依达拉奉对大鼠脑出血后水通道蛋白4及血脑屏障的影响

目的研究大鼠脑出血后血脑屏障（BBB）通透性与水通道蛋白4（AQP4）的关系及自由基清除剂依达扭奉的干预作用。方法采用自体动脉血注入尾状核法制成大鼠脑出血模型,Westernblot法观察AQP4的表达,伊文思兰法测量BBB通透性,干湿重法计算脑含水量表示脑水肿。结果与对照组相比,脑出血组及依达拉奉组BBB通透性均在出血后6h开始升高,l-3d最高,依达拉奉组低于脑出血组（P〈0．05）;两组AQP4表达也于6h即开始升高,3d时达到高峰,依达拉奉组低于脑出血组（P〈0．05）;BBB通透性与AQP4表达呈正相关（r=0．585,P〈0．05）,与脑水肿变化趋势一致。结论脑出血后可能通过上调APQ4表达,增加BBB通透性,参与脑水肿形成,依达拉奉可抑制此过程。     

抑肽酶对大鼠实验性脑出血后AQP4mRNA表达及脑水肿的作用

目的研究脑出血后的脑水肿形成与水孔蛋白-4(AQP4) mRNA表达的关系,以及抑肽酶的干预作用。方法采用自体动脉血注入法制作大鼠脑出血模型,RT-PCR法检测AQP4 mRNA表达,并观察给予抑肽酶处置后脑水肿(脑含水量)的变化。结果与对照组相比,脑出血组和抑肽酶组均从脑出血后6h开始出现脑水肿(P<0.05),3d时达到高峰(P<0.05),分别上升到(82.13±0.36)和(79.48±0.46),且抑肽酶组脑水肿程度低于脑出血组(P<0.05);AQP4 mRNA表达同样在3d时达到高峰(P<0.05),分别为(1.34±0.14)和(1.03±0.05)。脑水肿程度与AQP4 mRNA表达的变化呈显著正相关(r=0.815,P<0.01)。结论脑出血后AQP4 mRNA表达明显增加,提示AQP4参与了脑水肿的发生发展过程,而抑肽酶能够抑制脑水肿的形成。     

局部亚低温对大鼠脑出血后水通道蛋白4表达的影响

目的观察局部亚低温对大鼠自体血注入法脑出血模型水通道蛋白4(AQP-4)mRNA及蛋白质表达的影响,探讨局部亚低温减轻脑出血后水肿的可能机制。方法雄性W istar大鼠240只,随机分为脑出血(ICH)组和脑出血加局部亚低温(ICH+H)组。每组分为对照、脑出血后6、24、72 h,5、7 d共6个亚组,ICH+H组于注血后给予4 h的局部亚低温治疗,各亚组分别进行血脑屏障(BBB)通透性、脑水含量的检测以及应用逆转录(RT)-PCR及W estern印迹对AQP-4进行测定。结果ICH组大鼠脑组织水含量、BBB通透性以及AQP-4 mRNA表达的增加始于脑出血后6 h,AQP-4蛋白质表达的增加始于脑出血后24 h,均至72 h达高峰(P<0.01)。AQP-4 mRNA及蛋白质表达的变化与BBB通透性的变化呈正相关(r=0.78和r=0.76)。ICH+H组的脑组织水含量和BBB通透性在各时间点与ICH组相比明显下降,而AQP-4 mRNA吸光度值(A)在脑出血后48 h与ICH组相比开始较低,在72 h,由ICH组的1.25±0.03降至1.04±0.02(P<0.01),AQP-4蛋白质A值在各时间点与ICH组相比明显下降,在72 h,由ICH组的0.77±0.08下降至0.25±0.04(P<0.01)。结论脑出血后BBB完整性的破坏可以导致AQP-4表达的上升。局部亚低温可以抑制脑出血后AQP-4 mRNA和蛋白质表达的增加。局部亚低温可能既通过减轻BBB完整性的破坏在转录水平抑制AQP-4 mRNA表达的增加,也可以在翻译水平直接抑制AQP-4蛋白质的表达,来减轻脑出血后的脑水肿形成。     

