【作者】 王景叶；

【导师】 于榕； 姚明辉； 鲁映青；

【作者基本信息】 复旦大学 ， 药理学， 2009， 硕士

【摘要】 随着对急性脑缺血再灌注和缺氧复氧损伤研究的进展,人们对脑梗塞的病理生理机制有了新的认识。大量研究已证实急性缺血后恢复血液灌流,会加剧病变而发生再灌注损伤。目前从脂质过氧化损伤、细胞凋亡等角度研究缺血再灌注损伤较为广泛。红景天是蔷薇目景天科(Crassulaceae)红景天属(Rhodiola)植物,其主要药理学有效成分是红景天苷。近代药理学研究表明,红景天苷具有广泛的药理作用,包括心肌缺血再灌注损伤、增强记忆、改善脑血管系统功能、抗缺氧等,但对神经系统尤其是整体动物脑组织缺血再灌注损伤的研究尚不多见。本实验采用线栓法制备大鼠大脑中动脉缺血再灌注模型,经颈静脉给予红景天苷,模拟临床上脑缺血病例多发生在大脑中动脉,且治疗手段以立刻经静脉途径急性给药,研究红景天苷对大鼠脑缺血再灌注损伤后脑组织内源性自由基清除物质及凋亡相关蛋白表达的影响,探讨红景天苷对神经细胞损伤的作用及其机制。第一部分红景天苷对大鼠脑缺血再灌注损伤的治疗作用目的观察红景天苷对大鼠脑缺血再灌注损伤的作用。方法用线栓法制备SD大鼠大脑中动脉缺血再灌注模型(MCAO-I/R)。在缺血和再灌注即刻分别给予红景天苷(2.5、5、10 mg／kg)进行保护。脑缺血1.5 h再灌注24 h后按照Zea-Longa标准对各组大鼠进行神经功能评分；TTC染色法测定大鼠脑梗死面积。结果与模型组相比,红景天苷中、大剂量能显著改善MCAO-I/R大鼠的神经功能损伤、减小脑梗死面积。结论红景天苷对大鼠脑缺血再灌注损伤有保护作用。第二部分红景天苷对大鼠脑缺血再灌注损伤保护作用的机制研究目的探讨红景天苷对脑缺血再灌注大鼠脑组织氧化损伤和凋亡调节蛋白表达的影响。方法将大鼠分为假手术组、模型组、红景天苷5 mg/kg给药组。比色法测定大鼠缺血侧皮层和海马内谷胱甘肽过氧化物酶(GSH—PX)和诱导型一氧化氮合酶(iNOS)的活性；Western blot法检测大鼠缺血侧皮层和海马Bcl-2和Bax两种蛋白的表达水平。结果与模型组相比,红景天苷能显著提高缺血侧皮层和海马内GSH-PX活性、降低iNOS活性、增加Bcl-2表达、减少Bax表达。结论红景天苷可通过增加自由基清除、调节凋亡相关蛋白表达来减轻MCAO-I/R造成的大鼠脑组织损伤。更多还原

【Abstract】 As the advancement of the mechanism about cerebral ischemia-reperfusion injury,new physiopathologic mechanism has been recognized. A lot of investigations have been confirmed that reperfusion after acute focal cerebral ischemia can aggravate the injury.At present, the most extensively and deeply studied aspects are free radicle injury and the expression of the protein associated with apoptosis. Recently, salidroside which is the main effective ingredient of integripetal rhodiola herb has been reported possessing extensive pharmacological actions.The main effects of salidroside are enhancing memory, protecting cardiovascular system, enhancing immunity, resisting hypoxia and so on. More studies have been focused on the protective effect of salidroside against cardiovascular disease,however,the neuroprotective effect of salidroside especially in vivo was less studied.The purposes of the present study were to evaluate the effects of salidroside on free radical scavenger and the protein expression associated with apoptosis in MCAO rats.PartⅠOBJECTIVE To investigate the effects of salidroside on cerebral ischemia-reperfusion injury in middle cerebral artery occlusive (MCAO) rats.METHODS Focal cerebral ischemia in rats was produced by 1.5 h occlusion of the middle cerebral artery and 24 h reperfusion. Salidroside (2.5、5、10 mg·kg-1) was administered intravenously immediately after occlusion and reperfusion respectively. The neurologic deficit score was investigated according to Zea-Longa’s Standard. The infarct area was assessed with software Image pro Plus 6.0 after TTC stainingRESULTS Compared with the model group,salidroside (5、10 mg/kg) can significantly decrease the neurologic deficit score and reduce the infarct area of the brain in MCAO-I/R rats. CONCLUSION Salidroside could protect MCAO rats from cerebral ischemia-reperfusion injury.PartⅡOBJECTIVE To explore the effects of salidroside on activities of GSH-PX and iNOS as well as the expression of apoptosis related protein in MCAO-I/R rats.METHODS SD rats were randomly divided into sham group, model group and salidroside 5mg/kg group.The activities of inducible nitric oxide synthase (iNOS) and glutathione peroxidase (GSH-PX) were estimated with kit produced by Nanjing Jiancheng Bioengineering Institute. The levels of B cell lymphoma/lewkmia-2 (Bcl-2) and Bcl-2 assaciated X protein (Bax) in central neutral system were measured by western blot. RESULTS Salidroside could significantly increase the activity of GSH-PX and decrease the activity of iNOS,enhance the expression of Bcl-2 and inhibit the expression of Bax. CONCLUSION Salidroside has a protective effect on cerebral ischemia-reperfusion injury and this effect is related to attenuating lipid peroxidation, enhancing the expression of Bcl-2 and diminishing Bax expression.更多还原