厄贝沙坦对局灶脑缺血作用的实验研究

目的：研究1型血管紧张素Ⅱ受体阻滞剂厄贝沙坦对局灶性脑缺血的神经保护作用及其可能的细胞机制。方法：在激光多谱勒脑血流监测仪对局部脑血流的监测下,应用线栓法建立大鼠大脑中动脉阻塞模型。药物经侧脑室内微泵持续灌注雄性正常血压大鼠,术后行神经功能评分,测定梗死体积,并运用免疫组化染色观察活性Caspase-3及其下游多聚ADP-核糖聚合酶（PARP）p85裂解片断的改变,结合TUNEL,比较各组细胞凋亡情况。结果：厄贝沙坦明显改善大鼠的神经功能评分,第7d的梗死体积较对照组减少了42％,用药后缺血区的TUNEL阳性细胞数．荧光标记的活性Caspase-3以及PARP p85裂解片断表达均明显减少。结论：厄贝沙坦可改善局灶脑缺血的神经功能,抑制细胞凋亡可能是其神经保护机制之一。     

Dragon's blood dropping pills have protective effects on focal cerebral ischemia rats model

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis (Lour.) S.C.Chen (Yunnan, China). As a traditional Chinese medicinal herb, it has great traditional medicinal value and is used for wound healing and to stop bleeding. Its main biological activity comes from phenolic compounds. In this study, phenolic compounds were made into dropping pills and their protective effects were examined by establishing focal cerebral ischemia rats model used method of Middle Cerebral Artery Occlusion (MCAO), and by investigating indexes of neurological scores, infarct volume, cerebral index, cerebral water content and oxidation stress. Compared to model group, high, middle and low groups of Dragon's blood dropping pills could improve the neurological function significantly (p < 0.01) and reduce cerebral infarct volume of focal cerebral ischemia rats remarkably (p < 0.05–0.01). Meanwhile, each group could alleviate cerebral water content and cerebral index (p < 0.05–0.01) and regulate oxidative stress of focal cerebral ischemia rats obviously (p < 0.05–0.01). Activities of middle group corresponded with that treated with positive control drug. The results obtained here showed that Dragon's blood dropping pills had protective effects on focal cerebral ischemia rats.     

促红细胞生成素对脑缺血/再灌注损伤的保护作用

目的:探讨促红细胞生成素(Epo)对大鼠脑缺血/再灌注损伤的保护作用。方法:32只SD大鼠,采用夹闭双侧颈总动脉30min再灌注24h制作脑缺血/再灌注模型。随机分为4组(n=8):假手术组、脑缺血/再灌注组、Epo组及阳性对照组(尼莫地平),观察缺血/再灌注后血清一氧化氮(NO)和脑组织匀浆中超氧化歧化酶(SOD)活性、丙二醛(MDA)含量及脑组织含水量的变化。结果:Epo组血清NO和脑组织匀浆中MDA含量显著下降,SOD活性显著升高,脑组织含水量显著下降,与缺血/再灌注组相比有显著性差异。结论:大鼠脑缺血/再灌注后,Epo能减轻脑组织的含水量,减少自由基的生成,减轻脂质过氧化反应,对脑缺血/再灌注损伤有保护作用。     

参附注射液对大鼠全脑缺血/再灌注损伤的保护作用

目的:探讨参附注射液对大鼠全脑缺血/再灌注损伤的保护作用及其机制。方法:将SD雄性大鼠40只,随机分为4组(n=10):假手术组、模型对照组、尼莫地平组(30 mg/kg)和参附注射液组(10 mg/kg)。采用Pulsinelli’s四动脉阻断法造成全脑缺血/再灌注损伤模型(CI/R),分别于手术前1 d,术前1 h和再灌注前30 min给药,共3次。分别用高效液相色谱法测定脑组织谷氨酸(Glu)、天冬氨酸(Asp)和甘氨酸(Gly)含量,原子吸收分光光度测定Ca2+含量,干湿重法测定脑组织含水量,化学比色法测定脑组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。结果:与假手术组比较,CI/R模型组大鼠脑组织Glu、Ca2+、MDA含量和含水量明显升高(P<0.05,P<0.01),SOD活性明显降低(P<0.05);参附注射液能显著降低脑组织Glu、Ca2+含量和含水量(P<0.05,P<0.01),显著升高SOD活性及SOD/MAD比值(P<0.05)。结论:参附注射液防治脑缺血/再灌注损伤的机制与降低兴奋性氨基酸(EAA)毒性、阻滞Ca2+超载和提高抗氧化能力有关。     

