Abstract
We studied the effects of ethinyl oestradiol on the serum concentrations and metabolism of very-low- and low-density lipoproteins (VLDL and LDL) in Watanabe heritable hyperlipidaemic (WHHL) homozygous rabbits, an animal model for familial hypercholesterolaemia. The results were compared with those in untreated homozygotes as well as in heterozygotes treated or not with ethinyl oestradiol. The gain in body weight was similar in all groups. Treatment with ethinyl oestradiol resulted in the homozygotes in an approx. 80% decrease in the concentrations of lipids and apoprotein B in the d less than 1.019 lipoprotein fraction; those in the LDL fraction did not change. In the heterozygotes, basal serum lipids and apoprotein B levels in the d less than 1.019 fraction were low; ethinyl oestradiol treatment especially affected the LDL fraction (cholesterol -84%, apoprotein B -64%). Turnover experiments with 125I-labelled VLDL revealed that, on treatment with ethinyl oestradiol, the fractional catabolic rate in homozygous rabbits increased 2-fold. The secretion rates of lipids and protein in the d less than 1.019 fraction as estimated after injection of Triton WR-1339 was not decreased. In homozygotes and heterozygotes increases in post-heparin hepatic lipase activity of 62 and 80% respectively were observed, with no changes in lipoprotein lipase activity. We conclude that ethinyl oestradiol induces in homozygous WHHL rabbits a direct removal of VLDL and VLDL remnants from the plasma, apparently due to an increase in hepatic lipase activity.
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Selected References
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- Applebaum-Bowden D., McLean P., Steinmetz A., Fontana D., Matthys C., Warnick G. R., Cheung M., Albers J. J., Hazzard W. R. Lipoprotein, apolipoprotein, and lipolytic enzyme changes following estrogen administration in postmenopausal women. J Lipid Res. 1989 Dec;30(12):1895–1906. [PubMed] [Google Scholar]
- Belfrage P., Vaughan M. Simple liquid-liquid partition system for isolation of labeled oleic acid from mixtures with glycerides. J Lipid Res. 1969 May;10(3):341–344. [PubMed] [Google Scholar]
- Boberg J., Augustin J., Baginsky M. L., Tejada P., Brown W. V. Quantitative determination of hepatic and lipoprotein lipase activities from human postheparin plasma. J Lipid Res. 1977 Jul;18(4):544–547. [PubMed] [Google Scholar]
- Demacker P. N., Hijmans A. G., Vos-Janssen H. E., van't Laar A., Jansen A. P. A study of the use of polyethylene glycol in estimating cholesterol in high-density lipoprotein. Clin Chem. 1980 Dec;26(13):1775–1779. [PubMed] [Google Scholar]
- Demant T., Carlson L. A., Holmquist L., Karpe F., Nilsson-Ehle P., Packard C. J., Shepherd J. Lipoprotein metabolism in hepatic lipase deficiency: studies on the turnover of apolipoprotein B and on the effect of hepatic lipase on high density lipoprotein. J Lipid Res. 1988 Dec;29(12):1603–1611. [PubMed] [Google Scholar]
- Eriksson M., Berglund L., Rudling M., Henriksson P., Angelin B. Effects of estrogen on low density lipoprotein metabolism in males. Short-term and long-term studies during hormonal treatment of prostatic carcinoma. J Clin Invest. 1989 Sep;84(3):802–810. doi: 10.1172/JCI114239. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldstein J. L., Kita T., Brown M. S. Defective lipoprotein receptors and atherosclerosis. Lessons from an animal counterpart of familial hypercholesterolemia. N Engl J Med. 1983 Aug 4;309(5):288–296. doi: 10.1056/NEJM198308043090507. [DOI] [PubMed] [Google Scholar]
