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. 1981 Mar;78(3):1396–1400. doi: 10.1073/pnas.78.3.1396

Saturation and suppression of hepatic lipoprotein receptors: a mechanism for the hypercholesterolemia of cholesterol-fed rabbits.

P T Kovanen, M S Brown, S K Basu, D W Bilheimer, J L Goldstein
PMCID: PMC319137  PMID: 6262794

Abstract

Cholesterol-fed rabbits develop a marked in crease in plasma cholesterol levels. Most of the excess plasma cholesterol is contained in beta-migrating very low density lipoprotein (beta-VLDL), a cholesterol-rich particle that contains apoproteins B and E. When 125I-labeled beta-VLDL from cholesterol-fed rabbits was injected intravenously into normal rabbits, the lipoprotein was cleared rapidly from plasma, 80% of the radioactivity appearing in the liver within 4 min. In vitro binding assays showed that this uptake was due to the presence on liver membranes of a high-affinity, low-capacity binding site that resembles the low density lipoprotein receptor previously characterized on extrahepatic tissues. When the 125I-labeled beta-VLDL was injected into cholesterol-fed rabbits, hepatic uptake was reduced by more than 95% and the lipoprotein remained in the plasma. This defective uptake in cholesterol-fed rabbits was due to two factors: (i) saturation of the lipoprotein receptors by the high concentration of endogenous plasma beta-VLDL and (ii) a 60% reduction in the number of hepatic receptors after cholesterol feeding. Of the two factors, saturation of receptors was quantitatively more important. We suggest that, as a result of the saturation and suppression of receptors, the hepatic removal of beta-VLDL in the cholesterol-fed rabbit fails to increase commensurate with the diet-induced increase in beta-VLDL synthesis and profound hypercholesterolemia ensues.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bilheimer D. W., Eisenberg S., Levy R. I. The metabolism of very low density lipoprotein proteins. I. Preliminary in vitro and in vivo observations. Biochim Biophys Acta. 1972 Feb 21;260(2):212–221. doi: 10.1016/0005-2760(72)90034-3. [DOI] [PubMed] [Google Scholar]
  2. Chao Y. S., Jones A. L., Hradek G. T., Windler E. E., Havel R. J. Autoradiographic localization of the sites of uptake, cellular transport, and catabolism of low density lipoproteins in the liver of normal and estrogen-treated rats. Proc Natl Acad Sci U S A. 1981 Jan;78(1):597–601. doi: 10.1073/pnas.78.1.597. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dietschy J. M., Wilson J. D. Regulation of cholesterol metabolism. I. N Engl J Med. 1970 May 14;282(20):1128–1138. doi: 10.1056/NEJM197005142822005. [DOI] [PubMed] [Google Scholar]
  4. Goldstein J. L., Brown M. S. The low-density lipoprotein pathway and its relation to atherosclerosis. Annu Rev Biochem. 1977;46:897–930. doi: 10.1146/annurev.bi.46.070177.004341. [DOI] [PubMed] [Google Scholar]
  5. Goldstein J. L., Ho Y. K., Brown M. S., Innerarity T. L., Mahley R. W. Cholesteryl ester accumulation in macrophages resulting from receptor-mediated uptake and degradation of hypercholesterolemic canine beta-very low density lipoproteins. J Biol Chem. 1980 Mar 10;255(5):1839–1848. [PubMed] [Google Scholar]
  6. Innerarity T. L., Mahley R. W. Enhanced binding by cultured human fibroblasts of apo-E-containing lipoproteins as compared with low density lipoproteins. Biochemistry. 1978 Apr 18;17(8):1440–1447. doi: 10.1021/bi00601a013. [DOI] [PubMed] [Google Scholar]
