目的 研究注射用脑蛋白水解物（Ι）对血管性痴呆大鼠的保护作用。方法 采用改良两血管阻断法制备血管性痴呆（VaD）大鼠模型，假手术组分离颈总动脉后缝合切口。模型大鼠随机分为模型组，脑蛋白水解物注射液（Cerebrolysin，阳性药，10 mg/kg）组，注射用脑蛋白水解物（Ι）高、中、低剂量（20、10、5 mg/kg）组，尾iv给药，每天1次，连续给药2周；假手术组给予等体积生理盐水。采用Y迷宫和避暗实验法评价大鼠学习记忆能力；ELISA法检测VaD大鼠血清中胰岛素样生长因子1（IGF-1）水平。结果 与模型组比较，注射用脑蛋白水解物（Ι）显著增加VaD大鼠在Y迷宫实验的正确次数，显著降低在避暗实验的潜伏期时间，并显著提高VaD大鼠血清IGF-1水平；上述作用与同剂量Cerebrolysin比较无显著差异。结论 注射用脑蛋白水解物（Ι）能提高VaD大鼠学习记忆能力，其机制可能与提高机体IGF-1水平，促进脑损伤后的神经元修复和生长有关。

Objective To investigate the protective effects of Cerebroprotein Hydrolysate for injection (Ι) on vascular dementia (VaD) in rats.Method The permanent bilateral common carotid artery ligation method was used to prepare a VaD rat model. Suture of rats was performed after separation of the common carotid artery in Sham group. The model rats were randomly divided into model group, Cerebroprotein Hydrolysate Injection (Cerebrolysin, 10 mg/kg, positive drug group), Cerebroprotein Hydrolysate for injection (I) high, medium and low dose (20, 10 and 5 mg/kg) groups. Rats were treated with relative drug by tail iv injection once daily for two weeks, and rats in Sham group were given equal volume of saline. The learning and memory abilities were evaluated by Y maze and step-through tests. Besides, the levels of insulin-like growth factor-I (IGF-1) in VaD rat serum were determined by ELISA method.Results Compared with model group, Cerebroprotein Hydrolysate for injection (Ι) significantly increased the correct number in Y maze test, reduced the step-through latency time, and elevated serum IGF-1 level in VaD rats. The protective effects of Cerebroprotein Hydrolysate for injection (Ι) in VaD rats were equivalent to the same dose of Cerebrolysin.Conclusion Cerebroprotein Hydrolysate for injection (Ι) could significantly improve the learning and memory abilities of VaD rats, presumably through a mechanism of elevating IGF-1 level, which promotes the repairment and growth of neurons.