3种拟血管性痴呆大鼠模型的比较

Comparison of three rat models of synthetic vascular dementia

目的从行为学及病理学两层面,对3种"二血管阻断法"拟血管性痴呆(VD)大鼠模型进行评价比较。方法实验分为再灌注后结扎组、再灌注组、降压并结扎组以及对照组,用Morris水迷宫定向航行实验中的逃避潜伏期,空间探索实验中的目标区域穿越次数及中环区域活动比例评价各动物的学习记忆能力,HE染色观察海马CA1区锥体细胞病理损伤。结果 3种模型组间术后48 h死亡率无明显差异(P>0.05)。术后20 d时,3种模型组的学习记忆能力均明显下降,其中3种模型组的逃避潜伏期明显长于对照组(P<0.01),尤以再灌注后结扎组的逃避潜伏期最长,而再灌注组相对较短,且再灌注组随着时间的推移有恢复趋势;到术后30 d时其成绩与对照组差异已不显著(P>0.05),而再灌注后结扎、降压并结扎2组与对照组始终差异明显(P<0.01),但2组之间差异不明显(P>0.05),说明两者的Morris水迷宫学习成绩较为稳定。在海马CA1区锥体细胞病理损伤方面,以再灌注后结扎组最为严重,降压并结扎组次之,再灌注组则较轻。结论再灌注损伤大鼠VD模型不够稳定,而再灌注后结扎、降压并结扎两VD模型较稳定,有较好的表面效度和一定的结构效度,但尚待评价两模型的预测效度。

Objective To review and compare three rat models of synthetic vascular dementia （VD） established by two-vessel blockage method from the levels of ethology and pathology. Methods There were 3 groups in the test： group of common carotid artery. （CCA） ligation after reperfusion （CLR group） , reperfusion group （ R group） and group of reducing pressure and CCA ligation （ RPCL group） , and a control group （C group） was established. The learning and memory ability were reviews by escape latent） in Morris water maze directional navigation test, cross-over times in target area in spatial probe test and activity percentage in middle ring area. The pathological damage of pyramidal cells in hippocampus CA1 zone was observed through HE staining. Results The mortality was not significantly different among CLR group, R group and RPCL group （ P 〉 0.05 ） 48 hours after the operation, and learning and memory ability decreased significantly in 3 groups 20 days after the operation. The escape latency was much longer in CLR group, R group and RPCL group than that in C group （ P 〈 0.01 ） and it was the longest in CLR group. It was some shorter in R group and tended to recover to normal over time, while to 30 days after the operation, it was not different compared with C group （ P 〉 0.05 ）. The differences between CLR group or RPCL group to end, but difference between CLR group and and C group were significant （P 〈 0.05 ） from beginning RPCL group was not significant （ P 〉 0.05 ）, which indicated that their learning results in Morris water maze were stable. The pathological damage of pyramidal ceils in hippocampus CA1 zone was the worst in CLR group, worse in RPCL group and mild in R group. Conclusion The rat VD model of reperfusion injury is not stable, but VD models of ligation after reperfusion and reducing pressure and ligation are stable with good face validity and construct validity, while the predictive validity of them is to be reviewed.