中文摘要：

目的：观察外源性精胺对急性脑缺血-再灌注损伤大鼠的作用,并初步探讨其可能机制。方法：采用线栓法复制大鼠大脑中动脉缺血（2 h）-再灌注（2 h）模型。SD大鼠随机分为5组：假手术组、模型组和低、中、高剂量精胺组。检测指标有神经病学评分、脑梗死面积、皮层脑组织HE染色、电镜超微结构观察、超氧化物歧化酶活性（SOD）及丙二醛（MDA）含量。结果：与模型组相比,不同浓度精胺均能降低大鼠急性脑缺血-再灌注后神经功能学评分、梗死面积、缺血脑组织MDA含量,减轻脑组织形态学和超微结构损伤,增加缺血区SOD活性。结论：外源性精胺对大鼠局灶性急性脑缺血-再灌注损伤有保护作用,其机制可能与清除氧自由基有关。

英文摘要：

AIM： To study the effects and the possible mechanisms of exogenous spermine on the rats with acute transient focal cerebral ischemia/reperfusion（I/R） injury.METHODS： The rat model of focal cerebral ischemia/reperfusion was established by middle cerebral artery occlusion（2 h） and reperfusion（2 h）.Healthy adult SD rats were divided into 5 groups;sham group,I/R group and spermine（4,20 and 40 mmol/L）groups.The degree of cerebral injury was evaluated by neurological deficit score,infracted volume,superoxide dismutase（SOD） activity and malondialdehyde（MDA） content.The morphological changes of the brain were observed by HE staining and electron microscopy.RESULTS： Compared with I/R group,the neurological deficit score,infracted volume and the content of MDA were decreased,the SOD activity was increased and the ultrastructural changes were improved in spermine-treated groups.CONCLUSION： Exogenous spermine has a protective effect against acute focal cerebral ischemia/reperfusion injury.The mechanisms may be related to scavenging free radical by spermine.