Synaptosomal membrane lipids of mice during continuous exposure to ethanol
Synaptosomal membrane lipids of mice during continuous exposure to ethanol
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持续接触乙醇期间小鼠突触体膜脂质
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
G. John
中科院分区：
文献类型：
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作者：
J. Littleton;G. John
小鼠持续暴露于不断增加的乙醇蒸气中首先与对乙醇耐受性的产生有关，并且在更多剂量给药后，与对4-羟基乙醇的身体依赖性有关（Griffiths，利特尔顿和Ortiz，1974）。导致耐受性zd依赖性的中枢神经系统的变化尚不清楚，但Chin和Goldstein（1977）报道，在乙醇依赖性小鼠的分离的flaPt，c膜中可以证明对乙醇的物理cBcc的耐受性。（1976）提出，细菌对乙醇的耐受性是在细胞膜磷脂中掺入不同不饱和度的脂肪酸后产生的。我们自己的研究结果（A（，Murad，Begg & others，1977; Griffiths，Abu，gurad &利特尔顿，1977）暗示了在身体对乙醇依赖性的发展中脂质、的改变。这似乎是重要的，以确定是否在小鼠脑突触体膜的脂肪酸组成的dmg的发生在任何阶段，在连续给药的乙醇。将T O Swiss品系小鼠（LAB，达格纳姆，asex）以上述方法暴露于乙醇蒸汽中（Griffiths & others，1974）。在开始吸入乙醇后2小时，当没有观察到身体依赖的迹象时，或在开始吸入乙醇后10天，当乙醇的戒断导致身体戒断综合征时，处死小鼠（投入液氮中）。将这些乙醇处理过的动物的大脑与保持在相同条件下的小鼠的大脑进行比较，除了乙醇不存在于吸入的空气中。向一些对照脑中加入处理小鼠脑中获得的浓度的乙醇，以确定乙醇的存在对脂肪酸测量的影响。将单个小鼠全脑在10 G冷的0.32 M蔗糖中均质化，并以1500 g离心10 min。将上清液以25000 g在0 ℃离心30 min，并对沉淀中的粗突触体部分进行Folch提取。将磷脂吸附到油酸浆液上，然后用甲醇洗脱。碱性水解后，用三氟化硼-甲醇试剂（BDH）煮沸2 min使脂肪酸甲基化。用氯仿萃取并用蒸馏水洗涤后，在氮气下干燥β-乙基酯，并在层析前储存在“kat 4”中（最长时间为4小时）。用气-液色谱法（N，作载体，70 ml min-1）分离了酸甲酯，
ontinuous exposure of mice to increasing conozztions of ethanol vapour is associated first with the lopment of tolerance to ethanol and, after more nged administration, with physical dependence on 4anol (Griffiths, Littleton & Ortiz, 1974). The changes the central nervous system which lead to tolerance zd dependence are unknown, but Chin & Goldstein (1977) have reported that tolerance to the physical cBcctS .of ethanol can be demonstrated in the isolated flaPt,c membranes of ethanol-dependent mice. (1976) has suggested that development of ,lerance to ethanol by bacteria follows the incorporation of fatty acids of different degrees of unsaturation cell membrane phospholipids. Our own results (A(,,, Murad, Begg & others, 1977; Griffiths, Abu ,,gurad & Littleton, 1977) implicate alterations in lipid ,,,&olism in the development of physical dependence on ethanol. It seemed important to establish whether d m g e s in the fatty acid composition of synaptosomal membranes of mouse brain occurred a t any stage during the continuous administration of ethanol. Mice of the T O Swiss strain (LAB, Dagenham, asex) were exposed to ethanol vapour in the way p~viously described (Griffiths & others, 1974). Mice *re killed (plunging into liquid nitrogen) either 2 h rrfter commencing inhalation of ethanol, when no signs of physical dependence are seen, or 10 days after commencing inhalation, when withdrawal of ethanol results in a physical withdrawal syndrome. Brains from these ethanol-treated animals were compared with those of mice kept under identical conditions except that ethanol was not present in the inspired air. Ethanol, in the concentration obtained in brains of treated mice, was added to some control brains to establish the effect of the presence of ethanol on the measurement of fatty acids. Individual whole mouse brains were homogenized in ioGcold 0.32 M sucrose and centrifuged a t SOOg for 10 min. The supernatant was recentrifuged a t 25 OOOg for 30 min at 0" and the crude synaptosomal fraction in the Pellet subjected to Folch extraction. Phospholipids were adsorbed onto a silicic acid slurry and then eluted Mth methanol. After alkaline hydrolysis the fatty acids methylated by boiling for 2 min with boron tlfluoride-methanol reagent (BDH). After extraction W h chloroform and washing with distilled water, the -thYlesters were dried under nitrogen and stored in the &kat4" (maximum period 4 h) before chromatography. acid methylesters were separated by gas-liquid cbomatography (N, as carrier a t 70 ml min-' through a prolo