粒细胞集落刺激因子治疗大鼠局灶性脑缺血再灌注损伤

目的 探讨粒细胞集落刺激因子(G-CSF)对大鼠局灶性脑缺血再灌注损伤的治疗作用.方法 线栓法构建SD大鼠脑缺血再灌注损伤模型,线栓时间2 h.手术48 h后,对模型鼠神经功能缺失评分,将12分以下的20只大鼠随机平均分为两组:干预性治疗组:予G-CSF 20μg/(kg·d)皮下注射,共19 d;对照组皮下注射等量生理盐水,置同样环境饲养.两组同时腹膜腔注射脱氧溴化尿嘧啶(Brdu)10mg/kg共19 d.两组均于手术后每周进行神经系统功能缺失评测.术后3周,将实验鼠麻醉后处死取脑,脑沿冠状面将鼠脑切成等分,取第3块脑切块,做冰冻切片,行神经干细胞及神经胶质细胞特异性抗体与Brdu抗体免疫组化双染,观察梗死区新生神经细胞.结果 手术后3周,与对照组比较,G-CSF治疗组神经功能恢复好于对照组(P<0.0);治疗组脑组织梗塞灶周围新生神经干细胞和神经胶质细胞增生明显多于对照组.结论 G-CSF能促进脑梗死后神经功能恢复和神经细胞再生,是一有效的脑缺血干预性治疗用药.     

甲状腺激素T3对大鼠脑缺血再灌注损伤后NGF和BDNF表达的影响研究

目的 探讨甲状腺激素T3对大鼠脑缺血再灌注损伤的神经保护作用及机制.方法 雄性SD大鼠分为假手术+生理盐水组、假手术+T3组、大脑中动脉栓塞(MCAO)+生理盐水组、MCAO+T3组.应用MCAO法建立大鼠脑缺血再灌注损伤模型,分别于缺血后1 h及再灌注后6 h给予腹腔注射甲状腺激素10 μg/100 g,生理盐水为安慰剂.再灌注24 h后,观察不同组别大鼠神经功能损伤情况,梗死体积变化,以及缺血侧脑皮质中神经生长因子(NGF)和脑源性神经营养因子(BDNF)的mRNA及蛋白表达水平变化.结果 与MCAO+生理盐水组比较,MCAO+T3组大鼠神经功能缺损表现减轻,脑梗死体积减小,NGF、BDNF的mRNA和蛋白表达上升(P<0.05).结论 甲状腺激素对大鼠脑缺血再灌注损伤有神经保护作用,其机制与增加脑缺血再灌注损伤中NGF、BDNF的表达相关.     

新型查尔酮FMC对大鼠局灶性脑缺血再灌注损伤的保护作用

目的 研究新型查尔酮（FMC）（3''-甲酰基-4'',6''-二羟基-2''-甲氧基-5''-甲基查尔酮）对大鼠局灶性脑缺血再灌注损伤的保护作用。方法 建立重复性好、梗死部位恒定、成功率高的局灶性脑缺血再灌注损伤模型,以水溶性的FMC溶液腹腔注射,观察FMC对脑缺血大鼠神经行为、脑梗死范围以及脑组织的含水量、超氧化歧化酶（SOD）、丙二醛（MDA）的影响。结果 术后出现追尾征及特殊体态,于2h后大脑中动脉供血区出现缺血。脑组织TTC染色均匀,出现梗死的脑组织面积相对于全脑百分比为27.96%±9.45%,动物模型成功率为78.6%。FMC组的脑含水量、MDA显著降低,SOD显著升高,梗死率降低。结论 本方法构成局灶性缺血再灌注模型,操作简单,重复性好,大鼠体重和年龄、麻醉剂应用、栓线直径和插入深度、控制出血和术后护理等是模型制作成功的关键因素。FMC可能通过降低脑组织水含量、MDA水平,升高SOD水平,减少梗死体积,对缺血再灌注损伤的脑组织起到一定的保护作用。     

黄芪提取物对局灶性脑缺血再灌注损伤的保护作用

目的探讨黄芪提取物(EA)对实验性局脑缺血再灌注损伤的保护作用.方法用栓线法复制大鼠局灶性脑缺血(MCAO)再灌注模型,观察神经功能评分、脑梗死体积和脑含水量、病理组织学及血液流变学变化.结果与模型组比较,EA(20、40、80 mg/kg)对大鼠MCAO 2 h再灌注24 h的神经功能学评分均有明显的改善作用,能减轻大鼠脑缺血再灌注后的脑组织含水量的增加,减小MCAO 2 h再灌注后大鼠的脑梗死体积; EA各组均能不同程度的改善大鼠脑缺血再灌注后的脑组织病理变化;EA(80 mg/kg)对脑缺血再灌注后大鼠全血黏度、高切还原黏度、高切相对黏度、低切相对黏度的升高有一定的抑制作用.结论 EA对局灶性脑缺血再灌注损伤大鼠有一定的保护作用,其机制可能与其抑制脑缺血再灌注后血液流变学改变有关.     

