大鼠急性脑缺血再灌注损伤精氨酸加压素变化和脑水肿实验…

应用大鼠急性脑缺血再灌注动物模型，观察精氨酸加压素（ＡＶＰ）在急性脑缺血再灌注 伤中的变化及与脑水肿关系，结果表明后脑下部ＡＶＰ含量在脑缺血３０ｍｉｎ明显增加，再灌注６０ｍｉｎ后进一步增加，且与大脑皮层水含量呈显著相关性，提示，ＡＶＰ参与急性脑缺血再灌注损伤，丘脑下部ＡＶＰ含量增高，可加重或促进脑缺血再灌注后脑水肿形成。     

大鼠脑缺血再灌注海马区血小板活化因子和过氧化脂质的改变及药物影响

目的观察缺血性大鼠脑海马区血小板活化因子（ＰＡＦ）和过氧化脂质（ＬＰＯ）含量的改变及兆科蝮蛇抗栓酶的影响。方法用４ＶＯ大鼠脑缺血模型，用放免分析法和ＴＢＡ法测定ＰＡＦ及ＬＰＯ含量。结果缺血２０ｍｉｎ再灌注６０ｍｉｎ脑海马中ＰＡＦ及ＬＰＯ含量明显高于正常对照组（Ｐ＜０．０１），但造模前用兆科蝮蛇抗栓酶预处理动物，能够显著抑制缺血再灌注脑海马区ＰＡＦ及ＬＰＯ含量的升高。结论ＰＡＦ参与了脑缺血再灌注损伤，与ＬＰＯ生成密切相关，兆科蝮蛇抗栓酶对脑缺血再灌注损伤有保护作用。     

鼠脑缺血性损伤早期海马区PAF和LPO含量的动态观察及其意义

目的：运用脑缺血再灌注模型,探索血小板活化因子及自由基在缺血性脑损伤中的地位及意义,方法：分别应用放免法及ＴＢＡ法法测定大鼠海马组织中ＰＡＦ与ＬＰＯ含量。结果：缺血２０ｍｉｎ后灌注０ｍｉｎ组及６０ｍｉｎ组ＰＡＦ含量均显著高于手术对照组,而再灌注２４０ｍｉｎ组与假手术对照组比较已无显著差异。相应ＬＰＯ含量早期随再灌注时间延长逐渐升高。结论：ＰＡＦ可能主要能与脑缺血再灌注缺血期的病理损伤机制,而自由基     

全脑缺血后PAF和细胞内钙离子的变化及相关机制研究

目的 探讨血小板活化因子（ＰＡＦ）在缺血性脑损伤中的作用机制。方法 大鼠全脑缺血再灌注后,分别应用放免法和Ｆｕｒａ－２／ＡＭ荧光法测定海马组织中ＰＡＦ、突触体游离钙（「Ｃａ＾２＋」ｉ）浓度。结果 缺血２０ｍｉｎ后,ＰＡＦ含量显著高于对照组,再灌注２４０ｍｉｎ时已降至对照组水平,再灌注４８０ｍｉｎ后出现迟发性升高。对应「Ｃａ＾２＋」ｉ值随所观察的再灌注时间延长而增加。Ｔｅｔｒａｎｄｒｉｎｅ（钙拮抗剂）能明显降低再灌注４８０ｍｉｎ时ＰＡＦ和「Ｃａ＾２＋」ｉ水平。结论 全脑缺血再灌主后,ＰＡＦ的异常代谢与「Ｃａ＾２＋」ｉ水平密切关联,协同参与了神经细胞损伤的发生及发展。     

巴曲酶对脑缺血再灌注细胞外液单胺类及其代谢产物的影响——微透析研究

目的巴曲酶对脑缺血再灌流损伤的保护机理。方法采用脑内微透析技术结合高灵敏度的高压液相色谱－电化学检测手段（ＨＰＬＣ－ＥＤ），测定前脑缺血３０ｍｉｎ再灌注１２０ｍｉｎ时的纹状体细胞外液（ＥＣＦ）的ＤＡ、５－ＨＴ和ＮＥ及其代谢产物（５－ＨＩＡＡ）和ＨＶＡ的变化和巴曲酶的影响。结果显示脑缺血时，ＥＣＦＤＡ、ＮＥ及５－ＨＴ明显升高，巴曲酶能显著地降低脑缺血时ＥＣＦＤＡ及再灌注时ＥＣＦＨＶＡ和５－ＨＩＡＡ的水平。结论巴曲酶影响单胺神经递质是对脑缺血再灌注损伤起保护作用的机理之一     

