A high carbohydrate-fat free diet alters the proportion of heparin-bound VLDL in plasma and the expression of VLDL-apoB-100 epitopes.
High carbohydrate-fat free diets (CHO-diet) induce the secretion of increased numbers of very-low-density lipoprotein (VLDL) particles and alter the composition and metabolism of VLDL. The aims of this study were to examine VLDL in greater detail, specifically to document any CHO-diet-induced alterations of apolipoprotein B-100 (apoB-100) epitope expression of VLDL, and any changes induced in subclasses of VLDL, as defined by heparin Sepharose chromatography. Fifteen normolipidemic subjects participated in the study by eating a basal typical American diet for 7 days and high carbohydrate diet (85% carbohydrate, less than 1% fat) for another 7 days. The sequence was changed in seven subjects. Fasting blood samples were analyzed for lipoprotein lipid and apoprotein concentrations. Heparin affinity VLDL subclasses were characterized chemically and electrophoretically [sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE)]. Immunoreactivities of apoB in VLDL were tested in solid phase competitive-binding radioimmunoassays (RIAs) using five monoclonal anti-B antibodies that react with defined epitopes of apoB-100. The CHO diet produced consistent increases of plasma triglycerides in all subjects by a mean of 66% and decreases in plasma cholesterol by 18%. ApoB in plasma decreased by 21% and apoA-I by 17%; however, apoE and ApoA-II did not change. VLDL was enriched with triglycerides (55.0% +/- 0.8 v 57.0% +/- 0.7, P less than .05) and apoE (3.7% +/- 0.5 to 5.9% +/- 0.7, P less than .007) and the ratio between apoE and apoC in VLDL increased (0.15 +/- 0.03 to 0.25 +/- 0.03, P less than .002).(ABSTRACT TRUNCATED AT 250 WORDS)
Keidar
S
S
Department of Medicine, Washington University School of Medicine, St Louis, MO.
Goldberg
A C
AC
Cook
K
K
Bateman
J
J
Schonfeld
G
G
D000328:Adult; D000911:Antibodies, Monoclonal; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000097:blood* / Q000302:isolation & purification; D001056:Apolipoproteins C / Q000097:blood; D001057:Apolipoproteins E / Q000097:blood* / Q000302:isolation & purification; D001665:Binding Sites / Q000187:drug effects; D015243:Cholesterol, VLDL / Q000032:analysis; D002846:Chromatography, Affinity; D003429:Cross Reactions; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006493:Heparin / Q000378:metabolism; D006801:Humans; D008079:Lipoproteins, VLDL / Q000097:blood* / Q000302:isolation & purification; D008297:Male; D010743:Phospholipids / Q000032:analysis; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D001056:Apolipoproteins C; D001057:Apolipoproteins E; D015243:Cholesterol, VLDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D008079:Lipoproteins, VLDL; D010743:Phospholipids; D006493:Heparin