促红细胞生成素对大鼠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)对大鼠局灶性脑缺血再灌注后脑损伤的保护作用。方法:20只雄性SD大鼠,采用线栓法阻断大鼠一侧大脑中动脉(MCA)血流2h,再灌注48h制成局灶性脑缺血再灌注损伤模型。随机分为两组,治疗组于再灌注前经腹腔注射Epo(3000U/kg),对照组给予等量生理盐水腹腔注射,48h后断头取脑。制作2mm冰冻切片;以2%氯化-2,3,5三苯基四氮唑(TTC)对脑切片进行染色;经图像分析仪计算梗死体积占全脑体积的百分比。结果:治疗组脑梗死体积与对照组相比明显缩小(P<0.01)。结论:Epo能够显著缩小脑梗死体积,对脑缺血再灌注损伤有良好的保护作用。     

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 pilosatreated MCAO group (EEA), 6. Water extract of Agrimonia pilosatreated 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 (allP<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 Treatmentusingwater 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.     

大鼠局灶性脑缺血并发多器官功能障碍综合征肺、肠Bax和Bcl-2表达变化

目的研究大鼠急性局灶性脑缺血再灌注后Bax、Bcl-2在脑和肺、肠的表达变化规律,探讨急性局灶性脑缺血致多器官功能障碍综合征(MODS)的发病机制。方法采用阻断大鼠大脑中动脉后再灌注法建立大鼠局灶性脑缺血致MODS模型,将54只Wistar大鼠随机分为正常对照组(6只)、假手术组(6只)及手术组(42只),手术组又分为缺血再灌注后2、6、12、24、48、72 h及5 d 7个亚组(各6只)。应用苏木精-伊红染色观察大鼠各脏器的病理变化,免疫组织化学链霉菌抗生素蛋白过氧化酶连接法检测脑和肺、肠Bax、Bcl-2的蛋白表达,并计数阳性细胞数,计算平均阳性率(LI)。结果大鼠脑缺血后各时间点的肺、小肠组织均有不同程度的病理损害。大鼠急性脑缺血后全身炎症反应综合征(SIRS)的发生率为100.0%,MODS的发生率为57.1%;手术组大鼠大多时间点Bax和Bcl-2阳性表达明显高于正常对照组和假手术组(P值均<0.01)。结论SIRS和Bax与Bcl-2表达平衡的失调是脑缺血致MODS的可能机制。     

EFFECTS OF TRANSCRANIAL MAGNETIC STIMULATION ON MOTOR CORTICAL EXCITABILITY AND NEUROFUNCTION AFTER CEREBRAL ISCHEMIA-REPERFUSION INJURY IN RATS

Objective To clarify the effects of repetitive transcranial magnetic stimulation （rTMS） on rat motor cortical excitability and neurofunction after cerebral ischemia-reperfusion injury. Methods After determined awake resting motor threshold （MT） and motor evoked potentials （MEPs） of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion （MCAO） reperfusion injury, then rTMS were applied to rTMS group （n = 10） at different time, while control group （n = 10） received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed. Results： After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower （P〈 0.05）, as well as the infarct volumes reduced significantly（P 〈 0.05）. But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume （r = 0.64, P 〈 0.05）. Conclusion rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.     

链脲佐菌素诱导的大鼠糖尿病合并脑缺血损伤模型的建立

目的：建立稳定的大鼠糖尿病合并局灶性脑缺血损伤模型,并对有关建模成功的标准进行探讨与分析。方法：40只健康雄性SD大鼠随机分为正常饲养假手术组,正常饲养脑缺血再灌注损伤模型组,糖尿病脑缺血再灌注损伤模型组。糖尿病模型组一次性腹腔注射链脲佐菌素60 mg·kg ^-1建立I型糖尿病大鼠模型,分别在造模后1,4周检测各组大鼠的体质量和空腹血糖。在腹腔注射(ip) STZ后4周采用线栓法制备大鼠局灶性脑缺血再灌注模型,缺血30 min,复灌注24 h,进行神经功能评分,测定脑梗死体积并计算梗死体积百分比。结果：腹腔注射链脲佐菌素4周后,糖尿病模型组与正常组大鼠相比,体质量显著下降（P<0.001）,血糖值显著升高（P<0.001）。缺血复灌注损伤手术后,糖尿病模型组与正常组大鼠相比,再灌注损伤加重,脑梗死体积百分比显著增加（P<0.001）。模型成功率为73%。结论：本实验方法制备的大鼠糖尿病合并局灶性脑缺血损伤模型成功率较高,具有较好的重复性和稳定性。     

C-Rel与Bcl-xL在脑缺血再灌注大鼠脑组织中的表达及意义

目的：检测脑缺血再灌注大鼠脑组织C-Rel与Bcl-xL表达,探讨NF-κB信号通路在缺血性脑损伤中的作用机制。方法：大脑中动脉线栓法制作脑缺血再灌注动物模型,随机分为正常组（N组）、假手术组（S组）、缺血2h后再灌注2h组（M2组）、6h组（M6组）、12h组（M12组）、24h组（M24组）。RT-PCR和免疫组织化学法检测C-Rel与Bcl-xL,用图像分析仪测定吸光度值。结果：模型组与正常组、假手术组比较,C-Rel与Bcl-xL表达增高（P〈0.01）,4个模型组比较无统计学差异,C-Rel与Bcl-xL表达有正相关性。结论：C-Rel与Bcl-xL在脑缺血再灌注大鼠脑组织表达增高,NF-κB家族C-Rel通过增强抗凋亡基因Bcl-xL表达发挥脑保护作用。