Bochenek W J, Weber P, Slowinska R, Tang G X, Rodgers J B
Department of Medicine, Albany Medical College, New York 12208.
Lipids. 1990 Oct;25(10):665-8. doi: 10.1007/BF02536019.
Monosaccharide composition was determined in apolipoprotein B-48 (apoB) of chylomicrons of rat mesenteric lymph. Chylomicrons were separated into three fractions based on density. Triglyceride and apolipoprotein content were determined in each. ApoB was isolated and quantified using precipitation with isopropanol. Chylomicrons were collected in lymph under normal conditions, and with Poloxalene 2930 when chylomicron secretion was inhibited. Most of the triglyceride was carried in the least dense fraction, while the highest apoB content was in the most dense fraction under normal conditions. Mannose and galactosamine contents of apoB were similar in all fractions while contents of both glucosamine and galactose were highest in the least dense fraction. When chylomicron secretion was inhibited by Poloxalene, the amount of triglyceride recovered in the least dense fraction was significantly reduced. Despite the inhibition of lipid transport in the least dense fraction of chylomicrons by Poloxalene, there was little change in apoB recoveries and in the relative content of various monosaccharides in the apoB from each of the three fractions as compared to results obtained during lipid absorption under normal conditions. In conclusion, carbohydrate composition of apoB of chylomicrons is heterogeneous and varies with chylomicron density.
测定了大鼠肠系膜淋巴乳糜微粒中载脂蛋白B - 48（apoB）的单糖组成。根据密度将乳糜微粒分为三个组分。分别测定了各组分中的甘油三酯和载脂蛋白含量。使用异丙醇沉淀法分离并定量apoB。在正常条件下收集淋巴中的乳糜微粒，当乳糜微粒分泌受抑制时，使用泊洛沙林2930收集乳糜微粒。在正常条件下，大部分甘油三酯存在于密度最小的组分中，而载脂蛋白B含量最高的是密度最大的组分。各组分中apoB的甘露糖和半乳糖胺含量相似，而葡糖胺和半乳糖的含量在密度最小的组分中最高。当用泊洛沙林抑制乳糜微粒分泌时，密度最小的组分中回收的甘油三酯量显著减少。尽管泊洛沙林抑制了乳糜微粒密度最小的组分中的脂质转运，但与正常条件下脂质吸收时的结果相比，apoB的回收率以及三个组分中apoB各种单糖的相对含量几乎没有变化。总之，乳糜微粒apoB的碳水化合物组成是异质的，并且随乳糜微粒密度而变化。
