节eNOS、iNOS表达 ,减少心肌缺血 再灌注损伤。     

缺血预适应对局灶性脑缺血再灌注大鼠海马 CA1 区低氧诱导因子-1α、 血管内皮生长因子表达的影响#br#

目的 观察缺血预适应后局灶性脑缺血再灌注大鼠缺血侧海马 CA1 区低氧诱导因子（HIF） -1α、 血管内皮生长因子（VEGF）表达的变化, 探讨缺血预适应的脑保护机制。方法 雄性 SD 大鼠随机分为 3 组： 假手术（SO）组、 脑缺血（MCAO）组和缺血预适应（BIP）组, 后两组按缺血后再灌注时间不同分为再灌注 2、 6、 12、 24、 48、 72 h 6 个亚组。制备大鼠局灶性脑缺血预适应模型, 采用免疫组织化学法与 Western blot 法观察脑缺血后再灌注各个时间点海马 CA1 区 HIF-1α和 VEGF 的表达变化。结果 SO 组未见神经功能缺损症状, 与 MCAO 组相比, BIP 组再灌注各时间点神经功能缺损评分低 （P＜0.05）。MCAO 组、 BIP 组 HIF-1α、 VEGF 阳性细胞及蛋白表达均于再灌注 2 h 开始增多, 6～12 h 表达递增, 24 h 表达至高峰, 随后表达减少, 72 h 表达仍高于 SO 组。两组各时间点 HIF-1α和 VEGF阳性细胞及蛋白表达均高于 SO 组 （P＜0.05）。除再灌注 2 h、 6 h MCAO 组与 BIP 组 HIF-1α的阳性细胞表达差异无统计学意义外, 2 组各时间点 VEGF 阳性细胞表达、 HIF-1α、 VEGF 蛋白表达均是 BIP 组高于 MCAO 组（P＜0.05）。结论 脑缺血预适应可能通过上调 HIF-1α、 VEGF 的表达, 发挥脑保护作用。     

地高辛抗体对大鼠再灌注心肌一氧化氮合酶同工酶表达的影响

目的：观察心肌缺血再灌注（myocardial ischemia reperfusion,MIR）时大鼠心肌组织、血清NO水平及一氧化氮合酶（NOS）同工酶蛋白表达的变化和内洋地黄素特异性抗体对MIR时心肌NO系统损伤的保护作用。方法：采用左冠状动脉前降支结扎30min,复灌45min建立在体大鼠MIR模型,Sprauge-Dawley大鼠随机分成7组,每组10只：假手术组,MIR模型组,生理盐水组,维拉帕米组,小、中、高剂量地高辛抗血清组（9、18、36mg/kg）。各组于再灌注45min后立即取左室心尖部缺血区心肌并断尾取血,检测心肌匀浆和静脉血中NO含量,心肌匀浆中的内皮型一氧化氮合酶（eNOS）、诱导型一氧化氮合酶（iNOS）水平,免疫组织化学SABC法检测心肌组织eNOS、iNOS;光镜下观察心肌组织形态学变化。结果：MIR时心肌组织NO水平明显降低,但血清中NO水平无明显变化;eNOS表达明显减少,iNOS表达明显增加,心肌组织结构发生明显损伤;中、高剂量地高辛抗血清能有效降低心肌组织iNOS表达,恢复心肌细胞eNOS活性,提高心肌组织和血液中的NO水平,减轻MIR导致的心肌组织结构损伤。结论：内洋地黄素特异性抗体对MIR造成的心肌NO系统损伤具有明显的保护作用,其作用机制可能通过拮抗内洋地黄素,调节心肌NOS同工酶的表达紊乱而实现。     