氯喹,SOD防治脑缺血再灌注损伤的实验研究

探讨氯喹、超氧化物歧化酶（ＳＯＤ）防治脑缺血再灌注损伤的效果。用４血管阻断法造成大鼠全脑缺血，３０ｍｉｎ后再恢复双侧颈总动脉血流３０ｍｉｎ，此时大鼠脑组织磷脂酶Ａ（ＰＬＡ）活性和内皮素（ＥＴ）、过氧化脂质（ＬＰＯ）含量显著增高，而ＳＯＤ活性和维生素Ｅ（ＶｉｔＥ）含量明显降低，大脑皮层神经细胞和血脑屏障明显损害。预防用氯喹或ＳＯＤ治疗，部分抑制了ＬＰＯ、ＥＴ含量的增高和ＳＯＤ活性下降，明显减轻脑神经细胞和血脑屏障损伤程度；但对ＶｉｔＥ含量都无明显影响。氯喹、ＳＯＤ对缺血再灌注脑损伤有一定的防治作用。     

神经节苷脂对缺血性大鼠脑保护作用的研究

目的探讨神经节苷脂（ＧＭ１）的脑保护作用及其可能机制。方法用四血管闭塞（４ＶＯ）全脑缺血再灌注模型,用高效液相色谱仪柱前衍生色谱法测定假手术组、缺血３０ｍｉｎ再灌注６０ｍｉｎ生理盐水（ＮＳ）处理组、缺血３０ｍｉｎ再灌注６０ｍｉｎＧＭ１处理组的海马组织兴奋性氨基酸（ＥＡＡ）含量,并观察缺血３０ｍｉｎ再灌注４ｄ海马ＣＡ１区病理变化。结果缺血再灌注ＮＳ处理组海马组织ＥＡＡ含量显著性降低（Ｐ＜０．０１）,海马ＣＡ１区多数神经元坏死,残存神经元呈较严重缺血性改变,ＧＭ１处理组上述生化病理改变明显为轻。结论推测ＧＭ１可调控缺血再灌注早期ＥＡＡ的过度释放和（或）重摄取受阻,减轻其在细胞外堆聚引起的兴奋毒性损伤,具有脑保护作用。     

脑缺血纹状体细胞外液单胺类介质及其代谢物的微透析研究

目的观察脑缺血再灌注时鼠脑纹状体区细胞外液（ＥＣＦ）多巴胺（ＤＡ）、去甲肾上腺素（ＮＥ）、５－羟色胺（５－ＨＴ）及其代谢产物高香草酸（ＨＶＡ）和５－羟吲哚乙酸（５－ＨＩＡＡ）的动态变化。方法采用脑内微透析技术，用高压液相色谱测定了前脑缺血３０ｍｉｎ、再灌注１２０ｍｉｎ时ＥＣＦＤＡ、ＮＥ和５－ＨＴ的变化。结果脑缺血１０ｍｉｎ时ＥＣＦＤＡ、ＮＥ迅速升高为缺血前的２８２和９１４倍，持续整个缺血期，再灌注后迅速下降达缺血前水平。脑缺血期ＨＶＡ、５－ＨＩＡＡ迅速下降，在缺血３０ｍｉｎ时达缺血前的４５％和５２％，再灌注后升高并在再灌注后６０ｍｉｎ，９０ｍｉｎ达缺血前的１５０％、１１３％。结论单胺类介质代谢紊乱参与了缺血性神经元损害     

兴奋性氨基酸、氧自由基与缺血再灌注脑损伤关系的实验观察

目的：观察脑缺血再灌注过程中兴奋性氨基酸（Ｅｘｃｉｔａｔｏｒｙ ａｍｉｎｏ ａｃｉｄ,ＥＡＡ）、氧自由基的变化,研究探索脑缺血再灌注损伤的机制。方法：测定假手术组、缺血３０ｍｉｎ再灌注６０ｍｉｎ生理盐水（ＮＳ）处理组和单唾液酸四已糖神经节苷脂（ＧＭ１,１０ｍｇ／ｋｇ,ＩＰ）处理组,鼠脑海马组织ＥＡＡ、丙二醛（Ｍａｌｏｎｄｉａｄｅｈｙｄｅ,ＭＤＡ）的含量。实验应用全脑缺血（４ＶＯ）模型,ＥＡＡ采用Ｈ     

