脊髓缺血再灌注损伤的防治概况

脊髓缺血-再灌注损伤(SCII)是一种严重的神经系统损伤,是缺血脊髓组织恢复血液灌注后,脊髓组织的损伤反而加重,表现为其神经损害体征和形态学改变较前更加明显,其发生机制是多因素的综合结果,治疗措施也具有多样性,脊髓缺血后脊髓微血管结构及功能的破坏和脊髓水肿等是脊髓功能损害的主要诱因,至今为止,脊髓缺血再灌注损伤的防治主要有药物及物理治疗等方法,本文作者通过查阅中外文献对脊髓缺血再灌注损伤的特征、发生机制及防治措施作一综述,希望对研究脊髓缺血再灌注损伤防治的学者能有所帮助。     

大鼠放射性脊髓损伤脊髓血流量变化规律

目的:放射性脊髓损伤(Radiation spinal cord injury,RSCI)是头颈部、胸部及上腹部肿瘤放射治疗和射线意外照射时的常见并发症,一般认为,白质坏死、脱髓鞘为其主要的病理学变化.然而,越来越多的证据表明血-脊髓屏障破裂和血管通透性增加等血管损伤远早于白质坏死和脱髓鞘改变.所以本文阐明大鼠放射性脊髓损伤病理生理过程中脊髓血流量变化规律.方法:将60只Sprague-Dawley (SD)大鼠随机分为12组,1组为对照,其余11组采用60Co放射治疗机行30 Gy大鼠颈髓C2-T2单次照射,剂量率为153 cGy/min,源皮距为80 cm,照射时长为1153 s,照射范围为2.0× 1.0 cm,对照组大鼠于麻醉后置于60Co放射治疗机下,佯照,照射前及照射后分别采用激光多普勒法测量脊髓血流量,11组大鼠于照射前以及照射后1、3、7、14、21、30、60、90、120、150、180天进行测量,以照射前测量值为基数,各时间点以基数的百分比表示该时间点脊髓血流量.结果:大鼠放射性脊髓损伤后,脊髓血流量在照射早期即有降低,照射后90天达到最低,随后脊髓血流量进入平台期.结论:阐明了大鼠放射性脊髓损伤后脊髓血流量的变化规律.大鼠放射性脊髓损伤可影响脊髓血流量,导致脊髓长期处于持续低灌流、缺血缺氧状态,最终导致脊髓不可逆性损伤.临床上放射性脊髓损伤的病人感到疲乏无力,出现神经系统的症状体征,通常死于脑疝.本文为临床上疲乏无力,出现神经系统的症状体征,死于脑疝放射性脊髓损伤的病人的早期防治提供病理生理基础.     

自噬在高压氧预处理预防脊髓缺血再灌注损伤中 的作用机制研究*

目的:研究自噬在高压氧预处理预防脊髓缺血再灌注损伤中的机制。方法:新生大鼠脊髓神经元原代培养,分为对照组(氧糖剥夺)和高压氧(HBO)预处理组。通过应用免疫组织化学、Western blot分析两组LC3-Ⅱ与凋亡相关分子Beclin-1,Bcl-2,Casp-ase-3的表达变化。结果:发现重复高压氧预处理对氧糖剥夺诱导原代培养的脊髓神经元损伤具有明显的保护作用。免疫组化和Western blot显示与对照组相比高压氧预处理显著增加脊髓神经元细胞Bcl-2的表达,降低Beclin-1,Caspase-3以及自噬的特异性标记蛋白LC3-Ⅱ的表达。氧糖剥夺后对照组与高压氧组相比,LDH释放量明显增多(P<0.05)。结论:HBO预处理通过调节自噬减轻缺血再灌注损伤,为HBO预处理神经保护提供一条新的作用机制。     

