血红蛋白和血红素氧合酶抑制剂在脑出血迟发性脑水肿中的作用

目的 研究血红蛋白(Hb)与脑出血迟发性脑水肿的关系,锌原卟啉(ZnPP)在脑出血迟发性脑水肿中的作用,为治疗脑出血迟发性脑水肿提供新的方法.方法 将大鼠分为生理盐水组、血红蛋白组和ZnPP组,向大鼠的尾状核分别注入生理盐水(NS组)和自体Hb溶液(Hb组和ZnPP组),并向ZnPP组大鼠腹腔内注射ZnPP,观察各组血脑屏障(BBB)通透性的变化、Hb的分解情况、脑水肿的程度和脑组织病理表现.结果 与Hb组大鼠相比,ZnPP组大鼠BBB通透性降低、Hb的分解产物减少和脑含水量降低(P<0.05).结论 Hb可以引起脑水肿,ZnPP对脑出血迟发性脑水肿有治疗作用.     

红细胞致脑出血后血肿周围脑组织HO-1的表达与血脑屏障通透性变化的关系

脑出血是一种严重危害人们健康的疾病,病死率和致残率很高。而脑水肿是引起脑出血后继发性损伤的一个重要因素,脑出血的病死率和致残率与脑水肿的发生和发展有着密切的关系。研究表明,血肿成分及其降解产物的毒性作用是脑出血后脑水肿形成的重要原因。红细胞作为血肿中的主要成分对迟发性脑水肿的形成起着决定性的作用[1]。由于红细胞所引起的脑水肿是在脑出血后数天触发的,因此针对红细胞及其内容物的作用进行干预有可能是治疗脑出血后脑水肿的新方法[2]。血肿中的红细胞溶解破裂后,释放血红蛋白并降解为血红素,同时血红素在血红素氧合酶的…     

大鼠创伤性脑内出血中红细胞对脑水肿的影响

目的研究红细胞对创伤性脑内出血(TICH)后脑水肿的影响。方法自由落体打击造成大鼠脑外伤,借助鼠脑立体定向仪向伤区脑皮质内注射全血(WB)、溶解红细胞(LRBC)或压积红细胞(PRBC),制作TICH模型。于伤后1、3、5d处死大鼠,取伤区脑组织测含水量及Na 、K 、Ca2 含量,并作病理检查。结果(1)TBI、WB和PRBC3组第3d的脑含水量最高,LRBC组第1d的含水量最高;4组间比较,第1d时LRBC含水量最高,第3d时PRBC和WB组含水量最高。(2)Na 的变化与含水量的变化相一致。结论TICH所形成的脑水肿较单纯脑外伤重。在TICH中,红细胞对早期脑水肿的形成无明显作用,而对迟发性脑水肿的形成有重要作用。     

脑出血后脑水肿产生机制的研究进展

为了探索脑出血后脑水肿产生机制,对近5年来脑出血后脑水肿产生机制的研究进展进行了综述。研究表明脑出血后脑水肿的形成是多种因素共同作用的结果,大致包括三个阶段:早期(发病几个小时)是因为血浆蛋白积聚、血脑屏障渗透性升高引起;第二阶段(1天)是因为凝血酶的作用;第三阶段(大约3天)是因为红细胞溶解和血红蛋白的毒性作用。     

血红蛋白对高原地区高血压脑出血术后疗效的影响魏林节,董红让,冯国君,等简

目的探讨血红蛋白对高原地区高血压脑出血术后疗效的影响。方法回顾性分析83例高原地区高血压脑出血临床病例,正常血红蛋白组（血红蛋白≤180g/L）39例和高血红蛋白组（血红蛋白〉180g/L）44例。术后3d、7d、15d计算脑水肿体积,术后15d观察两组生存率;统计术后6个月内颅内再出血率和神经功能恢复情况。结果正常血红蛋白组脑水肿体积低于高血红蛋白组（P〈0．05）;高血红蛋白组病死率高于正常血红蛋白组（P〈0．05）;神经功能恢复情况正常血红蛋白组好于高血红蛋白组（P〈0．05）。结论高血红蛋白影响高原地区高血压脑出血病人的预后。     

大鼠脑出血后脑水肿形成特点的研究

目的 :研究脑出血后脑水肿形成的特点。方法 :建立大鼠尾状核出血模型 ,用干湿重法分别测定不同部位的脑组织在出血后1 ,2 ,3 ,5 ,7d的脑组织水分含量的变化 ,并与正常脑组织对比。结果 :脑出血后 2 4h内在血肿同侧基底节区及血肿同侧对应的皮质区形成明显的水肿 ,水肿的高峰在第 3天 ,持续 1周仍不消退 ,而血肿对侧对应的基底节区及皮质区脑组织水分含量则无明显变化。结论 :大鼠脑出血后脑水肿在 2 4h内形成 ,第 3天达到高峰 ,提示对临床脑出血病人脑水肿的防治要尽可能早     