全脑缺血再灌注兴奋性氨基酸、线粒体钙、钙调素含量的变化

目的：采用大鼠全脑缺血再灌注模型,观察海马组织兴奋性氨基酸、线粒体钙、钙调素含量的变化,研究分析脑缺血再灌注损伤中兴奋性氨基酸与钙平衡紊乱的变化和作用。方法：测定假手术组,缺血３０ｍｉｎ再灌注６０ｍｉｎ和缺血３０ｍｉｎ再灌注１２ｈ组,脑海马组织兴奋性氨基酸、线粒体钙、钙调素的含量。结果：缺血３０ｍｉｎ再灌注６０ｍｉｎ海马组织兴奋性氨基酸明显低于假手术组（Ｐ＜０．０１）,线粒体钙、钙调素含量显著性高于假手术组（Ｐ＜０．０１）,缺血３０ｍｉｎ再灌注１２ｈ组同假手术组比较没有显著性差异（Ｐ＞０．０５）。结论：我们从鼠脑缺血再灌注时线粒体钙、钙调素含量升高证实钙平衡紊乱参于兴奋性氨基酸的缺血再灌注脑损伤过程     

An experimental study of arginine vasopressin on acute ischemic brain edema in gerbils (1)]

The purpose of this experiments is to study the role of arginine vasopressin (AVP) in acute ischemic brain edema of mongolian gerbils. The results showed that the contents of AVP in ischemic cortex, hypothalamus and striatum increased remarkably in 15-120 minutes after ischemia, while the contents of AVP had no change in pons-medulla which was not affected from ischemia, and there was relationship between the contents of AVP in cortex and the ischemic cortical edema. Intracerebroventricular injection (ICV) of AVP exacerbated the ischemic cortical edema and it showed dose-response correlation. While ICV of AVP antiserum significantly decreased ischemic cortical edema. These suggested that AVP was involved in the pathophysiologic process of acute ischemic brain edema. The increasing of AVP contents in ischemic brain regions could exacerbate the formation of ischemic brain edema.     

Brain eicosanoid levels in spontaneously hypertensive rats after ischemia with reperfusion: leukotriene C4 as a possible cause of cerebral edema

The relation of brain eicosanoids to progression of cerebral edema was studied in stroke-resistant spontaneously hypertensive rats subjected to incomplete global brain ischemia induced by bilateral occlusion of the common carotid arteries. Thromboxane B2 and 6-keto prostaglandin F1 alpha levels were significantly elevated 5 minutes after reperfusion but returned to control levels by 30 minutes. In contrast, leukotriene C4 levels increased 2 hours after bilateral common carotid artery occlusion and peaked 30 minutes after reperfusion, with higher levels persisting until 60 minutes after reperfusion. Cerebral ischemia was accompanied by cerebral edema early after reperfusion. The edema correlated with increased leukotriene C4 levels. That the increased brain water content was causally related to an increase in leukotriene C4 was supported by results obtained following administration of the 5-lipoxygenase inhibitors ONO-LP-016 and AA-861. Both inhibitors suppressed the increased leukotriene C4 and brain water contents after reperfusion. Our results indicate that leukotriene C4 is closely associated with an induction of ischemic cerebral edema.     

莱菔硫烷对大鼠局灶性脑缺血再灌注损伤的保护作用及机制研究

目的 探讨莱菔硫烷对大鼠局灶性脑缺血再灌注损伤的保护作用及机制.方法 采用线栓法制备大鼠大脑中动脉阻断局灶性脑缺血模型,分别于MCAO后1h腹腔注射莱菔硫烷2.5mg/kg、5mg/kg、10mg/kg.于缺血2h再灌注24h时进行神经行为缺损评分,TTC染色评价脑梗死体积,测定脑组织中超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量.免疫荧光组织化学染色法检测黄核蛋白NQ01和脂质过氧化酶Prx6的表达.结果 莱菔硫烷给药组与对照组相比均能改善大鼠脑缺血再灌注后神经行为缺损评分,减少脑梗死体积.其中5mg/kg组能显著改善大鼠脑缺血再灌注后神经行为缺损评分,减少脑梗死体积,增强SOD活性,降低MDA含量.免疫荧光组织化学染色法提示NQ01和Prx6的表达明显增强.结论 莱菔硫烷对大鼠局灶性脑缺血再灌注损伤有神经保护作用,其机制可能与上调内源性抗氧化蛋白NQ01和Prx6的表达有关.     