Homer1a基因敲除对小鼠局灶性脑缺血再灌注损伤的作用

目的:通过研究homer1a基因敲除小鼠脑缺血再灌注损伤及海马区星形胶质细胞活化、数目形态变化,探讨homer1a基因在脑缺血损伤中的作用及机制。方法:取雄性homer1a基因敲除(Knock Out,KO)小鼠及同窝野生型(Wild Type,WT)小鼠各15只,分为基因敲除假手术组(Sham Knock Out,SKO,n=3)、基因敲除型缺血2 h再灌注24 h组(Model Knock Out,MKO,n=12)、野生型假手术组(Sham Wild Type,SWT,n=3)及野生型缺血2 h再灌24h组(Model Wild Type,MWT,n=12)。线栓法闭塞小鼠大脑中动脉制作脑缺血再灌注损伤模型(middle cerebral artery occlusion and reperfusion,MCAO/R),在缺血再灌注损伤前(0 h)及缺血再灌注后3 h、6 h、12 h、24 h后进行改良版神经损伤严重性评分(modified Neurological severity scores,m NSS)、2,3,5—氯化三苯基四氮唑(2,3,5triphenyltetrazolium chloride,TTC)染色、苏木素—伊红染色(Hematoxylin-eosin staining,HE)、原位末端转移酶标记技术(terminal deoxynucleotidyl transferase(Td T)-mediated deoxyuridine triphosphate(d UTP)nick end labeling,TUNEL)检测及免疫荧光染色观察海马区星形胶质细胞神经纤维酸性蛋白(Glial Fibrillary Acidic Protein,GFAP)改变。结果:SKO组、SWT组行为学m NSS评分均为0分,TTC染色未见梗死灶。TUNLE及GFAP染色阳性细胞数很少且未见统计学差异(P0.05)。脑缺血再灌注24 h后,MKO组m NSS评分较MWT组高;TTC染色MKO组较MWT组梗死百分比高;MKO组较MWT组TUNEL凋亡率高;GFAP免疫荧光染色阳性数MKO组少于MWT组,且均有统计学差异(P0.05)。结论:homer1a基因敲除加重了小鼠脑缺血再灌注损伤,星形胶质细胞可能参与并发挥复杂作用。     

人源抗ICAM-1单链抗体的制备及其生物学活性鉴定

利用噬菌体展示技术筛选特异性人源抗ICAM-1单链抗体（Anti-human ICAM-1 scFv）并进行生物学活性鉴定。应用Tomlinson I+J噬菌体抗体库,以P1抗原肽为包被抗原,经过4轮“吸附-洗脱-扩增”进行亲和富集筛选。以PCR反应、ELISA抗原交叉反应和Dot blotting实验进行阳性克隆的鉴定。scFv经原核表达和分离纯化后,以Western blotting实验、竞争ELISA实验和细胞黏附抑制实验对其生物学活性进行初步鉴定。Tomlinson I+J噬菌体抗体库经4轮亲和富集筛选,利用ELISA方法成功筛出4株阳性克隆。通过PCR鉴定反应、ELISA抗原交叉反应和Dot blotting实验,最终获得了1株既能与P1抗原肽特异结合又能与人ICAM-1抗原特异结合的阳性克隆J-A1。对scFv进行原核表达和亲和层析后获得了高纯度的目的蛋白。竞争ELISA实验和细胞黏附抑制实验证实纯化的scFv具有良好的亲和活性和抗细胞黏附活性。文中成功利用噬菌体展示技术筛选到特异性人源抗ICAM-1 scFv,为进一步探索该抗体在炎症相关性疾病治疗中的应用奠定了基础。     

电针预处理对脑缺血再灌注后小胶质细胞活化状态的影响

目的:观察电针预处理对脑缺血再灌注后小胶质细胞活化状态的影响。方法:成年雄性SD大鼠随机分为假手术组(sham)、缺血组(MCAO)、电针处理组(EA+MCAO)三组。采用大脑中动脉栓塞(MCAO)诱导大鼠局灶性脑缺血再灌注模型。缺血再灌注后6 h、24 h、3 d和7 d取材,运用Western blot及免疫荧光技术检测缺血半暗带小胶质细胞活化状态以及M1/M2型特异性标志分子的表达水平。结果:脑缺血再灌注后,小胶质细胞被激活,数量表达增加(P0.05,vs.sham组),形态从静息状态的分支状转变为圆形的阿米巴状。M1型标志分子i NOS主要表达于缺血再灌注后24小时(P0.05,vs.sham组),M2型标志分子Arginase主要表达于缺血再灌注后7天(P0.05,vs.sham组)。电针预处理上调Arginase的表达水平,下调i NOS的表达水平(P0.05,vs.MCAO组)。结论:缺血再灌注后小胶质细胞被激活,电针预处理促使活化的小胶质细胞由M1向M2转化。     

