Valenzuela C F, Cardoso R A, Wick M J, Weiner J L, Dunwiddie T V, Harris R A
Department of Pharmacology, University of Colorado Health Sciences Center, Denver 80262, USA.
Alcohol Clin Exp Res. 1998 Aug;22(5):1132-6.
We examined the effects of acute ethanol exposure on recombinant human glycine receptors transiently transfected into HEK 293 cells and stably transfected into Ltk- fibroblast-like cells. In our study of the effects of ethanol, we used the whole-cell patch-clamp configuration. Relatively low concentrations of ethanol (25 mM and 50 mM) did not affect glycine-gated currents in any of the cell lines studied. Higher concentrations of ethanol (100 mM and 200 mM) significantly potentiated glycine responses only in stably transfected Ltk- cells expressing alpha1 and alpha2 subunits and in HEK 293 cells transiently expressing alpha2 subunits. Cells stably expressing alpha1 versus alpha2 glycine receptors were modulated equally by ethanol. Both glycine alpha1 and glycine alpha1beta receptors transiently expressed in HEK 293 cells were insensitive to all concentrations of ethanol tested; however, there was a trend toward potentiation at 100 and 200 mM ethanol concentrations. A population of cells (41-87%) that was sensitive to the potentiating effects of 100 and 200 mM ethanol (defined as more than 10% potentiation) was identified in both cell lines tested. In these sensitive cells, ethanol (100 and 200 mM) produced significant potentiation, independent of the cell line and the glycine receptor subunit tested. Together with published results from studies with Xenopus oocytes, these data indicate that the sensitivity of recombinant glycine receptors to ethanol depends upon the expression system.
我们研究了急性乙醇暴露对瞬时转染到HEK 293细胞以及稳定转染到Ltk-成纤维样细胞中的重组人甘氨酸受体的影响。在我们对乙醇作用的研究中，采用了全细胞膜片钳记录模式。相对低浓度的乙醇（25 mM和50 mM）对所研究的任何细胞系中的甘氨酸门控电流均无影响。较高浓度的乙醇（100 mM和200 mM）仅在稳定表达α1和α2亚基的Ltk-细胞以及瞬时表达α2亚基的HEK 293细胞中显著增强了甘氨酸反应。稳定表达α1与α2甘氨酸受体的细胞对乙醇的调节作用相同。在HEK 293细胞中瞬时表达的甘氨酸α1和甘氨酸α1β受体对所有测试浓度的乙醇均不敏感；然而，在100 mM和200 mM乙醇浓度下有增强的趋势。在两个测试的细胞系中均鉴定出一群对100 mM和200 mM乙醇的增强作用敏感的细胞（41 - 87%）（定义为增强超过10%）。在这些敏感细胞中，乙醇（100 mM和200 mM）产生了显著的增强作用，与细胞系和所测试的甘氨酸受体亚基无关。结合已发表的非洲爪蟾卵母细胞研究结果，这些数据表明重组甘氨酸受体对乙醇的敏感性取决于表达系统。
