血管性痴呆模型大鼠海马CA3区微管相关蛋白-2的表达及其意义

目的:探讨海马CA3区神经元微管相关蛋白-2(MAP-2)表达变化与学习记忆功能的关系.方法:采用大白鼠大脑中动脉线栓法(MCAO)缺血再灌模型,分为缺血2h再灌(I/R)1d、7d、14d、30d、90d组和假手术组,免疫组织化学方法观察海马CA3区MAP-2表达,并用图像分析系统作定量分析;同时用Morris水迷宫检测再灌7d、14d、30d、90d组大鼠行为学变化.结果:缺血再灌1d海马CA3区MAP-2呈高表达突起断裂不均匀,再灌7d和14d表达最高,突起出现螺旋样变,再灌30d后MAP-2的表达开始恢复,突起依然断裂,再灌90d后突起形态基本恢复正常.行为学检测发现,大白鼠缺血再灌7d和14d组定位航行试验潜伏期明显延长,空间探索试验中跨平台次数减少,再灌30d开始恢复,再灌90d与假手术组无差别.结论:缺血再灌后,海马CA3区神经元处于高度可塑性状态,可能是神经元新的突触连接形成的结构基础之一,可部分代偿缺血敏感区CA1神经元丧失引起的学习记忆功能的下降.     

短暂性缺血对小脑皮质超微结构的损害

目的 探讨家兔全脑缺血对小脑皮质蒲肯野细胞的损害。方法 用电镜观察缺血后的超微结构改变,结果随着缺血,缺血再灌时间延长,蒲肯野细胞肿胀,线粒体嵴部分断裂,空泡样变。细胞突起间的部分桥粒样结构移位,结论 缺血再灌比单纯缺血对蒲肯野细胞的损害更大。     

大鼠脑缺血—再灌注损伤细胞间粘附分子—1表达的研究

本文用暂时性脑缺血的大鼠模型对血管内皮细胞间粘附分子１（ＩＣＡＭ１）的表达进行了研究。免疫组化显示,ＩＣＡＭ１的表达于缺血１ｈ再灌６ｈ后明显升高;激光共聚焦扫描显微镜定量检测说明再灌后其表达量比单纯缺血增加了４７％。脑组织过氧化物酶ＭＰＯ（μ／ｇ）含量检测及光镜观察均证实再灌后白细胞在缺血区聚集增多。局部脑组织ＩＬ１含量（ＯＤ值／ｇ）在灌流３ｈ后明显升高。结果说明：①脑缺血再灌注损伤时血管内皮细胞ＩＣＡＭ１的表达为时间依赖性增加;②ＩＣＡＭ１的调节表达与脑损伤时局部细胞因子ＩＬ１的分泌有关;③再灌注后脑缺血区有白细胞的大量聚集;④ＩＣＡＭ１表达量的增加是白细胞在缺血区粘附到血管壁、游出血管损伤周围脑组织的前提条件。     

美满霉素对沙鼠急性脑缺血后脑皮质钙视网膜蛋白表达的影响

目的:观察美满霉素对蒙古沙鼠短暂性脑缺血再灌后前额皮质中钙视网膜蛋白Calretinin(CR)表达的影响,为进一步研究其生理功能及治疗提供参考。方法:42只健康雄性蒙古沙鼠随机分为:正常组对照组、缺血再灌组,美满霉素治疗组。夹闭蒙古沙鼠双侧颈总动脉10 min诱导前脑缺血后,动物分别存活1天、3天或7天。用免疫组化方法检测前额皮质中CR的表达,用图像分析仪测定灰度值。结果:与正常组相比,缺血再灌组与美满霉素治疗组中前额皮质中CR表达均先减少后升高再下降。缺血再灌1天组,CR表达显著减少(P<0.05);3天组CR表达达到高峰(P<0.05);7天组CR表达减弱,但仍高于正常组(P<0.05)。美满霉素治疗各组中的CR表达均弱于对应的缺血再灌组(P<0.05)。结论:美满霉素能抑制蒙古沙鼠脑缺血再灌注后脑皮质中CR的表达来发挥脑保护作用。     