后适应对大鼠脑缺血-再灌注损伤线粒体结构和功能的影响

目的观察后适应对大鼠脑缺血-再灌注损伤线粒体结构和功能的影响。方法雄性SD大鼠随机分为假手术组、缺血-再灌注模型组(MCAO)、MCAO 预适应组、MCAO 后适应组和MCAO 尼莫地平组。大鼠脑缺血-再灌注24 h后,取脑进行TUNEL染色,免疫组织化学检察Bcl-2,Bax,Casepase-3和p53的蛋白表达,测定大鼠脑组织线粒体肿胀度、膜流动性、膜磷脂(PL)和丙二醛(MDA)含量、测定线粒体Na -K -ATP酶、Ca2 -ATP酶和超氧化物歧化酶(SOD)活性,并观察线粒体超微结构的改变。结果脑缺血-再灌注后半暗带线粒体的MDA含量明显增高,PL含量减少,膜脂流动性降低;ATP含量及Na -K -ATP酶、Ca2 -ATP酶、SOD活性明显降低。与MCAO组比较,后适应组大鼠凋亡细胞和Bax、Casepase-3、p53蛋白表达明显减少,ATP含量及Na -K -ATP酶、Ca2 -ATP酶、SOD活性明显升高。MCAO组大鼠脑线粒体肿胀,线粒体嵴断裂、溶解和消失,后适应明显减少缺血-再灌注引起的线粒体损伤程度。结论后适应对MCAO大鼠脑和线粒体的保护作用可能与其减少神经原凋亡,抑制p53、Bax、casepase-3表达,增加线粒体Na -K -ATPase、Ca2 -ATPase、SOD活性有关。     

后适应对大鼠实验性局灶性脑缺血/再灌注损伤的保护作用

目的研究后适应对大鼠局灶性脑缺血/再灌注损伤的保护作用与氧自由基的关系。方法大脑中动脉线拴法(MCAO)制作大鼠局灶性脑缺血/再灌注模型:50只♂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+nimodip-ine),每组10只大鼠。术后对大鼠进行神经缺陷评分,并取脑组织测量梗死体积。另取50只大鼠,分组、实验方法及步骤同上,术后取梗死侧脑组织做成匀浆,检测脑组织中丙二醛(MDA)、乳酸(LA)、超氧化物歧化酶(SOD)和谷胱甘肽(GSH)含量。结果后适应能减少大鼠实验性局灶性脑缺血的梗死体积、降低脑含水量,改善其神经行为。脑组织匀浆生化指标检测发现缺血后适应能降低脑组织中MDA和LA含量;升高SOD和GSH含量,与MCAO模型组比较,差异有显著性(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,其保护作用与增加脑组织的抗氧化能力有关。     

低氧预适应对大鼠脑缺血再灌注诱导内质网应激的影响

目的探讨低氧预适应对大鼠脑缺血再灌注诱导内质网应激的影响。方法健康雄性SD大鼠36只,采用随机数字表法随机分为假手术（S）组、缺血再灌注（I/R）组和低氧预适应（HPC）组,每组12只。采用右侧大脑中动脉阻闭1 h后再灌注24 h,制备局灶性脑I/R模型。HPC组吸入8%O23 h,制备HPC模型;S组只分离血管不置入线栓。于再灌注24 h时,行神经功能缺陷评分后断头取脑,免疫组化染色测定缺血皮质周围生长停止和DNA损伤诱导基因153（GADD153）蛋白表达,TUNEL法检测并计算细胞凋亡指数。结果与S组比较,I/R组和HPC组神经功能缺陷评分和凋亡指数升高,GADD153蛋白表达上调;与I/R组比较,HPC组神经功能缺陷评分和凋亡指数降低, GADD153蛋白表达下调（均P＜0.05）。结论低氧预适应可通过抑制内质网应激介导的细胞凋亡途径,减轻大鼠局灶性脑缺血再灌注损伤,其机制可能与下调GADD153蛋白表达有关。     

康脑液1号对大鼠脑缺血再灌注细胞凋亡及GFAP表达的影响

目的观察康脑液1号对SD大鼠脑缺血再灌注细胞凋亡及胶质纤维酸性蛋白（GFAP）表达的影响,探讨其对脑缺血再灌注保护作用的可能机制。方法采用栓线法复制SD大鼠大脑中动脉梗死模型（MCAO）,分别于缺血2h后再灌注1d、3d、7d。将180只大鼠随机分为5组（每组36只）：假手术组,模型（缺血再灌注）组,盐酸法舒地尔注射液组,康脑液1号A组,康脑液1号B组。观察康脑液1号对大鼠脑缺血再灌注神经功能、脑梗死面积和病理形态学的影响。采用TUNEL法检测缺血半暗带和灶中心区凋亡细胞,采用免疫组化法检测缺血半暗带和灶中心区GFAP表达的变化。结果模型组与假手术组相比,缺血半暗带凋亡细胞及GFAP阳性细胞数目增多（P〈0.05）。康脑液1号可不同程度地降低实验性脑缺血大鼠的神经功能评分、减小梗死灶面积并减轻脑组织病理形态改变（P〈0.05）;康脑液1号2组大鼠脑组织缺血半暗带凋亡细胞和GFAP表达减少,而梗死灶中心凋亡细胞和GFAP表达却增多。结论康脑液1号可能通过调节脑缺血再灌注细胞凋亡和GFAP表达而促进脑损伤修复及重塑,从而发挥脑保护作用。     

