Griffin H, Grant G, Perry M
Biochem J. 1982 Sep 15;206(3):647-54. doi: 10.1042/bj2060647.
Very-low-density (VLD) lipoproteins and portomicrons were isolated from the plasma of immature and laying hens and their size, lipid composition and susceptibility to hydrolysis by lipoprotein lipase were compared. In agreement with other studies, VLD lipoproteins from laying hens were found to be smaller and have a different lipid composition than VLD lipoproteins from immature hens. Portomicrons from immature and laying hens had mean diameters of about 150 nm and similar lipid compositions. Hydrolysis of VLD lipoproteins from immature hens, and portomicrons from immature and laying hens, proceeded rapidly until at least 40% of the substrate had been used. In contrast only 1--15% of laying-hen VLD-lipoprotein triacylglycerol was readily hydrolysis occurred slowly. The limited susceptibility of laying-hen VLD lipoproteins appeared to be due to their low content of lipoprotein lipase activator apoprotein, which occurred despite an abundance of activator in the high-density lipoproteins of laying-hen plasma. The results provide further evidence that the liver of the laying hen synthesizes specialized lipoproteins. Their limited susceptibility to hydrolysis by lipoprotein lipase is probably a major factor in ensuring transport of lipid to yolk rather than to other tissues. The form of transport of dietary lipid, however, is similar in immature and laying hens.
从未成熟母鸡和产蛋母鸡的血浆中分离出极低密度（VLD）脂蛋白和乳糜微粒，并比较了它们的大小、脂质组成以及对脂蛋白脂肪酶水解的敏感性。与其他研究一致，发现产蛋母鸡的VLD脂蛋白比未成熟母鸡的VLD脂蛋白更小，脂质组成也不同。未成熟母鸡和产蛋母鸡的乳糜微粒平均直径约为150纳米，脂质组成相似。未成熟母鸡的VLD脂蛋白以及未成熟母鸡和产蛋母鸡的乳糜微粒的水解迅速进行，直到至少40%的底物被消耗。相比之下，产蛋母鸡VLD脂蛋白的三酰甘油只有1%-15%易于水解，水解过程缓慢。产蛋母鸡VLD脂蛋白对水解的敏感性有限似乎是由于其脂蛋白脂肪酶激活载脂蛋白含量低，尽管产蛋母鸡血浆中的高密度脂蛋白中有大量激活剂，但仍出现这种情况。结果进一步证明产蛋母鸡的肝脏合成特殊的脂蛋白。它们对脂蛋白脂肪酶水解的敏感性有限可能是确保脂质运输到蛋黄而不是其他组织的一个主要因素。然而，未成熟母鸡和产蛋母鸡中膳食脂质的运输形式相似。
