A Study of the Chylomicron Metabolism in WHHL Rabbits After Fat Loading. Discrepancy Between Results Based on Measurement of Apoprotein B-48 or Retinyl Palmitate

Overview

Journal Biochem J

Specialty Biochemistry

Date 1992 Jul 15

PMID 1637354

Authors

P N Demacker

P J van Heijst

A F Stalenhoef

Affiliations

Soon will be listed here.

Abstract

We studied the metabolism of chylomicrons in homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits and in cholesterol-fed or normally fed New Zealand White (NZW) rabbits by measuring the concentrations of apoprotein B-48 and of retinyl palmitate in their serum after feeding fat plus this vitamin according to two different protocols. Compared with NZW controls, retinyl palmitate accumulated in both hyperlipidaemic groups under study, not only in the d less than 1.019 fraction but also in the low-density lipoprotein (LDL) fraction. A strong correlation was found between the retinyl palmitate concentration in either the d less than 1.019 fraction or the LDL fraction of the WHHL rabbits and the concentrations of cholesterol and triacylglycerols in these fractions. This suggests that retinyl palmitate is exchanged rapidly between exogenous and endogenous lipoproteins. This is supported by the lack of a correlation between the retinyl palmitate concentrations and the intensity of the apoprotein B-48 band in the respective d less than 1.019 fractions or LDL fractions; in most fractions, in which large amounts of retinyl palmitate were present, the intensity of the apoprotein B-48 band was not increased compared with the fasting concentrations. Assuming that retinyl palmitate is a marker for the transfer of exogenous lipids, the results of our experiments indicate that the removal of exogenous lipids is delayed by complexing to endogenously synthesized lipoproteins. However, the clearance of apoprotein B-48 is normal and thus independent of the LDL-receptor activity.

References

HAVEL R, EDER H, Bragdon J . The distribution and chemical composition of ultracentrifugally separated lipoproteins in human serum. J Clin Invest. 1955; 34(9):1345-53. PMC: 438705. DOI: 10.1172/JCI103182. View

Demacker P, Van t Laar A, Jansen A . A descriptive study of the different electrophoretic patterns on agarose of human serum very-low-density lipoproteins. Clin Chem. 1978; 24(9):1439-44. View

Bowler A, Redgrave T, Mamo J . Chylomicron-remnant clearance in homozygote and heterozygote Watanabe-heritable-hyperlipidaemic rabbits is defective. Lack of evidence for an independent chylomicron-remnant receptor. Biochem J. 1991; 276 ( Pt 2):381-6. PMC: 1151102. DOI: 10.1042/bj2760381. View

Mamo J, Bowler A, Elsegood C, Redgrave T . Defective plasma clearance of chylomicron-like lipid emulsions in Watanabe heritable hyperlipidemic rabbits. Biochim Biophys Acta. 1991; 1081(3):241-5. DOI: 10.1016/0005-2760(91)90277-o. View

Beaumont J, Assadollahi F . Retinyl palmitate labeled intestinally derived lipoproteins accumulate in the circulation of WHHL rabbits. Atherosclerosis. 1990; 85(2-3):103-11. DOI: 10.1016/0021-9150(90)90102-o. View

Demacker P, MOL M, Stalenhoef A . Increased hepatic lipase activity and increased direct removal of very-low-density lipoprotein remnants in Watanabe heritable hyperlipidaemic (WHHL) rabbits treated with ethinyl oestradiol. Biochem J. 1990; 272(3):647-51. PMC: 1149757. DOI: 10.1042/bj2720647. View

Kowal R, Herz J, Goldstein J, ESSER V, Brown M . Low density lipoprotein receptor-related protein mediates uptake of cholesteryl esters derived from apoprotein E-enriched lipoproteins. Proc Natl Acad Sci U S A. 1989; 86(15):5810-4. PMC: 297720. DOI: 10.1073/pnas.86.15.5810. View

Demacker P, Hijmans A, Stalenhoef A, Van t Laar A . Studies on the function of hepatic lipase in the cat after immunological blockade of the enzyme in vivo. Atherosclerosis. 1988; 69(2-3):173-83. DOI: 10.1016/0021-9150(88)90012-3. View

MOL M, Stalenhoef A, Demacker P, vant Laar A . Low-density lipoprotein catabolism in WHHL rabbits after partial ileal bypass surgery. Biochim Biophys Acta. 1989; 1003(2):167-74. DOI: 10.1016/0005-2760(89)90251-8. View

10.

Stalenhoef A, van Niekerk J, Demacker P, Van t Laar A . Partial ileal bypass reduces the production rate of low density lipoproteins in Watanabe heritable hyperlipidemic rabbits. J Lipid Res. 1984; 25(12):1350-7. View

11.

Berr F, KERN Jr F . Plasma clearance of chylomicrons labeled with retinyl palmitate in healthy human subjects. J Lipid Res. 1984; 25(8):805-12. View

12.

Brenninkmeijer B, Stuyt P, Demacker P, Stalenhoef A, Van t Laar A . Catabolism of chylomicron remnants in normolipidemic subjects in relation to the apoprotein E phenotype. J Lipid Res. 1987; 28(4):361-70. View

13.

Son Y, ZILVERSMIT D . Increased lipid transfer activities in hyperlipidemic rabbit plasma. Arteriosclerosis. 1986; 6(3):345-51. View

14.

Redgrave T, Maranhao R . Metabolism of protein-free lipid emulsion models of chylomicrons in rats. Biochim Biophys Acta. 1985; 835(1):104-12. DOI: 10.1016/0005-2760(85)90036-0. View

15.

Redgrave T, Callow M . The effect of insulin deficiency on the metabolism of lipid emulsion models of triacylglycerol-rich lipoproteins in rats. Metabolism. 1990; 39(1):1-10. DOI: 10.1016/0026-0495(90)90140-8. View

16.

Ha Y, Barter P . Differences in plasma cholesteryl ester transfer activity in sixteen vertebrate species. Comp Biochem Physiol B. 1982; 71(2):265-9. DOI: 10.1016/0305-0491(82)90252-8. View

17.

Shimada Y, Tanzawa K, Kuroda M, Tsujita Y, Arai M, Watanabe Y . Biochemical characterization of skin fibroblasts derived from WHHL-rabbit, a notable animal model for familial hypercholesterolemia. Eur J Biochem. 1981; 118(3):557-64. DOI: 10.1111/j.1432-1033.1981.tb05555.x. View

18.

Kita T, Goldstein J, Brown M, Watanabe Y, Hornick C, HAVEL R . Hepatic uptake of chylomicron remnants in WHHL rabbits: a mechanism genetically distinct from the low density lipoprotein receptor. Proc Natl Acad Sci U S A. 1982; 79(11):3623-7. PMC: 346475. DOI: 10.1073/pnas.79.11.3623. View

19.

Goodman D . Vitamin A and retinoids in health and disease. N Engl J Med. 1984; 310(16):1023-31. DOI: 10.1056/NEJM198404193101605. View

20.

Wilson D, Chan I, Ball M . Plasma lipoprotein retinoids after vitamin A feeding in normal man: minimal appearance of retinyl esters among low-density lipoproteins. Metabolism. 1983; 32(5):514-7. DOI: 10.1016/0026-0495(83)90016-1. View