Acupuncture effects on serum myelin basic protein and remyelination following 30 minutes and 2 hours of ischemia in a rat model of cerebral ischemia-reperfusion injury

BACKGROUND： Acupuncture treatment on injured cerebral axons has shown to provide efficacy in clinical practice. It is unknown whether acupuncture produces therapeutic effects by protecting injured cerebral myelin in ischemic stroke. OBJECTIVE： To test whether acupuncture provides protection for injured cerebral myelin, based on quantitative data from cerebral ischemia-reperfusion rats, and to compare the effects of early and late acupuncture on serum myelin basic protein （MBP） content and remyelination of the ischemic internal capsule.DESIGN, TIME AND SETTING： A randomized, controlled experiment was performed at the Neurobiological Laboratory, Sichuan University from March 2005 to March 2006. MATERIALS： ＂Hua Tuo＂ Brand filiform needles were produced by the Medical Instrument Factory of Suzhou, China.METHODS： A total of 52 adult, healthy, male, Sprague Dawley rats were randomly assigned to four groups： control （n = 4）, model （n = 16）, early acupuncture （n = 16）, and late acupuncture （n = 16）. The focal cerebral ischemia-reperfusion model was established by middle cerebral artery occlusion in the right hemisphere using the modified thread embolism method in the latter three groups. Early and late acupuncture groups underwent acupuncture after ischemia for 30 minutes and 2 hours using the Xingnaokaiqiao needling method, respectively. Acupoints were ＂Neiguarf＇ （PC 6） and ＂Sanyinjiao＂ （SP 6） on the bilateral sides, as well as ＂Shuigou＇ （DU 26） and ＂Baihui＂ （DU 20） with stimulation for 1 minute at each acupoint. Acupuncture at all acupoints was performed two or three times while the needle was retained, once per day. No special handling was administered to the control clroup.MAIN OUTCOME MEASURES： For each group, remyelination of the internal capsule was observed by Pal-Weigert＇s myelin staining and serum MBP content was detected using enzyme-linked immunosorbent assay method on days 1,3, 5, and 7 following ischemia-reperfusion injury.RESULTS： Compared with the control group, massive demyelination of the internal capsule occurred, and serum MBP content increased in the model group （P 〈 0.05）. Compared with the model group, the extent of demyelination in the internal capsule was less distinct and serum MBP content was significantly less in the early and late acupuncture group （P 〈 0.01 ）. Compared with the late acupuncture group, serum MBP content reached a peak later and the peak value was less in the early acupuncture group. CONCLUSION： Results suggest that acupuncture exerts a protective effect on injured cerebral myelin in ischemia-reperfusion rats by reducing serum MBP content and promoting remyelination. The study also suggests that the effect of early acupuncture is superior to late acupuncture.

Protective effect of ultrashortwave versus radix salviae miltiorrhizae on brains of rats with cerebral ischemia-reperfusion injury

