黄芩素甙对脑缺血沙土鼠海马CA1区微管运动蛋白Kinesin活性的影响(英文)

Influence of erigeron breviscapus on the activity of microtubule based motor protein-Kinesin in gerbil hippocampal CA1 region following cerebral ischemic injury

背景:脑缺血-再灌注损伤与 Kinesin 活性密切相关,研究认为微管运动蛋白 Kinesin 活性下降是脑缺血后神经细胞死亡的早期标志。黄芩素甙可以防止脑缺血-再灌注诱发的蛋白激酶 C 的激活、减轻钙超载,且可减小缺血梗死灶的体积,从而减轻脑缺血-再灌注损伤。但是黄芩素甙脑保护作用是否与 Kinesin 活性有关,目前很少报道。目的:观察黄芩素甙对脑缺血-再灌注期间海马锥体细胞微管运动蛋白Kinesin 活性的变化。设计:随机对照实验。单位:济宁医学院附属医院麻醉科及徐州医学院附属医院江苏省麻醉学重点实验室。材料:实验于 1999-02/08在江苏省麻醉学重点实验室完成。选用雄性沙土鼠 35只。方法:将沙土鼠随机分成假手术组(5只)、缺血再灌注对照组(15只)和黄芩素甙组(15只)3组,根据再灌注时间将缺血再灌注对照组和黄芩素甙组分为 3个亚组,即再灌注Ⅰ组(再灌注 6h)、再灌注Ⅱ组(再灌注 48h)和再灌注Ⅲ组(再灌注 96h)。每亚组 5只动物。缺血再灌注对照组和黄芩素甙组制备沙土鼠前脑缺血-再灌注损伤模型,脑缺血时间为 10m in。假手术组仅游离双侧颈总动脉但不予阻断。黄芩素甙组于缺血前 15m in 给予灯盏花素(其有效成分为黄芩素甙)45m g/kg腹腔注射,假手术组和缺血再灌注对照组则给予等量的生理盐水灌胃。应用免疫组织化学染色方法结合计算机图象分析技术测定海马微管运动蛋白 Kinesin 的活性。主要观察指标:各组动物 Kinesin 的活性及其变化。结果:纳入实验的动物为 35只,均进入结果分析,无实验动物脱失。在海马 CA1区,缺血再灌注对照组缺血-再灌注 6,48和 96h 时微管运动蛋白 Kinesin 活性分别降至假手术组的 58%,38%和 12%(P 均<0.01),而黄芩素甙组在再灌注 6,48和 96h 后,微管运动蛋白 Kinesin 活性分别为假手术组的 81%,61%和 21%,均明显高于缺血再灌注对照组(P均<0.05)。在海马 CA2,CA3和 CA4区,微管运动蛋白 Kinesin 的活性无明显变化。结论:黄芩素甙可通过抑制脑缺血-再灌注期间海马 CA1区微管运动蛋白 Kinesin 活性的下降达到脑保护作用。

BACKGROUND： Brain ischemia-reperfusion （IR） injury is closely con- nected with the activity of Kinesin. Previous research believes that reduced activity of Kinesin, a mierotubule based motor protein, is an early mark for nerve cell death induced by brain ischemia. Erigeron breviscapus cain prevent brain IR-induced proteinase C activation, reduce calcium overload, and reduce ischeraic infarctional volume, thus attenuating brain IR injury. However, it still remains less reported at present whether the neuroprotectire role of erigeron breviseapus is related to Kinesin activity. OBJECTIVE： To observe the effect of erigeron breviscapus on the activity of Kinesin, a microtubule based motor protein, in hippoeampal pyramidal cells during brain IR. DESIGN： Randomized controlled study. SETTING： Anesthesia Department, Affiliated Hospital of Jining Medical College; Anesthesiology Key Laboratory, Affiliated Hospital of Xuzhou Medical College. MATERIALS： This experiment was carried out in the Anesthesiology Key Laboratory, the Affiliated Hospital of Xuzhou Medical College, between February and August 1999. Totally 35 male gerbils were included. METHODS： Gerbils were randomized into sham-operation group （n=5）, isehemia-reperfusion control group （n=15） and erigeron breviscapus group （n=15）, the latter two of which were further divided into three subgroups according to repeffusion time, namely reperfnsion group Ⅰ （repeffusion of 6 hours）, reperfusion group Ⅱ （repeffusion of 48 hours） and reperfusion group Ⅱ （reperfusion of 96 hours） with 5 in each subgroup. Gerbils in IR group and erigeron breviscapus group were subjected to IR model preparation before experiment by brain arterial occlusion for 10 minutes, while gerbils in sham-operation group had only bilateral common carotid artery isolated without occlusion, Gerbils in erigeron breviscapus group were pretreated 15 minutes before ischemic inducement with intraperitoneal injection of breviscapine （its effective component is erigeron breviscapus） at a dosage of 45 mg/kg, which was replaced with the same volume of isometric normal saline in sham-operation group and IR group. IHC staining was used to detect hippocampus microtubule based motor protein-Kinesin activity with the assistance of computer imaging analysis technology. MAIN OUTCOME MEASURES： Activity and changes of Kinesin of animals in each group. RESULTS： Totally 35 animals were enrolled in this experiment and all entered the result analysis with no one lost during the experiment. In hippocampal CA1 region, Kinesin activity in IR group was found to descend to 58%, 38% and 12% respectively of that in sham-operation group at IR 6 hours, 48 and 96 hours （P 〈 0.01）. In erigeron breviscapus group at IR 6 hours, 48 hours and 96 hours it was 81%, 61% and 21% of that in shamoperation group, and was obviously higher than that in IR control group （P 〈 0.05）. However, the changes of Kinesin activity were not obviously different in hippoeampal CA2, CA3 and CA4 regions. CONCLUSION： Erigeron breviscapus can exert brain-protecting function by reducing hippocampal CA1 Kinesin activity during brain IR injury.