脑缺血再灌注后脑组织c-fos基因表达与丹参的影响

采用线栓法制成大鼠大脑中动脉缺血再灌注模型，用地高辛精标记ｃ－ｆｏｓ探针进行原位杂交。结果示缺血再灌注鼠栓塞侧皮层及海马ｃ－ｆｏｓ基因表达显著增多，图像分析灰阶值为１１８．６±５．１，对侧为１５９．６±３．１（Ｐ＜０．００１）。丹参组栓塞侧皮层及海马ｃ－ｆｏｓ基因表达亦增多，灰阶为１３５．００±２．０５，对侧为１６７．００±２．００（Ｐ＜０．００１）。丹参组与缺血再灌注组比较，栓塞侧丹参组ｃ－ｆｏｓ基因表达显著低于缺血再灌组（Ｐ＜０．０５），而两组栓塞对侧比较无显著差异。本实验表明，脑缺血再灌注后脑组织ｃ－ｆｏｓ基因表达显著增多，丹参能部分抑制缺血后ｃ－ｆｏｓ基因的表达，这可能是其治疗缺血性脑血管病的机理之一。     

脑缺血再灌注后脑组织C—fos基因表达与丹参的影响

采用线栓法制成大鼠大脑中动脉缺血再灌注模型,用地高辛精标记C-fos探针进行原位杂交。结果示缺血再灌注鼠栓塞侧和丹参组栓塞侧皮层及海马C-fos基因表达显著增多,但丹参组栓塞侧C-fos基因表达显著低于缺血再灌组(P<0.05),而两组栓塞对侧比较无显著差异。表明,脑缺血再灌注后脑组织C-fos基因表达显著增多,丹参能部分抑制缺血后C-fos基因的表达。     

脑缺血和再灌注后脑组织内皮素—1基因表达及…

为研究脑缺血和再灌注后脑组织内素素－１基因表达的变化以及丹参对它的影响，采用线栓法制成大鼠大脑中动脉缺血和再灌注模型，并用地高辛精标记ＥＴ－１基因进行原位杂交。结果显示，缺血组和再灌注组缺血组侧皮层及尾壳核ＥＴ－１基因表达均显著高于健侧相应的脑区，经丹参治疗后缺血或再灌注鼠缺血侧皮层及尾壳核ＥＴ－１基因表达均显著低于生理盐水对照组，但仍比健侧脑区显著增高。     

脑缺血后脑组织一氧化氮合成酶基因表达及丹参影响的初步研究

一氧化氮（ＮＯ）具有神经介质或调质的功能，广泛参与体内的生理及病理过程，具有扩张血管和神经毒性作用。体内ＮＯ系通过一氧化氮合成酶（ＮＯＳ）催化形成，并通过Ｃａ２＋／钙调素机理生成ＮＯ，因此ＮＯＳ是ＮＯ合成的关健因素。为研究脑缺血与脑组织ＮＯＳ的关系及丹参的影响，采用线栓法制成大鼠大脑中动脉缺血模型，用地高辛精标记的ＮＯＳ探针进行原位杂交。结果示缺血对照组栓塞侧皮层和尾壳核ＮＯＳ基因表达显著增多，图像分析灰阶值为：缺血侧皮层１１６．２±１．０，非缺血侧１３４．５±０．７（Ｐ＜０．０１）；缺血侧尾核壳核１２２．０±０．７，非缺血侧１３７．５±０．８（Ｐ＜０．０１）。阳性细胞数：缺血侧皮层３２６．７±８．２，非缺血侧１０７．５±９．９（Ｐ＜０．０１）；缺血侧尾壳核２６２．２±３．５，非缺血侧７２．２±９．８（Ｐ＜０．０１）。虽然丹参组缺血侧皮层和尾壳核ＮＯＳ基因表达亦显著高于非缺血侧（Ｐ＜０．０１），但显著低于缺血对照组（Ｐ均＜０．０１），而两组非缺血侧比较无显著差异。结果表明，脑缺血后脑组织ＮＯＳ基因表达显著增多，丹参能部分下调缺血所致的ＮＯＳ基因的异常表达，这可能是其治疗缺血性脑血管病的机理之一。     

脑缺血和再灌注后脑组织内皮素－1基因表达及丹参的影响

为研究脑缺血和再灌注后脑组织内皮素－１（ＥＴ－１）基因表达的变化以及丹参对它的影响，采用线栓法制成大鼠大脑中动脉缺血和再灌注模型，并用地高辛精标记ＥＴ－１基因进行原位杂交。结果显示，缺血组（缺血２４ｈ）和再灌注组（缺血１．５ｈ再灌注２４ｈ）缺血侧皮层及尾壳核ＥＴ－１基因表达均显著高于健侧相应的脑区（Ｐ＜０．０１，Ｐ＜０．０５），经丹参治疗后缺血或再灌注鼠缺血侧皮层及尾壳核ＥＴ－１基因表达均显著低于生理盐水（ＮＳ）对照组（Ｐ＜０．０５，Ｐ＜０．０１），但仍比健侧脑区显著增高。本实验表明，缺血和再灌注均可诱导脑组织ＥＴ－１基因的异常表达，进一步加重缺血和再灌注引起的脑损伤，丹参对缺血诱导的ＥＴ－１基因表达有部分抑制作用，这可能是丹参防治缺血性脑血管病的分子机理之一。     