十六酰胺乙醇对大鼠脑缺血再灌注损伤的抗氧化及抗凋亡作用

目的:探讨十六酰胺乙醇(Palmitoylethanolamide PEA)对大鼠脑缺血再灌注损伤的保护作用及机制。方法:将雄性SD大鼠随机分为:假手术组、药物组、模型组。采用线栓法制造大脑中动脉缺血再灌注模型,药物组于缺血后30分钟及再灌注后2小时给予PEA(10mg/Kg)腹腔注射。于再灌注24h后,对各组大鼠进行神经功能评分,TTC染色法测脑梗死体积,硫代巴比妥法测丙二醛(MDA)含量,黄嘌呤氧化酶法测超氧化物歧化酶(SOD)活性,WesternBlot法测Bcl-2和Bax蛋白含量。结果:药物组神经功能评分均值为1.33±0.49分,而模型组为2.20±0.41分,药物组神经功能评分显著低于模型组(P0.05);药物组的脑梗死体积为114.00±8.63mm3,而模型组脑梗死体积为243.40±14.19mm3,药物组脑梗死体积显著低于模型组(P0.05);药物组MDA含量为3.85±0.29nmol/mgprot,SOD活性为13.95±0.71U/mgprot,而模型组MDA含量为4.85±0.30nmol/mgprot,SOD活性为12.44±0.40U/mgprot,与模型组相比,药物组的MDA含量显著降低,而SOD活性显著增高(P0.05);药物组Bcl-2蛋白与β-action蛋白的IOD值比值为0.53±0.013%,Bax蛋白与β-action蛋白的IOD值比值为0.54±0.012%,模型组Bcl-2蛋白与β-action蛋白的IOD值比值为0.40±0.012%,Bax蛋白与β-action蛋白的IOD值比值为0.80±0.012%。药物组Bax蛋白含量显著低于模型组(P0.05),而Bcl-2蛋白含量显著高于模型组(P0.05)。结论:PEA对大鼠脑缺血再灌注损伤具有保护作用,可能是通过抗凋亡、抗氧化应激等作用实现。     

Effects of Metabotropic Glutamate Receptor Stimulation on Cerebral O2 Consumption and Blood Flow During Focal Cerebral Ischemia in Rats

This investigation was performed to evaluate the effects of ACPD [(1S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid], a metabotropic glutamate receptor agonist, on cerebral O₂ consumption during focal cerebral ischemia. Male Wistar rats were placed in control (n = 7) and ACPD (n = 7) groups under isoflurane anesthesia. Twenty minutes after middle cerebral artery (MCA) occlusion, gauze sponges with 10^–5 M ACPD or normal saline were placed on the ischemic cortex (IC) for a period of 40 min and were changed every 10 min. One hour after MCA occlusion, regional cerebral blood flow (rCBF) was determined using the C¹⁴-iodoantipyrine autoradiographic technique. Regional arterial and venous oxygen saturation were determined using microspectrophotometry. There were no statistical differences in vital signs, blood gases, and hemoglobin between the groups. In the control group, the cerebral blood flow and oxygen consumption of the IC were significantly lower than the contralateral cortex (rCBF: 45 ± 11 vs. 110 ± 11 ml/min/100 g, O₂ consumption: 2.9 ± 0.4 vs. 5.4 ± 1.1 ml O₂/min/100 g). ACPD did not change regional cerebral blood flow of the IC, but did significantly increase the oxygen extraction (7.8 ± 0.2 vs. 6.9 ± 0.3 ml O₂/100 ml) and oxygen consumption of the IC (4.3 ± 1.5 vs. 2.9 ± 0.4) compared to the control IC. Our data demonstrated that topical application of 10^–25 M ACPD to the ischemic area worsened cerebral O₂ balance. These data suggest that metabotropic glutamate receptors are not maximally activated during ischemia in the temporal cortex.     