实验性脑出血后大鼠行为学和血肿周围组织病理学的研究

目的观察大鼠脑出血后不同时间点神经行为学和血肿周围脑组织病理学的特点。方法将成年SD大鼠随机分为假手术组和脑出血组;脑出血组大鼠通过立体定向术向脑内注入VII型胶原酶制成脑尾状核出血模型,并按不同时间点（1、3、7、14、28d）分为5个亚组。采用神经功能评分和HE染色分别观察脑出血大鼠神经行为学和脑组织形态学的改变。结果与假手术组相比,脑出血组大鼠的神经行为学评分3d时最明显[3d与1、7d无明显差异（P〉0.05）;与14d和28d有显著差异（P〈0.05）]。脑出血后1d在尾壳核区域可见血肿形成,呈椭圆形或不规则形;3d时脑水肿明显;7d时血肿周围脑组织有胶质细胞增生;14d时血肿区逐渐形成不规则囊腔;28d时囊腔仍然存在,出血周边区见胶质细胞进一步增多。结论脑出血后神经行为学的改变、血肿及囊腔的形成与出血时间有关。     

红细胞对创伤性脑内出血大鼠脑含水量及HO-1表达的影响

目的研究大鼠创伤性脑内出血(TICH)中红细胞对脑含水量和血红素氧合酶-1(HO-1)表达的影响,并分析二者的关系,以探讨红细胞在TICH后脑水肿形成中的作用机制。方法120只大鼠随机分为创伤性脑损伤组(TBI组),TBI加注全血组(WB组),TBI加注溶解红细胞组(LRBC组)和TBI加注压积红细胞组(PRBC组),每组30只。4组均采用自由落体打击法造成大鼠脑外伤。后3组借助立体定向仪分别向伤区脑皮质内注射全血、溶解红细胞或压积红细胞,造成TICH模型。每组于伤后1、3、5d分别处死10只大鼠,5只测伤区脑组织含水量,5只用免疫组化法检测HO-1的表达。结果4组组内比较:TBI、WB和PRBC3组第3d的脑含水量最高(分别为82.85%±0.60%,85.00%±1.12%,84.93%±1.21%),LRBC组第1d的含水量最高(84.44%±0.85%;4组间比较,1d时LRBC组含水量最高,3d时WB和PRBC组含水量最高。在WB、PRBC和LRBC组,HO-1阳性表达的强弱与脑含水量的高低变化相一致。结论红细胞在TICH后迟发性脑水肿的形成中有重要作用,其机制涉及红细胞的降解产物。     

脑出血后血红蛋白对血脑屏障的影响

目的 探讨脑出血后血红蛋白(Hb)对血脑屏障结构和功能的影响. 方法 108只雄性SD大鼠按随机数字表法分为正常对照组(12只)、Hb组(48只)和假手术组(48只);再进一步依据模型制作完成后观察时间点的不同,将Hb组和假手术组分为6h、24 h、3d、7d共4个亚组(每个亚组12只).应用HE染色、铁染色分别观察Hb注入大鼠脑内后组织学变化和铁离子释放规律.利用伊文氏蓝检测血脑屏障的通透性.免疫荧光和荧光定量PCR检测血脑屏障紧密连接蛋白claudin-5和ZO-1表达的变化. 结果 Hb注入后大鼠脑组织中可见明显的水肿坏死,3d和7d时可见铁离子的释放和蓄积.Hb组的伊文氏蓝渗出量明显高于假手术组,差异有统计学意义(P＜0.05).免疫荧光结果显示Hb注入大鼠脑内后可见血管内皮细胞间紧密连接蛋白claudin-5和ZO-1表达不连续,表达水平下降.在mRNA水平,Hb组claudin-5和ZO-1表达水平明显低于假手术组,差异有统计学意义(P＜0.05). 结论 脑出血发生后,Hb可能直接引起血脑屏障结构和功能的破坏,进而参与脑水肿的发生、发展过程.     

