慢性肾血管性高血压大鼠脑细胞膜磷脂及游离脂肪酸含量变化

采用SD大鼠慢性肾血管性高血压模型，高效液相和气－液色诣定量法测定脑细胞胺磷脂、游离脂肪酸（FreeFattyAcidFFA）组分变化．结果显示：1．高血压组脑细胞膜磷脂组分中PI显著低于对照组（P＜0．O5），PS、PE、PC，组分轻微下降（P＞0．05）．2．FFA组分中C20；4，C22；6水平显著高于对照组（P＜0.01，P＜0．O5），C18：0水平显著低于对照组（P＜0．05），C16：0和C18：1轻度降低（P＞0．05）．提示继发性高血压大鼠伴有脑细胞膜磷脂、FFA代谢障碍．     

氯沙坦对卒中易感型自发性高血压大鼠的脑保护作用

目的 研究氯沙坦对卒中易感型自发性高血压大鼠(SHRsp)脑保护作用的机制。方法 6周龄雄性SHRsp随机分为生理盐水组、小剂量氯沙坦组(10mg·kg-1·d-1)和大剂量氯沙坦组(30mg·kg-1·d-1),记录血压和脑卒中临床表现评分,18周后处死,光镜观察脑卒中的发生率和脑血管结构;电镜观察脑组织的超微结构;TUNEL法检测神经细胞凋亡。结果 大剂量氯沙坦组血压明显低于未用药组(PO.05)。对照组SHRsp死亡率、脑动脉中膜厚度/管腔半径的比值和神经细胞凋亡率均高于小剂量和大剂量氯沙坦组,差异均有显著性意义(P相似文献   

核因子-κB对癫痫大鼠脑 P-糖蛋白表达的调控作用

目的 探讨核因子-κB(NF-κB)对癫痫大鼠脑P-糖蛋白(P-gP)表达的影响.方法 将雄性SD大鼠随机分为假手术组(n=9)、癫痫组(EP组,n=14)、NF-κB活性抑制剂吡咯烷二硫代氨基甲酸盐(PDTC)干预组(PDTC组,n=14).采用大鼠海马注射海人酸方法制作癫痫模型,PDTC组于癫痫造模前30 min给予腹腔注射PDTC(按体质量150 mg/kg).于造模后24 h处死各组大鼠,采用免疫组织化学方法检测并比较各组大鼠海马CA3区、齿状回、嗅周皮层、杏仁核复合体区P-gp和NF-κB亚基p65(NF-κBp65)表达情况.结果 与假手术组相比,EP组海马CA3区、齿状回、杏仁核复合体区P-gP和NF-κBp65表达显著增强(PO.05).结论 抑制NF-κB活化可以降低癫痫相关脑区P-gp过表达,癫痫发作所致脑内P-gp表达上调可能与NF-κB活化有关.     

阿托伐他汀对自发性高血压大鼠动脉血压和血管内皮功能的影响

目的探讨阿托伐他汀对自发性高血压大鼠(SHR)动脉血压和血管内皮功能的影响。方法选用8周龄SHR12只,随机分为阿托伐他汀治疗组(ATV组,n=6)、蒸馏水组(DW组,n=6),另选6只WKY大鼠作为正常对照。ATV组大鼠给以阿托伐他汀50mg/(kg·d)加适量蒸馏水灌胃。DW组和WKY组每天同时用等量蒸馏水灌胃。观察给药前后大鼠尾动脉血压的变化,测定大鼠血清总胆固醇(TC)、甘油三酯(TG)和高密度脂蛋白胆固醇(HDL-C)浓度,观察血浆内皮素1(ET-1)水平、主动脉组织一氧化氮合酶(NOS)活性的变化特点。结果ATV组大鼠动脉血压显著低于DW组(P＜0．01)；与DW组和WKY组比较,ATV组血清TC、TG和HDL-C浓度显著降低(P＜0．01,P＜0．05)；DW组血清ET-1水平显著高于WKY组(P＜0．05),主动脉组织NOS活性显著低于WKY组(P＜0．05),经ATV治疗后血清ET-1水平明显降低(P＜0．05),而主动脉组织NOS活性显著增高(P＜0．01)。结论长期应用阿托伐他汀可以显著降低动脉血压。阿托伐他汀通过改善血管内皮功能延缓高血压的病理过程。     