美满霉素对沙鼠急性脑缺血后脑皮质小白蛋白表达的影响

目的：观察美满霉素对蒙古沙鼠短暂性脑缺血再灌后前额皮质中小白蛋白Parvalbumin（PV）表达的影响，为进一步研究其生理功能变化及治疗提供参考。方法：42只健康雄性蒙古沙鼠随机分为：正常组对照组（6只）、缺血再灌组（18只），美满霉素治疗组（18只）。夹闭蒙古沙鼠双测颈总动脉10min诱导前脑缺血后，动物分别存活1天、3天或7天。用免疫组化方法检测前额皮质中PV的表达，用图像分析仪测定灰度值。结果：与正常组相比，各缺血再灌组与美满霉素治疗组中前额皮质中PV表达均先减少后回升。缺血再灌1天组，PV表达缓慢减少（P〉0.05）；3天组PV表达减少到低谷（P〈0.05）；7天组PV表达有明显的恢复，但仍低于正常组（P〈0.05）；然而美满霉素治疗各组中的PV表达均强于对应的缺血组（P〈0.05）。结论：美满霉素能抑制蒙古沙鼠脑缺血再灌注后脑皮质中小白蛋白的表达，发挥脑保护作用。     

全脑缺血-再灌注对老年鼠海马区细胞凋亡与神经再生的影响

目的通过比较老年小鼠与青年小鼠海马区中细胞凋亡相关分子、神经再生相关分子的表达,探讨全脑缺血再灌注对老年鼠海马区神经再生与细胞凋亡的影响。方法 18月龄雄性ICR小鼠与2月龄雄性ICR小鼠各15只,随机分为假手术组、缺血再灌注3d组和缺血再灌注7d组,采用二血管加低血压法制作全脑缺血再灌注模型,Western blot检测海马组织中细胞凋亡相关分子BAX、Bcl2、caspase9,神经再生相关分子nestin、doublecortin的表达。结果全缺血再灌注后,老年鼠海马区细胞凋亡相关分子BAX、Bcl2、caspase9的表达均显著高于青年鼠,而神经再生相关分子nestin、doublecortin的表达均较青年组低。结论缺血再灌注损伤促进老年鼠海马区细胞凋亡,并影响海马区神经再生能力,削弱组织的自我修复和功能恢复。     

短暂性缺血对小脑皮质影响的组织化学研究

为了探讨全脑短暂性缺血对小脑皮质蒲肯野细胞的影响 ,实验用组织化学方法对家兔全脑缺血 5分钟 (B组 )、 10分钟 (C组 )及缺血再灌 (D、 E组 )后蒲肯野细胞的酶组织化学变化进行了观察。结果显示 ,缺血 10分钟及缺血再灌后蒲肯野细胞的 SDH、Mg2 + - ATP活性及 PAS反应均降低 (P<0 .0 5 ) ,L DH增高 (P<0 .0 1)。结果提示家兔全脑缺血 10分钟和缺血再灌可损害小脑皮质蒲肯野细胞的能量代谢酶的活性     