BACKGROUND： HOW to control the effect of oxygen-derived free radicals on development of cerebral injury and cerebral edema is a key factor for treating cerebral ischemia-reperfusion injury. OBJECTIVE： To observe and compare the protective effects, synergistic action and mechanisms of ultrashortwave （USW） and radix salviae miltiorrhizae （RSM） on the focal cerebral ischemia-reperfusion injuries in rats. DESIGN： Randomized controlled animal study SEI-FING： Department of Rehabilitation Medicine, First Hospital affiliated to China Medical University MATERIALS： A total of 160 healthy Wistar rats of both genders and aged 18-20 weeks weighing 250-300 g of clean grade were selected in this study. 5 mL/ampoule RSM injection fluid was produced by the First Pharmaceutical Corporation of Shanghai （batch number： 011019, 0.01 mug）. The USW therapeutic device was produced by Shanghai Electronic Device Factory with the frequency of 40.68 MHz and the maximal export power of 40 W. The first channel of power after modulation was 11 W. METHODS： The experiment was carried out in the Rehabilitation Medicine Department of the First Hospital affiliated to China Medical University from May 2002 to January 2003. Focal ischemia-reperfusion model was established in rats by reversible right middle cerebral artery occlusion with filament. Right cerebral ischemia was for 2 hours and then with 24 hours reperfusion. The scores of neurological deficits were evaluated by 0 to 4 scales. After surgery, 64 successful rats models were divided into four groups according to digital table： control group, USW group, RSM group and RSM ＋ USW group with 16 cases in each group. Rats in control group were intraperitoneally injected with the same volume of saline （0.1 mL/g）; rats in USW group were given small dosage of USW on head for 10 minutes at 6 hours after reperfusion; rats in RSM group were intraperitoneally injected with 0.01 mL/g RSM solution at 30 minutes before reperfusion; rats in RSM ＋ USW group were intraperitoneally injected with 0.01 mL/g RSM parenteral solution at 30 minutes before reperfusion and given small dosage of USW on head for 10 minutes once at 6 hours after reperfusion; sixteen rats in sham operation group did not receive any treatment. All 80 rats were taken brains at 24 hours after reperfusion to measure wet and dry weights to calculate water content： Cerebral water content （%） = （1-dry/wet weight） × 100%. Superoxide dismutase （SOD） activity was measured by hydroxylamine method and malondialdehyde （MDA） content was measured by TBA photometric method. MAIN OUTCOME MEASURES ： Cerebral water content, SOD activity and MDA content RESULTS： All 160 rats except 80 failing in modeling were involved in the final analysis. （① The cerebral water content of left hemisphere made no significant difference （P 〉 0.05）. The cerebral water content of right hemisphere in the control group and the three treatment groups was obviously higher than that of the sham operation group [（81.26±0.77）%, （79.74±0.68）%, （79.76±0.81）%, （79.61±0.79）%, （77.43±0.61）%, P 〈 0.05]. The cerebral water content of right hemisphere in the three treatment groups was obviously lower than that of the control group （P〈 0.05）. There was no significant difference among the three treatment groups （P 〉 0.05）. ② Compared with the control group, SOD activity （right） of the control group decreased obviously （P 〈 0.05）, while MDA content increased obviously （P 〈 0.05）. SOD activity in the three therapeutic groups increased obviously, while MDA content decreased obviously （P 〈 0.05）; there was no significant difference among the three treatment groups （P 〉 0.05）. CONCLUSION： ① USW and RSM therapy have neuroprotective effects against focal cerebral ischemia-reperfusion injuries by means of decreasing cerebral water content and MDA and increasing the activity of SOD. ② Synergistic action was not observed between these two therapeutic methods.

Experimental Study on the Protection of Agrimony Extracts from Different Extracting Methods against Cerebral Ischemia-Reperfusion Injury

Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats were randomly assigned into seven groups: 1. Sham-operated group, 2. Untreated MCAO group (MCAO), 3. Petroleum ether extract of Agrimonia pilosa treated MCAO group (PEA), 4. Ethyl acetate extract of Agrimonia pilosa treated MCAO group (EAEA), 5. Ethanol extract of Agrimonia pilosa treated MCAO group (EEA), 6. Water extract of Agrimonia pilosa treated MCAO group (WEA), 7. Nimodipine treated MCAO group (NP). Intragastrical drug administration (i.g) was performed at 0 and 6 hours after MCAO.Neurological function tests were performed after reperfusion for 24 hours, then the brain was removed for the evaluations of the cerebral infarction volume (percentage of total brain volume) by immunohistochemistry,histological changes (hematoxylin-eosin staining), Na+/K+-ATPase, Ca2+-ATPase (modified method of Svoboda and Mosinger), mRNA expression of Tumor suppressor gene (P53) and hot shock protein (HSP70)(quantitative real-time PCR).Results The neurological function of MCAO group had significantly higher scores than the sham group (P<0.01). The WEA group showed a significantly lower neurological score than the MCAO group (P<0.05),indicating the protective effect of WEA on neurological deficits. The mean infarction volumes of WEA (13.5±6.6%, F=4.75, P<0.01), EEA (19.90±6.90%, F=5.23, P<0.01), PEA (20.40±5.30%, F=4.68,P<0.01) and EAEA (22.50±10.50%, F=6.25, P<0.05) group were all significantly smaller than that of MCAO group (29.40±6.50%). HE staining demonstrated that, compared to the treated groups, the infarcted cerebral tissue of MCAO group had more swelling neural cells, lighter stained nucleus, fewer and irregularly distributed neurons. The activity of Na+/K+-ATPase and Ca2+-ATPase reduced in the MCAO group (3.67±0.48 U/mg,1.28±0.26 U/mg, respectively), and were significantly higher in WEA group (7.56±0.85 U/mg, F=12.65,P=0.010; 3.59±0.22 U/mg, F=8.32, P=0.041, respectively). The MCAO group showed significantly elevated P53 and HSP70 mRNA expressions compared to the sham group (P<0.01, P<0.05). P53 mRNA expressions in Agrimony extracts treated groups were significantly lower than that of the MCAO group (all P<0.01), with the WEA group showing the greatest difference from MCAO group. The HSP70 mRNA level of the treated groups were not significantly different from that of the MCAO group.Conclusions Treatment using water extracts of agrimony can promote the best functional and metabolic recovery for rat model of cerebral ischemia-reperfusion injury, which maybe relate with the upregulation of energy metabolism in nerve cells after MCAO.

