神经生长因子预处理对深低温停循环下兔脑皮层神经细胞凋亡的影响

Effects of nerve growth factor pretreatment on neuron apoptosis in brain cortex after deep hypothermic circulatory arrest in rabbit

目的探讨神经生长因子(NGF)预处理对深低温停循环下兔脑皮层神经细胞凋亡的影响。方法采用深低温下夹闭兔双侧颈总动脉模型。新西兰大白兔幼兔20只随机均分为2组:深低温停循环前48h用生理盐水组(A组)、预处理组-深低温停循环前48h用NGF预处理组(B组),A、B各组分别在降温至20℃时停循环30min、恢复循环复温至常温,72h后处死取兔脑皮层组织标本,采用原位末端标记法(TUNEL法)观察深低温停循环再灌注后兔脑皮层神经细胞凋亡的变化。结果与A组相比,B组的兔脑皮层神经细胞凋亡数目显著减少,差异具有统计学意义(P=0.009)。结论深低温停循环前用外源性NGF预处理能明显减轻兔脑皮层神经细胞的凋亡,神经生长因子有一定的脑保护作用。

Objectives To investigate effect of nerve growth factor （NGF） pretreatment on neuron apoptosis in brain cortex under deep hypothermic circulatory arrest （DHCA） in rabbits. Methods The model of occluding bilateral common carotid artery in the deep hypothermic （20℃） rabbits was established. Twenty healthy baby rabbits weighting 0. 4-0.5 kg were randomly allocated to two groups （10 rabbits per group） ：In group A,the rabbits received DHCA and preconditioned with normal saline at 48 h before DHCA; In group B, animals received DHCA and preconditioned with NGF （1.0 μg/kg bolus at 48 h before DHCA）. All animals were executed at 3rd day after DHCA. The neuron apoptosis in cerebral cortex was detected by the method of TUNEL. Results As compared with group A,the number of apoptotic cells stained with TUNEL in group B was significantly reduced （ P = 0. 009 ）. Conclusion Exogenous NGF pretreatment can significantly decrease the neuron apoptosis of the cerebral cortex during DHCA in rabbits,suggesting that NGF is potentially a beneficial agent in treating DHCA - induced brain injury in rabbits.