异丙酚后处理对氧糖缺失-复氧复糖诱发大鼠海马神经元细胞周期异常启动的影响

Effect of propofol post-conditioning on oxygen-glucose deprivation and restoration-induced abnormal cell cycle activation in hippocampal neurons of rats

目的探讨异丙酚后处理对氧糖缺失-复氧复糖诱发大鼠海马神经元细胞周期异常启动的影响。 方法原代培养Wistar大鼠胎鼠海马神经元，培养7 d时，以5×105个/ml细胞密度接种于培养孔或培养瓶中，100 μl/孔，3 ml/瓶，采用随机数字表法，分为3组（n＝24）：正常对照组（C组）、氧糖缺失-复氧复糖组（OGD/R组）和异丙酚后处理组（PP组）。采用氧糖缺失1 h复氧复糖24 h的方法制备模型，PP组复氧复糖即刻加入异丙酚1.2 μg/ml，孵育2 h。复氧复糖24 h时收集细胞，采用MTT法测定细胞活力，采用流式细胞术检测线粒体膜电位（MMP）、胞浆Ca2＋浓度（[Ca2＋]i）和细胞周期分布。 结果与C组比较，OGD/R组和PP组细胞活力和MMP降低，[Ca2＋]i升高，G0/G1期细胞比例减少，S期和G2/M期的细胞比例增加（P〈0.05）；与OGD/R组比较，PP组细胞活力和MMP升高，[Ca2＋]i降低，G0/G1细胞比例升高，S期和G2/M期细胞比例降低（P〈0.05）。 结论异丙酚后处理减轻氧糖缺失-复氧复糖诱发大鼠海马神经元凋亡的机制与抑制细胞周期异常启动有关。

Objective To investigate the effect of propofol post-conditioning on oxygen-glucose deprivation and restoration （OGD/R）-induced abnormal cell cycle activation in hippocampal neurons of rats. Methods Primarily cultured hippocampal neurons obtained from fetal Wistar rats were cultured for 7 days and seeded in culture wells （100 μl/well） or in culture fasks （3 ml/flask） at a density of 5×105cells/ml. The neurons were divided into 3 groups （n=24 each） using a random number table： control group （group C） ; group OGD/R; propofol post-conditioning group （group PP）. The neurons were subjected to oxygen- glucose deprivation for 1 h followed by restoration of oxygen-gulcose supply for 24 h. Propofol 1.2 t^g/ml was added immediately after onset of oxygen-glucose restoration, and the neurons were incubated for 2 h in group PP. At 24 h of oxygen-glucose restoration, cells were collected for measurement of the cell viability by methyl thiazolyl tetrazolium assay, and the mitochondrial membrane potential （ MMP ） , intraeellular Ca2~concentration （[ Ca2＋]i） and distribution of cell cycle were determined using flow cytometry. Results Compared with group C, the cell viability and MMP were significantly decreased, ~ Ca2＋ ] ~ was significantly increased, the proportion of the cells in G0/Gl phase was significantly decreased, and the proportion of the cells in S and G2/M phases was significantly increased in OGD/R and PP groups （P〈0.05）, Com- pared with group OGD/R, the cell viability and MMP were significantly increased, [ Ca2＋ ]i was significant- ly decreased, the proportion of the cells in G0/G1 phase was significantly increased, and the proportion of the cells in S and G2/M phases was significantly decreased in group PP （P〈0.05）. Conclusion The mechanism by which propofol post-conditioning reduces OGD/R-induced apoptosis in hippocampal neurons of rats is associated with inhibition of abnormal cell cycle activation.