Middle cerebral artery occlusion methods in rat versus mouse model of transient focal cerebral ischemic stroke

Experimental stroke research commonly employs focal cerebral ischemic rat models （Bederson et al., 1986a; Longa et al., 1989）. In human patients, ischemic stroke typically results from thrombotic or embolic occlusion of a major cerebral artery, usually the mid- dle cerebral artery （MCA）. Experimental focal cerebral ischemia models have been employed to mimic human stroke （Durukan and Tatlisumak, 2007）. Rodent models of focal cerebral ischemia that do not require craniotomy have been developed using intraluminal suture occlusion of the MCA （MCA occlusion, MCAO） （Rosamond et al., 2008）. Furthermore, mouse MCAO models have been wide- ly used and extended to genetic studies of cell death or recovery mechanisms （Liu and McCullough, 2011）. Genetically engineered mouse stroke models are particularly useful for evaluation of isch- emic pathophysiology and the design of new prophylactic, neuro- protective, and therapeutic agents and interventions （Armstead et al., 2010）. During the past two decades, MCAO surgical techniques have been developed that do not reveal surgical techniques for mouse MCAO model engineering. Therefore, we compared MCAO surgical methods in rats and mice.

Gradual Clamping Reduced Ischemia-Reperfusion Injury in an Isolated Rat Heart Model

Objectives: We hypothesized that the organisms and their organs or tissues could adapt themselves to the gradual changes of environment for surviving or reducing damage. This study explored whether gradual clamping (GC) could reduce myocardial ischemia-reperfusion (IR) injury in rat heart. Methods: Twelve rats were randomized to IR group and GC group, then the hearts were isolated and perfused with Langendorff apparatus. Before cardioplegia, the perfusion was stopped abruptly in IR group while slowly with 5-minute in GC group. The hearts were subjected to 30-minute ischemia and 60-minute reperfusion. The left ventricular develop pressure (LVDP) and systolic pressure (LVSP), the maximal rate of the increase and decrease of left ventricular pressure (+dp/dtmax, ﹣dp/dtmax) were measured by polygraph system at different time points. The recovery of the variables was expressed as the ratio of these values at individual time point after reperfusion to the baseline respectively. Results: The recovery of LVDP after reperfusion was better than that in IR group (P = 0.034). No significant difference in the recovery of LVSP, +dp/dtmax and ﹣dp/dtmax between groups was observed. Conclusions: Gradual clamping could improve the recovery of LVDP after IR, suggesting that gradual clamping could reduce myocardial IR injury.