大鼠缺血再灌注肾组织一氧化氮合成酶mRNA表达的研究

目的 探讨大鼠缺血再灌注肾组织一氧化氮合成酶（NOS）mRNA表达的特点,分析缺血再灌注肾损伤的分子机制。方法 建立大鼠肾缺血再灌注模型。采用组织细胞原位杂交及图像分析技术对不同实验条件下各型NOS（eNOS,nNOS及iNOS)mRNA表达的定位及含量进行检测。并对肾组织NOS总活性及血肌酐（Cr)值进行生化测定。结果（1）正常情况下,eNOS,nNOS及iNOS在正常肾组织中均有表达,cNOS/iNOS比值为2.29;eNOS和nNOS主分布于肾小球及血管内皮;iNOS仅分布于皮质远,近曲小管上皮。（2）缺血时,肾组织NOS总活性显著下降,三种NOSmRNA在皮,髓质及小球中的表达均下调,以eNSO最明显,cNSO/iNOS比值降为2.01。（3）再灌注后,三种NOSmRNA的表达明显上调,以iNOSmRNA最明显,cNOS/iNOS比值降为1.77,eNOS及nNOS上调部位仅限于肾皮,髓质血管,而小球及小管中则表现为下调,尤以nNOSmRNA在小球中的下调最明显。结论 （1）缺血再灌注后,皮质肾小管上皮中iNOSmRNA的高表达是导致肾缺血再灌注损伤的重要分子机制。（2）cNOS/iN-OS比值与缺血再灌注过程中肾功能的变化密切相关,该比值的恒定对肾血流量和肾小球滤过率（GFR）的调节可能具有重要意义。     

硝酸异山梨酯对大鼠心肌后期预适应的诱导作用

目的：探讨硝酸异山梨酯（ISDN）能否诱导大鼠后期预适应及其可能机制。方法：采用大鼠在体缺血再灌注（I／R）模型，将动物随机分为生理盐水组、ISDN给药组、假手术组、后期缺血预适应组、生理盐水＋I，R组、ISDN＋I，R组、生理盐水＋格列苯脲＋I／R组、ISDN＋格列苯脲＋I／R组。前两组于给药24h后，测定心肌组织中的SOD和诱导型一氧化氮合成酶的含量，含I／R组于给药24h后进行缺血40min再灌注1．5h后测心肌梗死范围、心肌组织及血清学指标。结果：ISDN组心肌组织中诱导型一氧化氮合成酶浓度昵显比生理盐水组高（P〈0．01）；后期缺血预适应组和ISDN＋I／R组与生理盐水＋I/R组相比，心肌梗死面积、血清肌酸激酶和乳酸脱氢酶含量明显减少（前两者P〈0．05，后者P〈0．01），心肌组织中NO和锰-SOD显著增加，丙二醛显著下降（P〈0．05）。结论：ISDN能诱导心肌后期预适应，其机制与NO和诱导型一氧化氮合成酶的升高以及机体的抗氧化能力增强有关。     