影响脑出血后脑水肿产生的因素

对于脑出血后脑水肿的相关因素 ,目前研究较多的物质有凝血酶 ,血红蛋白 ,心钠素等。研究表明 :出血早期 4 8～ 72小时内脑水肿与凝血酶等物质的直接刺激有关 ,而 3天后脑水肿加重则可能与红细胞溶解后内容物的释放 ,如血红蛋白等有关。目前治疗除了脱水剂和肾上腺皮质激素 ,其他物质尚处于动物实验阶段。     

Oxidative brain injury from extravasated erythrocytes after intracerebral hemorrhage

Intracerebral infusion of lysed erythrocytes causes brain edema without inducing ischemic cerebral blood flow. Reports have indicated that oxidative damage contributes to secondary brain injury in stroke. In the present study, we investigated whether erythrocyte lysis after intracerebral hemorrhage (ICH) might result in oxidative brain damage. This study had four parts. Male Sprague-Dawley rats received an infusion of autologous lysed erythrocytes into the right striatum. Control rats only had a needle insertion. Neurological deficits, brain water and ion contents were determined in the first part. In the second part, hemoxygenase-1 (HO-1), manganese superoxide dismutase (Mn-SOD), copper/zinc SOD (CuZn-SOD) and protein carbonyl levels were determined by Western blot analysis. In the third part, immunohistochemistry was performed for HO-1. DNA damage was examined using DNA polymerase I-mediated biotin-dATP nick-translation (PANT) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) in the fourth part. Infusion of lysed RBCs induced marked edema in the ipsilateral striatum and profound neurological deficits. Western blot analysis and immunohistochemistry indicated that HO-1 was upregulated 24 h after infusion of lysed red blood cells. Both Mn-SOD and CuZn-SOD contents decreased, protein carbonyl levels increased in the ipsilateral striatum, and there was the appearance of PANT- and TUNEL-positive cells suggesting oxidative mechanisms in the erythrocyte-induced brain injury. In conclusion, oxidative stress caused by components of the lysed erythrocytes contributes to the brain injury after ICH.     

Thrombin preconditioning attenuates brain edema induced by erythrocytes and iron.

Pretreatment with a low intracerebral dose of thrombin reduces brain edema after hemorrhagic and thrombo-embolic stroke. We have termed this phenomena thrombin preconditioning (TPC) or thrombin-induced brain tolerance. Red blood cell lysis and iron overload contribute to delayed edema formation after intracerebral hemorrhage. The present study examined whether TPC can attenuate the brain edema induced by lysed red blood cells or iron. It also examined whether TPC is associated with increasing hypoxia inducible factor-1alpha (HIF-1alpha) levels and alterations in two HIF-1alpha target genes, transferrin (Tf) and transferrin receptor (TfR), within the brain. Brain edema was measured by wet/dry weight method. HIF-1alpha, Tf, and TfR were measured by Western blot analysis and immunohistochemistry. We found that TPC reduces the edema induced by infusion of lysed red blood cells and iron. Thrombin increases HIF-1alpha levels through p44/42 mitogen activated protein kinases pathway. Thrombin also increases Tf and TfR levels in the brain. These results indicate that HIF-1alpha and its target genes may be involved in thrombin-induced brain tolerance.     

大鼠尾壳核内注射凝血酶对AQP4蛋白表达的影响

目的研究凝血酶对水孔蛋白-4(aqaporin-4,AQP4)表达的影响及引起脑出血后脑水肿形成的机制.方法在立体定向仪下向大鼠右侧尾壳核注射15 U凝血酶,在不同时间段对注射部位邻近脑组织AQP4蛋白进行免疫组化检测.结果注射凝血酶6 h后尾壳核AQP4蛋白表达开始增高,在第1 d达高峰,并维持到第3 d,以后逐渐下降到正常水平.结论凝血酶能促进脑微血管周围的AQP4蛋白表达的增加,加速水分的跨膜流动,引起星形胶质细胞水肿和血脑屏障的破坏,导致脑出血早期阶段脑水肿的发生.     

大鼠自体动脉血脑出血动物模型的建立

目的:建立大鼠自体动脉血液脑出血模型,研究脑出血后大鼠行为学改变、脑水肿的变化规律。方法:参照Yang、Lee及Hua等方法,应用立体定向技术,用大鼠自体尾动脉不抗凝动脉血液50μl缓慢注入大鼠尾状核,制成中等量脑出血,通过动脉观察其行为学改变和脑水肿的变化规律建立稳定的脑出血动物模型。结果:对32只大鼠脑出血动物模型采用Longa评分法、肢体对称试验评分法、Berderson评分法和平衡木评分法进行评分,结果显示,大鼠脑出血后其行为学改变与对照组有显著性差异。脑出血周围组织含水量明显高于对照组,病变侧高于病变对侧脑组织,以出血后48～72h最明显。结论:大鼠自体动脉血脑出血后有一系列的行为学改变,其行为学改变能够反映脑血肿对神经功能影响的严重程度和病情的轻重,大鼠自体动脉血脑出血动物模型是比较理想的实验性脑出血模型。     