单一延长应激对Wistar大鼠海马Calcineurin表达的影响

目的探讨创伤后应激障碍模型-单一延长应激对Wistar大鼠海马钙调神经磷酸酶(Calcineurin,CaN)表达的影响。方法将Wistar大鼠(n=30)随机分为单一延长应激组(n=15)和对照组(Control,n=15)。前者对大鼠实施国际公认的创伤后应激障碍(posttraumatic stress disorder,PTSD)动物模型方法-单一延长应激(Single-Prolonged Stress,SPS)暴露,对照组不给予任何处理。14 d后断脑取海马,通过ELISA、Western blot、免疫组化等方法检测两组大鼠海马CaN的表达改变。结果 ELISA结果显示单一延长应激暴露后大鼠海马组织匀浆CaN水平明显降低(P 0. 05); Western blot检测示单一延长应激组大鼠海马CaN Aα蛋白表达显著低于对照组(P 0. 01);免疫组化表明单一延长应激后CaN Aα蛋白在海马CA_1、CA_3区表达明显减少(P 0. 01),而齿状回区(DG)无明显差异(P 0. 05)。结论单一延长应激可致CaN下调,CaN表达减少可能是PTSD海马损伤的重要分子机制之一。     

甲基-β-环糊精干扰脂质微区影响脑胶质瘤细胞系C6侵袭和迁移的体外研究

目的观察甲基-β-环糊精(MβCD)破坏脂质微区结构对经体外培养的大鼠脑胶质瘤细胞系C6细胞侵袭和迁移能力的影响。方法采用MβCD(5mmol/L)破坏经体外培养的大鼠脑胶质瘤细胞系C6细胞膜脂质微区,通过Transwell细胞侵袭和迁移实验检测细胞侵袭性和迁移能力;Western blotting检测细胞膜脂质微区结构蛋白Caveolin-1和膜受体表皮生长因子受体表达水平的变化。结果干扰组大鼠脑胶质瘤细胞系C6细胞Caveolin-1和表皮生长因子受体表达水平明显低于对照组(P=0.000,0.001)。对照组大鼠脑胶质瘤细胞系C6细胞穿过聚碳酸酯微膜数目为(54.00±9.59)个/视野,干扰组为(23.94±5.56)个/视野,两组比较差异有统计学意义(P=0.000)。对照组大鼠脑胶质瘤细胞系C6细胞迁移至空白端的细胞数目为(134.00±9.68)个/视野,干扰组为(88.00±6.22)个/视野,两组比较差异有统计学意义(P=0.000)。结论甲基-β-环糊精破坏脂质微区结构后可降低经体外培养的大鼠脑胶质瘤细胞系C6细胞的侵袭性和迁移能力,其机制可能与降低Caveolin-1和表皮生长因子受体等多种膜蛋白和受体表达水平有关。     

microRNA-146a对癫■大鼠脑内P-糖蛋白表达的影响

目的观察microRNA-146a(miR-146a)对癫■大鼠脑内P-糖蛋白(P-glycoprotein,P-gp)表达的影响。方法健康雄性SD大鼠随机分为3组:miR-146a给药(miR-146a)组(n=8),经立体定向侧脑室注射给药;正常对照组(n=8)和癫■组(n=8)给予相同体积的0.9%氯化钠溶液。癫■组和miR-146a组采用戊四氮腹腔注射建立癫■模型,大鼠点燃后的惊厥行为按照Racine标准进行观察评分。采用免疫荧光组化、RT-PCR和Western blot方法检测比较3组大鼠脑内P-gp表达。结果免疫荧光组化显示,3组大鼠皮质均可见P-gp阳性细胞表达。癫■组皮质P-gp阳性细胞数显著高于正常对照组(P0.01);miR-146a组显著低于癫■组(P0.01)。PCR检测显示,癫■组P-gp mRNA表达水平显著高于正常对照组(P0.004 4);miR-146a组皮质P-gp mRNA表达水平低于癫■组(P0.041 7)。Western blot示3组大鼠皮质GAPDH谱带浓度基本相似,P-gp谱带浓度由高至低依次为癫■组、miR-146a组和正常对照组;癫■组皮质P-gp蛋白相对表达比值显著高于正常对照组和miR-146a组(均P0.01)。结论 miR-146a可以下调P-gp在癫■大鼠脑内的表达,在癫■治疗上可能具有潜在的应用价值。     