双丹胶囊对大鼠脑缺血再灌注损伤保护作用研究

目的：观察双丹胶囊对大鼠局灶性脑缺血再灌注损伤的脑梗死体积、自由基变化的影响,探讨双丹胶囊对脑缺血损伤的保护作用。方法：复制大鼠中动脉缺血再灌注模型,分别给药干预,在给药后观察行为学、脑梗死率、脑指数、脑含水量、SOD、MAD等指标。结果：双丹胶囊可改善动物的神经行为学评分,明显降低动物的脑梗死率、脑指数、脑含水量、提高脑组织SOD活性、降低MDA含量,并成剂量依赖。结论：双丹胶囊对脑缺血再灌注损伤具有保护作用。     

Cerebroprotective activity of Wedelia calendulacea on global cerebral ischemia in rats

The present study was to investigate the effect of W. calendulacea on ischemia and reperfusion-induced cerebral injury. Cerebral ischemia was induced by occluding right and left common carotid arteries (global cerebral ischemia) for 30 min followed by reperfusion for 1 h and 4 h individually. Various biochemical alterations, produced subsequent to the application of bilateral carotid artery occlusion (BCAO) followed by reperfusion viz. increase in lipid peroxidation (LPO), hydrogen peroxide (H2O2), and decrease in reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD), level in the brain tissue, Western blot analysis (Cu-Zn-SOD and CAT) and assessment of cerebral infarct size were measured. All those enzymes are markedly reversed and restored to near normal level in the groups pretreated with W. calendulacea (250 and 500 mg/kg given orally in single and double dose/day for 10 days) in dose-dependent way. The effect of W. calendulacea had increased significantly the protein expression of copper/zinc superoxide dismutase (Cu-Zn-SOD) and CAT in cerebral ischemia. W. claendulacea was markedly decrease cerebral infarct damages but results are not statistically significant. It can be concluded that W. calendulacea possesses a neuroprotective activity against cerebral ischemia in rat.     

产前应激对子代大鼠脑缺血/再灌注后星形胶质细胞的影响

目的：探讨产前应激对雄性子代大鼠大脑中动脉缺血/再灌注后星形胶质细胞的影响。方法：SD孕鼠随机分为有产前应激处理（妊娠第15到21天每日3次限制活动）和无产前应激处理,并对其雄性子代大鼠采用线栓法制备大脑中动脉闭塞（MCAO）模型,共分为产前应激+假手术组、MCAO模型组、产前应激+MCAO组（n=10）,于再灌注后第5天检测脑梗死体积,免疫荧光双标染色检测缺血灶边缘区星形胶质细胞形态及促红细胞生成素肝细胞受体A4（EphA4）和胶质纤维酸性蛋白（GFAP）的共表达情况,并采用Western blot检测EphA4、GFAP和神经蛋白聚糖（Neurocan）蛋白表达。结果：产前应激+MCAO组子代大鼠脑梗死体积百分比、EphA4、GFAP和Neurocan蛋白表达均较MCAO组显著增加（P均<0.05）,且GFAP阳性细胞形态学改变及EphA4/GFAP共表达也较MCAO组明显。结论：产前应激可能改变子代大鼠脑缺血/再灌注后星形胶质细胞上EphA4受体的表达,促进星形胶质细胞活化,产生神经蛋白聚糖。     

海参多糖对急性不完全性脑缺血的保护及抗凝作用的研究

目的:研究海参多糖(PSU)对大鼠急性不完全性脑缺血(AICI)损伤的保护作用及抗凝血作用。方法:SD大鼠60只,随机分为5组(n=12):假手术组、模型组、海参多糖低(30 mg/(kg.d))、中(60mg/(kg.d))、高(120mg/(kg.d))剂量组。双侧颈总动脉永久性结扎法复制大鼠急性不完全性脑缺血模型,观察海参多糖对大鼠行为障碍、脑组织含水量、血清C-反应蛋白(CRP)水平的变化情况,以及对凝血酶原时间(PT)、活化的部分凝血酶时间(APTT)、凝血酶时间(TT)和纤维蛋白原含量(FIB)等血液凝血指标的影响。结果:海参多糖可改善行为学障碍,减少脑组织含水量,降低血清CRP水平;可显著延长APTT,TT时间,减少FIB含量(P<0.05)。结论:海参多糖能明显减轻大鼠急性不完全性脑缺血损伤,并具有显著的抗凝血作用。     