脑出血大鼠脑内神经干细胞移植的研究

目的分离并克隆新生大鼠神经干细胞,研究其移植入脑出血大鼠脑内的生物学特征,了解神经干细胞移植治疗脑出血的可行性.方法用尾状核注射Ⅶ型胶原酶制作脑出血模型,从Wistar新生大鼠脑室下区分离并克隆神经干细胞,经Brdu(5-溴脱氧尿嘧啶)掺入标记后移植入脑出血同侧的侧脑室或脑出血对侧的尾状核中.经免疫组织化学鉴定了解移植细胞在大鼠脑内的生存、迁移及分化情况.结果将稳定培养的神经干细胞移植入脑出血大鼠脑内,发现移植后4 d移植细胞仍存在.侧脑室移植组中移植细胞多在侧脑室周边区存在,尾状核移植组可见移植细胞开始向对侧迁移.免疫荧光双标证实细胞大多分化成神经元,少部分分化成胶质细胞.结论神经干细胞移植入脑出血大鼠脑内后能够存活,并能有效地穿过室管膜和向脑出血部位迁移.移植细胞在脑内大部分分化成神经元,少部分分化成胶质细胞.     

亚低温可促进脑出血大鼠内源性神经干细胞的增殖*

背景：亚低温对脑出血后脑组织保护作用的研究多集中在减轻脑水肿方面,对神经干细胞的增殖是否有促进作用研究很少。 目的：观察亚低温对脑出血大鼠血肿周围、侧脑室旁神经干细胞增殖的影响。 方法：采用自体血注入尾状核制作Wistar大鼠脑出血模型,亚低温组于制作模型后给予局部亚低温4 h,对照组给予常温处理。 结果与结论：脑出血后1,3,7,14 d,亚低温组Longa 5分制法评分低于对照组(P < 0.05)。免疫组织化学方法检测亚低温组各时间点血肿周边及侧脑室旁组织的BrdU阳性细胞数明显多于对照组(P < 0.05)。初步提示亚低温处理可以促进干细胞内源性增殖,对脑出血有保护作用。     

Collagenase-induced intracerebral hemorrhage in rats

Intracranial bleeding is an important cause of brain masses and edema. To study the pathophysiology of intracerebral hemorrhage, we produced experimental hemorrhages in 53 rats and characterized the lesion by histology, brain water content, and behavior. Adult rats had 2 microliters saline containing 0.5 unit bacterial collagenase infused into the left caudate nucleus. Histologically, erythrocytes were seen around blood vessels at the needle puncture site within the first hour. By 4 hours there were hematomas, the size of which depended on the amount of collagenase injected. Necrotic masses containing fluid, blood cells, and fibrin were seen at 24 hours. Lipid-filled macrophages were observed at 7 days and cysts at 3 weeks. Water content was significantly increased 4, 24, and 48 hours after infusion at the needle puncture site and for 24 hours in posterior brain sections. Behavioral abnormalities were present for 48 hours, with recovery of function occurring during the first week. Brain tissue contains Type IV collagen in the basal lamina. Collagenase, which occurs in an inactive form in cells, is released and activated during injury, leading to disruption of the extracellular matrix. Collagenase-induced intracerebral hemorrhage is a reproducible animal model for the study of the effects of the hematoma and brain edema.     

Role of red blood cell lysis and iron in hydrocephalus after intraventricular hemorrhage

Thrombin and iron are two major players in intracerebral hemorrhage-induced brain injury and our recent study found that thrombin contributes to hydrocephalus development in a rat model of intraventricular hemorrhage (IVH). This study investigated the role of red blood cell (RBC) lysis and iron in hydrocephalus after IVH. There were three parts to this study. First, male Sprague-Dawley rats received an injection of saline, packed, or lysed RBCs into the right lateral ventricle. Second, rats had an intraventricular injection of iron or saline. Third, the rats received intraventricular injection of lysed RBCs mixed with deferoxamine (0.5 mg in 5 μL saline) or saline. All rats underwent magnetic resonance imaging at 24 hours and were then euthanized for brain edema measurement, western blot analysis, or brain histology. We found that intraventricular injection of lysed RBCs, but not packed RBCs, resulted in ventricular enlargement and marked increases in brain heme oxygenase-1 and ferritin at 24 hours. Intraventricular injection of iron also resulted in ventricular enlargement and ventricular wall damage 24 hours later. Coinjection of deferoxamine reduced lysed RBC-induced ventricular enlargement (P<0.01). These results suggest that iron, a degradation product of hemoglobin, has an important role in hydrocephalus development after IVH.