Effects of NG-nitro-L-arginine on focal cerebral ischemic injury in rats

BACKGROUND： Previous researches have proved that aminoguanidin can cure cerebral ischemic injury remarkably as a selective induced nitricoxide synthase （iNOS） inhibitor. However, whether nonselective NOS inhibitor could protect cerebral ischemic injury or not is unclear. OBJECTIVE： To investigate the effects of NG-nitro-L-arginine （L-NA）, a nonselective nitricoxide synthase （NOS） inhibitor, on cerebral ischemic injury of rats and the possible mechanism.DESIGN： Randomized controlled study.SETTING ： Pharmacological Department of Medical Academy of Science of Hebei Province.MATERIALS： A total of 56 male healthy SD rats, of grade Ⅱ, weighting 250-290 g, were provided by the Experimental Animal Center of Hebei Province （certification： 04036）. METHODS： The experiment was completed in the Pharmacological Department of Medical Academy of Science of Hebei Province from March 2005 to January 2006.① Grouping： Rats were randomly divided into 3 groups： sham operation group （n=8）, model group （n=24） and L-NA group （n=24）.② Modeling： Middle cerebral artery （MCA） was established on rats in model group and L-NA group with intreluminal line occlusion methods, and rats in sham operation group were separated their external carotid arteries without occlusion of internal carotid artery. ③ Intervention study： Rats in model group and L-NA group were injected intreperitoneally with 10 mL/kg and 20 mg/kg L-NA at 2, 6 and 12 hours respectively after ischemia twice a day for 3 consecutive days. ④ Rats were sacrificed on the third day for measuring volume of cerebral infarction with image analysis and swelling degrees and activities of mitochondria with electron microscope. Effect of L-NA on ultrastructural changes of neurons in cortex was observed after ischemia. MAIN OUTCOME MEASURES：① Volume of cerebral infarction; ②Swelling degrees, contents of nitric oxide （NO） and malondialdehyde （MDA） and activities of adenosine triphosphatase （ATPase）, superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） in mitochondria;③ Ultrastructural changes of mitochondria in brain tissue after cerebral ischemia. RESULTS： ① At 12 hour after ischemia, volume of cerebral infarction in L-NA group was lower than that in model group （P 〈 0.01）. ② Content of NO in mitochondria in L-NA group was decreased as compared with that in model group at 2, 6 and 12 hours after ischemia （P 〈 0.05）; swelling degree of mitochondria in brain tissue was relieved in L-NA group at 12 hour after ischemia, and content of MDA was decreased （P 〈 0.05）; mitochondrial activity in L-NA group was increased at 12 hour after ischemia, and activities of ATPase, SOD and GSH-Px in mitochondria were increased （P 〈 0.05）.③ Degrees of mitochondrial injury in brain tissue were relieved in L-NA group at 12 hour after ischemia as compared with those in model group and L-NA group at 2 and 6 hours after ischemia. CONCLUSION ： ①L-NA can beneficially inhibit NO production, but not protect brain against damage in ischemia acute stage. ②L-NA might have protective effects on cerebral injury through inhibiting the production of oxygen free radical, increasing antioxidation, ameliorating energy metabolism, beneficially improving the integrity of form and function of mitochondria in brain tissue during postischemia in rats.

Blood microRNAs as potential diagnostic and prognostic markers in cerebral ischemic injury

MicroRNAs are a family of small, genome-encoded endogenous RNAs that are transcribed but are not translated into proteins. They serve essential roles in virtually every aspect of brain function, including neurogenesis, neural development, and cellular responses leading to changes in synaptic plasticity. They are also implicated in neurodegeneration and neurological disorders, in responses to hypoxia and ischemia, and in ischemic tolerance induced by ischemic preconditioning. In recent developments, miRNA expres- sion profiling has been examined in stroke, and these studies indicate that miRNAs have emerged as key mediators in ischemic stroke biology. Both increased and decreased miRNA levels may be needed either as prevention or treatment of stroke. Novel approaches are being developed to get miRNA related therapeu- tics into the brain across an intact blood-brain barrier, including chemical modification, use of targeting molecules and methods to disrupt the blood-brain barrier.

Neuroprotective effect of ischemic preconditioning in focal cerebral infarction: relationship with upregulation of vascular endothelial growth factor

Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic pre- conditioning in rats by simulating a transient ischemic attack twice （each a 20-minute occlusion of the middle cerebral artery） before inducing focal cerebral infarction （2 hour occlusion-reper- fusion in the same artery）. We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after ocdusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was significantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascu- lar endothelial growth factor.

