两侧大脑缺血-再灌流综合征的大白鼠新模型

A NEW MODEL OF CEREBRAL ISCHEMIA-REPERFUSION SYNDROME IN RAT

本文使用健康、雄性Wistar大鼠,在直视下结扎左右锁骨下动脉和颈总动脉,持续结扎时间分别为5、10、20和30min,然后解除两侧颈总动脉结扎使脑血管再通。在实验过程中动态观察脑电图、心电图和眩孔颜色的变化,实验结束后检查血管结扎是否准确,并从升主动脉注射伊文思蓝观察染料在脑内的分布,灌注固定后取脑进行形态学检查。结果发现全部动物血管结扎部位准确,注射染料证实,使用本方法造成的脑缺血和再灌流效果可靠。在血管结扎后的几秒钟到十几秒钟内全部动物的脑电图完全抑制,并在持续结扎的5、10、20和30min内持续不变;结扎5和10min后再灌组,脑电图有不同程度的恢复;结扎20和30min后再灌组,在观察的2h内,未见脑电图恢复。光镜检查:缺血5和10min后,未见明显形态学变化;缺血20和30min后,有轻到中度神经细胞变性;再灌后上述变化明显加重,并伴有显著水肿。

A new model of cerebral ischemia-reperfusion syndrome in rat is described. In the present study, transient ischemia was induced by bilateral common carotid arteries and subclavian arteries ligation for 5, 10, 20 and 30 minuies respectively, and followed by 2 hours of reperfusion by release of bilateral common carotid arteries. The electroencephalographic activity and electrocarogram were measured at regular intervals. Pupillary colour was observed. Evan's blue was injected into the ascending aorta to demonstrate the condition ofblood perfusion into the brain tissue. The histological alterations were observed. The results indicate that a new model of cerebral ischemia-reperfusion in Wistar rat can be successfully established by 4-vessels occlusion of bilateral common carotid arteries and subclavian arteries and by 2-vessels release of bilateral common carotid arteries. A dominant advatage of this method is that no need to incise chest wall is required. A longitudinal incision on the neck was made only. Then isolation and ligation of 4-vessels might be performed directly. Evan's blue injection and direct observation demonstrated that ische-mia and reperfusion were successful. The electroencephalographic acti-vity was suppressed severely during a few seconds after 4-vessels occlusion, recovered differently in the animals of reperfusion after 5 and 10 minutes occlusion, and not recovered in the animals of reperfusion after 20 and 30 minutes occlusion. Mild and moderate ische-mic tissue damage in the hippocampus, stratum and cortex were morphologically, demonstrated in the animals of 20-30 minutes occlusion and were aggravated on reperfusion.