Postprandial lipaemia is associated with increased levels of apolipoprotein A-IV in the triacylglycerol-rich fraction and decreased levels in the denser plasma fractions.
Apolipoprotein (apo) A-IV is primarily associated with HDL or with the lipoprotein-free fraction of plasma, and in small amounts with chylomicrons and VLDL. The aim of the present study was to assess the effect of a fatty meal on the postprandial variation in plasma apo A-IV and on its distribution among lipoprotein fractions following absorption of fat. Twenty healthy male subjects participated in the study. After an overnight fast, subjects were given a fatty breakfast containing 1 g fat/kg body weight (% energy: fat 65, carbohydrate 20; protein 15). Blood samples were taken every hour during the next 10 h. Apo A-IV was measured by ELISA. Postprandial lipaemia was associated with a moderate, although significant, increase in the plasma levels of apo A-IV. Apo A-IV increased from the median baseline value of 0.15 g/l to 0.165 g/l (median +17%; P < 0.01) 5 h after fat ingestion. The postprandial peak of apo A-IV occurred 1 h after the triacylglycerol peak. There were no statistically significant correlations between baseline lipids, baseline apo A-IV and postprandial changes in apo A-IV levels, or between postprandial changes in lipids and apo A-IV at any time. To assess apo A-IV distribution among lipoproteins, plasma was fractionated by fast performance liquid chromatography at baseline and 3, 6 and 10 h postprandially. There was a substantial heterogeneity in the apo A-IV distribution among lipoproteins following the fatty meal. At 3 h after fat ingestion, apo A-IV levels increased in the triacyglycerol-rich lipoprotein (TRL) fraction and decreased in the denser plasma fraction. At 6 h after the fatty meal, apo A-IV was still present in the TRL but was decreased in the HDL fractions. The findings of the present study support the concept that apo A-IV particles transfer from the denser plasma fraction to TRL during postprandial lipaemia.
Dallongeville
J
J
SERLIA, Institut Pasteur de Lille, France.
Lebel
P
P
Parra
H J
HJ
Luc
G
G
Fruchart
J C
JC
D000328:Adult; D001054:Apolipoproteins A / Q000032:analysis / Q000378:metabolism*; D002850:Chromatography, Gel; D004041:Dietary Fats / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D019518:Postprandial Period; D014280:Triglycerides / Q000097:blood*
D001054:Apolipoproteins A; D004041:Dietary Fats; D014280:Triglycerides; C022205:apolipoprotein A-IV