摘要
目的 通过观察海马区神经元的损伤情况 ,探讨深低温停循环 (DHCA)时中枢神经系统损伤的机制及其保护方法。方法 北京农业大学实验用小型猪 16头 ,体重 2 2～ 2 5kg。鼻咽温降至 18℃时分别给予如下处理 90min :DHCA(I组 ) ,顺行脑灌注 (ACP ,II组 ) ,逆行脑灌注 (RCP ,III组 ) ,RCP +尼莫地平 (IV组 )。复温 12 0min至鼻咽温 36℃。取左侧海马头部制备细胞悬液 ,AnnexinV FITC染色 ,应用流式细胞仪分析细胞凋亡情况。电镜观察细胞超微结构的变化。结果 正常细胞百分比I组明显低于其他3组 ,II组明显高于III组 ,II组、III组与IV组之间差异无显著性 ;早期凋亡细胞百分比I组明显高于其他3组 ,II组明显低于III组 ,II组、III组与IV组之间差异无显著性 ;坏死细胞百分比I组明显高于其他 3组 ,而其他 3组之间差异无显著性 ;死亡细胞百分比I组明显高于其他 3组 ,而其他 3组之间差异无显著性 (显著性界值P =0 0 5 )。结论 DHCA后神经元发生凋亡、坏死和死亡 ,是术后神经功能障碍的主要原因 ;ACP使细胞凋亡和死亡减少 ,神经元保护作用最佳 ;RCP亦能使细胞凋亡和死亡减少 ,但神经元保护作用次于ACP ;尼莫地平部分抑制了Ca2 +内流 ,脑保护效果一般。
Objective: This study is to examine the effects of different protective methods with DHCA on neuron injury of hippocampus. Methods: Sixteen pigs (22-25 kg) were divided randomly into four groups. Group I: DHCA; group II: ACP; group III: RCP; group IV: RCP+Nim. All animals were under deep hypothemia (18℃) and total circulatory arrest for 90 minutes, and then rewarmed 120 minutes until the pharyneal temperature to 36℃. End of the study, left hippocampi were removed and then dissociated. These dissociated cells were stained with Annexin V-FITC and then measured with flow cytometry to analyze neuron apoptosis. The morphological changes were examined by electron microscope. Results: Normal cell percentage was the lowest in group I. Compared with group III, normal cell percentage was higher in group II. There were no significant differences between group II and group IV, or group III and group IV. Early apoptotic cell percentage was higher in group I than that in the other three groups, and it is higher in group II than that in group III. There were no significant differences between group II and group IV, or group III and group IV. Both necrotic cell percentage and dead cell percentage were higher in group I than that in the other three groups and there was no significant difference between the other three groups (P=0.05). Conclusion: Apoptosis, necroses and death of neuron after DHCA is the main cause of postoperative nervous dysfunction. ACP has better protective effect on neuron by decreasing cell apoptosis and death. RCP could also reduce cell apoptosis and death but the effect is not as good as that of ACP. Nimodipine depresses partly calcium influx by blocking up VDCC and its protective effect is slight.
出处
《中华胸心血管外科杂志》
CSCD
北大核心
2003年第2期100-102,共3页
Chinese Journal of Thoracic and Cardiovascular Surgery
