颈总动脉结扎联合半乳糖注射制备老年期痴呆大鼠模型及行为学评价研究

Study on rats model of senile dementia by ligation of carotid arteries combined with injection of D-galactose and its application for behavioral evaluation

目的探讨不同制备方法对痴呆大鼠模型学习记忆能力的影响,为药效评价提供老年期痴呆大鼠模型。方法40只Wistar雄性大鼠随机分为5组:分期双侧颈总动脉永久结扎后D-半乳糖注射组(A组);D-半乳糖注射后分期双侧颈总动脉永久结扎组(B组);单次双侧颈总动脉永久结扎组(C组);D-半乳糖注射组(D组),正常对照组(E组),每组8只。除E组外,A组左侧颈总动脉结扎,间隔1周后行右侧颈总动脉结扎术;并于结扎术1周后行D-半乳糖腹腔注射(60 mg/kg体重,每天1次),共连续注射42 d;B组腹腔连续注射D-半乳糖(60 mg/kg体重)42 d后,再行双侧颈总动脉永久结扎术;C组仅行双侧颈总动脉永久结扎术42 d,腹腔不注射半乳糖;D组:仅连续腹腔注射D-半乳糖(60 mg/kg体重)42 d,不接扎其双侧颈总动脉。最后采用Morris水迷宫行为学测试法进行定位航行及空间探索实验;取各组大鼠海马CA1区进行电镜观察。结果与C、E组相比,A、B及D组游泳时间与距离均明显缩短,差异有统计学意义(P<0.01);而A组与B、D组之间差异无统计学意义(P>0.05);比较正常组各模型组海马CA1区锥体细胞有不同程度的丢失,且脑组织病理学改变明显。结论采用双侧颈总动脉永久结扎联合半乳糖腹腔注射方法,制备的老年期痴呆大鼠模型,记忆力明显减退,且脑组织病理学显著改变,能有效重现老年期痴呆患者的发病特点。

Objective To explore the effect of different preparation methods on learning and memory of senile dementia rats model,and to offer effective rats model for efficacy evaluation.Methods Totally 40 male Wistar rats were randomly divided into five groups：2-VO＋ D-galactose injected group （group A）; D-galactose injected＋2-VO group （group B）; 2-VO group （group C）; D-galactose injected group （group D）; normal control group （group E）; 8 rats in each group.Except the group E,unilateral common carotid artery were permanently ligated in the rats of group A,the other lateral artery then were permanently ligated after 7 days.With the interval of one week,the rats were injected with D-galactose （60 mg/kg,once every day） for 6 consecutive weeks.The rats of group B were injected with D-galactose （60 mg/ kg） for 6 consecutive weeks,then their bilateral common carotid arteries were permanently ligated,the bilateral common carotid arteries were permanently ligated only in the rats of group C.The rats of group D were injected peritoneally with D-galactose for 6 consecutive weeks only.Finally,the water maze experiment was taken to explore the place navigation and spatial experiments; and their hippocampal CA1 region in the rats of each group were observed with electron microscope.Results Compared with group C and E,the swimming time and distance in the rats of group A,B and D reduced obviously （P ＜ 0.01）,but there were rarely differents between the rats of group A with the rats of group B and D （P ＞ 0.05）.Compared with normal group,obvious loss of pyramidal cells hippocampal CA1 were found in every other group,and their cerebral pathology had significantly changes.Conclusion The senile dementia rats model established by the method of permanent bilateral common carotid artery ligation combined with intraperitoneal injection with D-galactose shows obvious loss in learning and memory,and has significant changes in their cerebral pathology,which represent the characteristics of the Senile dementia.