亚低温对糖尿病合并脑梗死大鼠缺血半暗带凋亡的作用及机制

目的探讨亚低温对糖尿病合并脑梗死(CI)大鼠缺血半暗带凋亡的作用及机制。方法健康雄性SD大鼠随机分为糖尿病组(n=42)和非糖尿病组(n=14),通过高脂饲料喂食联合链脲霉素(STZ)诱导2型糖尿病。制备大鼠永久性大脑中动脉栓塞模型,造模成功2周后随机分为糖尿病CI常温组(n=14)、糖尿病CI亚低温组(n=14)、糖尿病假手术组(n=14)、非糖尿病CI常温组(n=14)。建立永久性大脑中动脉栓塞CI模型后2 h开始对亚低温组进行亚低温干预6 h。于术后不同时间点进行神经行为学评估,术后3 d检测各组大鼠缺血半暗带的细胞凋亡程度以及基质金属蛋白酶9(MMP-9)表达量。结果①与非糖尿病CI常温组比较,糖尿病CI常温组神经功能评分降低(P 0. 05),缺血半暗带凋亡水平升高(P 0. 05),cleaved caspase-3和MMP-9蛋白表达量增加(P 0. 05),Bcl-2基因表达量降低(P 0. 05),Bim基因表达量增加(P 0. 05)。②与糖尿病CI常温组比较,糖尿病CI亚低温组神经功能评分增加(P 0. 05),缺血半暗带凋亡水平降低(P 0. 05),cleaved caspase-3和MMP-9蛋白表达量降低(P 0. 05),Bcl-2基因表达量增加(P 0. 05),Bim基因表达量降低(P 0. 05)。结论糖尿病加重CI大鼠的神经功能损伤,亚低温干预可以减轻糖尿病CI大鼠的神经功能损伤,减轻血脑屏障受损从而抑制缺血半暗带神经细胞凋亡可能是其保护机制。     

microRNA-146a对癫(癎)大鼠脑内P-糖蛋白表达的影响

目的 观察microRNA-146a(miR-146a)对癫(癎)大鼠脑内P-糖蛋白(P-glycoprotein,P-gp)表达的影响.方法 健康雄性SD大鼠随机分为3组:miR-146a给药(miR-146a)组(n=8),经立体定向侧脑室注射给药;正常对照组(n=8)和癫(癎)组(n=8)给予相同体积的0.9％氯...     

神经干细胞在脑损伤模型中的迁移、成活和神经生长因子表达

目的 探讨神经干细胞在脑损伤模型中的迁移、成活和神经生长因子(NGF)表达.方法 SD大鼠30只随机分为3组:正常对照组(n=5)、损伤组(n =10)和移植组(n=15).正常对照组不做任何处理,损伤组和移植组均制备脑损伤模型,且移植组大鼠从尾静脉注入外源性神经干细胞.并观察神经干细胞在大鼠脑内的迁移和存活情况,同时通过免疫组织化学染色检测各组大鼠脑内NGF阳性细胞数量.结果 神经干细胞移植2周后,其向脑损伤区域发生迁移,并在损伤区域聚集和存活;且移植组NGF阳性细胞数目较正常对照组和损伤组显著增多(p＜0.05).结论 外源性神经干细胞经尾静脉注射移植后能自动向脑损伤区域迁移、聚集并存活,并可促进受损脑内的NGF表达.     

