基于改良大鼠双侧颈总动脉结扎法建立血管性痴呆模型探讨脑血流量变化规律及对血管新生相关蛋白的影响

Modified bilateral carotid artery ligation to establish a vascular dementia rat model and investigate changes in cerebral blood flow and effects on angiogenesis-related proteins

目的 通过改良大鼠双侧颈总动脉结扎法建立血管性痴呆(cascular dementia,VD)大鼠模型观察其脑血流量变化规律及血管新生蛋白表达等变化。方法 将36只SD雄性大鼠随机分为假手术组(n=18)和模型组(n=18),假手术组只分离双侧颈总动脉不作结扎,模型组行双侧颈总动脉结扎法制备VD模型,于造模前、造模后14 d采用Morris水迷宫进行行为学测试,激光散斑衬比成像检测脑血流量变化,Western Blot法检测HIF-1α、VEGF及HO-1蛋白表达,ELISA法检测IL-4、IL-10含量。结果 造模后14 d,与假手术组比较,模型组逃避潜伏期延长、穿越平台次数减少(P<0.05);造模后2 h、3、7 d,模型组较假手术组脑血流量显著降低(P<0.05),造模后14、21 d,假手术组和模型组的脑血流量变化无显著差异(P>0.05);模型组在造模后2 h脑血流量降至最低(P<0.05),此后脑血流量开始恢复,恢复高峰期发生在造模后3~7 d,并于造模后14 d恢复至造模前水平;造模后21 d,模型组海马区HIF-1α、VEGF及HO-1蛋白表达含量较假手术组明显升高(P<0.05),模型组血清中IL-4、IL-10的含量较假手术组明显升高(P<0.05)。结论 改良大鼠双侧颈总动脉结扎法建立VD模型的脑血流量变化呈现一定时间规律,造模后21 d该模型海马区HIF-1α、VEGF及HO-1的表达显著增加,并伴随IL-4和IL-10含量的升高。

Objective Apply modified bilateral carotid artery ligation to establish a VD rat model to observe changes in cerebral blood flow and expression of angiogenic proteins.Methods Thirty-six SD male rats were randomly divided into a sham group(n = 18) and model group(n = 18).In the sham group,only the bilateral carotid artery was isolated without ligation,whereas in the model group,the bilateral carotid artery was ligated to establish the VD model.The Morris water maze behavior test was applied before and 14 days after modeling.Variation in cerebral blood flow was detected by laser speckle contrast imaging.Protein expression of HIF-1α,VEGF,and HO-1 was detected by Western Blot.IL-4 and IL-10 contents were measured by ELISA.Results At 14 days after modeling,escape latency was significantly prolonged and the frequency of crossing the platform had significantly decreased in the model group compared with the sham group(P < 0.05).At 2 hours,3 days,and 7 days after modeling,cerebral blood flow in the model group was significantly lower than that in the sham group(P < 0.05).At 14 and 21 days after modeling,no significant difference was found in cerebral blood flow between sham and model groups(P > 0.05).In the model group,cerebral blood flow was decreased to a minimum at 2 hours after modeling(P < 0.05) and then began to recover.The peak of recovery occurred at 3 ~ 7 days after modeling and returned to the level before modeling on day 14 after modeling.At postoperative day 21,expression of HIF-1α,VEGF,and HO-1 proteins in the hippocampus of the model group was increased remarkably(P < 0.05) and the serum contents of IL-4 and IL-10 in the model group were significantly increased compared with those in the sham group(P < 0.05).Conclusions The variation in cerebral blood flow in the VD rat model established by the modified bilateral carotid artery ligation was dependent on time.At postoperative day 21,HIF-1α,VEGF,and HO-1 in the hippocampus were increased significantly,which was accompanied by increased levels of IL-4 and IL-10.