水通道蛋白4在大鼠脑缺血再灌注损伤中的作用

目的研究水通道蛋白4(AQP4)在缺血再灌注损伤大鼠脑内表达及作用。方法以大脑中动脉线栓法建立大鼠缺血再灌注模型,采用干湿法测定模型的脑组织含水量及伊文氏蓝含量;免疫蛋白印记(WesternBlot)技术分析在缺血再灌注不同时程脑内AQP4的表达情况,以及AQP4与脑含水量和伊文氏蓝水平的相关性,并与对照组比较。结果与对照组相比,实验组大鼠脑组织含水量及伊文氏蓝水平在缺血再灌注后不同时间点明显高于对照组(P<0.05～0.01);AQP4蛋白表达明显增高(均P<0.05),并随着缺血再灌时间的延长,其表达量亦逐渐增加,在再灌后24～48h达到高峰。缺血再灌注后AQP4脑内的表达与脑组织含水量及伊文氏蓝水平呈正相关(r=0.38、r=0.45,均P<0.05)。结论AQP4的高表达参与了脑缺血再灌注后继发的血脑屏障的开放和脑水肿的发生,是脑水肿产生的重要分子基础。     

门冬氨酸钾减轻大鼠可控性皮质打击伤引起的脑损伤

目的 门冬氨酸钾（potassium aspartate,PA）作为一种电解质补充剂,在临床上广泛使用。以往的研 究发现门冬氨酸钾在脑缺血/再灌注大鼠中对细胞凋亡有神经保护的作用。本研究将探讨门冬氨酸 钾对创伤性脑损伤（traumatic brain injury,TBI）是否有保护作用。 方法 T BI通过大鼠可控性皮质打击伤（controlled c ortical i mpact,CCI）产生。门冬氨酸钾组或溶剂对 照组在CCI发生后30 min以腹腔注射给予生理盐水或62.5 mg/kg剂量的PA,观察脑血流灌注量,改良 神经功能缺损评分（modified Neurological Severity Score,mNSS）和皮质损伤体积,并检测脑水肿以及 脑组织三磷腺苷（adenosine triphosphate,ATP）、乳酸含量和钠钾ATP酶活性。 结果 在CCI引起的大鼠皮质损伤中,与溶剂对照组相比,急性给予62.5 mg/kg剂量的PA治疗可以明 显改善神经功能缺损（P＜0.05),降低皮质损伤体积（P＜0.01）,减轻脑水肿（P＜0.05）。此外,与溶 剂对照组相比,门冬氨酸钾治疗组显著减少ATP缺失（P＜0.01）,降低乳酸含量（P＜0.05）,并增加 钠钾ATP酶的活性（P＜0.05）。 结论 PA能通过增加ATP含量和钠钾ATP酶的活性并降低脑水肿,对TBI具有神经保护作用。这为PA 在临床脑损伤时的应用提供了实验证据。     

Role of arginine vasopressin V1 and V2 receptors for brain damage after transient focal cerebral ischemia.

Brain edema formation is one of the most important mechanisms responsible for brain damage after ischemic stroke. Despite considerable efforts, no specific therapy is available yet. Arginine vasopressin (AVP) regulates cerebral water homeostasis and has been involved in brain edema formation. In the current study, we investigated the role of AVP V1 and V2 receptors on brain damage, brain edema formation, and functional outcome after transient focal cerebral ischemia, a condition comparable with that of stroke patients undergoing thrombolysis. C57/BL6 mice were subjected to 60-min middle cerebral artery occlusion (MCAO) followed by 23 h of reperfusion. Five minutes after MCAO, 100 or 500 ng of [deamino-Pen(1), O-Me-Tyr(2), Arg(8)]-vasopressin (AVP V1 receptor antagonist) or [adamantaneacetyl(1), O-Et-D-Tyr(2), Val(4), Abu(6), Arg(8,9)]-vasopressin (AVP V2 receptor antagonist) were injected into the left ventricle. Inhibition of AVP V1 receptors reduced infarct volume in a dose-dependent manner by 54% and 70% (to 29+/-13 and 19+/-10 mm3 versus 63+/-17 mm3 in controls; P<0.001), brain edema formation by 67% (to 80.4%+/-1.0% versus 82.7%+/-1.2% in controls; P<0.001), blood-brain barrier disruption by 75% (P<0.001), and functional deficits 24 h after ischemia, while V2 receptor inhibition had no effect. The current findings indicate that AVP V1 but not V2 receptors are involved in the pathophysiology of secondary brain damage after focal cerebral ischemia. Although further studies are needed to clarify the mechanisms of neuroprotection, AVP V1 receptors seem to be promising targets for the treatment of ischemic stroke.     

