脑低灌注对大鼠海马胆碱能神经功能指标的变化

Changes of hippocampal cholinergic apoptosis in cerebral hypoperfusion

目的探讨脑低灌注大鼠海马胆碱能神经功能状态及细胞凋亡的变化。方法SD大鼠40只,随机分为2VO模型组和假手术组,每组20只;永久性阻断双侧颈总动脉制作2VO模型,造成脑部持续性低灌注状态。观察大鼠术后学习记忆能力的改变、胆碱乙酰转移酶(ChAT)和促凋亡指标Bax在海马的表达,以及海马乙酰胆碱酯酶(AChE)活性的变化。结果大鼠2VO术后14d和21d表现出学习记忆障碍,与假手术组比较有显著性差异(P<0.01);2VO模型组海马ChAT表达和海马AChE活性均较假手术组明显降低(P<0.01),而海马Bax的阳性细胞数较假手术组明显增加(P<0.01)。结论脑低灌注破坏海马胆碱能神经功能,学习记忆能力下降。细胞凋亡可能是胆碱能神经功能障碍的主要原因。

Objective To explore the changes of hippocampal cholinergic status and apoptosis in rat model of cerebral hypoperfusion. Methods A total of 40 SD rats were randomly divided into 2VO model group and sham-operated group. Rat was subjected to permanent occlusion of bilateral common carotid arteries to make 2VO model. The learning and memory ability were evaluated using Y maze before and after operation. The expression of ChAT and Bax in hippocampus was detected with immunohistochemistry. Hippocampal AChE activity was measured by Coomassie brilliant blue method. Results There was marked learning and memory impairment in 2VO group at 14d and 21d after occlusion compared to sham-operated group（P〈0. 01）. The expression of ChAT in hippocampus was lower in 2VO group than in sham-operated group（P〈0.01）. The hippocampal AChE activity was obviously decreased in 2VO model group. There was a significant difference between 2VO model group and sham-operated group（P〈0.01）. Whereas the expression of Bax in hippocampus was higher in 2VO model group than in sham-operated group（P〈0.01）. Conclusion Cerebral hypoperfusion can damage the hippocampal cholinergic function and result in cognitive decline. Cholinergic apoptosis might be tile chief mechanism of dementia following cerebral ischemia.