COX-2在全脑缺血再灌注大鼠皮层时程表达变化  

Time-dependent expression of COX-2 mRNA and protein in rat cortex after global cerebral ischemia reperfusion insult

作　　者：杨彬[1] 余丽娟[1] 王佳[1] 赵磊[1] 胡馨月[1] 纪超男[1] 魏玉玲[1] 阳群芳[1] 蒋青松[1] 杨俊卿[1] 

机构地区：[1]重庆医科大学药理学教研室,重庆市生物化学与分子药理学重点实验室,重庆400016

出　　处：《第三军医大学学报》2014年第2期135-139,共5页Journal of Third Military Medical University

基　　金：国家自然科学基金(81100905)~~

摘　　要：目的观察COX-2 mRNA与蛋白在全脑缺血再灌注大鼠皮层的时程表达变化特征。方法采用夹闭双侧颈总动脉合并低血压的方法建立大鼠全脑缺血再灌注脑损伤模型;水迷宫检测大鼠空间学习记忆能力;HE染色观察大鼠皮层神经元形态结构改变;黄嘌呤氧化酶法、TBA法分别测定大鼠皮层中SOD活性和MDA含量变化;RT-PCR及Western blot分别检测大鼠皮层COX-2 mRNA与蛋白表达情况。结果与假手术组比较,缺血再灌注组大鼠寻台潜伏期显著增加,寻台次数显著减少(P<0.05),通过目标象限百分比明显减少(P<0.01);皮层神经元出现严重核固缩,细胞层次紊乱;SOD活性随再灌注时间延长而降低,在7 d时达最低(P<0.01),MDA含量随再灌注时间延长而增加,在7 d时达峰值(P<0.01);COX-2 mRNA及蛋白表达明显增加,mRNA再灌注后48 h达峰值(P<0.05),蛋白再灌注后7 d达峰值(P<0.01),15 d时均仍高于假手术组(P<0.05)。结论全脑缺血再灌注诱导大鼠皮层COX-2表达明显增加,并具有时间依赖性。Objective To study the time course of COX-2 mRNA and protein expression in rat cortex after global cerebral ischemia reperfusion insult. Methods The rat model of global cerebral ischemia reperfu- sion was established by bilateral common carotid arteries occlusion and systemic hypotension. Morris water maze was used to investigate spatial learning and memory was employed to examine the morphologic changes function of the rats. Histological examination by HE staining of rat cortex neurons. The SOD activity and MDA content in rat cortex were evaluated by xanthinoxidase assay and TBA assay respectively. Expression of COX-2 mRNA and protein in the cortex was examined by reverse-transcription polymerase chain reaction （RT-PCR） and Western blotting, respectively. Results Compared with the sham group, all global cerebral ischemia rats showed significantly longer incubation period of seeking the platform, significantly less frequent cross-platform movement （P 〈0. 05 ） and shorter dwelling times in the platform quadrant （P 〈 0. 01 ）. Cortex neurons in the model group showed obvious karyopycnosis with remarkable cell loss and irregular cell contours. The SOD activity was obviously decreased and the MDA content was significantly increased in the global cerebral ischemia reperfusion group. The COX-2 mRNA and protein expression in rat cortex was remarkably increased in global cerebral ischemia reperfusion group. The COX-2 mRNA level reached the peak at 48 h （P 〈 0. 05 ） after reperfusion and the protein reached the peak at 7 d （P 〈 0. 01 ） after reperfusion. Conclusion Global cerebralischemia reperfusion insults significantly increase the expression of COX-2 in rat cortex in a time-dependent manner.

关 键 词：全脑缺血再灌注 环氧化酶2 皮层 氧化应激 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学] R363.21[医药卫生—基础医学]