低氧预适应上调大鼠海马神经元和星形胶质细胞在急性缺氧时的葡萄糖转运蛋白的活性和基因表达

目的 研究低氧预适应对海马神经元和星形胶质细胞在急性缺氧暴露时的葡萄糖转运蛋白的活性和基因表达的影响。方法 培养大鼠海马神经元和星形胶质细胞,每天间歇暴露于低氧混合气体（1% O2、10% CO2、89% N2）20min,连续6d。最后1次低氧暴露24h后,将细胞暴露于无氧混合气体（10% CO2、90% N2）6h,然后立即检测[3H]-2-脱氧葡萄糖（2-DG）的摄取率、GLUT1和GLUT3的mRNA水平及神经元的存活率。结果 低氧预适应上调急性缺氧时神经元和星形胶质细胞的2-DG吸收率、星形胶质细胞GLUT1 mRNA的表达及神经元GLUT1和GLUT3 mRNA的表达,提高神经元存活率,这一作用可被细胞松弛素B消除。结论 低氧预适应上调海马神经元和星形胶质细胞在急性缺氧时的葡萄糖摄取率和葡萄糖转运蛋白的基因表达。

Hypoxic preconditioning up-regulates the activity and gene expressions of glucose transporters (GLUT1 and GLUT3) in cultured rat hippocampal neurons and astrocytes under anoxic condition

Objective To explore the effect of hypoxic preconditioning on the activity and gene expressions of glu-cose transporters in the cultured rat hippocampal neurons and astrocytes under anoxic condition. Methods The cultured rat hippocampal neurons and astrocytes were treated for 6 days by intermittently exposing to hypoxic gas mixture (1% O_2, 10% CO_2, 89% N_2) for20 min each day. 24 h after the last hypoxic exposure, the cells were exposed to anoxic gas mixture (10% CO_2, 90% N_2) for 6 h, and the uptake rate of [~3H]-2-deoxyglucose (2-DG), the levels of glucose transporter GLUT1 and GLUT3 mRNAs and the cell survival rate were examined im-mediately after anoxic exposure. Results Neurons and astrocytes preconditioned with hypoxia showed higher 2-DG uptake rates and increased expressions of GLUT 1 mRNA in the astrocytes and GLUT 1 and GLUT 3 mRNA in the neurons. The preconditioned neurons also showed an increased tolerance to anoxia. Conclusion Hypoxic precon-ditioning up-regulates the activity and gene expressions of glucose transporters of hippocampal neurons and astro-cytes under anoxic condition.