【作者】 谢晓丽；

【导师】 王守彪；

【作者基本信息】 青岛大学 ， 人体解剖及组织胚胎学， 2012， 硕士

【摘要】 目的：研究胡黄连营Ⅱ(Picroside Ⅱ)对大鼠脑缺血损伤后神经细胞凋亡以及细胞色素C(CytC)和卡配因(Calpain)基因表达的影响,探讨其治疗脑缺血的作用机制。方法：大鼠大脑中动脉阻塞(MCAO)再灌注模型应用线栓法建立,缺血2h经腹腔注射Picroside Ⅱ注射液(10mg／kg)干预治疗,Bederson评分评价大鼠脑缺血2h再灌注2h、6h、12h、24h、2d、3d、7d和14d时间点神经行为功能的变化,原位末端标记(TUNEL)方法观察细胞凋亡,原位杂交技术观察CytC mRNA和Calpain mRNA的表达。结果：(1)脑缺血再灌流后3d开始,大鼠神经行为功能逐渐恢复,治疗组与对照组比较,再灌注7-14d有显著性差异。(2)脑缺血再灌注后2h,皮层和纹状体区即出现凋亡神经细胞,随时间延长逐渐增多,分别于1d和2d达到高峰,之后逐渐减少,再灌注14d接近假手术组水平。经Picrosidell治疗后,细胞凋亡数量明显减少,其中再灌注12-7d与对照组比较差异显著。(3)CytC mRNA表达于脑缺血再灌注后2h逐渐出现,皮层区12h达高峰,纹状体区1d达高峰,以后逐渐下降,7d、14d明显减少,但仍显著高于假手术组。再灌流12h及以后时间点,Picroside Ⅱ治疗组CytC mRNA在皮层和纹状体区的表达均显著低于对照组。(4)皮层区和纹状体区Calpain mRNA表达于脑缺血再灌注后2h逐渐出现,再灌注6h明显增加,皮层区12h达高峰；纹状体区1d达高峰,以后逐渐降低。Picroside Ⅱ治疗组再灌注12h及以后时间点,Calpain mRNA在皮层区和纹状体区的表达较对照组有显著降低。结论：脑缺血损伤后CytC和Calpain基因表达的时序和区域一致,并先于凋亡细胞而出现,提示CytC和Calpain表达可能是细胞凋亡发生的关键环节。Picroside可下调CytC和Calpain基因表达,提示其具有神经保护作用。更多还原

【Abstract】 Objective:To investigate the effects of picroside Ⅱ on neuronal apoptosis and gene expressions of cytochrome c (CytC) and calpain in neurons after cerebral ischemia in rats, and to explore the neuroprotective mechanisms of picroside Ⅱ.Methods:The model of focal ischemia in Wistar rats was induced by intraluminal middle cerebral artery occlusion (MCAO) with a nylon monofilament suture. Picroside Ⅱ (10mg/kg) was injected intraperitoneally2hours after cerebral ischemia. The neurological function scores were determined by Bederson’s method. Apoptosis was characterized by terminal deoxynucleotidyl transferase-mediated uridine5’-triphosphate-biotin nick end-labeling (TUNEL) staining. In situ hybridization was performed to examine the expressions of Cyt C and calpain mRNA in cortex and striatum.Results:(1) The neurological behavioral function recovered gradually from reperfusion3d, and significantly at7-14d compared with sham group.(2) TUNEL-positive cells were observed2h after reperfusion in and peaked at1and2d afte reperfusion in cortex and striatum respectively. Picroside Ⅱ decreased the number of TUNEL-positive cells at and after12h after reperfusion.(3) The expressions of CytC and calpain mRNA were weakly in shame-operated group and were detected in cortex and striatum of ischemic hemisphere as early as2h after reperfusion and reached a peak at12h in cortex and1d in striatum respectively. Picroside treatment diminished the CytC and calpain mRNA expressions at and after reperfusion12h.Conclusions:These results indicate that picroside II might promote neurological function recovery by means of inhibiting ischemic neuronal apoptosis and by inhibiting gene expression of CytC and calpain. It may be a potential compound in treating stroke.更多还原