EGb761对大鼠局灶性脑缺血再灌注损伤的保护作用

目的 :观察 EGb76 1对大鼠局灶性脑缺血再灌注损伤的保护作用。方法 :45只大鼠随机分为假手术组 (A组 ) ,脑缺血再灌注损伤组 (B组 ) ,EGb76 1治疗组 (C组 ) ,每组 15只。以线栓法制作大鼠脑缺血再灌注损伤模型。每组 10只缺血 6 0 min再灌注 6 0 min后断头处死 ,取脑测定 NO、NOS、MDA和 SOD变化 ,其余 5只缺血 3h再灌注 2 4h后断头处死 ,观察常规病理、Niss小体及凋亡细胞变化。C组于实验前 3天开始灌胃给 EGb76 1(15 0 mg/ kg,每日 2次 ,术前 1h、术后 12 h灌 EGb76 115 0 mg/ kg)。结果 :脑缺血再灌注后 ,B组 NO、MDA含量 ,NOS活性较 A组升高 ,SOD活性降低 (P<0 .0 5 ) ,病理变化明显 ,凋亡细胞增多。C组 NO、MDA含量及 NOS活性降低 ,SOD活性升高 (P<0 .0 5 ) ,C组病理变化减轻 ,凋亡细胞减少 (P<0 .0 5 )。结论 :EGb76 1对大鼠局灶性脑缺血再灌注损伤具有保护作用。     

Edema, cation content, and ATPase activity after middle cerebral artery occlusion in rats.

BACKGROUND AND PURPOSE: Reduction of cerebral blood flow results in several acute metabolic disturbances, including a reduction in Na,K-ATPase activity. The relation between this reduction and the onset of edema is unknown, as is the effect of restoration of blood flow. Therefore, we investigated the role of decreased Na,K-ATPase activity in the pathogenesis and time course of ischemic brain edema and reperfusion. METHODS: The middle cerebral arteries of rats were occluded by cannulation with a nylon suture for 30, 60, 120, or 240 minutes. The animals were then decapitated (permanent occlusion) or the suture was withdrawn to allow 24 hours of reperfusion before decapitation (temporary occlusion). Na,K-ATPase activity and Na+, K+ and water contents were measured at various intervals. RESULTS: In the ischemic hemisphere, Na,K-ATPase activity was significantly decreased at 30, 60, 120, and 240 minutes of permanent occlusion (p less than 0.05). There was also a significant decrease in rats subjected to 60 or 120 minutes of temporary occlusion followed by 24 hours of reperfusion. Water content increased after 60, 120, or 240 minutes of permanent occlusion (p less than 0.01); after 24 hours of reperfusion, water content remained elevated (p less than 0.01). The Na+ content increased after both permanent and temporary occlusion, and the K+ content decreased only after permanent occlusion. Increases in water content correlated with decreases in Na,K-ATPase activity after temporary occlusion and with the Na+:K+ ratio after permanent occlusion. CONCLUSION: Reduction in Na,K-ATPase activity resulting in disruption of cellular ionic homeostasis may account for early development of cytotoxic brain edema after permanent occlusion of the middle cerebral artery. Such edema is also present 24 hours after 60 and 120 but not 30 minutes of temporary occlusion.     

急性脑缺血再灌注损伤钙离子与氧自由基作用实验研究

为探讨钙离子与氧自由基在急性脑缺血再灌注损伤中的作用，用复制大鼠急性脑缺血再灌注动物模观察脑缺血再灌注过程中脑组织H2O2、Ca^2 、MDA含量及病理学变化及尼莫地平对上述指标的影响，结果表明，急性脑缺血再灌注后有细胞内钙超载和自由基代谢紊乱，且在再灌注损伤中有协同作用，加重组织损伤，促进脑水肿，尼莫地平对其有保护作用。     

丁苯肽软胶囊对大鼠急性脑缺血再灌注损伤脑组织含水及含钙量的影响

目的 研究丁苯肽软胶囊对大鼠急性脑缺血再灌注损伤脑组织含水量及含钙量的影响.方法 选取健康SD大鼠60只,按照随机数字表随机分为6组,采用4血管法造脑缺血再灌注损伤模型,给药组分别给予不同剂量的丁苯肽软胶囊和复方丹参注射液,观察丁苯肽软胶囊对大鼠急性脑缺血再灌注损伤脑组织含水量及含钙量的影响.结果 丁苯肽软胶囊高剂量组可降低大鼠急性脑缺血再灌注损伤脑组织含水量（75.60%）及含钙量（114.53 pg/g）;中剂量组降低大鼠急性脑缺血再灌注损伤脑组织含水量（80.03%）,降低大鼠急性脑缺血再灌注损伤脑组织含钙量（132.33 pg/g）;低剂量组对大鼠急性脑缺血再灌注损伤脑组织含水量（73.93）及含钙量（106.35 pg/g）有降低趋势,但差异无统计学意义（P＞0.05）.结论 丁苯肽软胶囊能降低大鼠急性脑缺血再灌注损伤脑组织含水量及含钙量,具有脑保护作用.