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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 inhibitory effect of 15-hydroxyeicosatetraenoic acid (15-LOX) inhibitor nordihydroguaiaretic acid (NDGA) , 15-HETE) were used to detect the expression of phosphorylated extracellular signal-regulated kinase (p-ERK1 / 2) in rat brain during ischemia-reperfusion injury and to explore the role of p-ERK1 / 2 in the role of 15-HETE involved in cerebral ischemia-reperfusion injury and its expression changes. Methods: The middle cerebral artery occlusion (MCAO) was used to make a rat model of cerebral ischemia 2 hours reperfusion. The rats were randomly divided into three groups: sham operation group (sham group), DMSO control group, NDGA treatment group. The latter two groups were divided into three subgroups according to different perfusion time: reperfusion 1 hour group, reperfusion 6 hours group, reperfusion 24 hours group. TTC staining was used to detect the volume of cerebral infarction in rats 24 hours after reperfusion. The expression of p-ERK1 / 2 in the infarcted area and the infarcted area was measured by Western blotting at different time points after infarction. Results: There was only a small amount of p-ERK1 / 2 expression in sham operation group. The expression of p-ERK1 / 2 in the infarcted core of DMSO group increased gradually from 1 hour after IRI (1.43 ± 0.06), reached the peak at 6 hours (2.02 ± 0.14) and decreased at 24 hours (1.16 ± 0.21 ), Compared with the sham operation group (0.62 ± 0.08), the P values were all less than 0.01; p-ERK1 / 2 in the peri-infarct area showed the same trend. Compared with the DMSO control group, the volume of cerebral infarction in NDGA-treated group was significantly decreased (20.10 ± 0.12% vs 17.24 ± 0.16%, P = 0.009, P <0.05), and the expression of p-ERK1 / 2 was decreased at all time points. Compared with the infarct core area, p-ERK1 / 2 (1.16 ± 0.21 vs 1.86 ± 0.14) was still detected in the surrounding infarct area 24 hours after infarction, but the infarct core area was relatively low. CONCLUSION: The expression of p-ERK1 / 2 increases after cerebral ischemia-reperfusion injury, indicating that p-ERK1 / 2 is involved. The expression of p-ERK1 / 2 decreases and the volume of cerebral infarction decreases after NDGA. ERK1 / 2 is involved in 15-HETE-mediated cerebral ischemia-reperfusion injury and may be involved in cell apoptosis in this process.