Orme F W, Moronne M M, Macey R I
Department of Physiology-Anatomy, University of California, Berkeley 94720.
J Membr Biol. 1988 Aug;104(1):57-68. doi: 10.1007/BF01871902.
Aliphatic alcohols are found to stimulate the transmembrane fluxes of a hydrophobic cation (tetraphenylarsonium, TPA) and anion (AN-12) 5-20 times in red blood cells. The results are analyzed using the Born-Parsegian equation (Parsegian, A., 1969, Nature (London) 221:844-846), together with the Clausius-Mossotti equation to calculate membrane dielectric energy barriers. Using established literature values of membrane thickness, native membrane dielectric constant, TPA ionic radius, and alcohol properties (partition coefficient, molar volume, dielectric constant), the TPA permeability data is predicted remarkably well by theory. If the radius of AN-12 is taken as 1.9 A, its permeability in the presence of butanol is also described by our analysis. Further, the theory quantitatively accounts for the data of Gutknecht and Tosteson (Gutknecht, J., Tosteson, D.C., 1970, J. Gen. Physiol. 55:359-374) covering alcohol-induced conductivity changes of 3 orders of magnitude in artificial bilayers. Other explanations including perturbations of membrane fluidity, surface charge, membrane thickness, and dipole potential are discussed. However, the large magnitude of the stimulation, the more pronounced effect on smaller ions, and the acceleration of both anions and cations suggest membrane dielectric constant change as the primary basis of alcohol effects.
已发现脂肪醇可刺激红细胞中疏水性阳离子（四苯基砷鎓，TPA）和阴离子（AN - 12）的跨膜通量达5 - 20倍。使用博恩 - 帕塞吉安方程（帕塞吉安，A.，1969年，《自然》（伦敦）221:844 - 846）以及克劳修斯 - 莫索蒂方程来分析结果，以计算膜介电能垒。利用已确定的膜厚度、天然膜介电常数、TPA离子半径和醇类性质（分配系数、摩尔体积、介电常数）的文献值，理论对TPA渗透率数据的预测非常准确。如果将AN - 12的半径设为1.9埃，我们的分析也能描述其在丁醇存在下的渗透率。此外，该理论定量解释了古特克内希特和托斯特森（古特克内希特，J.，托斯特森，D.C.，1970年，《普通生理学杂志》55:359 - 374）的数据，这些数据涵盖了醇类在人工双层膜中引起的3个数量级的电导率变化。还讨论了其他解释，包括膜流动性、表面电荷、膜厚度和偶极势的扰动。然而，刺激的幅度之大、对较小离子的影响更显著以及对阴离子和阳离子的加速作用表明，膜介电常数的变化是醇类作用的主要基础。