PEP-1 超氧化物歧化酶对大鼠脑缺血再灌注后Bcl-2 的影响

目的:观察细胞穿透肽-铜,锌超氧化物歧化酶(PEP-1-SOD1)预处理对大鼠局灶性脑缺血再灌注损伤的改善作用及其脑保护机制。方法:线栓法建立大鼠局灶性脑缺血6h后再灌注损伤模型,进行神经行为评分,并通过HE染色在光镜下观察神经细胞损伤变化,免疫组化法检测B细胞淋巴瘤基因-2(B-cell lymphoma-2,Bcl-2)蛋白的阳性表达。结果:盐水对照组(缺血再灌注组或模型组)神经障碍显著高于假手术组(P<0.05),与模型组相比,PEP-1-SOD1预处理组可降低神经障碍评分(P<0.05);光镜下,假手术组神经细胞结构正常,PEP-1-SOD1预处理组和缺血再灌注组均有不同程度的缺血再灌注损伤,PEP-1-SOD1预处理组较缺血再灌注组损伤轻;假手术组Bcl-2蛋白表达极弱,缺血再灌注组和PEP-1-SOD1预处理组在脑缺血再灌注后6h在缺血半暗带周围出现Bcl-2蛋白阳性表达,24h达到高峰,48h表达开始减少。与假手术组相比,PEP-1-SOD1预处理组和缺血再灌注组Bcl-2蛋白阳性细胞数显著增多(P<0.05);与缺血再灌注组相比,PEP-1-SOD1预处理组Bcl-2蛋白阳性细胞数显著增多(P<0.05)。结论:PEP-1-SOD1对大鼠局灶性脑缺血再灌注损伤有保护作用,PEP-1-SOD1可通过上调Bcl-2蛋白的表达发挥脑保护作用。     

大鼠脑缺血再灌注后海马神经细胞NOS表达与细胞凋亡及复方丹参的保护作用

目的探讨大鼠局灶性脑缺血再灌注后海马神经细胞一氧化氮合酶(NOS)的表达与神经细胞凋亡的关系及中药复方丹参的保护作用。方法采用大脑中动脉内栓线阻断法(MCAO)造成局灶性脑缺血再灌注模型。用原位细胞凋亡检测方法观察海马神经细胞凋亡;用免疫组织化学方法检测大鼠海马神经细胞(nNOS、iNOS)的表达并做图像分析。结果与假手术对照组比较,脑缺血再灌注2h后缺血侧海马CA1、CA3区神经细胞nNOS、iNOS表达升高,并出现神经细胞凋亡,随着再灌注时间的延长,神经细胞iNOS的表达明显增强,凋亡神经细胞数逐渐增多,至24h达高峰,但神经细胞nNOS的表达并未见明显增强。复方丹参保护组神经细胞nNOS、iNOS的表达和凋亡神经细胞数明显低于缺血再灌组(P<0.01)。结论脑缺血再灌注后缺血侧海马CA1、CA3区神经细胞nNOS的表达增强,iNOS的表达显著升高,使NO的形成增加,这可能是介导脑缺血再灌注后神经细胞凋亡的机制之一。复方丹参具有下调神经细胞nNOS、iNOS的表达,减少NO的生成,抑制细胞凋亡,减轻缺血再灌注对大鼠海马损伤的作用。     

PEP-1超氧化物歧化酶对大鼠脑缺血再灌注后Bcl-2的影响

目的：观察细胞穿透肽-铜,锌超氧化物歧化酶（PEP-1-SOD1）预处理对大鼠局灶性脑缺血再灌注损伤的改善作用及其脑保护机制。方法：线栓法建立大鼠局灶性脑缺血6h后再灌注损伤模型,进行神经行为评分,并通过HE染色在光镜下观察神经细胞损伤变化,免疫组化法检测B细胞淋巴瘤基因-2（B—celllymphoma-2,Bcl-2）蛋白的阳性表达。结果：盐水对照组（缺血再灌注组或模型组）神经障碍显著高于假手术组（P〈0．05）,与模型组相比,PEP-1-SOD1预处理组可降低神经障碍评分（P〈0．05）;光镜下,假手术组神经细胞结构正常,PEP-1-SDO1预处理组和缺血再灌注组均有不同程度的缺血再灌注损伤,PEP-1-SOD1预处理组较缺血再灌注组损伤轻;假手术组Bcl-2蛋白表达极弱,缺血再灌注组和PEP-1-SOD1预处理组在脑缺血再灌注后6h在缺血半暗带周围出现Bcl-2蛋白阳性表达,24h达到高峰,48h表达开始减少。与假手术组相比,PEP-1-SOD1预处理组和缺血再灌注组Bcl-2蛋白阳性细胞数显著增多（P〈0．05）;与缺血再灌注组相比,PEP-1-SOD1预处理组Bcl-2蛋白阳性细胞数显著增多（P〈0．05）。结论：PEP-1-SOD1对大鼠局灶性脑缺血再灌注损伤有保护作用,PEP-1-SOD1可通过上调Bcl-2蛋白的表达发挥脑保护作用。     

