title: Serum high-density lipoprotein particles of alcohol-fed rats are deficient in apolipoprotein E.
abstract: Effects of chronic ethanol consumption on serum lipoproteins have been studied in the rat. The serum levels of triglycerides, cholesterol, phospholipids and apolipoproteins AI and AIV increased significantly after 1 week of ethanol feeding, and they remained elevated up to 7 weeks of alcohol drinking. By contrast, serum total apolipoprotein E decreased or, sometimes, did not change. Very-low-density lipoprotein cholesterol, triglycerides and very-low-density lipoprotein apolipoprotein E of the alcohol-fed rats increased in parallel and were about 2- to 2.5-fold over the controls. Whereas high-density lipoprotein cholesterol, phospholipids, apolipoprotein AI and AIV increased 1.2-fold by chronic alcohol feeding, the level of high-density lipoprotein apolipoprotein E decreased to 70% of that of the control rats. The rates of secretion of apolipoprotein AI, E and AIV into the culture medium by hepatocytes isolated from ethanol-fed rats were 1.8-, 1.3- and 1.1-fold higher than those from control rats. These data indicate that (i) chronic ethanol feeding increases very-low-density lipoprotein and high-density lipoprotein in the rat; (ii) serum high-density lipoprotein particles of the ethanol-fed rats are deficient in apolipoprotein E, and (iii) chronic ethanol feeding increases hepatic secretion of apolipoprotein AI, E and AIV. Since the steady-state serum level of apolipoprotein E decreases or remains unchanged in the presence of increased hepatic apolipoprotein E secretion, this imbalance suggests that alcohol feeding either accelerates the rate of degradation of serum apolipoprotein E or suppresses apolipoprotein E synthesis by nonhepatic tissues.
authors.affiliation: Veterans Administration Medical Center, Indianapolis, Indiana 46202.
authors.forename: R C
authors.initials: RC
authors.lastname: Lin
authors.forename: L
authors.initials: L
authors.lastname: Lumeng
authors.forename: V L
authors.initials: VL
authors.lastname: Phelps
mesh_terms: D000418:Albumins / Q000378:metabolism; D000818:Animals; D016632:Apolipoprotein A-I; D001053:Apolipoproteins / Q000378:metabolism; D001054:Apolipoproteins A / Q000097:blood; D001057:Apolipoproteins E / Q000097:blood / Q000172:deficiency*; D002784:Cholesterol / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000494:pharmacology; D004435:Eating; D004591:Electrophoresis, Polyacrylamide Gel; D000431:Ethanol / Q000494:pharmacology*; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000097:blood; D014280:Triglycerides / Q000097:blood; D015430:Weight Gain
chemical_list: D000418:Albumins; D016632:Apolipoprotein A-I; D001053:Apolipoproteins; D001054:Apolipoproteins A; D001057:Apolipoproteins E; D004040:Dietary Carbohydrates; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C022205:apolipoprotein A-IV; D000431:Ethanol; D002784:Cholesterol