姜黄素对脑出血大鼠血肿周围脑组织氧化损害保护作用的研究

目的:探讨姜黄素对脑出血(ICH)后脑组织氧化损害的保护作用。方法:120只SD大鼠随机分为姜黄素治疗组(Cur治疗组,n=40)、脑出血对照组(ICH对照组,n=40)和假手术组(n=40)。每组分为手术前、术后6h、12h、24h、48h、72h、96h、120h等8个时点,每个时点5只大鼠。采用立体定向自体血注入大鼠尾状核建立ICH模型,观察各组术前及术后各时点血肿周围脑组织超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量及含水量变化。结果:ICH对照组术后各时间点SOD活性明显低于假手术组(P<0.05),而术后各时间点MDA含量显著高于假手术组(P<0.05),ICH对照组术后各时点含水量与SOD活力呈明显负相关(r=-0.626,P<0.05),与MDA含量呈明显正相关(r=0.648,P<0.001)。Cur治疗组术后12～120h各时点的SOD活力显著高于ICH对照组(P<0.05),12～96h各时点MDA含量明显低于ICH对照组(P<0.001),Cur治疗组术后各时点含水量与SOD活力呈显著负相关r=-0.458,P<0.05),与MDA含量呈显著正相关(r=0.407,P<0.05)。结论:脑出血大鼠血肿周围脑组织具有显著的氧化损害,此损害与脑水肿形成有关。Cur治疗脑出血大鼠使氧化损害明显减轻,Cur对抗脑出血后脑水肿形成可能与抑制自由基产生和清除自由基有关。     

Brain and tissue distribution of polyethylene glycol-conjugated superoxide dismutase in rats.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the distribution of polyethylene glycol-conjugated superoxide dismutase in the brain, cerebrospinal fluid, and various organs. METHODS: Distribution of iodine-125-labeled polyethylene glycol-conjugated superoxide dismutase was determined in three groups of male Sprague-Dawley rats: a normotensive sham control group (n = 9) and groups given 125I-labeled polyethylene glycol-conjugated superoxide dismutase either 30 minutes before (n = 10) or 30 minutes after (n = 7) norepinephrine-induced hypertensive injury. RESULTS: In the first 30 minutes after intravenous administration, polyethylene glycol-conjugated superoxide dismutase plasma activity declined to 70% of the initial value and then decreased negligibly between 30 and 90 minutes. Levels of 125I-labeled polyethylene glycol-conjugated superoxide dismutase in normotensive animals were low in the brain and cerebrospinal fluid and highest in kidney. Brain levels of polyethylene glycol-conjugated superoxide dismutase were elevated only in those rats that received it before hypertensive injury; however, cerebrospinal fluid levels were elevated in animals receiving the drug either before or after hypertensive injury. CONCLUSION: Our results suggest that the blood-brain barrier becomes more permeable to polyethylene glycol-conjugated superoxide dismutase only during the hypertensive period but that the blood-cerebrospinal fluid barrier sustains more permanent injury. We suggest that the therapeutic effectiveness of polyethylene glycol-conjugated superoxide dismutase in hypertensive brain injury is due to its action in the vascular wall or to its extracellular activity in the cerebrospinal fluid.     

ACE基因插入／缺失多态性与脑血管病的关联性研究

目的:探讨血管紧张素转换酶(ACE)基因插入(I)/缺失(D)多态性与脑血管病(CVD)的关系。方法:采用聚合酶链反应技术(PCR)检测19Z例卒中患者、95例高血压病人和124例正常人的ACE基因多态性。结果:CVD组ACE基因D等位基因频率为0.58,明显高于高血压对照组(P＜0.02)和正常对照组(P＜0.01),DD基因型频率明显高于正常对照组(P＜0.05)。腔隙性梗死(LACI)组的DD基因型显著高于对照组(P＜0.05)。多元回归分析发现ACE*DD基因型与卒中无明显相关性(P＜0.08),而与LACI存在明显相关性(P=0.048)。结论:ACE基因缺失多态性在LACI的形成中可能产生重要作用。     

Brain atrophy and white matter hyperintensity change in older adults and relationship to blood pressure