Post-ischemic hypothermia promotes generation of neural cells and reduces apoptosis by Bcl-2 in the striatum of neonatal rat brain

Hypothermia is a potential therapy for cerebral hypoxic ischemic injury in adults and neonates. However, the mechanism of hypothermia neuroprotection after hypoxic-ischemia (HI) on the developing rat brain remains unclear. In this research, 7-day-old rats were subjected to left carotid artery ligation followed by 8% oxygen for 2h. They were divided into hypothermia (rectal temperature, 32-33°C for 24h) and normothermia (36-37°C for 24h) groups immediately after hypoxia-ischemia. All rats were given 50mg/kg/day 5-bromodeoxyuridine (BrdU) intraperitoneally at 4-6 days and sacrificed at 1 or 2 weeks after HI. There was a significant decrease in infarct volume in the hypothermia group at 7 days after HI compared with that in the normothermia group. The numbers of nestin-labeled cells did not change greatly, but β-tubulin III (Tuj-1) immuno-positive cells increased significantly in the striatum at 1 and 2 weeks after HI in the hypothermia compared to normothermia group. Neurogenesis was assessed by double immunohistochemical/immunofluorescent labeling of BrdU with nestin, Tuj-1 or microtubule-associated protein 2 (Map-2). Newborn neural progenitors (BrdU(+)-nestin(+)) did not change dramatically, but newborn immature (BrdU(+)-Tuj-1(+)) and mature (BrdU(+)-Map-2(+)) neurons increased significantly in the hypothermia compared with normothermia group. Meanwhile, the apoptosis rate of neural precursors, immature and mature neurons, assessed by double labeling of active Casp-3 with nestin/Tuj-1/Map-2, decreased noticeably in the hypothermia compared with normothermia group. We also found that hypothermia significantly increased expression of Bcl-2, which coexisted with nestin/Tuj-1/Map-2. Inhibition of Bcl-2 expression reversed the decreased apoptosis rate of neural precursors and neurons in hypothermia animal striatum of neonatal rat brain. These results suggest that neuroprotection effects of hypothermia on injured developing rat brain may associate with enhanced generation of neuronal cells and Bcl-2-mediated reduction of apoptosis of these cells. These observations are noteworthy regarding clinical hypothermia therapy following cerebral HI injury during the perinatal period.     

Spatio-temporal properties of 5-lipoxygenase expression and activation in the brain after focal cerebral ischemia in rats

The role of 5-lipoxygenase (5-LOX) in brain injury after cerebral ischemia has been reported; however, the spatio-temporal properties of 5-LOX expression and the enzymatic activation are unclear. To determine these properties, we observed post-ischemic 5-LOX changes from 3 h to 14 days after reperfusion in rats with transient focal cerebral ischemia induced by 30 min of middle cerebral artery occlusion. We found that the expression of 5-LOX, both mRNA and protein, was increased in the ischemic core 12-24 h after reperfusion, and in the boundary zone adjacent to the ischemic core 7-14 days after reperfusion. The increased 5-LOX was primarily localized in the neurons in the ischemic core at 24 h, but in the proliferated astrocytes in the boundary zone 14 days after reperfusion. As 5-LOX metabolites, the level of cysteinyl-leukotrienes in the ischemic brain was substantially increased 3 h to 24 h, near control at 3 days, and moderately increased again 7 days after reperfusion; whereas the level of LTB(4) was increased mildly 3 h but substantially 7-14 days after reperfusion. Thus, we conclude that 5-LOX expression and the enzymatic activity are increased after focal cerebral ischemia, and spatio-temporally involved in neuron injury in the acute phase and astrocyte proliferation in the late phase.     