大鼠局灶性脑缺血后扩布性阻抑的发作及电针对其影响

目的：观察Wistar大鼠局灶性脑缺血后扩布性阻抑（SD）的发作情况及缺血后电针的影响。方法：线检法闭塞大鼠大脑中动脉,制备局灶性脑缺血模型。用神经电生理、神经病理等方法检测局灶性脑缺血后3h内SD发作情况及电针“合谷”穴（LI4）对SD的影响。结果：电针可减少局灶性脑缺血时SD的发作。结论：电针减少局灶性脑缺血时SD的发作,可能与电针缩小局灶性脑梗塞体积有关。     

脑缺血和缺血再灌注大鼠皮层神经元自噬的动态变化

目的：探讨脑缺血和缺血/再灌注不同时间大鼠大脑皮层神经元自噬的变化。方法：健康雄性SD大鼠60只,随机分为：假手术（Sham）组（n=10）,脑缺血和缺血/再灌注模型组（n=50）.模型组分别在缺血30min、2h,缺血2h再灌注1h、6h、24h五个时间点,随机抽取10只大鼠,测定脑梗死体积和脑含水量,同时采用Western印迹法测定各组大鼠大脑皮层中微管相关蛋白轻链3-Ⅱ（LC3-Ⅱ）的水平,透射电镜检测大脑皮层神经细胞自噬情况。结果：脑缺血30min时LC3-Ⅱ/Ⅰ比值未见明显上升,缺血2h时LC3-Ⅱ/Ⅰ比值开始升高,明显高于Sham组（P<0.01）;缺血/再灌注1h、6h时LC3-Ⅱ/Ⅰ比值虽较缺血2h组有所下降,但仍明显高于Sham组（P<0.05）;缺血/再灌注24h时LC3Ⅱ/Ⅰ比值达高峰,明显高于Sham组（P<0.01）。透射电镜观察进一步证实该现象。缺血/再灌注6h和24h时大鼠脑梗死体积明显增加,与Sham组比较有统计学差异（P<0.01）。缺血/再灌注24h大鼠脑组织含水量明显增加,明显高于Sham组（P<0.05）。HE染色显示：仅在缺血/再灌注24h组大鼠皮层见组织水肿、疏松,部分细胞变性、凋亡,海马区见大量神经元细胞核皱缩、深染呈变性凋亡状。结论：局灶性脑缺血和缺血/再灌注模型中大脑皮层缺血2 h神经元自噬即明显激活,缺血/再灌注1 h、6 h自噬均持续增高,缺血/再灌注24 h自噬达高峰。     

Antioxidant effects of antihypoxic drugs in cerebral ischemia]

Cerebral ischemia in rats (both carotid arteries occlusion) during 30 min, 3 hours and recirculation (1 hour) after ischemia (30 min) stimulated diene conjugates and fluorescent products accumulation in brain tissue. Intraperitoneal injection of sodium hydroxybutyrate (100 mg/kg), bemitil (50 mg/kg), ethomersol (50 mg/kg) reduced brain lipid peroxidation and did not yield in this respect to emoxypin (5 mg/kg). In contrast to emoxypin, sodium hydroxybutyrate, bemitil and ethomersol had no antiradical activity.     

Reduction of cellular damage induced by cerebral ischemia in rats

A model of incomplete cerebral ischemia involving bilateral ligation of the common carotid arteries in rats, was used to examine the potential of a Chinese herbal preparation and of nifedipine to reduce cell damage following cerebral ischemia. The herbal preparation contained ginsengosides and extracts ofPanax notoginseng, Ligusticum chuanxiong Hort.,Carthamus tinctorius L. andSalvia militorrhiza Bge. Histological evidence of cell damage and the formation of peroxidation products were both reduced in rats pretreated with the herbal preparation or with nifedipine. It has been suggested that the free radical reaction is involved in tissue damage, particularly in the pathological neurocyte injury of cerebral ischemia. The results show that in this model of incomplete cerebral ischemia, the degree of lipid peroxidation can be lowered by the pretreatment with Chinese herbs containing ginsengosides or with nifedipine. These drugs maybe beneficial in the treatment of cerebral ischemia in humans.Special issue dedicated to Dr. Lawrence Austin.     

