TRANSBILAYER EFFECTS OF ETHANOL ON FLUIDITY OF BRAIN MEMBRANE LEAFLETS
TRANSBILAYER EFFECTS OF ETHANOL ON FLUIDITY OF BRAIN MEMBRANE LEAFLETS
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DOI：
10.1016/0005-2736(88)90460-9
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发表时间：
1988-12-08
期刊：
影响因子：
--
通讯作者：
WOOD, WG
中科院分区：
文献类型：
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作者：
SCHROEDER, F;MORRISON, WJ;WOOD, WG
以前的工作对乙醇的膜效应集中在流化的散装膜脂双层。这项工作在本研究中扩展到乙醇对脂质结构域的影响。两个独立的方法被开发来检查乙醇对突触质膜（SPM）的内外小叶的影响。首先，差分偏振相位和调制荧光法和选择性淬灭的二苯基-1，3，5-己三烯（DPH）被用来检查个人小叶。SPM中DPH的极限各向异性和旋转松弛时间均表明外叶比内叶更具流动性。第二，质膜侧选择性荧光DPH衍生物，阳离子1-[4-（三甲基铵基）苯基]-6-苯基己-1，3，5-三烯（TMA-DPH）和阴离子3-[p-6-苯基）-1，3，5-己三烯基]苯基丙酸（PRO-DPH），证实了这种跨膜流动性差异。TMA-DPH和PRO-DPH分别优先定位于SPM的内、外小叶。与内瓣叶相比，体外乙醇在外瓣叶中具有更大的流化作用。因此，乙醇表现出特定的，而不是非特异性的流化作用内transbilayer SPM域。SPM外叶的这种优先流化可能在乙醇影响神经系统跨膜信号传导中起作用。
Previous work on membrane effects of ethanol focused on fluidization of the bulk membrane lipid bilayer. That work was extended in the present study to an examination of ethanol''s effect on lipid domains. Two independent methods were developed to examine the effects of ethanol on the inner and outer leaflets of synaptic plasma membranes (SPM). First, differential polarized phase and modulation fluorometry and selective quenching of diphenyl-1,3,5-hexatriene (DPH) were used to examine individual leaflets. Both limiting anistropy and rotational relaxation time of DPH in SPM indicated that the outer leaflet was more fluid than the inner leaflet. Second, plasma membrane sidedness selective fluorescent DPH derivatives, cationic 1-[4-(trimethylammonio)phenyl]-6-phenylhexa-1,3,5-triene (TMA-DPH) and anionic 3-[p-6-phenyl)-1,3,5-hexatrienyl]phenylpropionic acid (PRO-DPH), confirmed this transmembrane fluidity difference. TMA-DPH and PRO-DPH preferentially localized in the inner and outer leaflets of SPM, respectively. Ethanol in vitro had a greater fluidizing effect in the outer leaflet as compared to the inner leaflet. Thus, ethanol exhibits a specific rather than nonspecific fluidizing action within transbilayer SPM domains. This preferential fluidization of the SPM outer leaflet may have a role in ethanol affecting transmembrane signaling int he nervous system.