水蛭素、尼膜同对大鼠实验性脑出血后AQP4mRNA表达及脑水肿的作用研究

目的研究脑出血后的脑水肿形成与水孔蛋白4(AQP4)mRNA表达的关系,以及水蛭素、尼膜同的干预作用。方法采用自体动脉血注入法制作大鼠脑出血模型,RT-PCR法检测AQP4mRNA表达,并分别观察给与水蛭素、尼膜同后脑水肿(脑含水量)的变化。结果与对照组相比,脑出血组、水蛭素组及尼膜同组均从脑出血后6h开始出现脑水肿(P<0.05),3d时达到高峰(P<0.05),分别上升到(82.13±0.36)、(79.48±0.46)及(81.26±0.42),且水蛭素、尼膜同组脑水肿低于脑出血组(P<0.05);AQP4mRNA表达同样在3d时达到高峰(P<0.05),分别为(1.34±0.14)、(1.03±0.05)及(1.27±0.14)。脑水肿程度与AQP4mRNA表达的变化呈显著正相关(r=0.815,P<0.01)。结论脑出血后AQP4mRNA表达明显增加,提示AQP4参与了脑水肿的发生发展过程,而水蛭素、尼膜同能够抑制脑水肿的形成。     

水通道蛋白4与脑出血后脑水肿

脑水肿是影响脑出血后脑组织二次损伤的重要因素,目前对水通道蛋白4(AQP-4)在脑水肿中的作用有了一定的研究。AQP-4是广泛分布于中枢神经系统的介导脑组织中水分子流动最主要的水通道蛋白,与血脑屏障功能的完整性密切相关,在脑出血后表达增高,导致血脑屏障通透性和脑组织含水量增加,参与脑出血后脑水肿的形成,成为目前防治脑出血后脑水肿的新靶点。     

AQP-4与创伤性脑水肿

水通道蛋白4(AQP-4)是脑组织内高表达的一种水通道蛋白,主要表达于星形胶质细胞和室管膜细胞,尤其在与毛细血管和软脑膜直接接触的星形胶质细胞表达丰富,是参与脑水肿形成的重要分子,在水分子快速跨膜转运中发挥重要作用。最近研究表明,AQP-4在创伤性脑水肿的病理生理变化中发挥重要的作用。深入研究AQP-4与创伤性脑水肿之间的关系,将可能为临床治疗脑水肿提供新的思路和途径。     

载脂蛋白E短肽COG1410对蛛网膜下腔出血后早期脑水肿的影响

目的 探讨载脂蛋白E短肽COG1410对蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后早期脑损伤(early brain injury,EBI)中脑水肿、小鼠运动功能和水通道蛋白4(aquaproins-4,AQP-4)的影响.方法 108只C57BL/6J小鼠分成假手术对照组(sham)、生理盐水组(SAH+生理盐水)、治疗组(SAH+ COG1410),采用血管内穿刺法建立SAH模型.观察小鼠运动功能变化,用干湿质量法测定脑含水量的变化,免疫组化法测定表达AQP-4阳性细胞数,酶联免疫吸附法(ELISA)测定AQP-4蛋白含量及实时定量PCR测定AQP-4 mRNA的变化.结果 SAH后生理盐水组和治疗组神经功能评分均明显高于假手术对照组(P＜0.05),且生理盐水组和治疗组之间差异有统计学意义(P＜0.05).SAH后各时间点生理盐水组脑含水量、AQP4蛋白含量和AQP4mRNA表达的变化与假手术对照组对比显著升高(P＜0.05).生理盐水组和治疗组脑含水量、AQP4蛋白含量和AQP4 mRNA表达均在SAH后1d明显增加,2d达到高峰,之后逐渐下降,2组间差异均有统计学意义(P＜0.05).结论 载脂蛋白E短肽COG1410可能通过抑制AQP-4的过表达缓解EBI中的脑水肿.     