Role of nitric oxide in the renal protective effects of ischemic preconditioning

Possible involvement of nitric oxide (NO) in the protective effect of ischemic preconditioning against the ischemia/reperfusion-induced acute renal failure was investigated. Ischemic preconditioning, which consists of three cycles of 2-minute ischemia followed by 5-minute reperfusion, was performed prior to 45-minute ischemia. Ischemic preconditioning significantly improved the renal dysfunction induced by 45-minute ischemia followed by 24-hour reperfusion. Histopathological examination of the kidney of ischemia/reperfusion rats revealed severe renal damage, and suppression of the damage was seen with the ischemic preconditioning treatment. NO metabolites (NOx) production in the kidney after 45-minute ischemia and reperfusion was markedly increased in ischemia/reperfusion rats with ischemic preconditioning, compared with animals not subjected to ischemic preconditioning, and these increases correlated with changes in endothelial NO synthase (eNOS) protein expression in renal tissues. The improvement of renal dysfunction in ischemic preconditioning rats was abolished by the pretreatment with NG-nitro-L-arginine, a nonselective NOS inhibitor, but not with aminoguanidine, an inducible NOS inhibitor. In addition, increment of endothelin-1 (ET-1) content in the kidney after the reperfusion was markedly suppressed by ischemic preconditioning treatment. These findings suggest that the protective effect of ischemic preconditioning on ischemia/reperfusion -induced acute renal failure is closely related to the renal nitric oxide production following the increase in eNOS expression after the reperfusion and that the suppressive effect of ischemic preconditioning on the ischemia/reperfusion -induced renal ET-1 overproduction may be partly involved in the ameliorating effect of ischemic preconditioning.     

辛伐他汀对大鼠脑缺血再灌注后脑组织NOS表达的影响

目的观察辛伐他汀对大鼠脑缺血再灌注后脑组织eNOS、nNOS和iNOS表达的影响。方法24只Wistar大鼠随机分为假手术组(Sham)、缺血再灌注IR组(IR)、辛伐他汀预处理高、低剂量组,每组6只。高剂量组和低剂量分别以阿伐他汀6mg/kg和1.5mg/kg连续灌胃7天。用线栓法制备大脑中动脉缺血再灌注模型,缺血2h,再灌注22h,应用免疫组化法检测脑组织中eNOS、nNOS和iNOS的表达。结果与缺血再灌注组比较,辛伐他汀低剂量组eNOS表达差异无显著意义(P>0.05),高剂量组eNOS表达显著增加(P>0.05);高剂量和低剂量组nNOS和iNOS的表达显著降低(P<0.01,P<0.05)。结论辛伐他汀预处理能抑制大鼠脑缺血再灌注后脑组织iNOS、nNOS的表达、上调eNOS表达。     

Refined Qing Kai Ling, traditional Chinese medicinal preparation, reduces ischemic stroke-induced infarct size and neurological deficits and increases expression of endothelial nitric oxide synthase

Refined Qing Kai Ling (RQKL) is an improved injectable multi-component preparation derived from Qing Kai Ling, which could offer the neuroprotection effect in middle cerebral artery occlusion (MCAO) model of rats by relieving the damage of vascular endothelial cell as well as inhibiting the process of inflammation. Herein, we observed whether RQKL could exert influence on the expression of endothelial nitric oxide synthase (eNOS), as a mechanism of its protective effects against ischemia. Sprague-Dawley rat model of focal cerebral ischemia was established by permanent filament occlusion of the left middle cerebral artery. We found that the administration of RQKL could reduce the ischemic infarct size as well as neurological deficit of model rats. Furthermore, it was showed that the eNOS level was consistently increased in endothelium of blood vessels of the ischemic penumbra after 2 to 72 h of permanent MCAO, and the expression of eNOS increases more in animals treated with RQKL. Our results suggested that eNOS levels in penumbral zone were enhanced after permanent focal ischemia, and RQKL could stimulate postischemic eNOS expression, which may be an important mechanism in RQKL's protection against cerebral ischemia.     

一氧化氮在大鼠心肌缺血后处理中的作用

目的:探讨在体条件下,一氧化氮(NO)对缺血后处理心肌保护作用的影响及可能的途径。方法:建立大鼠在体缺血再灌注模型,将24只大鼠随机分为假手术组、缺血再灌注组、缺血后处理组及一氧化氮合酶(NO S)抑制剂NW-L硝-基精氨酸甲酯(L-NAM E)药物干预后处理组(药物干预组)。于再灌注末测定血浆肌钙蛋白I(cT n I),NO,超氧化物歧化酶(SOD)及丙二醛(M DA)的含量,测定心肌组织梗死面积,免疫组化方法观察心肌组织内皮型一氧化氮合酶(eNO S)的表达。结果:与缺血再灌注组及药物干预组相比,缺血后处理组心肌梗死面积明显减少,血浆cT n I,M DA含量降低,血浆NO,SOD含量升高,心肌细胞胞浆内eNO S表达增加。结论:缺血后处理通过eNO S/NO信号通路,抑制脂质过氧化反应,减轻心肌缺血/再灌注损伤。     