Occlusion-reperfusion model of cerebral ischemia in Fischer 344 rats]

The effect of transient cerebral ischemia (from 15 to 180 min) by bilateral carotid arterial occlusion on postischemic mortality rate and the signs of nervous disorder in Fischer 344 rat was studied. Total mortality rate was 40 to 60% during 72 hr of reperfusion following 2 hr ischemia. Postischemic mortality rate did not vary distinctly with 10, 20 and 40 weeks-old.     

Cynandione A mitigates ischemic injuries in rats with cerebral ischemia

Cynandione A, an acetophenone from the roots of Cynanchum auriculatum and other species in the genus attenuates neurotoxicity of a variety of neurotoxic agents such as l-glutamate in vitro. In this study, we sought to further characterize the neuroprotective effects of cynandione A and other acetophenones from the roots of C. auriculatum in pheochromocytoma tumor cell line PC12 and investigate whether cynandione A protected against ischemic injuries in rats with experimentally induced cerebral ischemia. Viability assays using the 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophen-yl)-2H-tetrazolium monosodium salt method and lactate dehydrogenase (LDH) release assays showed that cynandione A dose-dependently attenuated glutamate-induced cytotoxicity. Comparative proteomic analysis by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight MS/MS of PC12 cells treated with cynandione A showed 10 μM cynandione A caused broad changes in protein expression in PC12 cells including down-regulation of high mobility group box 1 (HMGB1) and dihydropyrimidinase-like 2 (DPYSL2). Immunoblotting studies showed that 10 μM cynandione A aborted glutamate-induced increase in DPYSL2 and HMGB1 levels in PC12 cells and 30 mg/kg cynandione A also attenuated the rise in HMGB1 levels and mitigated DPYSL2 cleavage in brain tissues of rats with cerebral ischemia. Furthermore, rats with cerebral ischemia treated with 30 mg/kg cynandione A exhibited markedly improved neurological deficit scores at 24 and 72 h compared with control and a 7.2% reduction in cerebral infarction size at 72 h (p < 0.05 vs. control). Our findings demonstrated that cynandione A mitigated ischemic injuries and should be further explored as a neuroprotective agent for ischemic stroke.     

Neuroprotective effect of curcumin in middle cerebral artery occlusion induced focal cerebral ischemia in rats

Free radical induced neuronal damage is implicated in cerebral ischemia reperfusion (IR) injury and antioxidants are reported to have neuroprotective activity. Several in vitro and in vivo studies have proved the antioxidant potential of curcumin and its metabolites. Hence, in the present study the neuroprotective potential of curcumin was investigated in middle cerebral artery occlusion (MCAO) induced focal cerebral IR injury. 2 h of MCAO and 22 h of reperfusion resulted in the infarct volume of 210.39 +/- 31.25 mm3. Administration of curcumin 100 and 300 mg/kg, i.p. 30 min. after MCAO produced 37.23 +/- 5.10% and 46.39 +/- 10.23% (p < 0.05) reduction in infarct volume, respectively. Ischemia induced cerebral edema was reduced in a dose dependent manner. Curcumin at 300 mg/kg, i.p. produced 50.96 +/- 6.04% reduction in edema (p < 0.05) volume. Increase in lipid peroxidation after MCAO in ipsilateral and contralateral hemisphere of brain was observed, which was reduced by curcumin (300 mg/kg, i.p.)-treatment. Decrease in superoxide dismutase and glutathione peroxidase activity was observed in ipsilateral hemisphere of MCAO animal. Curcumin-treatment (300 mg/kg, i.p.) prevented IR injury mediated fall in glutathione peroxide activity. Peroxynitrite measured using rhodamine123 fluorescence and anti-nitrotyrosine immunofluorescence indicated increased peroxynitrite formation after IR insult. Curcumin-treatment reduced peroxynitrite formation and hence the extent of tyrosine nitration in the cytosolic proteins. These results suggest the neuroprotective potential of curcumin in cerebral ischemia and is mediated through its antioxidant activity.