急性全脑缺血-再灌注后大鼠海马回中脑红蛋白与NF-κBp65表达的关系

Expression of NGB and NF - κB p65 in rat hippocampus after global cerebral ischemia -reperfusion

目的通过探讨急性全脑缺血-再灌注（I／R）后大鼠海马回中脑红蛋白（NGB）与核因子-KappaBp65（NF-κB065）的表达关系，研究其在再灌注损伤后的作用。方法60只健康SD大鼠，随机分为假手术组（S0）30只和1／R组30只。观察I／R后3、6、12、24和48h苏木素一伊红（HE）染色海马CA1区存活锥体细胞数目；TUNEL原位末端标记法检测的锥体细胞凋亡率；免疫组织化学法检测锥体细胞中NF-κBp65、NGB的表达。结果NGB的表达随I／R时间的延长而下调，各时间点比较差异有统计学意义（P〈0．01），与SO组比较在3、6h下调不明显（P〉0．05），但到12h降低明显（P〈0．01）；锥体细胞凋亡率（AP）随再灌注时间的延长而提高，与NGB表达呈负相关（r=-0．813，P〈0．01）；NF-κBp65在胞核中的表达随1／R时间的延长而增强，各时间点问差异有统计学意义（P〈0．01），与SO组各相应观察时间点间差异有统计学意义（P〈0．01），与NGB的表达呈负相关（r=-0．767，P〈0．01）。结论随全脑I／R时间的延长，NGB在海马CAl区锥体细胞中的表达下调。NGB与抑制NF-κBp65的表达及抗神经元凋亡作用密切相关，因此短期内可能有一定的脑保护作用。

Objective To investigate the expression of NGB and NF - κB p65 in rat hippocampus after the acute global cerebral Ischemia - Reperfusion, and to study its role in reperfusion injury. Methods 60 healthy SD rats were randomly divided into sham operation （SO） group （ n = 30） and global cerebral ischemia - reperfusion （I/R） group （ n = 30 ）. Using hematoxylin - eosin （ HE ） staining to observe the number of surviving pyramidal ceils in hippocampal CA1 area, terminal in situ nick end labeling TUNEL to detect the apoptosis rate of pyramidal cell, and immunohistochemistry to detect the expression of NGB and NF - κB p65 in pyramidal cells at 3,6,12,24,48 h after reperfusion. Results the expression of NGB reduced with the extension of reperfusion, compared between different time points（P 〈 O. O1 ）, then compared with SO group obvious reduction at 3,6 h （ P 〉 0.05 ）, nostatistically significant, but to 12 h were significantly lower（ P 〈 0.01 ） ; the apoptosis rate of pyramidal cell （AP） increased with the prolongation of reperfusion, and the NGB was negatively correlated with the AP（ r = - 0.813, P 〈 0.01 ） ; the expression of NF - κB p65 in the nucleus enhanced with the extension of reperfusion, Compared between different time points （P 〈 0. O1 ）, and compared with the corresponding time point in the SO group（P 〈 O. 01 ）, the correlation with the expression of NGB was negative（r = - 0. 767, P 〈 0. O1 ）. Conclusion The expression of NGB in the hippocampal CA1 pyramidal cells may downregulate with the extension of reperfusion. NGB is closely related to theinhibition of NF - κB p65 expression and anti - neuronal apoptosis , so possibly have the role of brain protection during short- term.