Biliary tract injury caused by different relative warm ischemia time in liver transplantation in rats

BACKGROUND: There is a controversy over the degree of liver and biliary injury caused by the period of secondary warm ischemia. A liver autotransplantation model was adopted because it excludes the effects of infection and immunological rejection on bile duct injury. This study was undertaken to assess biliary tract injury caused by relative warm ischemia (secondary warm ischemia time in the biliary tract) and reperfusion. METHODS: One hundred and two rats were randomly divided into 5 groups: group I (control); groups 11 to V, relative warm ischemia times of 0 minute, 30 minutes, I hour and 2 hours. In addition to the levels of serum alkaline phosphatase, and total bilirubin, pathomorphology assessment and TUNEL assay were performed to evaluate biliary tract damage. RESULTS: Under the conditions that there were no significant differences in warm ischemia time, cold perfusion time and anhepatic phase, group comparisons showed statistically significant differences. The least injury occurred in group H (portal vein and hepatic artery reperfused simultaneously) but the most severe injury occurred in group V (biliary tract relative warm ischemia time 2 hours). CONCLUSIONS: Relative warm ischemia is one of the factors that result in bile duct injury, and the relationship between relative warm ischemia time the bile injury degree is time-dependent. Simultaneous arterial and portal reperfusion is the best choice to avoid the bile duct injury caused by relative warm ischemia. (Hepatobiliary Pancreat Dis Int 2009; 8: 247-254)

Quantitative Mitochondrial Proteomics Study on Protective Mechanism of Grape Seed Proanthocyanidin Extracts Against Ischemia/Reperfusion Heart Injury in Rat

Cardiac ischemia/reperfusion（I/R） injury is a critical condition,often associated with high morbidity and mortality.The cardioprotective effect of grape seed proanthocyanidin extracts（GSPE） against oxidant injury during I/R has been described in previous studies.However,the underlying molecular mechanisms have not been fully elucidated.This study investigated the effect of GSPE on reperfusion arrhythmias especially ventricular tachycardia（VT） and ventricular fibrillation（VF）,the lactic acid accumulation and the ultrastructure of ischemic cardiomyocytes as well as the global changes of mitochondria proteins in in vivo rat heart model against I/R injury.GSPE significantly reduced the incidence of VF and VT,lessened the lactic acid accumulation and attenuated the ultrastructure damage.Twenty differential proteins related to cardiac protection were revealed by isobaric tag for relative and absolute quantitation（iTRAQ） profiling.These proteins were mainly involved in energy metabolism.Besides,monoamine oxidase A（MAOA） was also identified.The differential expression of several proteins was validated by Western blot.Our study offered important information on the mechanism of GSPE treatment in ischemic heart disease.

基于脑小血管病临床脑血流特点构建并评估不完全性全脑缺血再灌注大鼠模型

目的:基于脑小血管病(CSVD)的脑血流特点构建和评估不完全性全脑缺血再灌注大鼠模型,以期为CSVD等缺血性脑血管疾病的基础研究提供理想的大鼠实验模型。方法:将126只雄性SD大鼠随机分为假手术(sham)组、轻损伤模型组(minor组)和重损伤模型组(serious组),每组42只。采用双侧颈总动脉夹闭-开放循环操作的方法,构建大鼠不完全性全脑缺血再灌注模型,激光散斑血流成像系统评估脑血流实时变化;于造模后2、24和72 h,评估造模动物存活率和动物行为学(平衡木实验,BBT)评分;于造模2、24和72 h取材,采用HE染色观察大鼠不同脑区组织病理形态改变;并运用非靶向代谢组学分析模型大鼠血浆和脑皮质区差异代谢物,评估模型损伤程度。结果:(1)与sham组比较,minor组和serious组大鼠总存活率平均值分别为83.2%和73.7%(P<0.05);(2)残存脑血流量平均值分别为56.3%和40.9%;(3)神经功能检查显示,与sham组比较,minor组和serious组造模后2、24和72 h的BBT评分均显著升高(P<0.05);(4)HE染色镜下可见广泛脑皮质(M1区和RSA区最为明显)、腹内测下丘脑腹外侧部(VMHvl)和海马C2区神经细胞形态发生不同程度改变。(5)非靶向代谢组学结果显示,sham组和serious组大鼠血浆差异性代谢物总数45个,上调代谢物总数33个,下调代谢物总数12个;脑皮质RSA区差异性代谢物总数19个,上调代谢物总数6个,下调代谢物总数13个,提示造模导致了大鼠神经-内分泌功能的紊乱。结论:双侧颈总动脉夹闭-开放循环造模方法可导致大鼠脑皮质、VMHvl和海马C2区散在性广泛损伤,其损伤机制可能与代谢紊乱、氧化应激损伤等有关。该模型为研究CSVD反复缺血再灌注损伤提供了新的大鼠实验模型。

