title: Properties and metabolic fate of two very low density lipoprotein subfractions from rhesus monkey serum.
abstract: Physical, chemical and physiological approaches were used to examine the properties of two very low density lipoproteins, VLDL-I (slow-beta), and VLDL-II (pre-beta), which were isolated by agarose column chromatography from the serum of rhesus monkeys fed either Purina Chow or one of four hyperlipidemic diets containing 0.5-20% cholesterol suspended in either coconut oil, peanut oil, mixed coconut oil and butter fat or lard. In the coconut oil-fed hyperlipidemic animals, the majority of the apolar lipids of VLDL-I was represented by cholesteryl esters. The small percentage of triacylglycerol (15%) had a fatty acid composition which resembled that of the fatty acid in each of the diets. In turn, VLDL-II had a triacylglycerol-rich core and differed from VLDL-I in apolipoprotein distribution (VLDL-I: low molecular weight apolipoprotein B, 36%; apolipoprotein E, 64%; and VLDL-II: high molecular weight apolipoprotein B, 38%; apolipoprotein E, 3%; and apolipoprotein C, 65%). Both VLDLs were hydrolyzed in vitro by milk lipoprotein lipase by first-order kinetics although VLDL-I exhibited a slightly slower reaction rate. When an oral dose of [3H]retinol was given to one of the animals, both VLDLs became labeled but the specific activity of VLDL-I was six times higher than that of VLDL-II and the other lipoproteins. We conclude that VLDL-I represents a cholesteryl ester-rich lipoprotein probably of intestinal origin, whereas VLDL-II may be a particle of hepatic derivation modified by its interaction with the other plasma lipoproteins.
mesh_terms: D000818:Animals; D001053:Apolipoproteins / Q000097:blood; D004587:Electrophoresis, Agar Gel; D005227:Fatty Acids / Q000032:analysis; D007700:Kinetics; D008071:Lipoprotein Lipase / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000097:blood*; D008253:Macaca mulatta; D008297:Male; D008970:Molecular Weight; D011485:Protein Binding; D014280:Triglycerides / Q000032:analysis; D014801:Vitamin A / Q000378:metabolism
chemical_list: D001053:Apolipoproteins; D005227:Fatty Acids; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D014801:Vitamin A; D008071:Lipoprotein Lipase