Age-Related Ischemia in the Brain Following Bilateral Carotid Artery Occlusion—Collateral Blood Flow and Brain Metabolism

Cerebral blood flow (CBF) and cerebellar blood flow (CeBF) were measured and correlated with brain lactate, pyruvate and adenosine triphosphate concentrations from groups representing 3-week old suckling (n = 10), 18–22-week old adult (n = 9) and 70-week old aged (n = 7) Sprague-Dawley rats before and during bilateral carotid occlusion (BCO). The steal ratio, calculated as the ratio of %control CBF to %control CeBF, was 1.02 ± 0.06 (mean ± SEM) at 60 minutes of BCO in adult rats that exhibited normal levels of brain metabolites. By contrast, the ratios significantly decreased to 0.74 ± 0.06 in suckling rats and 0.69 ± 0.06 in aged rats with simultaneous increases by 2.4 to 2.9-fold of tissue lactate. Pyruvate and lactate/pyruvate ratio also increased by 1.4 to 1.8 times control in both suckling and aged rats. We conclude that there is age-related steal phenomenon occurring with blood flow during BCO. Ischemic derangement of the brain metabolism is in part related to poor blood supply from the posterior circulation in suckling and aged rats.     

三七皂苷Rg1对大鼠脑缺血再灌注损伤海马部位保护作用机制的研究

本文探讨三七皂苷Rg1对局灶性脑缺血再灌注损伤大鼠海马部位的脑源性神经营养因子(brain-derivedneurotrophic factor,BDNF)阳性蛋白的含量和阳性神经元数目是否具有上调作用。实验结果表明三七皂苷Rg1高、中、低剂量组和阳性对照组均能明显改善脑缺血的神经缺失症状,并能上调大鼠脑缺血再灌注损伤海马部位的BDNF阳性蛋白的含量和阳性神经元数量(P<0.05);与阳性对照组(尼莫地平1 mg/kg)相比,用药7 d时,Rg1中剂量组(100 mg/kg)在改善脑缺血的神经缺失症状以及上调大鼠脑缺血再灌注损伤海马部位的BDNF阳性蛋白的含量和阳性神经元数量方面,作用上强于尼莫地平(P<0.05)。三七皂苷Rg1能上调BDNF阳性蛋白的表达,通过BDNF对脑缺血再灌注神经元损伤所起的保护作用,从而发挥其对脑缺血的治疗作用,这可能是三七皂苷Rg1对脑缺血保护作用的机制之一。     

Cerebral Oxidative Metabolism and Blood Flow During Acute Hypoglycemia and Recovery in Unanesthetized Rats

Abstract: Progressive neurological depression leading to coma was produced in unanesthetized rats at a constant level of hypoglycemia induced by insulin. High-energy phosphate concentrations in brain remained normal during hypoglycemic lethargy, but ATP declined by 6% during stupor and by 40% during coma that was characterized by an isoelectric EEG. Cerebral blood flow (CBF) remained normal during hypoglycemia whereas the cerebral metabolic rates for oxygen (CMRo₂) and glucose (CMR_glucose) decreased by 45 and 73%, respectively, indicating oxidation of nonglucose fuels. A plot of CMRo₂ and CMR_glucose versus plasma glucose indicated increasing oxidation of alternate substrates (elevated CMRo²/CMR_glucose) at plasma glucose concentrations below 2.5 mm . The cerebral uptake of β-hydroxybutyrate increased during hypoglycemic stupor and its complete oxidation could account for the CMRo₂ in excess of glucose utilization. Brain ammonia, a byproduct of amino acid metabolism, reached a level during hypoglycemic coma sufficient to produce coma in normoglycemic animals. The rate and degree of recovery after glucose administration depended on the duration of hypoglycemia and the pretreatment neurological state of the animal. Following 10 min of glucose infusion, ATP levels that were modestly depressed in stuporous rats recovered fully, paralleling the animals' apparently full neurological recovery. Rats that had been in hypoglycemic coma for 1 min or less fully recovered high-energy phosphate concentrations in brain. However, when normalization of plasma glucose was delayed for more than 1 min of coma, the CMRo₂ remained depressed, CBF decreased to 40% of control, and high-energy substrates failed to normalize. In keeping with the depression of oxidative metabolism and blood flow, neurological function and the EEG remained abnormal even after 1 h of glucose infusion. The findings suggest that irreversible brain injury may develop within the first minutes of hypoglycemic coma.     