改良的四血管间断阻塞法制作大鼠全脑缺血再灌注损伤模型

目的改良Pulsinelli与Brierley建立的经典四血管阻塞(4VO)模型。方法80只雄性SD大鼠。其中32只随机分为:假手术组、I4VO-Con10组、I4VO-Int10组和I4VO-Int15组。假手术组暴露双侧椎动脉与颈总动脉但不夹闭;I4VO-Con10为持续缺血组,夹闭双侧椎动脉与颈总动脉10 min,再灌注24 h;I4VO-Int10组和I4VO-Int15组为间断缺血组,I4VO-Int10组进行5 min缺血、5 min再灌注及5 min缺血,然后再灌注24 h;I4VO-Int15组缺血5 min、再进行2次5 min/5 min的再灌注/缺血循环,随即再灌注24 h。激光多普勒监测局部脑血流量,观察大鼠生存情况,HE染色观察海马组织病理改变,以此确定最优改良方法;48只大鼠按照最优改良方法(I4VO-Int15)建立I4VO模型,随机分为假手术组和5个I4VO模型组。5个I4VO模型组根据再灌注时间点(1、3、7、14、28 d)分为I4VO-D1、I4VO-D3、I4VO-D7、I4VO-D14和I4VO-D28组。记录各组大鼠体质量与生存状况,HE染色观察海马、视网膜与视束形态学改变;Y迷宫实验、明暗箱实验评估I4VO-D28组大鼠认知功能与视功能。结果I4VOInt15是最优改良方法;I4VO-D1组、I4VO-D3组、I4VO-D7组、I4VO-D14组和I4VO-D28组体质量较对应时间点假手术组的体质量明显降低,存活率无显著性差异,海马神经元损伤、丢失进行性加重;I4VO-D28组大鼠出现认知障碍;I4VO-D28组大鼠视网膜、视束未见明显缺血性损伤。结论改良的I4VO模型能够成功复制大鼠全脑缺血再灌注损伤的主要病理过程;改良的I4VO模型未引起视功能损伤。

脑泰通组方对局灶性脑缺血再灌注大鼠模型的影响及保护机制

目的:观察脑泰通组方对局灶性脑缺血再灌注大鼠模型的影响及保护机制。方法:构建局灶性脑缺血再灌注大鼠模型,成模后随机分为模型对照组、阳性药物组、中药组、联合用药组,另选取健康斯泼累格·多雷(SD)大鼠作为假手术组。观察并评估各组大鼠的美国国立卫生研究院卒中量表(NIHSS)评分、脑组织含水量、脑梗死体积百分比,免疫组织化学法检测脑组织Bcl-2相关X蛋白(Bax)、B细胞淋巴瘤-2(Bcl-2)的平均光密度值,蛋白质免疫印迹法、实时定量PCR(QT-PCR)检测脑组织叉头框转录因子3a(FoxO3a)基因、低氧诱导因子-1α(HIF-1α)、核因子κB(NF-κB)、脑源性神经营养因子(BDNF)蛋白及mRNA的表达水平。结果:与假手术组比较,模型对照组NIHSS评分,脑组织含水量,脑组织缺血体积百分比,脑组织FoxO3a、HIF-1α、NF-κB、BDNF蛋白和mRNA的表达水平,Bax、Bcl-2平均光密度值以及Bax/Bcl-2值均显著升高(均P<0.05);与模型对照组比较,药物干预各组的NIHSS评分、脑组织含水量、脑梗死体积百分比、Bax平均光密度值、Bax/Bcl-2值、脑组织NF-κB蛋白和mRNA的表达水平显著降低(均P<0.05),其中联合用药组的降低程度最大(均P<0.05),Bcl-2平均光密度值,脑组织FoxO3a、HIF-1α、BDNF蛋白和mRNA的表达水平显著升高(均P<0.05),其中联合用药组的升高程度最大(均P<0.05)。结论:脑泰通组方能有效保护局灶性脑缺血再灌注大鼠模型脑组织损伤,改善局部脑缺血,其作用机制可能与脑泰通组方调控FoxO3a/HIF-1α/NF-κB信号通路相关。

