低氧对大鼠海马神经干细胞增殖的影响

目的观察和分析不同低氧浓度对海马神经千细胞（NSCs）增殖的影响。方法在体积分数4％O2、1％O2及常氧环境下培养新生SD大鼠海马神经干细胞，观察低氧对神经球数量和直径的影响。结果（1）对海马神经干细胞增殖效率的影响：体积分数1％低氧组神经球数量明显低于常氧对照组，具有显著性差异（P〈0．05）；体积分数4％低氧组神经球数量有高于对照组的趋势，但不具有显著性差异。（2）对海马神经干细胞增殖速度的影响。在培养24h、36h和48h后，体积分数1％低氧组神经球的直径都小于对照组，且在24h和36h时具有显著性差异（P〈0．05），在48h具有极显著性差异（P〈0．01）；在培养24h、36h和48h后，体积分数4％低氧组神经球的直径都大于对照组，在36h时具有显著性差异（P〈0．05），在48h时具有极显著性差异（P〈0．01）。结论体积分数4％低氧浓度环境既提高海马神经干细胞的增殖效率也提高海马神经千细胞的增殖速麾体积分数1％低氧浓度环境则既抑制海马神经干细胞的增殖效率也抑制海马神经干细胞的增殖速度。提示中度低氧有利于海马神经干细胞的增殖：过度低氧不利于海马神经千细胞的增殖。

Effects of Hypoxia on Proliferation of Hippocampal Neural Stem Cells in Rat

Objective To observe the effects of hypoxia on proliferation of rat＇s hippocampal neural stem cells. Methods The hippocampal neural stem cells from newborn SD rats were cultured in the concentration of 1%, 4%, and 20% oxygen respectively, and the diameter and number of neurospheres were observed under the low oxygen. Results （1） Effects of hypoxia on proliferation efficiency. Thenumber of neurospheres of 1% group was significantly lower than control group, （P〈0.05）. The number of neurospheres of 4% group was higher than control group, but no significantly difference. （2） Effects of hypoxia on proliferation rate. The diameter of 1% group was significantly shorter than control group at 24 h, 36 h and 48h,and reached the extremely significant levelat 48 h （P〈0.01）. The diameter of 4% group was longer than control group in 24 h, 36 h and 48 h. There was a significant difference at 36h and an extremely significant difference at48 h. （P〈0.01）. Conclusion 4% oxygen concentration can not only improve proliferation efficiency of rat＇s hippocampal neural stem cells, but also improve its prolif- eration rate. 1% oxygen concentration can not only inhibit proliferation efficiency of rat＇s hippocampal neural stem ceils, but also inhibit its proliferation rate. This suggests us that moderate hypoxia can improve the proliferation of rat＇s hippocampal neural stem cells, while server hypoxia inhibits its proliferation.