Effects of dietary saturated and polyunsaturated fat on the metabolism of apolipoproteins A-I and B. Study of a patient with type IIb hyperlipoproteinaemia.
The effects of dietary saturated and polyunsaturated fat on the metabolism of apolipoprotein A-I (apoA-I) and apolipoprotein B (apoB) were studied in a patient with type IIb hyperlipoproteinaemia. On the saturated fat diet, the rate of synthesis of very low density lipoprotein apoprotein B (VLDL-apoB) was approximately twice normal, accounting for the increased plasma VLDL pool in this subject. However, 54% of the synthesized VLDL-apoB was catabolized by a pathway independent of low density lipoproteins (LDL). The metabolic conversion rate of VLDL-apoB to LDL-apoB was normal in this subject and his expanded plasma LDL-apoB pool resulted, not from increased input of the apoprotein from VLDL, but from a decrease in its fractional clearance rate. On the polyunsaturated diet, there was a significant fall in the plasma cholesterol and triglyceride concentrations and a change in the fatty acid composition of all plasma lipoprotein fractions. These changes were accompanied by a decrease in the plasma concentrations of apoA-I and apoB which resulted from a reduction of apoprotein synthetic rate.
D000368:Aged; D001053:Apolipoproteins / Q000097:blood*; D002784:Cholesterol / Q000097:blood; D004041:Dietary Fats / Q000494:pharmacology* / Q000627:therapeutic use; D005224:Fats, Unsaturated / Q000494:pharmacology*; D005227:Fatty Acids / Q000097:blood; D005231:Fatty Acids, Unsaturated / Q000097:blood; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood* / Q000178:diet therapy / Q000235:genetics*; D007700:Kinetics; D008075:Lipoproteins, HDL / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood*; D008297:Male; D008954:Models, Biological
D001053:Apolipoproteins; D004041:Dietary Fats; D005224:Fats, Unsaturated; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D002784:Cholesterol