Dwight J F, Hendry B M
Department of Medicine, King's College School of Medicine and Dentistry, London, UK.
Clin Chim Acta. 1995 Dec 15;243(1):73-85. doi: 10.1016/0009-8981(95)06156-8.
Erythrocyte membrane incorporation of exogenous short-chain diacyl phosphatidylcholines (PC) has been quantified by gas chromatography of fatty acid methyl esters of extracted membrane lipids after incubation of cells with sonicated aqueous suspensions of PC. The PCs studied included didecanoyl PC (C10-PC), dilauroyl PC (C12-PC), dimyristoyl PC (C14-PC) and dipalmitoyl PC (C16-PC). PC incorporation of 10-15 mol% was achieved by incubation at 37 degrees C for 0.5-24 h. Control cells incubated in saline alone showed a progressive reduction in endogenous polyunsaturated acyl chain content. Incubation with C10-PC and C16-PC was associated with reductions in membrane cholesterol. Experiments were performed with mixtures of PC and cholesterol in order to minimise this effect. Short-chain PC incorporation was associated with increases in intracellular Na+ and reduced intracellular K+ concentrations. Sodium pump activity was measured as the ouabain-sensitive rate of 86Rb+ influx and was significantly reduced by all PCs tested; mean reductions were 13-30%. These results confirm that the sodium pump in situ is sensitive to lipid acyl chain composition.
在用磷脂酰胆碱（PC）的超声水悬浮液孵育细胞后，通过对提取的膜脂脂肪酸甲酯进行气相色谱分析，对外源性短链二酰基磷脂酰胆碱（PC）掺入红细胞膜的情况进行了定量。所研究的PC包括二癸酰PC（C10-PC）、二月桂酰PC（C12-PC）、二肉豆蔻酰PC（C14-PC）和二棕榈酰PC（C16-PC）。在37℃孵育0.5至24小时可实现10 - 15摩尔%的PC掺入。仅在盐水中孵育的对照细胞显示内源性多不饱和酰基链含量逐渐降低。与C10-PC和C16-PC孵育会导致膜胆固醇降低。为了尽量减少这种影响，用PC和胆固醇的混合物进行了实验。短链PC掺入与细胞内Na⁺增加和细胞内K⁺浓度降低有关。钠泵活性通过哇巴因敏感的⁸⁶Rb⁺流入速率来测量，并且所有测试的PC均使其显著降低；平均降低幅度为13 - 30%。这些结果证实原位钠泵对脂质酰基链组成敏感。