栀子提取物对局灶性脑缺血损伤模型大鼠凝血功能及脑血管内皮功能的影响

目的:观察栀子提取物(GE)对局灶性脑缺血损伤模型大鼠凝血功能及脑血管内皮功能的影响。方法:采集新鲜干燥栀子,制备GE。将48只SD大鼠随机分为假手术组(sham组)、模型组(model组)、GE高剂量组(GE-H组)、GE低剂量组(GE-L组),每组12只。构建大鼠局灶性脑缺血损伤模型,术后采用Longa神经学评分对符合局灶性脑缺血损伤标准大鼠进行实验。采用Longa神经学评分标准比较用药前后神经功能改善情况;采用断尾法及玻片法检测大鼠凝血时间(CT)和出血时间(BT);凝血酶活性荧光检测凝血酶时间(TT)及凝血酶含量,观察大鼠凝血因子Ⅹa含量,判断大鼠凝血功能变化情况;检测大鼠大脑动脉环(Willis)一氧化氮(NO)、内皮型一氧化氮合酶(eNOS)、血管壁血栓素A_(2)(TXA_(2))、血浆前列环素I_(2)(PGI_(2))、内皮组织纤维溶酶原激活物(t-PAT)及其抑制剂(PAI)活性,判断大鼠脑血管内皮功能变化情况;苏木精-伊红(HE)染色法检测各组大鼠脑部损伤情况。结果:sham组大鼠脑组织正常,与sham组比较,model组CT、BT、TT缩短,t-PAT、PGI_(2)、NO、eNOS降低,凝血酶生成及内源性、外源性凝血因子Ⅹa生成、PAI、TXA_(2)升高(P<0.05),且大鼠脑组织出现局灶性脑缺血损伤。与model组比较,GE-H组和GE-L组CT、BT、TT延长,t-PAT、PGI_(2)、NO、eNOS升高,凝血酶生成及内源性、外源性凝血因子Ⅹa生成、PAI、TXA_(2)降低(P<0.05),脑组织损伤情况较model组明显好转。与sham组比较,model组治疗后Longa神经学评分升高;与model组比较,GE-H组和GE-L组Longa神经学评分降低(P<0.05)。结论:GE作用可延长CT、BT、TT,降低凝血酶和凝血因子含量,增强NO、eNOS活性,提高t-PAT、PGI_(2)表达同时抑制PAI、TXA_(2)表达,可改善局灶性脑缺血损伤凝血功能,恢复脑血管内皮功能。

大鼠局灶性脑缺血模型的有效制备

目的比较三种不同手术方法制作大鼠永久性脑缺血模型的效果,包括死亡率、神经功能评分、脑梗死体积、手术效率。方法将采用不同手术方法制备脑缺血模型的大鼠随机分为三组。1组在术中分别结扎颈总动脉(CCA)、颈外动脉(ECA)、枕动脉、翼腭动脉,并且用动脉夹对颈内动脉(ICA)进行临时夹闭;2组在术中分别结扎颈总动脉、颈外动脉,暴露枕动脉和翼腭动脉但不结扎,用丝线悬挂颈内动脉而不是用动脉夹夹闭,线栓在显微镜直视下插入颈内动脉越过翼腭动脉起始点至大脑中动脉分叉处;3组只暴露颈总动脉、颈外动脉和颈内动脉,结扎颈总动脉、颈外动脉,丝线悬挂颈内动脉,显微镜下将线栓盲插至颈内动脉大脑中动脉分叉处。分别检测三组模型的死亡率、神经功能评分、梗死体积、手术时间。结果第3组制作动物模型的方法所花费时间平均为17.5 min,死亡率较低,神经功能评分及梗死体积稳定。结论采用第3组手术方法可以缩短手术时间,提高手术效率,能够高效地制作出更加稳定的可用于临床实验的大鼠脑缺血模型。

