ESTABLISHMENT AND EVALUATION OF AN EXPERIMENTAL ISCHEMIC TOLERANCE MODEL

Objective To establish a rat model of ischemic tolerance and study its significance. Methods Eighty-four healthy wistar rats were randomly divided into three groups: ① Ischemic preconditioning and MCAO group (IP+MCAO), the rats were given 10 minutes’ focal ischemic preconditioning, and 1,3,7,14, and 21 days later, 2-hour cerebral artery occlusion was done followed by 22-hour reperfusion. The rats were sacrificed immediately after reperfusion. ② Sham and middle cerebral artery occlusion group (SS+MCAO), sham operation replaced ischemic preconditioning, all the rest was the same as the first group. ③ Sham surgery group (SS+SS), two times of sham operation were performed on rats. The model was evaluated by neurological function scoring, cerebral infarction volume measurement, and pathological study. Results The neurological function scores at day 4 and day 7 of IP+MCAO group were significantly lower compared with that of the SS+MCAO groups (t=4.025,2.683;P0.05). The cerebral infarct volume at day 1, 3 and 7 of IP+MCAO group was significantly smaller compared with that of the SS+MCAO group (t=8.940-10.554,P0.05). Conclusion Suturing occlusion method is a practicable technique for the establishment of ischemic tolerance model.