Down regulation of cyclooxygenase-2 is involved in delayed neuroprotection by ischemic preconditioning in rats

Aim: To examine whether the prostaglandins (PGs) pathway is involved in triggering delayed neuroprotection by ischemic preconditioning (IPC) and evaluate the effects of IPC on cyclooxygenase-2 (COX-2) expression following focal cerebral ischemia and reperfusion in rats. Methods: IPC was induced by 10min of saline infusion into the left internal carotid artery with the right common carotid artery clamped at the same time. Middle cerebral artery occlusion (MCAO) and reperfusion model was prodt:ced using intraluminal filament method. Results: IPC 48h priorto MCAO significantly reduced infarct area as compared with MCAO alone. A nonselective inhibitor of COX indomethacin (3mg/kg ip) applied 1h prior to or 1h after IPC failed to affect its protective effects. IPC had no direct effect on the cortex COX-2 mRNA and protein expression 72h later, but decreased the expression of COX-2 mRNA and protein following ischemia and reperfusion insult. Conclusion: PGs pathways was not involved in triggering delayed neuroprotection by IPC, and IPC induced down-regulation of COX-2 following focal cerebral ischemia and reperfusion in rats in vivo.     

Differential role of nitric oxide pathway and heat shock protein in preconditioning and lipopolysaccharide-induced brain ischemic tolerance

The purposes of this study were to investigate the role of nitric oxide (NO), nitric oxide synthase (NOS), and 70 kDa heat shock protein in brain ischemic tolerance induced by ischemic preconditioning and lipopolysaccharide. Focal cerebral ischemia was induced in rats by intraluminal middle cerebral artery occlusion. Infarct volume was significantly reduced (1) in rats subjected to 3 min ischemia 72 h prior to 60 min ischemia; (2) in rats administered lipopolysaccharide (0.5 mg/kg; i.p.) 72 h prior to 60 min ischemia compared with controls. The beneficial effect of ischemic preconditioning was unchanged despite prior administration of nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor. Conversely, the protective effect of lipopolysaccharide was nullified by L-NAME. Using immunohistochemical techniques, we observed that (1) ischemic preconditioning but not lipopolysaccharide induces the expression of 70 kDa heat shock protein in cerebral cortex and (2) lipopolysaccharide induces early increased expression of endothelial NOS in cerebral blood vessels. The results suggest that (1) endothelium-derived NO plays a role of a trigger in the brain tolerance induced by lipopolysaccharide, and (2) 70 kDa heat shock protein is involved in the protection afforded by ischemic preconditioning but not by lipopolysaccharide.     

前列地尔对局灶性脑缺血模型大鼠大脑皮层中iNOS和eNOS表达的影响

目的:探讨前列地尔对局灶性脑缺血模型大鼠大脑皮层中诱导型一氧化氮合酶(iNOS)和内皮型一氧化氮合酶(eNOS)表达的影响。方法:取大鼠随机分为假手术组、模型组、阳性对照(尼莫地平1mg.kg-1)组和前列地尔低、中、高剂量(1.25、2.50、5.00μg.kg-1)组,每组10只,腹腔注射相应药物6d,每日1次,末次给药后建立局灶性脑缺血模型,大鼠清醒后进行神经功能缺损评分,采用免疫组化法和免疫印迹法检测各组大鼠建模2h后iNOS、eNOS的表达。结果:与假手术组比较,其余各组神经功能缺损评分均明显增加,iNOS阳性细胞数和表达量均明显增加,除模型组外其余各组eNOS阳性表达量均增加(P均<0.05);与模型组比较,阳性对照组和前列地尔中、高剂量组神经功能缺损评分均明显降低,阳性对照组和前列地尔3个剂量组iNOS阳性细胞数和表达量均明显降低、eNOS阳性细胞数和表达量均明显增加(P均<0.05)。结论:前列地尔预处理对局灶性脑缺血模型大鼠具有保护作用,其机制可能与下调大脑皮层iNOS、上调eNOS的表达有关。