Abstract: Objective: To establish a reliable model of focal cerebral ischemia injury in diabetic rats, and to explore the criteria for successful modeling. Methods: Forty healthy male SD rats were randomly divided into three groups: a normal sham-operation group, a normal cerebral ischemia-reperfusion injury group and a group of diabetes combined with cerebral ischemia-reperfusion injury. Type I diabetes was induced by an intraperitoneal injection of streptozotocin (STZ, 60 mg·kg^-1). The body mass and the level of fasting blood glucose in each group were measured on Weeks 1 and 4 after STZ injection. A focal cerebral ischemia-reperfusion model was prepared by a thread occlusion method four weeks after STZ treatment. The scores of neurological function were assessed and the percentage of infarct volume were calculated after 30 min ischemia followed by 24 h of reperfusion. Results: The body mass (P<0.001) was reduced and the fasting blood glucose (P<0.001) was increased significantly in diabetic rats than those in normal rats four weeks after STZ injection. The percentage of infarct volume (P<0.001) was increased more significantly and the brain injury appeared more severe in diabetic rats than in normal rats after reperfusion. The success rate of this model was 73%. Conclusion: In this study, we developed a model of focal cerebral ischemia injury in diabetic rats that demonstrates a high success rate and good reliability and stability.

Key words: cerebral ischemia, diabetes mellitus, streptozotocin, rats, animal model