- HAVEL R. J., EDER H. A., BRAGDON J. H. The distribution and chemical composition of ultracentrifugally separated lipoproteins in human serum. J Clin Invest. 1955 Sep;34(9):1345–1353. doi: 10.1172/JCI103182. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henriksson P., Stamberger M., Eriksson M., Rudling M., Diczfalusy U., Berglund L., Angelin B. Oestrogen-induced changes in lipoprotein metabolism: role in prevention of atherosclerosis in the cholesterol-fed rabbit. Eur J Clin Invest. 1989 Aug;19(4):395–403. doi: 10.1111/j.1365-2362.1989.tb00248.x. [DOI] [PubMed] [Google Scholar]
- Hornick C. A., Kita T., Hamilton R. L., Kane J. P., Havel R. J. Secretion of lipoproteins from the liver of normal and Watanabe heritable hyperlipidemic rabbits. Proc Natl Acad Sci U S A. 1983 Oct;80(19):6096–6100. doi: 10.1073/pnas.80.19.6096. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huttunen J. K., Ehnholm C., Kinnunen P. K., Nikkilä E. A. An immunochemical method for the selective measurement of two triglyceride lipases in human postheparin plasma. Clin Chim Acta. 1975 Sep 16;63(3):335–347. doi: 10.1016/0009-8981(75)90055-8. [DOI] [PubMed] [Google Scholar]
- Iverius P. H., Brunzell J. D. Relationship between lipoprotein lipase activity and plasma sex steroid level in obese women. J Clin Invest. 1988 Sep;82(3):1106–1112. doi: 10.1172/JCI113667. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- MATTHEWS C. M. The theory of tracer experiments with 131I-labelled plasma proteins. Phys Med Biol. 1957 Jul;2(1):36–53. doi: 10.1088/0031-9155/2/1/305. [DOI] [PubMed] [Google Scholar]
- Shiomi M., Ito T., Watanabe Y. Increase in hepatic low-density lipoprotein receptor activity during pregnancy in Watanabe heritable hyperlipidemic rabbits; an animal model for familial hypercholesterolemia. Biochim Biophys Acta. 1987 Jan 13;917(1):92–100. doi: 10.1016/0005-2760(87)90288-8. [DOI] [PubMed] [Google Scholar]
- Sigurdsson G., Noel S. P., Havel R. J. Quantification of the hepatic contribution to the catabolism of high density lipoproteins in rats. J Lipid Res. 1979 Mar;20(3):316–324. [PubMed] [Google Scholar]
- Stalenhoef A. F., Casparie A. F., Demacker P. N., Stouten J. T., Lutterman J. A., van 't Laar A. Combined deficiency of apolipoprotein C-II and lipoprotein lipase in familial hyperchylomicronemia. Metabolism. 1981 Sep;30(9):919–926. doi: 10.1016/0026-0495(81)90072-x. [DOI] [PubMed] [Google Scholar]
- Stoudemire J. B., Renaud G., Shames D. M., Havel R. J. Impaired receptor-mediated catabolism of low density lipoproteins in fasted rabbits. J Lipid Res. 1984 Jan;25(1):33–39. [PubMed] [Google Scholar]
- Tikkanen M. J., Nikkilä E. A. Regulation of hepatic lipase and serum lipoproteins by sex steroids. Am Heart J. 1987 Feb;113(2 Pt 2):562–567. doi: 10.1016/0002-8703(87)90633-8. [DOI] [PubMed] [Google Scholar]
- Weinstein I., Wilcox H. G., Heimberg M. Effects of high-dose ethinyl estradiol on serum concentrations and hepatic secretion of the very-low-density lipoprotein, triacylglycerol, cholesterol, and apolipoprotein A-I in the rat. Biochim Biophys Acta. 1986 May 21;876(3):450–459. doi: 10.1016/0005-2760(86)90031-7. [DOI] [PubMed] [Google Scholar]
- 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]
- Yamada N., Havel R. J. Measurement of apolipoprotein B radioactivity in whole blood plasma by precipitation with isopropanol. J Lipid Res. 1986 Aug;27(8):910–912. [PubMed] [Google Scholar]