水通道蛋白4与脑水肿的研究进展

水通道蛋白4(AQP4)是一种脑内主要的水通道蛋白,它广泛表达于星形胶质细胞膜表面、室管膜细胞外侧基膜等部位。AQP4在脑内的这种分布特点表明,它对水进出脑组织起调节作用,在脑水肿形成和消除过程中都起重要作用,调节其在脑内的表达可以为脑水肿及水代谢疾病提供分子水平的理论依据,对脑出血、脑缺血、脑积水、肿瘤、颅脑外伤等疾病的治疗具有重要意义。     

肿瘤坏死因子α诱发脑水肿的机制

目的:研究肿瘤坏死因子α(Tumor necrosis fctor-alpha,TNF-α)对水通道蛋白4(Aquaporin4,AQP4)和血脑屏障(Blood-brain barrier,BBB)通透性的影响,探讨TNF-α诱发脑水肿的机制.方法:90只成年SD大鼠,其中45只用于脑含水量和脑组织AQP4 mRNA表达的测定,将其随机分为空白对照组(A组,n=5)、生理盐水组(NS组,n=20)、TNF-α组(TNF-α组,n=20),NS组和TNF-α组按注射后处死的时间再分为1h组、6h组、24h组、72h组,每组各为5只;其余45只用于BBB通透性的观察,分组方法同前.采用干湿重法计算脑含水量,采用RT-PCR法观察脑组织AQP4 mRNA表达的变化,采用伊文思兰法监测BBB通透性.结果:大鼠脑内注射TNF-α仅后脑含水量和脑组织AQP4 mRNA表达在1h均未见明显变化(P0.05),均于6h达到高峰,之后逐渐降低,72h脑含水量降到正常水平,但AQP4 mRNA表达仍高于正常(P<0.05);脑组织EB含量1h开始升高,6h迅速达到高峰,之后逐渐降低,72h仍高于正常(P<0.05);BBB通透性与AQP4 mRNA表达呈显著正相关(R=0.839,P<0.01),与脑水肿变化趋势一致.结论:TNF-α通过上调APQ4表达,增加BBB通透性,参与脑水肿形成和发展.     

地塞米松对脑出血大鼠脑AQP4影响的研究

目的通过建立大鼠自体血脑出血(ICH)模型,观察地塞米松对水孔蛋白4(AQP4)表达的影响及血脑屏障(BBB)的通透性与AQP4表达的关系。方法建立自体血ICH模型后,大鼠随机分为脑出血模型对照组(ICH组)和脑出血加地塞米松干预组(DEX组),观察脑出血后12h、1d、3d、5d、7d各点大鼠BBB通透性及AQP4的表达。结果ICH组大鼠BBB通透性从12h开始明显增加,1d达高峰(20.350±1.294),灶周AQP4的蛋白及其mRNA光密度值均至第3天达到高峰(0.806±0.113,1.112±0.072),BBB通透性的变化与AQP4蛋白及其mRNA的变化成正相关(r=0.898和r=0.847,P<0.01)。脑出血12h后DEX组BBB通透性和AQP4的表达均较ICH组降低。结论地塞米松可以保护脑出血大鼠BBB,并降低AQP4的表达,并且BBB通透性与AQP4及其mRNA成正相关。     

Relationship between AQP4 expression and structural damage to the blood-brain barrier at early stages of traumatic brain injury in rats

