摘要
目的 通过观察海马区神经元细胞内 Ca2 +荧光强度的变化 ,说明 DHCA时不同脑保护方法对细胞内游离钙离子浓度的影响 ,并证明细胞内钙超载在神经元损伤中的作用。方法 北京农业大学实验用小型猪 16头 ,体重 2 2 kg～ 2 5 kg。鼻咽温降至 18℃时分别给予如下处理 90 m in:DHCA( 组 ) ,ACP( 组 ) ,RCP( 组 ) ,RCP+Nim ( 组 )。复温 12 0 m in至鼻咽温 3 6℃。取左侧海马头部制备细胞悬液 ,Fluo- 3染色 ,应用流式细胞仪分析细胞内 Ca2 +荧光强度的变化情况。电镜观察神经元线粒体超微结构的变化。结果 细胞内 Ca2 +荧光强度 组明显高于其他 3组 , 组明显高于 组 , 组和 组、 组和 组之间无显著差异 (显著性界值 P =0 .0 5 )。与之相应 ,线粒体损伤 组最重 , 组最轻。结论 DHCA时神经元内钙超载 ,线粒体损伤严重 ,可能与 DHCA后中枢神经系统功能障碍有关 ;ACP明显减轻细胞内钙超载 ,线粒体损伤轻 ,脑保护作用效果理想 ;RCP亦能减轻细胞内钙超载、减轻线粒体损伤 ,但作用不及 ACP;Nim通过阻断电压依赖性钙通道 ,部分抑制了 Ca2 +内流 ,加强了 RCP的作用 。
OBJECTIVE This study examined the variation of fluorescent intensity of neuron dissociative calcium in hippocampus as to explore the effects of different protective methods with DHCA and correlate the effects of calcium over loading to the neuron injury. METHODS Sixteen pigs (22~25 kg) were divided randomly into four groups, and 4 in each group group Ⅰ DHCA; group Ⅱ ACP; group Ⅲ RCP; group Ⅳ RCP+Nim. All animals were cooled 90 minutes at 18 degrees ℃ (pharyngeal) for 90 min and then rewarmed 120 minutes to 36℃. Left hippocampi were removed and then dissociated. These dissociated cells were stained with Fluo 3 and then measured with Flow Cytometry to analyze the variation of fluorescent intensity of neuron dissociative calcium. The mitochondrial ultrastructure changes were examined by electron microscope. RESULTS Free calcium fluorescent intensity was higher in group Ⅰ than in the other three groups; group Ⅲ was higher than group Ⅱ. There were no significant difference between group Ⅱ and group Ⅳ; group Ⅲ and group Ⅳ. (P=0.05) Accordingly, the severest injuries of mitochondria were found in group Ⅰ and the mildest in group Ⅱ. CONCLUSIONS Neuron calcium overload after DHCA, ie severe injuries of mitochondria was probably relative to central nerve system dysfunction. ACP could protect brain best by decreasing calcium overload ie milder injuries of mitochondria. RCP could also depress calcium overload and alleviate mitochondrial injury. But its effect was less than ACP. Nimodipine depressed partly calcium influx by blocking up VDCC (voltage dependent calcium channel) and enhanced the effect of RCP. But its effect was nonremarkable.
出处
《中国体外循环杂志》
2003年第1期19-21,共3页
Chinese Journal of Extracorporeal Circulation
基金
国家自然科学基金资助项目 (3 9770 73 3 )
关键词
深低温停循环
顺行脑灌注
逆行脑灌注
脑保护
尼莫地平
钙积聚
线粒体
流式细胞测量术
Deep hypothermic circulatory arrest
Antigrade cerebral perfusion
Retrograde cerebral perfusion
Brain protection
Nimodipine
Calcium accumulation
Mitochondrial
Flow cytometry