HTEA对全脑缺血/再灌注大鼠脑血流及海马细胞凋亡的影响

目的:研究上胸段硬膜外阻滞(high thoracic epidural anesthesia,HTEA)对大鼠全脑缺血再灌注损伤(global cerebral ischemia,GCI)再灌注期间脑血流及凋亡相关蛋白Bcl-2和Bax的影响。方法:本研究选用成年雄性Wistar大鼠成功进行T4-5间隙硬膜外置管,并建立四血管阻断的全脑缺血模型进行15 min的全脑缺血。根据通过硬膜外导管输注药物不同,随机分为四组:假手术组(Sham,0.9%生理盐水)、假手术-硬膜外组(Sham-HTEA,0.25%布比卡因)、全脑缺血组(GCI,0.9%生理盐水)和硬膜外组(HTEA,0.25%布比卡因)。给药时间从缺血前15 min开始以20μL/h的速度持续输注至再灌注24 h。缺血前至再灌注2 h观察平均动脉压(MAP)和心率(HR),激光多普勒血流仪监测脑血流(cerebral blood flow,CBF),Western-blot检测再灌注24 h海马凋亡蛋白Bcl-2和Bax含量。结果:HTEA组与GCI组相比,缺血期间及再灌注2 h内的MAP和HR无统计学差异,而与Sham组相比,GCI组的MAP缺血时升高,而再灌注时降低(P0.05);再灌注10 min的高灌注期HTEA组CBF明显低于GCI组(123.1%±35.2%vs 177.5%±32.4%,P0.01),再灌注60 min至120 min的低灌注期的大部分时间点HTEA组CBF均高于GCI组(P0.05);再灌注24 h海马组织Bax/Bcl-2比例明显降低(P0.01)。结论:0.25%的布比卡因20μL·h-1连续上胸段硬膜外阻滞可以维持血流动力学稳定,且可改善大鼠全脑缺血再灌注后低灌注期的脑血流量,并减少再灌注24 h海马Bax/Bcl-2比例。     

姜黄素后处理通过SIRT1/FOXO1信号通路拮抗小鼠脑缺血再灌注损伤

目的:探究姜黄素后处理是否通过激活SIRT1/FOXO1信号通路抵抗小鼠脑缺血再灌注损伤。方法:小鼠脑缺血30 min,再灌注24 h建立脑缺血再灌注模型。手术前脑室内注射SIRT1特异性抑制剂EX527。再灌注后腹腔注射姜黄素。小鼠随机分为以下6组:假手术组;单纯姜黄素后处理组;缺血再灌注组;缺血再灌注+姜黄素后处理组;EX527预处理+缺血再灌注+姜黄素后处理组;EX527预处理+脑缺血再灌注组。再灌注24 h检测脑梗体积、Complex I活性、ROS含量以及SIRT1、Ac-FOXO1、Bax、Bcl-2、Caspase-3蛋白表达情况。结果:与手术组相比,姜黄素后处理组梗死区脑组织SIRT1的表达量及活性明显增加,脑梗体积降低,ROS含量降低而Complex I活性增高,Bcl-2的表达增高而Bax和Caspase-3的表达量降低(均P0.05)。阻断SIRT1信号通路后上述姜黄素脑保护作用均减弱(P0.05)。结论:我们的研究首次证实姜黄素后处理通过激活SIRT1/FOXO1信号通路,进而降低氧化应激与凋亡,最终减轻脑缺血再灌注损伤。     

Superoxide Generation by Kupffer Cells and Priming of Neutrophils During Reperfusion After Hepatic Ischemia

