摘要
目的:通过应用15-脂氧化酶(15-Lipoxygenase,15-LOX)抑制剂去甲二氢愈创木酸(nordihydroguaiaretic acid,NDGA)抑制15-羟基-二十碳四烯酸(15-hydroxyeicosatetraenoic acid,15-HETE)的生成,观察缺血再灌注损伤中大鼠脑组织磷酸化细胞外信号调节酶(phosphor-extracellular signal-regulated kinase,p-ERK1/2)表达的变化,探讨p-ERK1/2在15-HETE参与的脑缺血再灌注损伤中的作用及其表达变化。方法:应用大脑中动脉线栓栓塞法(MCAO)制作大鼠脑梗死2小时再灌注模型。将大鼠随机分为三组:假手术组(sham组)、DMSO对照组、NDGA处理组。后两组再根据不同的灌注时间分为三个亚组:再灌注1小时组、再灌注6小时组、再灌注24小时组。采用TTC染色法检测再灌注24小时大鼠脑梗死体积;免疫印迹(Western blot)法测定梗死后再灌注不同时间点梗死核心区和梗死周围区的p-ERK1/2的表达。结果:假手术组仅有少量p-ERK1/2的表达。DMSO对照组梗死核心区p-ERK1/2的表达从梗死再灌注后1小时即开始逐渐升高(1.43±0.06),6小时达高峰(2.02±0.14),24小时有所下降(1.16±0.21),与假手术组(0.62±0.08)比较P值均<0.01;梗死周围区p-ERK1/2表现出相同的变化趋势。与DMSO对照组比较,NDGA处理组大鼠脑梗死体积显著减小(20.10±0.12%vs 17.24±0.16%,P=0.009,P<0.05),各时间点p-ERK1/2的表达均下降。与梗死核心区相比较,梗死周围区24小时仍可检测到较高含量的p-ERK1/2(1.16±0.21 vs 1.86±0.14),但梗死核心区表达相对较少。结论:脑缺血再灌注损伤中,p-ERK1/2的表达增加,说明p-ERK1/2参与其中;应用NDGA后,p-ERK1/2的表达降低,脑梗死体积减小,证实p-ERK1/2参与了15-HETE介导的脑缺血再灌注损伤,并在此过程中可能参与了细胞的凋亡。
Objective： To investigate the expression of phosphor-extracellular signal-regulated kinase p-ERK1/2 in the rats of 15-HETE-invovled cerebral ischemia reperfusion （IR） by using NDGA, an inhibitor of 15-LOX and its role. Methods： The rats models of middle cerebral artery occlusion （MCAO） were established and reperfused with introducing a nylon suture to the right internal carotid artery. The rats were randomly divided into three groups： the sham operation group, the ischemia-reperfusion group and NDGA group. According to different time points after IR, the animals were designated as subgroups lh, 6h and 24h.The cerebral infarction volume was measured by TTC staining. The content ofp-ERK1/2 detected by Western blot analyses. Results： A few ofp-ERK1/2 were expressed in the sham group. Compared with the sham group, the expressions of the p-ERK1/2 in the DMSO group began to increase at 1 h after reperfusion, reach a peak at 6 h, and descend at 24 h. Compared with the DMSO group, the cerebral infarction volume was significantly reduced and the contents of the p-ERK1/2 were decreased in each time group. The contents of p-ERK1/2 at 24h in the infarction core area were higher than that of the ischemic penumbra. Conclusion： The expressions of the p-ERK1/2 increased on the rats of cerebral ischemia reperfusion and decreased by the inhibitor NDGA through the 15-HETE pathway, which suggested that p-ERK1/2 might be involved in the cerebral ischemia reperfusion injury, and p-ERK1/2 in this pathway might be also involved in apoptosis.
出处
《现代生物医学进展》
CAS
2014年第35期6855-6858,6873,共5页
Progress in Modern Biomedicine
基金
国家自然科学基金项目(81171077)
