Renner F, Samuelson A, Rogers M, Glickman R M
J Lipid Res. 1986 Jan;27(1):72-81.
The effect of saturated and unsaturated lipids on the composition of mesenteric lymph triglyceride-rich lipoproteins was studied in rats. A short-term steady-state infusion model was developed in mesenteric lymph fistula rats. Micellar solutions of linoleate, oleate, or palmitate were infused intraduodenally. Steady-state conditions of lymph flow, triglyceride, and apoA-I and apoB secretion rates were achieved in hours 3-5 after the start of the infusion. During this steady-state period, triglyceride-rich lipoproteins were prepared and characterized. With lipid infusion there were the expected increases in secretion rates of triglyceride, apoB, and apoA-I both in whole lymph and in the d less than 1.006 g/ml lipoproteins. Compositional analysis of d less than 1.006 g/ml lipoproteins revealed no difference in the ratios of phospholipid or apoA-I (surface) to triglyceride (core) constituents between saturated and unsaturated lipids, suggesting a similar particle size. This was directly verified by agarose gel filtration and electron microscopy carried out at 27 degrees C, which showed no difference in particle size between linoleate and palmitate chylomicrons. When these lipoproteins were prepared at 4 degrees C, palmitate lipoproteins exhibited dramatically changed gel filtration elution profiles, suggesting a shift to smaller or at least distorted particles and questioning earlier results suggesting a smaller size for saturated fat d less than 1.006 g/ml lipoproteins. Despite the similarity of size between saturated and unsaturated chylomicrons, the apoB content of unsaturated linoleate chylomicrons was significantly lower than that of palmitate chylomicrons. This difference was present whether chylomicrons were prepared by centrifugation or by gel filtration. The clearance of palmitate chylomicrons from the circulation of recipient rats was slightly more rapid than that of linoleate chylomicrons. The mechanism for this apparently selective increase in the apoB content of saturated fat chylomicrons is unknown but the present studies suggest that these changes may be of physiologic significance, perhaps relating to the potential atherogenicity of saturated lipids.
在大鼠中研究了饱和与不饱和脂质对肠系膜淋巴富含甘油三酯脂蛋白组成的影响。在肠系膜淋巴瘘管大鼠中建立了一个短期稳态输注模型。将亚油酸、油酸或棕榈酸的胶束溶液经十二指肠输注。在输注开始后的3至5小时内达到淋巴流量、甘油三酯以及载脂蛋白A-I和载脂蛋白B分泌率的稳态条件。在此稳态期间，制备并表征了富含甘油三酯的脂蛋白。随着脂质输注，全淋巴以及密度小于1.006 g/ml的脂蛋白中甘油三酯、载脂蛋白B和载脂蛋白A-I的分泌率均出现预期的增加。对密度小于1.006 g/ml的脂蛋白进行成分分析发现，饱和与不饱和脂质之间磷脂或载脂蛋白A-I（表面）与甘油三酯（核心）成分的比例没有差异，表明颗粒大小相似。这通过在27摄氏度下进行的琼脂糖凝胶过滤和电子显微镜直接得到验证，结果显示亚油酸和棕榈酸乳糜微粒之间的颗粒大小没有差异。当这些脂蛋白在4摄氏度下制备时，棕榈酸脂蛋白表现出显著改变的凝胶过滤洗脱图谱，表明转变为更小或至少是变形的颗粒，这对早期表明饱和脂肪密度小于1.006 g/ml的脂蛋白颗粒较小的结果提出了质疑。尽管饱和与不饱和乳糜微粒的大小相似，但不饱和亚油酸乳糜微粒的载脂蛋白B含量显著低于棕榈酸乳糜微粒。无论乳糜微粒是通过离心还是凝胶过滤制备，这种差异都存在。棕榈酸乳糜微粒从受体大鼠循环中的清除比亚油酸乳糜微粒略快。饱和脂肪乳糜微粒载脂蛋白B含量这种明显选择性增加的机制尚不清楚，但目前的研究表明这些变化可能具有生理意义，也许与饱和脂质潜在的致动脉粥样硬化性有关。