脑缺血再灌注损伤时 c-fos、c-jun 的表达和细胞凋亡

目的　研究脑缺血再灌注大鼠神经细胞凋亡和原癌基因c fos、c jun表达。 方法　 8周龄健康雄性Wistar大鼠 2 4只 ,随机分为缺血再灌注组、假手术组和对照组 ,每组各 8只。制作大鼠大脑中动脉栓塞 (MCAO)再灌注模型 ,缺血 4h再灌注 2h后断头处死 ,TUNEL法检测神经细胞凋亡 ,免疫组织化学法检测神经细胞c fos、c jun蛋白的表达。结果　缺血再灌注组细胞凋亡率、平均吸光度及c fos、c jun阳性细胞率、平均吸光度均高于假手术组和对照组 (P <0 .0 5 )。结论　脑缺血再灌注损伤可诱导c fos、c jun蛋白的表达和细胞凋亡 ;脑缺血再灌注大鼠神经功能评分与c fos、c jun蛋白的表达和细胞凋亡呈正相关。     

促红细胞生成素对大鼠脑缺血再灌注损伤后缺血侧皮层神经元凋亡和Bcl-2表达的影响

目的探讨促红细胞生成素(Erythropoietin，EPO)对大鼠局灶性脑缺血再灌注损伤后的保护作用。方法采用线栓法阻断大鼠一侧大脑中动脉(MCA)血流2h，再灌注24h制成局灶性脑缺血再灌注损伤模型。将32只雄性SD大鼠随机分成EPO组、缺血再灌注组、假手术组和正常组。于缺血开始时EPO组给EPO 3000U／kg腹腔注射；缺血再灌注组和假手术组给予等剂量生理盐水。再灌注24h后断头取脑、切片，进行HE染色、Bcl-2免疫组化染色和细胞凋亡检测。结果缺血2h再灌注24h后，EPO组和缺血再灌注组大鼠缺血侧皮层可检测到凋亡细胞，且EPO组凋亡细胞数明显少于缺血再灌注组，假手术组和正常组未见凋亡细胞；EPO组和缺血再灌注组缺血侧皮层Bcl-2阳性细胞数均高于假手术组和正常组，与缺血再灌注组相比，EPO组Bcl-2蛋白表达显著增高。结论EPO可抑制缺血再灌注损伤后缺血侧皮层的细胞凋亡，其机制可能是通过上调bcl-2基因表达而实现。     

巴曲酶对大鼠大脑缺血及缺血再灌注ET1基因表达的影响

本实验采用大鼠急性脑缺血及缺血再灌注模型，研究巴曲酶对脑缺血及脑缺血再灌注时内皮素（ET1）基因表达的影响。用中大脑动脉（MCA）线检法大鼠模型，共12只，分为缺血组及缺血再灌注组（每组各6只），每组又分为巴曲酶组及盐水组（对照组）。缺血组在缺血后24h，再灌注组则在缺血1．5h及再灌注24h后用原位杂交，并采用IBHS图像分析系统研究ET1基因表达。发现巴曲酶组或对照组手术侧大脑皮质及尾壳核ET1mRNA表达均显著高于对侧（非手术侧）。但是巴曲酶组手术侧的ET1mRNA表达显著低于对照组。结果提示，巴曲酸可使缺血及缺血再灌注ET1基因表达下调。这可能是巴曲酶对缺血再灌注的脑保护作用机理之一。     

促红细胞生成素对大鼠脑缺血再灌注损伤后缺血侧皮层神经元凋亡和Bcl-2表达的影响

目的　探讨促红细胞生成素 (Erythropoietin ,EPO)对大鼠局灶性脑缺血再灌注损伤后的保护作用。方法　采用线栓法阻断大鼠一侧大脑中动脉 (MCA)血流 2h ,再灌注 2 4h制成局灶性脑缺血再灌注损伤模型。将 3 2只雄性SD大鼠随机分成EPO组、缺血再灌注组、假手术组和正常组。于缺血开始时EPO组给EPO 3 0 0 0U/kg腹腔注射 ;缺血再灌注组和假手术组给予等剂量生理盐水。再灌注 2 4h后断头取脑、切片 ,进行HE染色、Bcl -2免疫组化染色和细胞凋亡检测。结果　缺血 2h再灌注 2 4h后 ,EPO组和缺血再灌注组大鼠缺血侧皮层可检测到凋亡细胞 ,且EPO组凋亡细胞数明显少于缺血再灌注组 ,假手术组和正常组未见凋亡细胞 ;EPO组和缺血再灌注组缺血侧皮层Bcl -2阳性细胞数均高于假手术组和正常组 ,与缺血再灌注组相比 ,EPO组Bcl-2蛋白表达显著增高。结论　EPO可抑制缺血再灌注损伤后缺血侧皮层的细胞凋亡 ,其机制可能是通过上调bcl-2基因表达而实现。     

