SURFACE CHANGES INDUCED BY OSMOTIC-STRESS AND ITS INFLUENCE ON THE GLYCEROL PERMEABILITY IN LIPID BILAYERS
SURFACE CHANGES INDUCED BY OSMOTIC-STRESS AND ITS INFLUENCE ON THE GLYCEROL PERMEABILITY IN LIPID BILAYERS
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DOI：
10.1016/0005-2736(91)90097-r
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发表时间：
1991-10-14
期刊：
影响因子：
--
通讯作者：
DISALVO, EA
中科院分区：
文献类型：
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作者：
BIONDI, AC;FELIZ, MR;DISALVO, EA
甘油穿过脂质双层的渗透速率可以通过将填充有0.1 M葡萄糖溶液的脂质体分散在甘油的等渗或高渗溶液中来测定。甘油渗透的动力学被认为是在这些情况下的每一个不同的。脂质体分散在相变温度以上的高渗溶液中显示出表面极化的增加，通过mercury 540测量。在此条件下，甘油的渗透表现出两步动力学，这是一个非fickean扩散过程的指示。与此相反，脂质体分散在等渗溶液中的渗透显示出fickean行为。膜界面极化的变化归因于由于渗透塌陷和与外表面接触的甘油浓度引起的表面电位的变化。因此，极性分子的渗透性可以被认为是脂质体表面电位的函数，这与文献中先前的数据一致，文献中报道水渗透性增加是高渗溶液中脂质体收缩的zeta电位的函数。
The penetration rate of glycerol across lipid bilayers can be assayed dispersing liposomes filled with a 0.1 M glucose solution in an isotonic or a hypertonic solution of glycerol. The kinetic of glycerol permeation is found to be different in each of those cases. Liposomes dispersed above the phase transition temperature in hypertonic solutions show an increase in the surface polarization as measured by means of merocyanine 540. Under this condition, the permeation of glycerol shows a two-step kinetic which is indicative of a non-fickean diffusion process. In contrast, liposomes dispersed in isotonic solutions of the permeant show a fickean behavior. The changes in polarization of the membrane interface are ascribed to variations in the surface potential due to the osmotic collapse and the glycerol concentration in contact with the outer surface. The permeability of polar molecules can, in consequence, be considered as a function of the surface potential of the liposome which is congruent with previous data in literature reporting that water permeability increases as a function of the zeta potential of liposomes shrunken in hypertonic solutions.