Background Although some studies have reported that aquaporin-4 （AQP4） plays an important role in the brain edema after traumatic brain injury （TBI）, little is known about the AQP4 expression in the early stage of TBI, or about the correlation between the structural damage to the blood-brain barrier （BBB） and angioedema. The aim of this project was to investigate the relationship between AQP4 expression and damage to the BBB at early stages of TBI. Methods One hundred and twenty healthy adult Wistar rats were randomly divided into two groups： sham operation group （SO） and TBI group. The TBI group was divided into five sub-groups according to the different time intervals： 1, 3, 6, 12, and 24 hours. The brains of the animals were taken out at different time points after TBI to measure brain water content. The cerebral edema and BBB changes in structure were examined with an optical microscopy （OM） and transmission electron microscopy （TEM）, and the IgG content and AQP4 protein expression in traumatic brain tissue were determined by means of immunohistochemistry and Western blotting. The data were analyzed with SPSS 13.0 statistical software. Results In the SO group, tissue was negative for IgG, and there were no abnormalities in brain water content or AQP4 expression. In the TBI group, brain water content significantly increased at 6 hours and peaked at 24 hours following injury. IgG expression significantly increased from 1 to 6 hours following injury, and remained at a high level at 24 hours. Pathological observation revealed BBB damage at 1 hour following injury. Angioedema appeared at 1 hour, was gradually aggravated, and became obvious at 6 hours. Intracellular edema occurred at 3 hours, with the presence of large glial cell bodies and mitochondrial swelling. These phenomena were aggravated with time and became obvious at 12 hours. In addition, microglial proliferation was visible at 24 hours. AQP4 protein expression were reduced at 1 hour, lowest at 6 hours, and began to increase at 12 hours, showing a V-shaped curve. Conclusions The angioedema characterized by BBB damage was the primary type of early traumatic brain edema. It was followed by mixed cerebral edema that consisted of angioedema and cellular edema and was aggravated with time. AQP4 expression was down-regulated during the angioedema attack, but AQP4 expression was upregulated during intracellular edema.     

水通道蛋白-4对蛛网膜下隙出血后脑水肿的影响

目的研究大鼠蛛网膜下隙出血(SAH)后脑水肿病理过程中水通道蛋白-4(AQP-4)的表达与脑水肿形成之间的关系。方法采用大鼠断尾取血,枕大池注入自体血的方法制作大鼠SAH模型,用干湿质量法和免疫组化法分别检测SAH后不同时间段脑含水量和AQP-4蛋白表达的变化。结果SAH后8 h,脑组织AQP-4蛋白在脑水肿区表达开始增强,至2 d达到高峰,此时脑组织严重水肿;第7天,AQP-4的表达已减少,脑水肿减轻。结论SAH后AQP-4表达明显增强,与脑水肿呈正相关关系。AQP-4可能在SAH后脑水肿的形成过程中起重要作用。     

Effects of dexamthasone with different doses on aquaporin-4 in brain of intracerebral hemorrhage rats

Objective:To determine the relationship between the expression of aquaporin-4(AQP4) after intracerebral hemorrhage and dexamethasone treated. Methods:Collagenase Ⅶ was injected in caudate nucleus in a stereotaxis frame to establish the intracerebral hemorrhage(ICH) animal models. The intracerebral hemorrhage(ICH) rats were randomly divided into four groups: the sham group (group A), the ICH group(group B), low dose-treated group(group C), moderate dose group(group D) and high dose group(group E). The groups were respectively received an intraperitoneal dexamethasone injection with 1 mg/kg, 15 mg/kg, 30 mg/kg, twice a day for three days. The brain water content(BWC), the permeability of blood-brain barrier(BBB) and the expression of AQP4 were observed. Results:Both the BBB disruption and AQP4 expression decreased in treated groups, and the AQP4 expression had a dose-dependent manner in the dexamethasone treatment. And it seemed that low dose dexamethasone was in favor of brain swelling elimination, but the higher dosage had not similar effect. Conclusion:Dexamethesone may play a critical role on expression of AQP4 in the physiopathology of hemorrhagic edema.     

Effects of dexamethasone with different doses on aquaporin-4 in brain of intracerebral hemorrhage rats

Objective：To determine the relationship between the expression of aquaporin-4（AQP4） after intracerebral hemorrhage and dexamethasone treated. Methods：Collagenase Ⅶ was injected in caudate nucleus in a stereotaxis frame to establish the intracerebral hemorrhage（ICH） animal models. The intracerebral hemorrhage（ICH） rats were randomly divided into four groups： the sham group （group A）, the ICH group（group B）, low dose-treated group（group C）, moderate dose group（group D） and high dose group（group E）. The groups were respectively received an intraperitoneal dexamethasone injection with 1 mg/kg, 15 mg/kg, 30 mg/kg, twice a day for three days. The brain water content（BWC）, the permeability of blood-brain barrier（BBB） and the expression of AQP4 were observed. Results：Both the BBB disruption and AQP4 expression decreased in treated groups, and the AQP4 expression had a dose-dependent manner in the dexamethasone treatment. And it seemed that low dose dexamethasone was in favor of brain swelling elimination, but the higher dosage had not similar effect. Conclusion：Dexamethesone may play a critical role on expression of AQP4 in the physiopathology of hemorrhagic edema.     

