Stokes J A, Harris R A
Mol Pharmacol. 1982 Jul;22(1):99-104.
Synaptosomes were isolated from rat and mouse brain and the effects of alcohol addition on calcium uptake were studied in vitro. Ethanol inhibited potassium-, glutamate-, and veratridine-stimulated calcium uptake. The inhibitory effects were obtained with concentrations of ethanol (less than or equal to 100 mM) which did not alter synaptosomal membrane potentials. Elevation of extrasynaptosomal calcium reduced the inhibitory effect of ethanol, resulting in apparently competitive kinetics. The inhibitory potencies of a series of alkanols were correlated with their membrane/buffer partition coefficients, implicating hydrophobic regions of the membrane as the site of alcohol action. However, not all nerve endings were equally sensitive to ethanol. Inhibition of potassium-stimulated calcium uptake was greater with synaptosomes prepared from cerebellum and striatum than with preparations from cortex or brain stem. In contrast, veratridine-stimulated calcium uptake (which is dependent upon sodium influx) was inhibited more strongly in cortex than in cerebellum. These results suggest that the calcium channels in cerebellum are more sensitive to ethanol than the calcium channels in cortex, whereas sodium channels in cortex are more sensitive than those in cerebellum.
从大鼠和小鼠大脑中分离出突触体，并在体外研究添加酒精对钙摄取的影响。乙醇抑制钾、谷氨酸和藜芦碱刺激的钙摄取。在不改变突触体膜电位的乙醇浓度（小于或等于100 mM）下可获得抑制作用。突触体外钙的升高降低了乙醇的抑制作用，导致明显的竞争性动力学。一系列链烷醇的抑制效力与其膜/缓冲液分配系数相关，这表明膜的疏水区域是酒精作用的部位。然而，并非所有神经末梢对乙醇的敏感性都相同。从小脑和纹状体制备的突触体对钾刺激的钙摄取的抑制作用大于从皮质或脑干制备的突触体。相反，藜芦碱刺激的钙摄取（依赖于钠内流）在皮质中比在小脑中受到更强的抑制。这些结果表明，小脑的钙通道比皮质的钙通道对乙醇更敏感，而皮质的钠通道比小脑的钠通道更敏感。
