改良四血管阻塞法建立大鼠全脑缺血模型

Modifying the four-vessel occlusion method to establish the global brain ischemic model of rat

目的 对四血管阻塞法(4- VO)建立大鼠全脑缺血模型进行改良,以提高模型的可靠性。方法 以微型磨钻,扩大第一颈椎上之翼孔,充分暴露其中穿行的椎动脉,显微镜直视下电凝阻断;夹闭双侧颈总动脉以出现静息脑电波为判定大鼠已达全脑缺血的标准对4 VO法建立大鼠全脑缺血模型进行改良。全脑缺血15min后行再灌注, 7d后以海马CA1区神经元出现大部分死亡作为判定模型成功的标准,对两种建模方法进行评定。结果 4- VO法制作大鼠全脑缺血再灌注模型,大鼠存活7d的存活率为90% ( 27 /30 ),改良4 VO法制作大鼠全脑缺血再灌注模型,大鼠存活率为86. 7%(26 /30),二者无明显差异(P>0. 05); 4 VO法制作大鼠全脑缺血再灌注模型其成功率仅为70% (21 /30),改良4 VO法制作大鼠全脑缺血再灌注模型,成功率为86. 7% (26 /30),明显高于4 VO法。结论改良4-

Objective To modify the four-vessel occlusion rat model to improve its reliability.Methods The four-vessel occlusion rat model was modified by enlarging the alar foramina of the first cervical vertebra through which the vertebral arteries travelled with the micro-grinding drill in order to visualize the vertebral arteries sufficiently and then to electrocauterize the vertebral arteries under the microscope. An isoelectric electroencephalogram (EEG) pattern which occurred following bilateral carotid artery clamping was adopted as the standard for judging whether the rat got the global brain ischemic state. The brain of rat was reperfused after 15 minutes of global brain ischemia. The four-vessel occlusion and the modified four-vessel occlusion modeling methods were assessed with the standard that the most neurons in CA1 region of hippocampus died 7 days following global brain ischemia.Results The livability of rat in the four-vessel occlusion rat model group was 90%(27/30), while the livability of rat in modified four-vessel occlusion rat model group was 86.7%(26/30), but there was no obvious difference between two groups. The achievement ratio of the modified four-vessel occlusion rat model was 86.7%(26/30) , much higher than that of the four-vessel occlusion rat model which was only 70%(21/30).Conclusion The modified four-vessel occlusion to establish the rat global brain ischemic model can improve the reliability and the achievement ratio of the model.