The Role of HSPA12B in Regulating Neuronal Apoptosis

Heat shock protein A12B (HSPA12B) is the newest member of a recently defined subfamily of proteins distantly related to the 70-kDa family of heat shock proteins (HSP70) family. HSP70s play a crucial role in protecting cells, tissues, organs and animals from various noxious conditions. Here we studied the dynamic expression changes and localization of HSPA12B after middle cerebral artery occlusion (MCAO) with reperfusion induced ischemic insult processes in adult rats. Apoptosis, as indicated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, was also increased in the peri-ischemic cortex compared to non-ischemic hemisphere. The expression of HSPA12B was strongly induced in the ischemic hemisphere of MCAO reperfusion rats in vivo. In vitro studies indicated that the up-regulation of HSPA12B may be involved in oxygen-glucose deprivation-induced PC12 cell death. And knockdown of HSPA12B in cultured differentiated PC12 cells by siRNA showed that HSPA12B inhibited the expression of active caspase-3. Collectively, these results suggested that HSPA12B may be required for protecting neurons from ischemic insults.     

Hypothermia Protects the Brain from Transient Global Ischemia/Reperfusion by Attenuating Endoplasmic Reticulum Response-Induced Apoptosis through CHOP

Endoplasmic reticulum (ER) stress has been implicated in the pathology of cerebral ischemia. Apoptotic cell death occurs during prolonged period of stress or when the adaptive response fails. Hypothermia blocked the TNF or Fas-mediated extrinsic apoptosis pathway and the mitochondria pathway of apoptosis, however, whether hypothermia can block endoplasmic reticulum mediated apoptosis is never known. This study aimed to elucidate whether hypothermia attenuates brain cerebral ischemia/reperfusion (I/R) damage by suppressing ER stress-induced apoptosis. A 15 min global cerebral ischemia rat model was used in this study. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) positive cells in hippocampus CA1 were assessed after reperfusion of the brain. The expressions of C/EBP-homolo gous protein (CHOP) and glucose-regulated protein 78 (GRP78) in ischemic hippocampus CA1 were measured at 6, 12, 24 and 48 h after reperfusion. The results showed that hypothermia significantly attenuated brain I/R injury, as shown by reduction in cell apoptosis, CHOP expression, and increase in GRP78 expression. These results suggest that hypothermia could protect brain from I/R injury by suppressing ER stress-induced apoptosis.     

神经调节素对大鼠脑缺血再灌注损伤后炎症反应的抑制作用和机制研究

目的：研究神经调节素及基质金属蛋白酶-9对于小鼠大脑缺血再灌注损伤后炎症反应的抑制作用和机制。方法：选取100只成年雄性大鼠,随机分成对照和治疗组。采用线栓方法由颈内到颈外进行插线处理,造成大脑中动脉处于闭塞状态的再灌注动物模型。治疗组颈动脉进行注射少量NRG-1β干预性治疗,通过氯化三苯基四氮唑（TTC）检查脑梗塞范围,细胞凋亡采用原住脱氧核糖核苷酸末端转移酶介导缺口末端进行标记,采用免疫组织化学、免疫荧光双标记法及免疫印迹法观察脑组织基质金属蛋白酶-9（MMP-9）表达。结果：脑缺血再灌注损伤后,随时间延长及缺氧,对照组大鼠大脑皮质和纹状体区脑组织细胞凋亡,并且胶质细胞MMP-9蛋白表达逐渐增加。治疗组大鼠经注射NRG-1β干预性治疗后,缺血脑组织梗死范围及其细胞凋亡数量相对呈明显下降趋势。胶质细胞MMP-9表达呈降低趋势。结论：大鼠脑缺血再灌注损伤后体内NRG-1β抑制胶质细胞MMP-9的表达,控制缺血脑组织梗死的范围并抑制正常细胞的凋亡,发挥了重要的抗炎作用,可作为对于大脑缺血再灌注损伤的研究新靶点。     