The objective of this study was to identify the cellular source of the vascular oxidant stress in hepatic ischemia-reperfusion injury in male Fischer rats. Nonparenchymal cells (Kupffer cells, endothelial cells) and neutrophils were isolated from postischemic liver lobes by collagenase-pronase digestion followed by centrifugal elutriation. The spontaneous and stimulated generation of superoxide by these cells were subsequently quantified in vitro. Large Kupffer cells from the postischemic lobes spontaneously generated 300% more superoxide than similar cells from control animals. No difference in spontaneous superoxide formation was found when the small Kupffer cells were compared. No other cells isolated from the postischemic lobes or control liver including neutrophils released any detectable superoxide spontaneously. In contrast, small Kupffer cells and neutrophils from the postischemic liver generated significantly more superoxide after stimulation with phorbol ester or opsonized zymosan than the controls. The considerably higher response with zymosan stimulation compared to phorbol ester indicates a particular priming for a receptor-mediated signal transduction pathway during reperfusion. These studies demonstrate that Kupffer cells are the principal source of the oxidant stress during the initial reperfusion phase after hepatic ischcmia. The priming of neutrophils during this time may be an important factor for the later neutrophil-induced injury phase.     

Changes in Phosphorylation of τ During Ischemia and Reperfusion in the Rabbit Spinal Cord

Abstract: The microtubule-associated protein τ plays an important role in the dynamics of microtubule assembly necessary for axonal growth and neurite plasticity. Ischemia disrupts the neuronal cytoskeleton both by promoting proteolysis of its components and by affecting kinase and phosphatase activities that alter its assembly. In this study the effect of ischemia and reperfusion on the expression and phosphorylation of τ was examined in a reversible model of spinal cord ischemia in rabbits. τ was found to be dephosphorylated in response to ischemia with a time course that closely matched the production of permanent paraplegia. Dephosphorylation of τ was limited to the caudal lumbar spinal cord. In a similar manner, Ca²⁺/calmodulin-dependent kinase II activity was reduced only in the ischemic region. Thus, dephosphorylation of τ is an early marker of ischemia as is the rapid loss of Ca²⁺/calmodulin-dependent kinase II activity, τ, however, was rephosphorylated rapidly during reperfusion at site(s) that cause a reduction in its electrophoretic mobility regardless of the neurological outcome. Alterations in phosphorylation or degradation of τ may affect microtubule stability, possibly contributing to disruption of axonal transport but also facilitating neurite plasticity in a regenerative response.     

活性氧簇在脑缺血-再灌注损伤中的损伤与保护作用

活性氧簇是细胞有氧代谢过程中产生的一类化学基团。线粒体是活性氧簇的主要生成位点。一般观点认为,在脑缺血-再灌注损伤过程中,活性氧簇发挥神经细胞损伤作用。活性氧簇不仅直接参与神经细胞氧化损伤过程,也可通过外源性途径和内源性途径,引起神经细胞凋亡。然而,除神经细胞损伤作用外,活性氧簇也可发挥神经细胞保护作用。活性氧簇可激活低氧诱导因子、核转录因子κB、PI3K/Akt通路和MAPK通路等,参与神经细胞存活机制,减轻神经细胞损伤。本文对活性氧簇在脑缺血-再灌注损伤中的双重作用进行综述。     

Protective effect of vitamin E on spinal cord injury by compression and concurrent lipid peroxidation

Studies were made on the influence of vitamin E on the effects of compression injury of the spinal cord associated with ischemia in rats. The motor disturbance induced by spinal cord injury was greatly reduced by vitamin E supplementation. After injury, the spinal cord evoked potentials showed greater recovery of both amplitude and latency in the vitamin E-supplemented group than in the control group. Spinal cord blood flow was promptly restored and remained normal after injury in the vitamin E-supplemented group, but was significantly decreased from 3 h after injury in the control group. Thiobarbituric acid (TBA)—reactive substances in the spinal cord was immediately increased by compression injury in both groups, and after injury it persisted at a high value for 24 h in the control group, but decreased within 1 h in the vitamin E-supplemented group. Pathological examination of the spinal cord showed less damage, such as bleeding and edema, in the vitamin E-supplemented group than in the control group. Vitamin E may have protective effects on the spinal cord by inhibiting damage induced by lipid peroxidation and/or by sustaining the blood flow by maintaining the normal metabolism of arachidonic acid.     

