大黄素甲醚对脑缺血再灌注损伤大鼠的保护作用

背景白细胞介素1β和细胞黏附分子1可介导中性粒细胞浸润,与脑缺血再灌注损伤密切相关.目的研究大黄素甲醚对缺血再灌注后脑组织炎性反应的影响.设计以实验动物为研究对象,完全随机对照研究.单位一所大学医院的神经内科.材料实验于2003-09/12在河北省职工医学院动物实验室完成.健康雄性SD大鼠91只,由河北医科大学动物中心提供.实验分为假手术组、缺血再灌注组和正常组以及大黄素甲醚20 mg/kg组和大黄素甲醚40 mg/kg组,前二组分为再灌注6,12,24,48 h时间段组,后两组又分为脑缺血再灌注12,24 h两组,每组为7只.干预制备大脑中动脉闭塞模型,用放射免疫的方法检测白细胞介素1β,用免疫组织化学方法检测细胞黏附分子1.主要观察指标各组大鼠脑组织中白细胞介素1β水平及细胞黏附分子1的阳性表达.结果大鼠脑缺血再灌注6 h达高峰,随之开始逐渐下降.大黄素甲醚40 mg/kg组再灌注12 h及再灌注24 h,以及20mg/kg组再灌注12 h病变侧脑组织白细胞介素-1β含量与模型组相应时间段比较明显降低(P＜0.01).正常组及假手术组大鼠大脑皮质可见少量细胞黏附分子1表达,黄褐色反应物出现在血管内皮细胞的胞浆和细胞膜上.缺血再灌注24 h可见大血管的内皮细胞呈阳性表达,并逐渐加深(积分吸光度值31.89±4.38;面密度值0.018 5±0.003 1).大黄素甲醚40 mg/kg组再灌注12 h(积分吸光度值13.33±6.12;面密度值0.007 6±0.002 2)、24 h(积分吸光度值20.04±4.65;面密度值0.012 9±0.003 6)以及20 mg/kg组再灌注24 h(积分吸光度值23.73±4.51;面密度值0.014 1±0.003 8)梗死灶周边的细胞黏附分子1蛋白的表达与相应时间段的模型组比较明显较少(P＜0.01或P＜0.05).结论大黄素甲醚能降低脑缺血再灌注后脑组织白细胞介素1β,细胞黏附分子1的表达,减轻脑缺血再灌注损伤.

Protective effects of physcion on cerebral ischemia-reperfusion injury in rats

BACKGROUND: Interleukin-1 (IL-1β) and intercellular adhesion molecule-1 (ICAM-1 ) can mediate neutrophilic infiltration, which is closely relevant to cerebral ischemia-reperfusion injury.OBJECTIVE: To investigate the effect of physcion on cerebral inflammatory reaction after ischemia-reperfusion injury.DESIGN: A completely randomized study based on animals.SETTING: Neurological department in a university hospital.MATERIALS: From September to December 2003, the study was conducted in the Animal Laboratory, Hebei Staff and Workers Medical College. Totally 91 healthy male SD rats, supplied by Laboratory Animal Center of Hebei Medical University, were used in the experiments. They were divided into sham operation (SO) group, ischemia-reperfusion group, normal control group, 20 mg/kg physcion group and 40 mg/kg physcion group.Each of the former two groups would be divided into 4 subgroups named as the 6th-hour-after-reperfusion group, the 12th-hour-after-reperfusion group, the 24th-hour-after-reperfusion group and the 48th-hour-after-reperfusion group. Each of the latter two groups were divided into 2 subgroups named as the 12thhour-after-reperfusion group and the 24th-hour-after-reperfusion group. Each subgroup contained 7 rats.INTERVENTIONS: Middle cerebral artery occlusion model (MCAO model) was applied, and IL-1β was measured by radioimmunoassay and ICAM-1 was detected by immunohistochemical staining.MAIN OUTCOME MEASUREMENTS: The IL-1 β level and the positive expression of ICAM-1 in the rats' cerebella were observed.RESULTS: Cerebral ischemia-reperfusion injury in the rats reached its peak 6 hours after reperfusion, and then it decreased gradually. In the 12-hour-after-reperfusion subgroup amd the 24-hour-after-reperfusion subgroup of the 40 mg/kg physcion group, and the 12-hour-after-reperfusion subgroup of the 20 mg/kg physcion group, IL-1β in the injured parts of the cerebella decreased dramatically, compared with MCAO model controls ( P＜ 0.01 ). In the normal control group and SO group, a small quantity of ICAM-1 was detected in rat' s cerebral cortex, and some fulvous staining substance was observed in the plasma and membrane of cerebral vascular endothelium cells. In the cerebral ischemia-reperfusion injury group, positive staining substance could be observed 24 hours after the reperfusion, then darkened gradually (integral absorbency value: 31.89 ± 4.38, area density value: 0. 018 5 ± 0. 003 1). In the 12-hour-after-reperfusion subgroup of the 40 mg/kg physcion group (integral absorbency value: 13.33 ±6. 12, area density value: 0. 007 6 ± 0. 002 2) and the 24-hour-after-reperfusion subgroup of the 40 mg/kg physcion group (integral absorbency value: 20.04 ±4.65,area density value: 0. 012 9 ±0. 003 6), and in the 24-hour-after-reperfusion subgroup of the 20 mg/kg physcion group (integral absorbency value:23.73 ±4.51 area density value: 0. 014 1 ±0. 003 8), expressions of ICAM-1 around the infarctions significantly decreased as compared with those in the MCAO model controls respectively ( P ＜ 0.01 or P ＜ 0.05).CONCLUSION: Physcion tends to decrease the expressing of IL-1β and ICAM-1 in a cerebellum after ischemia-reperfusion injury, thus, it may help alleviate the ischemia-reperfusion injury.