Rudel L L, Greene D G, Shah R
J Lipid Res. 1977 Nov;18(6):734-44.
A group of 14 adult male rhesus monkeys was maintained on a low cholesterol-high fat diet. Periodically, animals were fasted and blood samples were taken for characterization of the plasma lipoproteins. Complete separation of individual plasma lipoprotein classes was not achieved by traditional sequential ultracentrifugation techniques. Rather, initial separation of lipoprotein classes according to size was effected and density centrifugation was used subsequently for further separation. At least six lipoprotein fractions were identified, each of which was unique as defined by the properties of size, density (d), and electrophoretic mobility. These lipoprotein fractions were characterized by determination of chemical compositions and apoprotein patterns. The lipoproteins present in highest concentration in these monkeys were designated as region IV lipoproteins. This fraction had alpha-migration on agarose electrophoresis, 1.063 < d < 1.225, and the size, composition, and apoprotein pattern characteristic of HDL. No fewer than three fractions were identified with densities that overlapped the 1.019 < d < 1.063 range. Of these, the fraction designated as region III lipoproteins was present in highest concentration, had beta-migration by agarose electrophoresis, a predominant B apoprotein, and a chemical composition and size characteristic of LDL. Two larger subfractions, identified as region II lipoproteins, were separated from each other at a density of 1.050 g/ml. Agarose electrophoresis showed that the fraction with d < 1.050 had a migration intermediate between beta and pre-beta. The chemical composition and apoprotein pattern were consistent with the possibility that these lipoproteins were remnants of VLDL catabolism. The fraction with d > 1.050, had pre-beta mobility and a size and composition similar to the Lp(a) lipoprotein in plasma of human beings. At least two VLDL subfractions, identified as region I and IIa lipoproteins, were found although both were present in very low concentrations. Region I lipoproteins were larger and contained relatively more cholesteryl ester and more of the apoproteins that migrated with the mobility of apo-B and arg-rich apoprotein in SDS-polyacrylamide gel electrophoresis. Some of the region I lipoproteins were beta-migrating by agarose electrophoresis. These results suggested the possibility that a beta-migrating VLDL was present in these normal animals.
一组14只成年雄性恒河猴被给予低胆固醇-高脂肪饮食。定期让动物禁食，并采集血样以对血浆脂蛋白进行表征。传统的连续超速离心技术未能实现单个血浆脂蛋白类别的完全分离。相反，首先根据大小对脂蛋白类别进行分离，随后使用密度离心进行进一步分离。至少鉴定出六个脂蛋白组分，每个组分根据大小、密度（d）和电泳迁移率的特性都是独特的。通过测定化学组成和载脂蛋白模式对这些脂蛋白组分进行了表征。这些猴子中浓度最高的脂蛋白被指定为IV区脂蛋白。该组分在琼脂糖电泳上呈α迁移，1.063 < d < 1.225，具有HDL的大小、组成和载脂蛋白模式特征。鉴定出不少于三个密度与1.019 < d < 1.063范围重叠的组分。其中，被指定为III区脂蛋白的组分浓度最高，在琼脂糖电泳上呈β迁移，主要为B载脂蛋白，具有LDL的化学组成和大小特征。在密度为1.050 g/ml时分离出两个较大的亚组分，被鉴定为II区脂蛋白。琼脂糖电泳显示，d < 1.050的组分迁移介于β和前β之间。化学组成和载脂蛋白模式与这些脂蛋白可能是VLDL分解代谢残余物的可能性一致。d > 1.050的组分具有前β迁移率，大小和组成与人类血浆中的Lp(a)脂蛋白相似。尽管两者浓度都非常低，但至少发现了两个被鉴定为I区和IIa区脂蛋白的VLDL亚组分。I区脂蛋白更大，含有相对更多的胆固醇酯以及更多在SDS-聚丙烯酰胺凝胶电泳中以apo-B和富含精氨酸载脂蛋白的迁移率迁移的载脂蛋白。一些I区脂蛋白在琼脂糖电泳上呈β迁移。这些结果表明这些正常动物中可能存在呈β迁移的VLDL。