脑疏宁对脑外伤大鼠脑水肿及脑组织AQP4表达的影响

目的 观察脑疏宁对脑外伤大鼠脑组织含水量及水通道蛋白4(AQP4)表达的影响,探讨其治疗创伤性脑水肿的机制.方法 SD大鼠264只,随机分为假手术组(88只)、模型组(88只)和脑疏宁组(88只),建立大鼠创伤性脑损伤模型.分别在6 h,1、3、5 d 4个时间点测定脑组织含水量、伊文思蓝(EB)含量,并采用免疫组化方法检测脑组织AQP4蛋白的表达,电镜观察血脑屏障超微结构改变.结果 模型组大鼠伤后各时间点伤侧脑组织含水量、EB含量及伤灶周围AQP4蛋白表达水平明显高于假手术组(均P<0.001);电镜下内皮细胞紧密连接开放、星形胶质细胞足突肿胀.中药治疗组各时间点脑组织含水量、EB含量及AQP4表达水平均较模型组降低(P<0.05);血脑屏障紧密连接的破坏减少、星形胶质细胞足突肿胀减轻.结论 脑疏宁可改善血脑屏障损伤,减轻创伤后脑水肿.其作用可能与抑制AQP4在损伤脑组织中的表达、减轻星形胶质细胞损害有关.     

ERK介导的AQP4对脑出血后早期脑水肿的影响

目的探讨大鼠实验性脑出血后细胞外信号调节激酶(ERK)介导的水通道蛋白4(AQP4)的不同表达对早期脑水肿的影响。方法72只健康雄性大鼠随机分为出血组、PD98029组、截体溶液对照组和假手术组,每组各18只。采用大鼠缓慢注射自体血出血模型,测定脑组织含水量及伊文斯蓝含量,并采用免疫组织化学、Westernblot检测AQP4的表达,测定预先经尾静脉给予PD98059后的丝裂原活化蛋白激酶(MAPKs)信号通路关键蛋白酶ERK1/2磷酸化水平,同时观察PD98059对AQP4和脑水肿的影响。结果假手术组AQP4表达较低;在出血组AQP4表达升高,脑组织含水量及伊文斯蓝含量增加;给予PD98059后AQP4的表达和脑组织含水量降低,同时ERK1/2磷酸化水平降低。结论出血性损伤后AQP4表达上升,脑水肿明显,早期预先给予PD98059可抑制AQP4的表达,降低BBB通透性,减轻脑水肿。     

异丙酚减轻大鼠创伤性脑水肿及相关机制的研究

目的观察异丙酚对大鼠创伤性脑损伤后脑水肿和水通道蛋白4(AQP4)的影响。方法健康雄性Sprague-Dawley大鼠,体质量230～280 g,随机分为假手术组(n=8只)、生理盐水组(n=8只)、异丙酚组(n=8只)。按Feeney自由落体撞击法建立大鼠创伤性脑损伤(TBI)模型。生理盐水组术后腹腔注射生理盐水(50 mg/kg),异丙酚组术后腹腔注射异丙酚(50 mg/kg)。干/湿法测定大鼠建模后48 h脑损伤区头侧的组织含水量,取出脑损伤区尾侧切片进行HE染色观察神经细胞的形态学变化。采用反转录-聚合酶链反应检测脑损伤区AQP4的表达。结果异丙酚组较生理盐水组水肿明显减轻(P<0.05),固缩神经元数量及神经元缺失相对减少,脑损伤区组织AQP4表达下调(P<0.05)。结论异丙酚可显著减轻脑水肿,并且可能下调与脑水肿密切相关的AQP4的表达。