Early Detection of DNA Strand Breaks in the Brain After Transient Focal Ischemia: Implications for the Role of DNA Damage in Apoptosis and Neuronal Cell Death

Abstract: Using in situ DNA polymerase I-mediated biotin-dATP nick-translation (PANT) and terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling (TUNEL), we investigated the evolution of DNA strand breaks, a marker of DNA damage, in rat brain after 1 h of middle cerebral artery occlusion and various durations of reperfusion. DNA single-strand breaks (SSBs) detected by PANT were present in neurons after as little as 1 min of reperfusion. Numbers of neurons containing an SSB increased progressively in the ischemic core but decreased in the ischemic penumbra after 1 h of reperfusion. DNA double-strand breaks (DSBs) detected by TUNEL were first seen in neurons after 1 h of reperfusion, and their numbers then increased progressively in the ischemic core, with a regional distribution similar to that of SSBs. However, the number of SSB-containing cells was greater than that of DSB-containing cells at all time points tested. SSB-containing cells detected within the first hour of reperfusion were exclusively neuronal and exhibited normal nuclear morphology. At 16–72 h of reperfusion, many SSB- and DSB-containing cells, including both neurons and astrocytes, showed morphological changes consistent with apoptosis. Gel electrophoresis of DNA isolated from the ischemic core showed DNA fragmentation at 24 h, when both SSBs and DSBs were present, but not at 1 h, when few DSBs were detected. These results suggest that damage to nuclear DNA is an early event after neuronal ischemia and that the accumulation of unrepaired DNA SSBs may contribute to delayed ischemic neuronal death, perhaps by triggering apoptosis.     

Dynamic Expression Pattern of Neuro-oncological Ventral Antigen 1 (Nova1) in the Rat Brain after Focal Cerebral Ischemia/Reperfusion Insults

The present study aimed to evaluate the expression of neuro-oncological ventral antigen 1 (Nova1) in cerebral ischemia/reperfusion (I/R) insults by immunohistochemistry. The focal cerebral I/R model was induced by right middle cerebral artery occlusion (MCAO) for 120 min followed by 1 day, 7 days, and 14 days of reperfusion in Sprague-Dawley (SD) rats. The results showed that Nova1 was expressed in nearly the whole brain, although with higher density in hippocampus, hypothalamus, cingulate cortex, and medial habenular nucleus. The immunoreactivity of Nova1 neurons was increased dramatically, especially on both sides of the hippocampal CA₁ region, after 1 day of reperfusion. A strong response occurred at the ipsilateral CA₁ region between 1 day and 7 days of reperfusion. Likewise, strong compensatory responses of Nova1 expression were observed on the contralateral side of the striate cortex, dentate gyrus, and hypothalamus. Interestingly, more Nova1 neurons were observed to translocate to the dendrites and growth cones of the axons in the hypothalamus on the ischemic side after 7 days of reperfusion. In conclusion, our data suggest that Nova1 might mediate neuronal responsiveness, and its expression might positively correlate with neural repair after I/R insults in the rat brain.     

大鼠脑缺血区细胞间粘附分子ICAM-1表达和LFA-1阳性细胞浸润的研究

研究粘附分子和白细胞与脑缺血／再灌流损伤的病理联系,运用原位杂交和免疫组化技术对36只SD大鼠脑缺血区细胞间粘附分子（ICAM－1）表达和淋巴细胞机能相关抗原（LFA－1）阳性细胞浸润进行了观察。结果显示,脑缺血区的毛细胞血管内皮细胞表达ICAM－1 mRNA发生于脑缺血1h,在脑缺血1h／再灌流8h达到高峰。而脑缺血区毛细血管ICAM－1蛋白质的表达则发生于脑缺血1h／再灌流2h,高峰出现于脑缺血1h／再灌流16h,LFA－1阳性细胞在脑缺血区的聚集发生在脑缺血1h,并随再灌流时间延长,其聚集数量逐渐增加。结果提示,脑缺血／再灌流能诱导缺血区的血管内皮细胞表达ICAM－1 mRNA和蛋白质,进而导致白细胞在脑缺血区的浸润,此可能是脑缺血／再灌流损伤的病理机制之一。     

