文章基本信息

标题：Apolipoprotein E metabolism in normolipoproteinemic human subjects.
本地全文：下载
作者：R E Gregg ; L A Zech ; E J Schaefer 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：1984
卷号：25
期号：11
页码：1167-1176
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Human apolipoprotein E (apoE) is a constituent of plasma very low density and high density lipoproteins and is important in modulating the catabolism of remnants of triglyceride-rich lipoproteins. There are three common isoforms of apoE, designated apoE-2, E-3, and E-4, which are coded by three separate alleles (epsilon 2, epsilon 3, and epsilon 4) at a single genetic locus and inherited in the population in a co-dominant fashion. ApoE-3 is the predominant apoE isoform in the normolipidemic population, and epsilon 3 has been proposed to be the normal allele. ApoE-3 metabolism was studied in nine normolipidemic subjects homozygous for the epsilon 3 allele. In these subjects, the plasma apoE-3 concentration was 4.8 +/- 1.2 mg/dl (mean +/- SD), the plasma apoE-3 residence time was 0.73 +/- 0.18 days, and the plasma apoE-3 production rate was 3.4 +/- 1.5 mg/kg-day. The apoE in males, when compared to females, tended to have a shorter residence time (0.63 +/- 0.15 days versus 0.83 +/- 0.16), a higher production rate (4.20 +/- 1.73 mg/kg-days versus 2.60 +/- 0.78), but a similar plasma concentration (5.1 +/- 1.5 mg/dl versus 4.5 +/- 0.8). ApoE-3 had a more rapid catabolism from plasma than other apolipoproteins previously studied (apolipoproteins A-I, A-II, A-IV, B-100, C-II, and C-III) except for apolipoprotein B-48. The catabolism of apoE-3 in the individual lipoprotein subfractions was also examined and apoE was shown to be catabolized most rapidly from the VLDL and slowest from the HDL. The results of the kinetic analysis of apoE metabolism are consistent with apoE being important in the catabolism of triglyceride-rich lipoproteins and with HDL serving as a reservoir for apoE to reassociate with newly secreted triglyceride-rich lipoproteins.