关键词: 大脑中动脉闭塞; 脑缺血再灌注; 不对称性; 大鼠

Abstract:

Objective To investigate the effect of different side middle cerebral artery occlusion (MCAO) model at different time point on the infarct volume and neurological function in the rats by application of Zea-longa method. Methods Middle cerebral artery occlusion (MCAO) was induced in rats by filament insertion for 1.5 h according to Zea-Longa method. A total of 36 Sprague-Dawley rats were randomly divided into left MCAO and right MCAO groups. Behavior scores, trapezoid balance bar experiment and Morris water maze experiment were all carried out to evaluate the recovery of neural function and infarct volume of the brains were measured at the 1st, 3rd, 7th day after operation respectively. Results Compared with the right MCAO group, the motor function, balancing function of the left MCAO group all decreased at the 1st, 3rd, 7th day after cerebral ischemia-reperfusion, however, memory function was obviously higher than that of right MCAO group, especially at 7th day after I/R. Total infarction volume was the largest at 3rd day after I/R, and smallest at 7th in the two groups. There was no significant difference in infarct volume of the two groups at the 1st and 3rd day after I/R. But at 7th day, infarct volume in left MCAO group was significantly larger than that in the right MCAO group. Conclusion Whether the left or the right MCAO model does not much affect the infarct volume at early stage. However, the infarct volume of left MCAO was larger than that of right MCAO at later stage. More serious movement is caused in the left MCAO group and more serious memory impairments is caused in the right MCAO group. These findings suggest there may be structural and functional asymmetry in hemispheres of rat, which affects the outcome of the focal cerebral ischemia.

Key words: Middle cerebral artery occlusion (MCAO); Cerebral ischemia reperfusion; Asymmetry; Rats