电针对局灶性脑缺血成年大鼠神经干细胞增殖、分化的影响

目的:观察电针对成年大鼠局灶性脑缺血后神经干细胞增殖、分化的影响,探讨其治疗脑梗死的可能机制。方法:采用线栓法制备大鼠MCAO模型,应用BrdU/NeuN、BrdU/GFAP免疫荧光双标法观察再灌注损伤后第4、7、14天时大鼠神经干细胞增殖、分化情况。结果:脑缺血后第4、7、14天3个时间点室管膜下区、缺血边缘区均有BrdU阳性细胞表达,BrdU阳性细胞数在第7天达高峰;电针组第7天BrdU阳性细胞数高于相同时间段模型组(P<0.05);电针组BrdU/GFAP双标阳性细胞数在7天高于相同时间段模型组(P<0.05);电针组和模型组BrdU/NeuN双标阳性细胞数在缺血后第4、7和14天差异无显著性(P>0.05)。结论:缺血损伤可诱发室管膜下区、缺血边缘区神经干细胞的增殖,少量的新增殖细胞可以向神经元和星型胶质细胞分化;电针可以促进脑缺血后细胞增殖作用并可激发新增殖细胞向星型胶质细胞分化,而对向神经元细胞分化则影响不明显。

局灶性脑缺血再灌注动物模型的制备及评价

目的 :研究局灶性脑缺血再灌注动物模型在缺血 90 ,12 0 ,180min恢复再灌后对脑梗死体积和行为学方面的影响。方法 :采用线栓法建立SD大鼠局灶性脑缺血再灌注模型 ,并将其分为假手术对照组、缺血 90 ,12 0和180min再灌组共 4组。用盐酸 2 ,3,5 三苯基四氮唑 (TTC)染色法测定脑梗死体积和神经功能评分法评价其行为学。结果 :TTC染色显示该模型的缺血区主要位于视交叉后 2～ 4mm脑皮质。缺血 90min再灌组、缺血 12 0min再灌组和缺血 180min再灌组脑梗死体积差异无统计学意义 ,缺血 12 0 ,180min再灌组 2组脑梗死体积较 90min再灌注组有增加趋势 ,3组行为学改变以再灌注后 3～ 6h最明显。结论 :选择脑缺血 12

SD大鼠线栓法局灶性脑缺血/再灌注模型的改进

目的探索大鼠线栓法局灶性脑缺血/再灌注模型制备方法的改进。方法按照文献方法,用头端处理过的尼龙钓丝,从颈外动脉向颈内动脉插入,可逆性阻断大鼠一侧中动脉。结果在模型制作过程中,遇到的最大困难是栓线插线时的大出血,以及有时栓线无法正确插入颈内动脉。除了用血管夹夹闭颈总、颈内动脉外,直接在颈总、颈内动脉套上一根丝线牵拉,既有助于手术分离,又有助于控制出血;遇到栓线插入困难时,颈总、颈内动脉的复流可以有效地消除颈内动脉痉挛,成功率明显提高。结论采用预先在颈总、颈内动脉套线,可以方便有效地控制出血。插线困难时,颈总、颈内动脉的复流可以提高成功率。

银杏内酯对大鼠局灶性脑缺血的保护作用

目的 研究银杏内酯对大鼠局灶性脑缺血的作用。方法 选用中动脉阻塞 再灌模型观测对比脑缺血大鼠给药组和模型组的各项指标。结果 银杏内酯口服能使脑缺血大鼠的神经行为明显改善 ,脑梗塞面积和脑含水量显著降低 ;高、中、低三个剂量组与缺血模型组相比均有显著性差异。该药还能降低缺血后脑组织匀浆中的MDA、LD含量 ,提高SOD和GSH活性。脑组织病理切片也证实了该药对神经细胞的保护作用。结论 银杏内酯对大鼠局灶性脑缺血有保护作用。

栓线法制作局灶性大鼠脑缺血再灌注模型的改进及效果

目的 建立一种较理想的实验性局灶性脑缺血模型。方法 参照Longa和Koizumi腔内线栓法制作大鼠局灶性可逆性大鼠中动脉缺血 (MCAO)模型 ,对栓线的制备、手术操作进行改进 ,通过病理学观察栓线直径、插入深度以及大鼠体重对缺血模型有效性的影响。结果 大鼠体重 2 50～ 2 80g ,插线头端浸蜡 ,直径 0 .2 6mm ,由颈内动脉插入大脑中动脉 ,插入深度 (18± 1)mm ,可获得较成功的局灶性脑缺血模型。结论 改进的模型操作简单 ,成功率高 ,稳定性强 。