NMDA受体对乙醇、乙醛调控大脑皮质神经元神经甾体水平的影响

 目的研究乙醇、乙醛对原代培养大鼠大脑皮质神经元神经甾体水平的影响以及与N-甲基-D-天门冬氨酸(NMDA)受体调控的相关性。方法应用不同浓度乙醇或乙醛处理神经元,同时应用地佐环平(dizocilpine,MK801)阻断NMDA受体,收集细胞培养上清,采用HPLC-MS/APCI法分离测定游离型神经甾体孕烯醇酮(PREG)、脱氢表雄酮(DHEA)、别孕烯醇酮(AP)及结合型神经甾体脱氢表雄酮硫酸酯(DHEAS)、孕烯醇酮硫酸酯(PREGS)的含量,观察乙醇、乙醛对原代培养神经元神经甾体水平的影响以及与NMDA受体调控的相关性。结果与PBS对照组相比,25,50,100mmol·L^-1的乙醇均可显著升高神经元培养液中PREGS的水平(P<0.05);25和50mmol·L^-1的乙醇均可显著升高神经元培养液中AP的水平(P<0.05);50mmol·L^-1的乙醇还可显著升高神经元培养液中PREG的水平(P<0.05)。与PBS对照组相比,12.5,25,50mmol·L^-1的乙醛可显著升高神经元培养液中DHEA的水平(P<0.05,P₅₀<0.01);25,50mmol·L^-1的乙醛可显著升高神经元培养液中PREG和DHEAS的水平(P<0.05),12.5mmol·L^-1的乙醛显著降低神经元培养液中DHEAS的水平(P<0.05)、显著升高其AP的水平(P<0.05),50mmol·L^-1的乙醛却显著降低其AP的水平(P<0.05);25mmol·L^-1乙醛还可使神经元培养液中PREGS的水平显著升高(P<0.05)。MK801反转了50mmol·L^-1乙醇升高PREGS水平的作用(P<0.01)以及25mmol·L^-1乙醛升高PREG和DHEAS水平的作用(P<0.01)。结论乙醇、乙醛对神经元神经甾体水平的影响存在着一定的量效关系且对游离型和结合型神经甾体的影响各不相同;NMDA受体阻断了乙醇上调PREGS以及乙醛上调PREG和DHEAS的作用。

Effects of NMDA Receptor on Ethanol or Aldehyde Induced Neurosteroids Release in Rat Primary Cortical Neurons

OBJECTIVE To investigate the effects of NMDA receptor on ethanol or aldehyde induced neurosteroids in primary cultural cortical neuron from rat brain.METHODS Primary cultured cortical neurons were treated with different concentration of ethanol or aldehyde.Dizocilpine(MK801) was used to block the NMDA receptor,using HPLC-MS/APCI for analyzing and determining the concentration of unconjugated neurosteroids(PREG,DHEA and AP) and conjugated neurosteroids(DHEAS and PREGS)in culture media.RESULTS Compared with PBS control group,the levels of PREGS were increased significantly(P<0.05)by 25,50 or 100 mmol·L^-1 ethanol.The level of AP was increased significantly(P<0.05)by 25 or 50 mmol·L^-1 ethanol.The level of PREG was increased significantly(P<0.05)by 50 mmol·L^-1 ethanol.The level of DHEA was increased significantly(P<0.05,P₅₀<0.01)by 12.5,25,50 mmol·L^-1 aldehyde.The levels of PREG and DHEAS were increased significantly(P<0.05) by 25 or 50 mmol·L^-1 aldehyde.The level of DHEAS was decreased but that of AP was increased significantly(P<0.05)by 12.5 mmol·L^-1 aldehyde.The level of AP was decreased significantly(P<0.05)by 50 mmol·L^-1 aldehyde.But PREGS was increased significantly(P<0.05) by 25 mmol·L^-1 aldehyde.MK801 reversed the level of PREGS(P<0.01) increased by 50 mmol·L^-1 ethanol and the levels of PREG and DHEAS(P<0.01) increased by 25 mmol·L^-1 aldehyde.CONCLUSION Both ethanol and aldehyde showed effects on the levels of neurosteroids in primary cultural cortical neurons with different characteristics.NMDA receptor blocked the increase of PREGS induced by ethanol as well as the increase of PREG and DHEAS induced by aldehyde.