慢性脑低灌注大鼠海马神经元损伤的机制研究

目的 探究慢性脑低灌注大鼠海马神经元损伤的机制.方法 双侧颈总动脉结扎(2VO)制备慢性脑低灌注大鼠模型,2VO术后8周取材,分别进行HE染色、电镜、流式细胞术以及Western Blotting检测.结果 HE结果显示2VO组的海马神经元排列稍紊乱,且数量与假手术对照相比有不同程度减少[CA2区:(34.75±3.40)个,(49.25±9.67)个,P＜0.05;DG区:(73.50±9.26)个,(90.75±4.35)个,P＜0.05];电镜观察发现2VO组大鼠海马区部分神经元胞核中略有固缩,出现异染色质边集,胞浆则出现水肿,以线粒体与内质网尤甚;流式细胞术结果表明2VO组海马神经元早期凋亡率[(9.117±2.540)%]高于假手术对照组[(4.750±3.481)%],差异有统计学意义(P＜0.05);Western Blotting检测发现procaspase-3在2VO组大鼠海马的表达与假手术对照组差异无显著性(P＞0.05).结论 慢性脑低灌注大鼠海马神经元的损伤主要由凋亡造成.

Abstract：

Objective To explore the the cellular damage of hippocampus neuron in a rat model of chronic cerebral hypoperfusion. Methods Rat model of chronic cerebral hypoperfusion was established by permanent bilateral common carotid arteries occlusion (2VO). Eight weeks after the operation,the brains were removed and examined with histological stains, electron microscope, flow cytometer and Western Blotting. Results Compared with the control group,the arrangement of hippocampus neurons in 2VO rats appeared to be more irregular, and the number of the neurons decreased partly ( CA2: ( 34.75 ± 3.40) vs (49.25 ± 9.67 ), P ＜ 0. 05; DG: ( 73.50 ± 9.26)vs ( 90.75 ± 4.35 ), P ＜ 0. 05 ). By electron microscopic study of hippocampus neurons in 2VO rats, the nuclei became smaller and the heterochromatin assembled in the border of the nuclei in some neurons, while cytoplasm swelled,especially in mitochondria and endoplasmic reticulum. The rate of apoptosis of hippocampus neurons in 2VO rats( (9. 117 ±2. 540)% ) ,detected by the flow cytometer,was higher than that of sham group( (4. 750 ±3.481 ) % ) (P ＜ 0. 05 ). The expression of pro-caspase-3 in hippocampus of 2 VO rats was not altered significantly compared with the control group(P ＞ 0. 05 ). Conclusion The cellular damage of hippocampus neuron in 2VO rats was mainly caused by apoptosis.

Investigation on the cellular damage of hippocampus neuron in a rat model of chronic cerebral hypoperfusion

Objective To explore the the cellular damage of hippocampus neuron in a rat model of chronic cerebral hypoperfusion. Methods Rat model of chronic cerebral hypoperfusion was established by permanent bilateral common carotid arteries occlusion (2VO). Eight weeks after the operation,the brains were removed and examined with histological stains, electron microscope, flow cytometer and Western Blotting. Results Compared with the control group,the arrangement of hippocampus neurons in 2VO rats appeared to be more irregular, and the number of the neurons decreased partly ( CA2: ( 34.75 ± 3.40) vs (49.25 ± 9.67 ), P ＜ 0. 05; DG: ( 73.50 ± 9.26)vs ( 90.75 ± 4.35 ), P ＜ 0. 05 ). By electron microscopic study of hippocampus neurons in 2VO rats, the nuclei became smaller and the heterochromatin assembled in the border of the nuclei in some neurons, while cytoplasm swelled,especially in mitochondria and endoplasmic reticulum. The rate of apoptosis of hippocampus neurons in 2VO rats( (9. 117 ±2. 540)% ) ,detected by the flow cytometer,was higher than that of sham group( (4. 750 ±3.481 ) % ) (P ＜ 0. 05 ). The expression of pro-caspase-3 in hippocampus of 2 VO rats was not altered significantly compared with the control group(P ＞ 0. 05 ). Conclusion The cellular damage of hippocampus neuron in 2VO rats was mainly caused by apoptosis.