头颅局部亚低温对脑梗死治疗作用的临床研究

目的：观察头颅局部行亚低温治疗脑梗死后患者血清一氧化氮、内皮素以及细胞间粘附分子含量的变化,探讨亚低温治疗对脑组织发挥保护作用的机制。方法：搜集2012年5月至2013年2间,哈尔滨医科大学附属第四医院神经内科收治的62例脑梗死患者,并随机分为亚低温治疗组（32例）和常规治疗对照组（30例）,治疗组在药物治疗脑梗死的同时加用局部亚低温治疗技术,在治疗前、治疗后3、7、14d进行一氧化氮、内皮素及细胞间粘附分子的测定;两组患者分别于治疗前以及治疗后第30d,对神经功能缺损采用NIHSS量表进行评分,对日常生活活动能力采用Bathel指数评分,对运动功能采用FuglMeyer法进行评价。结果：在治疗后第3、7、14天,亚低温治疗组一氧化氮含量较对照组显著升高（均为P〈0．01）,在治疗后第7天亚低温治疗组内皮素含量低于对照组（P〈0．05）,第3、14天亚低温组内皮素含量显著低于对照组（P〈0．01）;治疗前两组NIHSS评分、Bamel指数和FuglMeyer评分差异均无显著性意义（P〉0．05）。在治疗组治疗后的第3、7、14天,亚低温治疗组细胞间粘附分子与治疗前相比,均出现降低（P〈0．05）;而且在第3天,治疗组和对照组有显著性差异（P〈0．05）。治疗1个月后,亚低温治疗组NIHss评分比常规治疗组显著降低,亚低温治疗组Bathel指数和FuglMeyer评分均明显高于对照组,差异具有显著性。结论：局部亚低温治疗对血管内皮细胞功能有较好的保护作用,可改善脑梗死患者神经功能缺损及预后。     

心肺复苏后脑缺血再灌注损伤治疗理念及相关动物模型研究进展

心肺复苏后脑缺血再灌注损伤是一个复杂的病理生理变化过程,由多种损伤机制共同参与。自心肺复苏后系统性综合治疗和亚低温治疗在临床上广泛应用后,目前已有多种治疗理念在不同的动物实验和动物模型基础上被提出,包括缺血预处理、药物预处理、缺血后处理、和药物后处理,而后吸入麻醉药对心肺复苏后脑缺血再灌注损伤的保护作用受到了人们的重视,而七氟烷后处理已经成为目前研究的热点之一。为了指导临床上的心肺复苏,人们一直在利用不同动物模型,探究不同保护方法,寻找有效的脑保护药物。而各种治疗理念的提出均是建立在动物实验和动物模型的基础上,窒息性心肺复苏模型模拟围术期气道梗阻,能较贴切的复制临床上由窒息引起的心肺复苏后脑损伤,对将来指导临床复苏具有重大意义。     

Augmentation of Nitric Oxide,Superoxide, and Peroxynitrite Production During Cerebral Ischemia and Reperfusion in the Rat

The effect of ischemia produced by bilateral occlusion of the common carotid arteries (30 min) followed by 4 hours of reperfusion on total and inducible nitric oxide synthase (NOS) activity and the production of nitric oxide (NO), superoxide and peroxynitrite in the cerebral hemispheres was determined in the rat. Compared to sham-operated controls, cerebral ischemia-reperfusion resulted in a significant increase in total and inducible NOS activity and a significant increase in the production of NO and superoxide in the cerebral hemispheres. The level of NO in the plasma and the peripheral leukocyte count were also significantly increased. Immunohistochemical staining for nitrotyrosine (a marker of peroxynitrite production) showed that ischemia-reperfusion resulted in increased synthesis of cerebral peroxynitrite. Administration of the irreversible NOS inhibitor, N-nitro-L-arginine (L-NA), increased superoxide levels in the brain and significantly reduced plasma NO. Total and inducible NOS activity as well as NO and immunoreactive nitrotyrosine, in the cerebral hemispheres were reduced with L-NA administration. The number of leukocytes in the plasma was unaffected by administration of L-NA. These findings suggest that cerebral ischemia-reperfusion causes increased production of reactive oxygen species in the cerebral hemispheres and that the production of peroxynitrite, and not superoxide, may be dependent upon the availability of NO.