Børsum K, Aksnes J, Müller F, Hagve T A, Kierulf P, Rollag H
Institute of Clinical Biochemistry, National Hospital, University of Oslo, Norway.
APMIS. 1997 Sep;105(9):671-9. doi: 10.1111/j.1699-0463.1997.tb05070.x.
Administration of total parenteral nutrition (TPN) with soybean oil emulsion leads to a linoleic acid enrichment of the plasma membrane that may explain an in vivo activation of mononuclear cells (MNC) seen in our previous studies. Fatty acids from the lipid emulsion may have been accessible to MNC after endocytosis of lipid particles, or by direct uptake of fatty acids after lipoprotein lipase hydrolyzation of the emulsion triglycerides. To resemble the incorporation of fatty acids in vivo, we have modified MNC membrane lipid composition by incubation with different albumin-bound unsaturated fatty acids (UFA) or soybean oil emulsion. After incubation with albumin-bound linoleic and oleic acid, the unstimulated release of superoxide anion was unchanged, while zymosan-stimulated release was 140% (n.s) and 112% (p < 0.05) and phorbol-myristate-acetate (PMA)-stimulated release 148% (p < 0.05) and 124% (p < 0.05) of controls, respectively. Incubation with other UFAs or emulsion did not change superoxide anion release. Unstimulated lymphocyte proliferation increased 3 to 13-fold (p < 0.05) after incubation with all UFAs compared to controls, while UFA incubation did not change phytohemagglutinin (PHA) or PMA-stimulated proliferation. Unstimulated lymphocyte proliferation was decreased after incubation with emulsion, while PHA/PMA-stimulated proliferation was unchanged. Increase in membrane fluidity was detectable only after incubation with emulsion. The increased reactivity may have been caused by changes in the lipid environment surrounding membrane-bound enzymes important for signal transduction through the plasma membrane.
使用大豆油乳剂进行全胃肠外营养（TPN）会导致质膜中富含亚油酸，这可能解释了我们之前研究中观察到的体内单核细胞（MNC）激活现象。脂质乳剂中的脂肪酸可能在脂质颗粒被MNC内吞后进入细胞，或者在脂蛋白脂肪酶水解乳剂甘油三酯后通过直接摄取脂肪酸进入细胞。为了模拟体内脂肪酸的掺入情况，我们通过与不同的白蛋白结合不饱和脂肪酸（UFA）或大豆油乳剂孵育来改变MNC膜脂质组成。与白蛋白结合的亚油酸和油酸孵育后，超氧阴离子的基础释放量未改变，而酵母聚糖刺激的释放量分别为对照的140%（无统计学意义）和112%（p<0.05），佛波酯-肉豆蔻酸酯-乙酸酯（PMA）刺激的释放量分别为对照的148%（p<0.05）和124%（p<0.05）。与其他UFA或乳剂孵育未改变超氧阴离子的释放。与对照相比，所有UFA孵育后基础淋巴细胞增殖增加了3至13倍（p<0.05），而UFA孵育未改变植物血凝素（PHA）或PMA刺激的增殖。与乳剂孵育后基础淋巴细胞增殖减少，而PHA/PMA刺激的增殖未改变。仅在与乳剂孵育后可检测到膜流动性增加。反应性增加可能是由于对通过质膜进行信号转导很重要的膜结合酶周围脂质环境的变化所致。
