灯盏花素对大鼠脑缺血再灌注损伤时分泌型磷脂酶A_2的影响

Effect of breviscapine on the secretory phospholipase A_2 in rats with cerebral ischemia reperfusion injury

目的探讨灯盏花素在脑损伤时对脑细胞凋亡及分泌型磷脂酶A2(sPLA2)及其相关介质的影响。方法将雄性Wistar大鼠18只分为模型组(IR组)、灯盏花素组及假手术组各6只。用线栓法制成大脑中动脉缺血再灌注(MCA-IR)模型,用TUNEL法检测脑细胞凋亡,用免疫组织化学法检测sPLA2在脑细胞中的表达,用[3H]标记大肠杆菌膜为底物的液闪方法和ELISA法分别检测血清中sPLA2活性和肿瘤坏死因子-α(TNF-α)、前列腺素E2(PGE2)水平。结果缺血0.5h再灌注24h,IR组海马与皮质凋亡细胞数均多于假手术组和灯盏花素组(P<0.01)。缺血0.5h再灌注12h,IR组海马sPLA2阳性细胞数及皮质sPLA2细胞数多于假手术组和灯盏花素组,差异有统计学意义(P<0.01)。缺血0.5h再灌注12h,IR组TNF-α、sPLA2及PGE2水平均高于假手术组和灯盏花素组,差异均有统计学意义(P<0.05)。结论灯盏花素对MCA-IR脑损伤有良好的保护作用,其机理在于抑制sPLA2的激活、表达及其相关介质的水平。

Objective To study the effect of breviscapine on cerebral apoptosis, secretory phospholipase A2 （ sPLA2 ） and relative mediators in brain injury. Methods 18 male Wistar rats were divided into model group（IR group） ,breviscapine group and sham operation group, each of 6 rats. Made ischemic models of middle cerebral artery ischemia-reperfusion （ MCA- IR） by thread technique. Brain cell apoptosis detected by the TUNEL assay. Detected sPLA2 expression in brain cells by immu- nohistochemical method. [ 3H ] labeled E. coli membrane substrate liquid scintillation and ELISA were used to detect serum sPLA2 activity, tumor necrosis factor-or （TNF-a） and prostaglandin E2 （ PGE2 ） level. Results Reperfused 24h after ischemaed for 0. 5h, the number of apoptotic cells in the hippocampus and cortex in IR group were more than those in sham group and breviscapine group（P 〈 0.01 ）. Reperfused 12h after ischemiaed for 0.5h, the hippocampus sPLA2 positive cells and cortical sPLA2 cell number of IR group were more than those in sham group and breviscapine group, the difference was statistically significant（P〈0.01） ;The TNF-a,sPLA2 and PGE2 level of IR group were higher than those in sham group and breviscapine group, the difference were statistically significant（P 〈 0. 05）. Conclusion Breviscapine has a good protective effect on MCAIR injury of rats. The mechanism is considered to inhibit the activation and expression of sPLA2 and relative mediators level.