Alimentary lipemia: plasma high-density lipoproteins and apolipoproteins CII and CIII in healthy subjects.
Three healthy male and three female inpatient volunteers consumed isocaloric diets for 4 wk. At weekly intervals, a fatty meal (100 g fat) was consumed by each fasting subject and blood drawn at 2 h intervals for 12 h. Of the four oral fat loads, two contained saturated fat (polyunsaturated/saturated fat ratio = 0.34) and two contained unsaturated fat (polyunsaturated/saturated fat = 2.21). The magnitude of alimentary lipemia, expressed as area under the plasma triglyceride curve, was 3- to 4-fold higher in males than females. Alimentary lipemia was inversely related to the subjects' fasting plasma high-density lipoprotein (HDL)-cholesterol, HDL apolipoprotein (apo) CIII and directly related to plasma triglycerides. The P/S ratios of the daily diet or the fat meal did not significantly influence the plasma triglyceride curve. After fat intake, mean (+/- SEM) plasma total apoCII and CIII fell to 54 +/- 20% and 73 +/- 5% of base-line, respectively, at 12 h in five of six subjects. After oral fat, an initial fall and a subsequent rise in apoCII and CIII in HDL was associated with reciprocal changes in apoC concentrations in very low-density lipoproteins. We speculate from the data that 1) plasma HDL and their apoC concentrations are important determinants of chylomicron clearance and 2) transfer of apoCs from HDL to triglyceride-rich lipoproteins in the early phase of fat absorption does not result in the total recycling of apoCs from these lipoproteins to HDL during the late phase of alimentary lipemia.
D000293:Adolescent; D000328:Adult; D053304:Apolipoprotein C-II; D053305:Apolipoprotein C-III; D001053:Apolipoproteins / Q000097:blood*; D001056:Apolipoproteins C; D004041:Dietary Fats / Q000008:administration & dosage*; D004064:Digestive System / Q000378:metabolism*; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood*; D008297:Male; D012737:Sex Factors; D014280:Triglycerides / Q000097:blood*
D053304:Apolipoprotein C-II; D053305:Apolipoprotein C-III; D001053:Apolipoproteins; D001056:Apolipoproteins C; D004041:Dietary Fats; D008075:Lipoproteins, HDL; D014280:Triglycerides