低分子肝素钙联合东菱克栓酶治疗进展性脑梗死

目的观察低分子肝素钙联合东菱克栓酶治疗进展性脑梗死的疗效。方法进展性脑梗死60例,随机分为2组,治疗组采用低分子肝素钙联合东菱克栓酶治疗,对照组采用低分子肝素钙治疗。结果治疗组和对照组比较,总有效率显著提高(P<0.05)。结论低分子肝素钙联合东菱克栓酶治疗进展性脑梗死的疗效令人满意。     

C—fos反义寡脱氧核苷酸部分阻断MCAO大鼠缺血侧皮质内BDNF的表达

用c fos反义寡脱氧核苷酸侧脑室微量注射和细胞免疫化学等技术和方法 ,探讨大鼠局灶性脑缺血(MCAO)模型中 ,即早反应基因c fos表达与脑源性神经营养因子 (BDNF)表达的关系。结果表明 ,局灶性脑缺血再灌注可引起c fos和BDNF在缺血侧皮质的大量表达。侧脑室微量注射c fos反义寡脱氧核苷酸后 ,脑内BDNF的部分表达明显被阻断 ,脑缺血损伤加重。提示脑缺血损伤后 ,脑内BDNF的表达对脑缺血再灌注损伤起一定的保护作用 ;脑缺血后BDNF的表达可能部分通过c fos调控。     

用逆转录-多聚酶链反应检测局灶脑缺血及再灌注后c-fos和c-jun基因表达

本研究应用逆转录－多聚酶链反应（ＲＴ－ＰＣＲ）方法检测大鼠局灶脑缺血模型中即早基因ｃ－ｆｏｓ和ｃ－ｊｕｎ的表达。结果发现缺血１５ｍｉｎ时可见到ｃ－ｆｏｓ和ｃ－ｊｕｎｍＲＮＡ表达缺血３０ｍｉｎ时引起轻微左侧局灶脑缺血改变，可诱导左侧局灶脑缺血区ｃ－ｆｏｓ和ｃ－ｊｕｎｍＲＮＡ广泛的表达；缺血９０ｍｉｎ后，导致大面积局灶脑缺血改变，诱导上述两种基因在同侧缺血区与同侧非大脑中动脉（ＭＣＡ）供血区的海马中表达。后者有相当轻的缺血症状。再灌流６０ｍｉｎ后诱导两种基因的共同表达立即达高峰。我们采用标准化的大鼠局灶脑缺血及再灌注模型，在分子水平上动态观察缺血／再灌注后基因变化特征，为缺血性脑损害的防治提供实验依据。     

巴曲酶的神经保护作用—缺血再灌注后不同时程热休克蛋白70及病理组织学变化的相关性研究

本文研究目的为巴曲酶是否影响热休克蛋白起到神经保护作用。用中大脑动脉(MCA)线栓法缺血再灌注大鼠模型。Wistar大鼠共51只。发现:在再灌注1h、2h、3h对照组与巴曲酶组(8BU/kg ip)HSP70均呈轻度表达,从再灌注12h起表达显著,至再灌注后24h达高峰,至再灌注后6d仅见于坏死灶周围,至再灌注后14d恢复至假手术组水平。巴曲酶组的HSP70表达变化在时程上与对照组一致,但在再灌注12h起至6d较对照组显著,同时相应时间点的MCA血供区皮层神经细胞有缺血变性者巴曲酶组少而轻。本文结果提示巴曲酶的神经保护作用,可能与它能影响HSP70蛋白合成的调控机制有关。     

巴曲酶对大鼠脑缺血再灌流损伤保护作用机理的研究

为探讨巴曲酶对大鼠短暂性脑缺血再灌流损伤引起的细胞凋亡有无抑制作用，参照Ｓｍｉｔｈ等（１９８４）方法，制备大鼠前脑短暂性缺血再灌流模型，采用ＴＵＮＥＬ（脱氧核苷酸转移酶末端介导的ｄＵＴＰ－生物素切口末端标记）法，观察了海马脑区细胞凋亡的特征变化—ＤＮＡ降解片段（凋亡小体）。发现脑缺血１０ｍｉｎ再灌流２４ｈ，海马ＣＡ１区即可见凋亡小体，于再灌流４８ｈ、９６ｈ凋亡小体明显增多。给予巴曲酶（１．６ＢＵ／ｋｇ．ｉｖ）后上述变化被明显逆转。本实验提示巴曲酶对脑缺血再灌流损伤所引起的细胞凋亡有抑制作用。     