Identification of stathmin as a novel marker of cell proliferation in the recovery phase of acute ischemic renal failure

Ischemic renal injury can be classified into the initiation and extension phase followed by the recovery phase. The recovery phase is characterized by increased dedifferentiated and mitotic cells in the damaged tubules. Suppression subtractive hybridization was performed by using RNA from normal and ischemic kidneys to identify the genes involved in the physiological response to ischemia-reperfusion injury (IRI). The expression of stathmin mRNA increased by fourfold at 24 h of reperfusion. The stathmin mRNA did not increase in sodium-depleted animals or in animals with active, persistent injury secondary to cis-platinum. Immunofluorescent labeling demonstrated that the expression of stathmin increased dramatically at 48 h of reperfusion. Labeling with antibodies to stathmin and proliferating cell nuclear antigen (PCNA) indicates that the expression of stathmin was induced before the upregulation of PCNA and that all PCNA-positive cells expressed stathmin. Double immunofluorescent labeling demonstrated the colocalization of stathmin with vimentin, a marker of dedifferentiated cells. Stathmin expression was also significantly enhanced in acute tubular necrosis in humans. On the basis of its induction profile in IRI, the data indicating its enhanced expression in proliferating cells and regenerating organs, we propose that stathmin is a marker of dedifferentiated, mitotically active epithelial cells that may contribute to tubular regeneration and could prove useful in distinguishing the injury phase from recovery phase in IRI.     

神经途径在肢体缺血预处理抗脑缺血/再灌注损伤中的作用

目的：探讨神经途径在肢体缺血预处理（limbi schemic preconditioning,LIP）抗脑缺血／再灌注损伤中的作用。方法：脑缺血采用四血管闭塞模型,重复短暂夹闭放松大鼠双侧股动脉3次作为LIP。将凝闭椎动脉的大鼠随机分为sham组、脑缺血组、股神经切断＋脑缺血组、LIP＋脑缺血组、股神经切断＋LIP＋脑缺血组。于Sham手术和脑缺血后7d处死大鼠,硫堇染色观察海马CA1区锥体神经元迟发性死亡的变化。于Sham手术和脑缺血后6h心脏灌注固定大鼠,免疫组化法测定海马CAI区c-Fos表达的变化。结果：硫堇染色结果显示,与sham组比较。脑缺血组和股神经切断＋脑缺血组大鼠海马CAI区均有明显组织损伤。LIP＋脑缺血组CAI区无明显细胞缺失,神经元密度明显高于脑缺血组（P〈0．01）。而股神经切断＋LIP＋脑缺血组大鼠海马CA1区明显损伤,锥体细胞缺失较多,与LIP＋脑缺血组组比较,神经元密度显著降低（P〈O．01）,提示LIP前切断双侧股神经取消了LIP抗脑缺血／再灌注损伤作用。c—Fos免疫组化染色结果显示,Sham组海马CAI区未见明显的c-Fos蛋白表达。脑缺血组海马CAI区偶见c—Fm的阳性表达。LIP＋脑缺血组c—Fos表达增强,数量增加,与Sham组和脑缺血组比较。c-Fos阳性细胞数和光密度均明显升高（P〈0．01）。而股神经切断＋LIP＋脑缺血组c-Fos表达明显减少,仅见少量弱阳性e-Fos表达。结论：LIP可通过神经途径发挥抗脑缺血／再灌注损伤作用,而LIP诱导c—Fos表达增加可能是LIP诱导脑缺血耐受神经途径的一个环节。