还原型谷胱甘肽对大鼠局灶性脑缺血再灌注后细胞间黏附分子1表达的影响

Influence of reduced glutathione on expression of intercellular adhesion molecule-1 in rats after focal cerebral ischemia reperfusion

目的:观察还原型谷胱甘肽对大鼠短暂性局灶性脑缺血再灌注后细胞间黏附分子1表达的影响。方法:实验于2005-06在兰州大学基础医学院人体解剖学教研室实验中心完成。采用线栓法制备大鼠大脑中动脉缺血2h再灌注24h模型,随机分为假手术组、缺血再灌注模型组和还原型谷胱甘肽处理组。每组15只。制模成功后观测各组大鼠的神经行为变化,脑梗死体积,行苏木精-伊红染色计数缺血区中性粒细胞浸润数目,应用免疫组化方法检测细胞间黏附分子1的表达情况。结果:实验中假手术组未见动物死亡,缺血再灌注组2只动物死亡,还原型谷胱甘肽处理组1只动物死亡。死因均为蛛网膜下腔出血所致。①还原型谷胱甘肽处理组及缺血再灌注模型组动物均有不同程度的神经功能缺损,且还原型谷胱甘肽处理组动物神经行为学评分有改善眼(2.04±0.47),(2.71±0.29),分(P<0.05)演;还原型谷胱甘肽处理组梗死体积小于缺血再灌注模型组眼(20.21±1.55),(29.57±4.40)%,P<0.05演,假手术组未见梗死灶。②脑缺血2h再灌注24h后大鼠脑血管细胞间黏附分子1表达增加。阳性反应的细胞间黏附分子1主要见于脑缺血侧梗塞区及其周围的毛细血管壁,于神经元和胶质细胞也可见。还原型谷胱甘肽处理组的表达较缺血再灌注模型组减少眼(11.29±1.11),(17.14±1.77),P<0.05演。③假手术组细胞形态正常;缺血再灌注模型模型组右侧大脑缺血范围内皮质水肿明显,神经细胞外周隙扩大,毛细血管周隙增宽,血管内血栓形成,在皮质和纹状体可见大量死亡神经元,可见筛状坏死灶,间质水肿呈松网状,有大量中性粒细胞的浸润;还原型谷胱甘肽处理组大脑皮质神经细胞层次尚清晰,未见明显坏死灶,神经细胞及毛细血管周围间隙稍大,但明显小于缺血再灌注模型组。间质水肿、中性粒细胞的浸润也轻于缺血再灌注模型组。结论:外源性谷胱甘肽可以改善大鼠局灶性脑缺血引起的神经行为障碍,减少脑梗死体积,通过减少脑缺血引起细胞间黏附分子1表达,抑制中性粒细胞的浸润,从而减轻脑缺血再灌注后的炎症反应,而发挥对脑缺血后的保护作用。

AIM： To observe the influence of reduced glutathione （GSH） on the expression of intercellular adhesion molecule-1 （ICAM-1） protein after focal cerebral ischemia repeffusion in rats. METHODS： The experiment was conducted at the Experimental Center of Department of Human Anatomy, School of Basic Medicine of Lanzhou University in June 2005. Rat models were established with filament method after 2-hour middle cerebral artery ischemia and 24-hour repeffusion, and divided at random into three groups： sham-operated group, model group and treatment group, with 15 in each group. After the model establishments, the change of neurological impairment and the volume of cerebral infarction were evaluated. The infiltration of neutrophil in ischemia areas was counted by hematoxylin-eosin staining, and the expression of ICAM-1 protein was tested by immunohistochemical meth.od. RESULTS： There were 2 rats in the model group and 1 rat in the treatment group died, because of subaraehnoid hemorrhage while no rat in the sham-operated group died. No rat was died in the control group. ①The rats in the model group and the treatment group were all found the neurologie impairment of different levels, moreover the scores, of neurdogical behavior in rats in the treatment group were improved [（204±0.47）, （2.71±0.29）,P 〈 0.05]; The infarcted volume of rats in treatment group was smaller than that of model group [（20.21±1.55）,（29.57±4.40）, P 〈 0.05]. No infarction was found in the sham-operated group. ②The expression of ICAM-1 in rats increased after 2-hour cerebral ischemia and 24-hour reperfusion. ICAM-1 expressed positively in the infarcted region and vessel wall of blood capillary around the region, and also found in the neurons and glial cells.And the expression was lower in the treatment group than in the model group [（11.29±1.11）,（17.14±1.77）,P 〈 0.05].③The cells in the sham-operated group were formed normally. In the model group, the cortex located the ischemia region of right brain were edematous significantly, the circumference spaces of nerve cells enlarged, and the perivascular space of blood capillary broadened. There were thrombosis in vessels and mass death neurons in cortex and striatum, moreover a lot of neutrophil infiltrations were observed in infarcted region, In the treatment group, the stratifications of nerve cells of brain cortex were clear and there were no remarkable necrosis found. The enlargement of interspaces surrounding neurons and blood capillary was obviously smaller compared with the model group, Interstitial edema and the infiltration of neutrophil were lighter than those of the model group, CONCLUSION： GSH can improve the neurological impairment, decrease the infarcted volume, and reduce the expressions of ICAM-1, restrain the infiltration of neutrophil so as to relieve the inflammatory reaction and play an neuroprotective effect after focal cerebral ischemia reperfusion in rats.