Effect of dietary cholesterol on apolipoprotein E synthesis in the rabbit.
Female New Zealand White rabbits were fed either rabbit chow or rabbit chow plus 1% (w/w) cholesterol for 14 days. The chow-fed rabbits had normal plasma lipoprotein profiles on agarose gel electrophoresis, 59 +/- 5 mg of cholesterol and 5.5 +/- 0.4 mg of apolipoprotein E (apoE) per dl of serum. The cholesterol-fed rabbits had significant amounts of beta-VLDL in their serum, 1870 +/- 140 mg of cholesterol and 96 +/- 12 mg of apoE per dl of serum. Relative rates of apoE synthesis were determined by incubating hepatocytes in culture medium containing [3H]leucine for 15 min at 37 degrees C and expressing the radioactivity incorporated into immunoprecipitable apoE as a percentage of the radioactivity incorporated into total protein. Hepatocytes from cholesterol-fed rabbits had twice the relative rate of apoE synthesis (1.05 +/- 0.18%) of hepatocytes from chow-fed rabbits (0.55 +/- 0.07%). This increase in synthesis could be a major contributor to the 17-fold increase in serum apoE levels in the cholesterol-fed rabbit.
D000818:Animals; D001053:Apolipoproteins / Q000096:biosynthesis* / Q000097:blood; D001057:Apolipoproteins E; D002478:Cells, Cultured; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D004587:Electrophoresis, Agar Gel; D005260:Female; D008079:Lipoproteins, VLDL / Q000096:biosynthesis* / Q000097:blood; D008099:Liver / Q000166:cytology / Q000378:metabolism; D011817:Rabbits
D001053:Apolipoproteins; D001057:Apolipoproteins E; D002791:Cholesterol, Dietary; D008079:Lipoproteins, VLDL; D002784:Cholesterol