Abstract Hypertension is a major risk factor for stroke and dementia and is associated with white matter hyperintensities (WMH) and reduced brain volumes. We measured the increase in WMH volume, and rate of cerebral atrophy over two years, in hypertensive subjects participating in the Study on COgnition and Prognosis in the Elderly (SCOPE), receiving candesartan or placebo, and normotensive controls. We recruited 163 subjects who had MRI (FLAIR and volumetric T1) at 2 and 4 years after baseline assessment. From these two scans, volumetric change in WMH (n = 133) and brain atrophy rates (n = 95) were determined. Total WMH fraction increased in both normotensive and treated hypertensive groups (p < 0.01) median change: 0.05% of brain volume [range: -0.45% to 1.51%]. Deep WMH increased in hypertensive (p = 0.001) but not the normotensive group. The number of subjects with an increase of total WMH in the 5^th quintile differed between the treatment groups (chi square p = 0.006), being greatest in the placebo group (32%), then candesartan (20%) then normotensive (5%). Regression analysis found significant predictors of change in WMH to be blood pressure and initial deep WMH, but not treatment group. Increased atrophy rate was predicted by baseline systolic blood pressure (p = 0.02) but was not associated with measures of WMH. Similar to WMH, there was a trend with treatment, with atrophy in normotensive < Candesartan < Placebo (Spearman's rho = 0.23, p = 0.026). Hypertension in older people is associated with increased rates of progressive whole brain atrophy and an increase in WMH. These changes are independent. Successful hypertension treatment was associated with reduced risk of WMH progression and possibly brain atrophy. We thank the Astra Research Foundation UK and AstraZeneca International for financial support of these studies. The main SCOPE trial was supported by AstraZeneca International.     

脑心通对大鼠局灶性脑缺血脑组织补体C3的影响

目的:探讨脑心通对大鼠局灶性脑缺血损伤后脑组织补体C3表达的影响。方法:参照longa等方法制成大鼠局灶性大脑中动脉阻断(MCAO)模型,将大鼠分为假手术组、生理盐水组、大剂量脑心通组、中剂量脑心通组、小剂量脑心通组,分别给予不同剂量药物,于术后6h,24h,48h,72h和7d进行神经功能评分(NDS),处死后取脑组织观察脑含水量的变化,病理切片HE染色观察组织病理学改变,免疫组织化学的方法测定补体C3的动态变化。结果:脑心通治疗组的神经功能评分均降低,病理损伤均减轻,大、中剂量脑心通组治疗后脑水肿明显减轻(P<0.05),补体C3的表达明显减少(P<0.05)。结论:脑心通可能通过减轻脑水肿,降低脑内补体C3的表达对大鼠缺血脑组织损伤产生保护作用。     

Mechanisms of impaired endothelium-dependent cerebral vasodilatation in response to bradykinin in hypertensive rats

Bradykinin produces less dilatation of pial arterioles in stroke-prone spontaneously hypertensive rats than in normotensive Wistar-Kyoto rats. The goals of this study were to determine the mediator of bradykinin-induced dilatation in cerebral arterioles of rats and to determine whether responses to this mediator are altered in hypertensive rats. Diameter of pial arterioles (20-65 microns) was measured using intravital microscopy in 18 normotensive and 17 hypertensive rats. Superfusion of 3 x 10(-7) M bradykinin dilated pial arterioles by 53 +/- 4% (mean +/- SEM) in normotensive rats but only 33 +/- 6% in hypertensive rats (p less than 0.05 versus normotensive rats). Vasodilatation in response to bradykinin was almost completely inhibited by 280 units/ml catalase in both normotensive and hypertensive rats (n = 7 and n = 7, respectively) whereas 150 units/ml superoxide dismutase (n = 6 and n = 5, respectively) and 1 mM deferoxamine (n = 5 and n = 5, respectively) did not attenuate bradykinin-induced vasodilatation. These findings suggest that hydrogen peroxide is the mediator of bradykinin-induced dilatation in cerebral arterioles of rats. We also examined responses of cerebral arterioles to hydrogen peroxide in five normotensive and six hypertensive rats. Dilator responses of cerebral arterioles to 3.2 x 10(-5) M to 1.6 x 10(-4) M hydrogen peroxide did not differ in normotensive and hypertensive rats, which suggests that impaired dilatation of cerebral arterioles in response to bradykinin is not related to altered responsiveness of smooth muscle to an endothelium-derived relaxing factor.(ABSTRACT TRUNCATED AT 250 WORDS)     

