Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about. OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI). DESIGN: Repetitive measure animal experiment. SETTING: Zhongshan Hospital Affiliated to Dalian University. MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory), Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12–15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German. METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas. MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI. RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI: There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI: There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI. CONCLUSION: It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI.     

益气活血方对气虚血瘀证脑缺血再灌注损伤大鼠Fas、FasL蛋白表达的影响

目的：探讨益气活血方对气虚血瘀证局灶性脑缺血再灌注损伤大鼠Fas、FasL蛋白表达的影响。方法：采用气虚血瘀证局灶性脑缺血再灌注损伤大鼠模型，用线栓法阻塞大鼠大脑中动脉复制局部脑缺血再灌注模型，缺血2h后再灌注l，3，7d。用免疫组化染色法分别检测缺血皮质Fas、FasL蛋白表达。结果：与模型组比较。益气活血方组Fas、FasL蛋白表达显降低。结论：益气活血方可能通过抑制Fas、FasL蛋白表达，减轻气虚血瘀证局灶性脑缺血再灌注损伤。     

星蒌承气汤对脑缺血再灌注大鼠脑组织ICAM-1和NF-κB表达的影响

目的观察星蒌承气汤对脑缺血再灌注大鼠脑组织细胞间黏附分子-1（ICAM-1）和核因子-κB（NF-κB）蛋白表达影响,探讨其抗脑缺血再灌注炎性损伤的机制。方法将63只Wistar大鼠随机分为正常对照组、模型组、星蒌承气汤组,各21只。模型组和星蒌承气汤组采用线栓法制备大鼠局灶性脑缺血再灌注模型。星蒌承气汤组于造模前30 min予星蒌承气汤7.01 g/（kg.d）灌胃,约2 mL,造模后每日给药3次,每次均2 mL;对照组、模型组予0.9%氯化钠注射液2 mL,每日3次灌胃。模型组和星蒌承气汤组大鼠脑缺血2 h分别再灌注244、8和72 h后断头取脑组织,采用免疫组化SABC染色法分别检测缺血半暗带ICAM-1和NF-κB蛋白表达。结果模型组ICAM-1蛋白表达阳性细胞数明显增加,与正常对照组比较差异有统计学意义（P〈0.01）;星蒌承气汤组再灌注244、8、72 h ICAM-1蛋白表达阳性细胞数显著减少,与模型组比较差异有统计学意义（P〈0.05,P〈0.01）。模型组NF-κB蛋白表达阳性细胞数明显增加,与正常对照组比较差异有统计学意义（P〈0.01）;星蒌承气汤组再灌注24 h NF-κB蛋白表达阳性细胞数降低,但与模型组比较差异无统计学意义（P〉0.05）;星蒌承气汤组再灌注487、2 h NF-κB蛋白表达阳性细胞数显著减少,与模型组比较差异均有统计学意义（P〈0.05,P〈0.01）。结论星蒌承气汤能够对抗脑缺血大鼠脑组织中的ICAM-1和NF-κB蛋白表达,有效防止脑缺血再灌注炎性损伤。     

胃饲乙醇预处理诱导肝脏缺血耐受性的可行性探讨

目的探讨胃饲乙醇预处理对肝脏缺血再灌流损伤的影响,并初步评价其预处理的可行性。方法40%乙醇胃饲Wistar大鼠。分组:①大鼠36只,随机分6组:A组8g/kg、B组7g/kg、C组6g/kg、D组5g/kg、E组4g/kg、正常组0g/kg;以中毒症状及肝组织病理为指标,判定大鼠乙醇急性中毒剂量。②大鼠78只,随机分为4组:正常对照组(N)、单纯乙醇组(E)、单纯缺血组(ISCH)、胃饲乙醇预处理组(EPC);采用尾叶转流下的肝缺血模型,于再灌流3、6、12、24h留取标本。结果急性胃饲乙醇≤5g/kg预处理后,动物中毒症状轻,无死亡;乙醇预处理可以在一定程度上减轻肝脏90min的缺血再灌流损伤。结论适当剂量的乙醇胃饲预处理是一种安全的预处理措施,有望成为增强肝脏对缺血再灌流损伤耐受性的一种较好的预处理方式。     

钠钙交换器抑制药在心律失常治疗中的应用

心肌钠钙交换在调节心肌细胞内外钠、钙平衡中发挥重要作用。钠钙交换分为前向型和逆向型2种。在心力衰竭、心肌缺血、心肌再灌注等病理情况下,通过钠钙交换器的离子交换可产生致心律失常性的一过性内向电子流,引起延迟后除极和非折返激动型的室性心动过速。钠钙交换器抑制药在预防这些病理情况下的心律失常具有潜在的作用。     

缺血预适应对缺血-再灌注心肌细胞的保护作用

目的观察缺血预处理（IPC）对心肺转流（CPB）中缺血-再灌注心肌损伤及心功能恢复的影响。方法将72只健康家猫随机均分为：单纯CPB组、缺血-再灌注组和IPC组。在猫CPB模型的基础上，测定猫心肌丙二醛（MDA）含量、血清乳酸脱氢酶（LDH）水平和心肌组织磷脂酶A2（PLA2）活性的变化，观察术中心功能的变化。结果IPC组CPB中的血清LDH浓度、心肌MDA含量和心肌组织PLA2活性均明显低于缺血-再灌注组，心脏复跳后各心功能指标的恢复明显优于缺血-再灌注组。结论IPC可减轻CPB中缺血-再灌注心肌细胞的损伤，有利于术后早期心功能的恢复。     

雌激素对慢性脑缺血大鼠认知功能及突触素的影响

目的 研究苯甲酸雌二醇对慢性脑缺血大鼠认知功能及突触素的影响.方法 采用双侧颈总动脉永久性结扎制备慢性脑缺血模型,30只大鼠随机分为3组,A组:假手术组;B组:缺血组;C组:雌激素治疗组.各组于手术60d后,应用Y迷宫、免疫组化及图像分析系统测定大鼠认知功能及海马、齿状回突触素的含量.结果 治疗组较缺血组认知障碍明显改善(P＜0.01),与假手术组相比,缺血组突触素的含量明显下降,治疗组以上变化明显减轻(P＜0.01).结论 苯甲酸雌二醇能改善慢性脑缺血大鼠的认知功能,这可能与增加大鼠脑内突触素的含量有关.     

阿片肽与缺血性脑损伤

阿片肽及其受体系统在缺血性脑损伤的病理生理发展过程中具有非常重要的作用。其在缺血性脑损伤中的作用尚存争议，本文综述了阿片肽及其受体系统在缺血性脑损伤中的作用及其可能机制，有助于探索阿片肽在围术期的合理应用，为缺血性脑损伤防治研究提供新方向。