Alteration of serum/glucocorticoid regulated kinase-1 (sgk-1) gene expression in rat hippocampus after transient global ischemia

Expression of the serum/glucocorticoid regulated kinase-1 (sgk-1) gene has been reported to be induced by various stress stimuli such as hyper- or hypo-osmotic stress, UV irradiation, and heat shock stress; however, its association with global ischemia in the brain has not been studied. Using high-density oligonucleotide array analysis, we found that the sgk-1 gene was one of the genes showing alteration of expression in the rat hippocampus during 1-4 h of reperfusion after 10 min of transient global cerebral ischemia. Using TaqMan RT-PCR analysis, we confirmed an increased level of sgk-1 gene expression with statistical significance in the rat hippocampus at 2 h of reperfusion after 10 min of transient global cerebral ischemia. Using in situ hybridization (ISH) analysis, the increased level of sgk-1 gene expression was found to localize in pyramidal cells of CA2 and CA3 regions of the hippocampus after 2 h of reperfusion. These results provide an insight into the alterations of sgk-1 gene expression in the rat hippocampus after transient global cerebral ischemia.     

Correlation of aquaporin-4 expression to blood-brain barrier permeability in rats with focal cerebral ischemia

BACKGROUND: Ischemic cerebrovascular disease causes injury to the blood-brain barrier. The occurrence of brain edema is associated with aquaporin expression following cerebral ischemia/reperfusion. OBJECTIVE: To analyze the correlation of aquaporin-4 expression to brain edema and blood-brain barrier permeability in brain tissues of rat models of ischemia/reperfusion. DESIGN, TIME AND SETTING: The randomized control experiment was performed at the Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, China from December 2006 to October 2007. MATERIALS: A total of 112 adult, male, Sprague-Dawley rats, weighing 220-250 g, were used to establish rat models of middle cerebral artery occlusion and reperfusion by the suture method. Rabbit anti-aquaporin-4 (Santa Cruz, USA) and Evans blue (Sigma, USA) were used to analyze the tissue. METHODS: The rats were randomized into sham-operated (n = 16) and ischemia/reperfusion (n = 96) groups. There were 6 time points in the ischemia/reperfusion group, comprising 4, 6, 12, 24, 48, and 72 hours after reperfusion, with 16 rats for each time point. Rat models in the sham-operated group at 4 hours after surgery and rat models in the ischemia/reperfusion group at different time points were equally and randomly assigned into 4 different subgroups. MAIN OUTCOME MEASURES: Brain water content on the ischemic side and the control side was measured using the dry-wet weight method. Blood-brain barrier function was determined by Evans Blue. Aquaporin-4 expression surrounding the ischemic focus, as well as the correlation of aquaporin-4 expression with brain water content and Evans blue staining, were measured using immunohistochemistry and Western blot analysis. RESULTS: Brain water content on the ischemic side significantly increased at 12 hours after reperfusion, reached a peak at 48 hours, and was still high at 72 hours. Brain water content was greater on the ischemic hemispheres, compared with the control hemispheres at 6, 12, 24, 48, and 72 hours after reperfusion, as well as both hemispheres in the sham-operated group (P<0.05). Evans blue content significantly increased on the ischemic side at 4 hours after ischemi',dreperfusion, and reached a peak at 48 hours. Evans blue content was greater on the ischemic hemispheres, compared with the control hemispheres at various time points, as well as both hemispheres in the sham-operated group (P<0.05). Aquaporin-4-positive cells were detected in the cortex and hippocampus, surrounding the ischemic penumbra focus, at 4-6 hours after ischemia/reperfusion. The number of positive cells significantly increased at 12 hours and reached a peak at 48-72 hours. Aquaporin-4 was, however, weakly expressed in the control hemispheres and the sham-operated group. The absorbance ratio of aquaporin-4 to β-actin was greater at 12, 24, 48, and 72 hours following cerebral ischemia/reperfusion, compared with the sham-operated group (P<0.05). Aquaporin-4 expression positively correlated to brain water content and Evans blue staining following cerebral ischemia/reperfusion (r1 = 0.68, r2= 0.81, P<0.05). CONCLUSION: Aquaporin-4 is highly expressed in brain tissues, participates in the occurrence of ischemic brain edema, and is positively correlated to blood-brain barrier permeability following cerebral ischemia/reperfusion.