PTZ致痫大鼠海马区神经元损伤的研究

目的:为了解癫痫(Epilepsg,EP)发生后大脑海马区的损害情况,本文采用戊四氮诱导建立大鼠癫痫模型, 采用酶标免疫吸附法(EIA)和免疫组化染色法检测NSE的改变,使用电子显微镜研究超微结构的改变,探讨EP后脑组织的损坏情况。方法:雄性SD大鼠54只,随机分为对照组(A=13)及实验组(41只)。实验组腹腔注射(IP)PTZ 50mg/ kg体重1次,对照组IP生理盐水。根据EP发作分级,0-1级7只,视为B组,立即取脑:2级以上发作34只,随机抽样于EP发作后0h(C=10);6h(D=14);24h(E=10)断头。取脑前抽取躯干血,分离海马。A、D组随机抽取3只进行电镜观察。采用EIA法测试血清和海马NSE-值;以S-P免疫组化染色法染色,观察各组大鼠海马的NSE表达。结果:实验组海马和血清的NSE均明显高于对照组:即使无EP大发作,但有兴奋症状的大鼠,NSE亦高于对照组,表明也有脑组织损害。免疫组化染色显示:对照组海马组织几乎未见NSE的表达,即大发作后海马的NSE表达明显增加,但随时间推移而降低。电镜观察发现EP后大鼠海马CA1区的神经元细胞出现水肿、基质密度变淡、微丝溶解消失、细胞器减少、毛细血管周围间隙扩大等明显改变。结论:EP发作对大鼠海马区神经细胞造成了明显的损害。     

骨髓间充质干细胞立体定向移植治疗大鼠脑缺血损伤的实验研究

目的观察立体定向移植骨髓间充质干细胞(BMSC)治疗MCAO大鼠的效果并探讨其可能机制。方法用改良线拴法制作大脑中动脉闭塞(MCAO)模型。60只模型大鼠随机分为移植组(A组)、磷酸盐缓冲液溶液组(B组)与假手术组(C组)。在模型建立后7 d,通过立体定向方式将1×106个BMSCs移植入A组大鼠损伤侧纹状体,B组大鼠以同样方式在同样部位移植等体积的磷酸盐缓冲液,C组完成立体定向过程,但无液体注入。应用改良大鼠神经功能缺损评分(m NSS评分)、水迷宫测试观察大鼠神经功能恢复状况,并取大鼠脑组织行免疫组织化学染色。结果 A组m NSS评分优于B组、C组(P0.05);A组逃避潜伏期明显缩短(P0.05);跨越平台次数明显增多(P0.05)。A组大鼠在脑损伤中心及周围区,可见Brdu单染阳性细胞及Brdu+BDNF、Brdu+GFAP、Brdu+v WF、Brdu+VEGF双染阳性细胞。结论立体定向移植BMSCs可以显著改善MCAO大鼠神经功能恢复。     

Delayed hemorrhagic hypotension exacerbates the hemodynamic and histopathologic consequences of traumatic brain injury in rats.

Alterations in cerebral autoregulation and cerebrovascular reactivity after traumatic brain injury (TBI) may increase the susceptibility of the brain to secondary insults, including arterial hypotension. The purpose of this study was to evaluate the consequences of mild hemorrhagic hypotension on hemodynamic and histopathologic outcome after TBI. Intubated, anesthetized male rats were subjected to moderate (1.94 to 2.18 atm) parasagittal fluid-percussion (FP) brain injury. After TBI, animals were exposed to either normotension (group 1: TBI alone, n = 6) or hypotension (group 2: TBI + hypotension, n = 6). Moderate hypotension (60 mm Hg/30 min) was induced 5 minutes after TBI or sham procedures by hemorrhage. Sham-operated controls (group 3, n = 7) underwent an induced hypotensive period, whereas normotensive controls (group 4, n = 4) did not. For measuring regional cerebral blood flow (rCBF), radiolabeled microspheres were injected before, 20 minutes after, and 60 minutes after TBI (n = 23). For quantitative histopathologic evaluation, separate groups of animals were perfusion-fixed 3 days after TBI (n = 22). At 20 minutes after TBI, rCBF was bilaterally reduced by 57% +/- 6% and 48% +/- 11% in cortical and subcortical brain regions, respectively, under normotensive conditions. Compared with normotensive TBI rats, hemodynamic depression was significantly greater with induced hypotension in the histopathologically vulnerable (P1) posterior parietal cortex (P < 0.01). Secondary hypotension also increased contusion area at specific bregma levels compared with normotensive TBI rats (P < 0.05), as well as overall contusion volume (0.96 +/- 0.46 mm(3) vs. 2.02 +/- 0.51 mm(3), mean +/- SD, P < 0.05). These findings demonstrate that mild hemorrhagic hypotension after FP injury worsens local histopathologic outcome, possibly through vascular mechanisms.