  7. Kovanen P. T., Basu S. K., Goldstein J. L., Brown M. S. Low density lipoprotein receptors in bovine adrenal cortex. II. Low density lipoprotein binding to membranes prepared from fresh tissue. Endocrinology. 1979 Mar;104(3):610–616. doi: 10.1210/endo-104-3-610. [DOI] [PubMed] [Google Scholar]
  8. Kovanen P. T., Bilheimer D. W., Goldstein J. L., Jaramillo J. J., Brown M. S. Regulatory role for hepatic low density lipoprotein receptors in vivo in the dog. Proc Natl Acad Sci U S A. 1981 Feb;78(2):1194–1198. doi: 10.1073/pnas.78.2.1194. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Kovanen P. T., Brown M. S., Goldstein J. L. Increased binding of low density lipoprotein to liver membranes from rats treated with 17 alpha-ethinyl estradiol. J Biol Chem. 1979 Nov 25;254(22):11367–11373. [PubMed] [Google Scholar]
  10. Kovanen P. T., Goldstein J. L., Chappell D. A., Brown M. S. Regulation of low density lipoprotein receptors by adrenocorticotropin in the adrenal gland of mice and rats in vivo. J Biol Chem. 1980 Jun 25;255(12):5591–5598. [PubMed] [Google Scholar]
  11. Kushwaha R. S., Hazzard W. R. Catabolism of very low density lipoproteins in the rabbit. Effect of changing composition and pool size. Biochim Biophys Acta. 1978 Feb 27;528(2):176–189. doi: 10.1016/0005-2760(78)90192-3. [DOI] [PubMed] [Google Scholar]
  12. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  13. Mahley R. W., Innerarity T. L., Brown M. S., Ho Y. K., Goldstein J. L. Cholesteryl ester synthesis in macrophages: stimulation by beta-very low density lipoproteins from cholesterol-fed animals of several species. J Lipid Res. 1980 Nov;21(8):970–980. [PubMed] [Google Scholar]
  14. Mahley R. W., Innerarity T. L., Weisgraber K. B., Oh S. Y. Altered metabolism (in vivo and in vitro) of plasma lipoproteins after selective chemical modification of lysine residues of the apoproteins. J Clin Invest. 1979 Sep;64(3):743–750. doi: 10.1172/JCI109518. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Mahley R. W., Weisgraber K. H., Innerarity T. Canine lipoproteins and atherosclerosis. II. Characterization of the plasma lipoproteins associated with atherogenic and nonatherogenic hyperlipidemia. Circ Res. 1974 Nov;35(5):722–733. doi: 10.1161/01.res.35.5.722. [DOI] [PubMed] [Google Scholar]
  16. Redgrave T. G., Dunne K. B., Roberts D. C., West C. E. Chylomicron metabolism in rabbits fed diets with or without added cholesterol. Atherosclerosis. 1976 Sep;24(3):501–508. doi: 10.1016/0021-9150(76)90142-8. [DOI] [PubMed] [Google Scholar]
  17. Ross A. C., Zilversmit D. B. Chylomicron remnant cholesteryl esters as the major constituent of very low density lipoproteins in plasma of cholesterol-fed rabbits. J Lipid Res. 1977 Mar;18(2):169–181. [PubMed] [Google Scholar]
  18. Sherrill B. C., Innerarity T. L., Mahley R. W. Rapid hepatic clearance of the canine lipoproteins containing only the E apoprotein by a high affinity receptor. Identity with the chylomicron remnant transport process. J Biol Chem. 1980 Mar 10;255(5):1804–1807. [PubMed] [Google Scholar]
  19. Shore V. G., Shore B., Hart R. G. Changes in apolipoproteins and properties of rabbit very low density lipoproteins on induction of cholesteremia. Biochemistry. 1974 Apr 9;13(8):1579–1585. doi: 10.1021/bi00705a004. [DOI] [PubMed] [Google Scholar]
  20. Windler E. E., Kovanen P. T., Chao Y. S., Brown M. S., Havel R. J., Goldstein J. L. The estradiol-stimulated lipoprotein receptor of rat liver. A binding site that membrane mediates the uptake of rat lipoproteins containing apoproteins B and E. J Biol Chem. 1980 Nov 10;255(21):10464–10471. [PubMed] [Google Scholar]

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