HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Field, F. J. Articles by Mathur, S. N. Search for Related Content PubMed PubMed Citation Articles by Field, F. J. Articles by Mathur, S. N. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 24, 409-417, April 1983
Copyright © 1983 by Lipid Research, Inc.

ßbeta;-Sitosterol: esterification by intestinal acylcoenzyme A:cholesterol acyltransferase (ACAT) and its effect on cholesterol esterification

F. Jeffrey Field and Satya N. Mathur

Department of Internal Medicine, University of Iowa School of Medicine, Iowa City, IA 52242

Rabbits were fed either 10% coconut oil, 10% coconut oil and 1% ßbeta;-sitosterol, 10% coconut oil and 1% cholesterol, or 10% coconut oil and 1% ßbeta;-sitosterol plus 1% cholesterol for 4 weeks. Microsomal membranes from intestines of animals fed the 1% ßbeta;-sitosterol diet had 48% less cholesterol and were enriched twofold in ßbeta;-sitosterol compared to membranes from animals fed the coconut oil diet alone. Acylcoenzyme A:cholesterol acyltransferase (ACAT) activity in jejunum and ileum was decreased significantly in animals fed the plant sterol alone. In membranes from animals fed 1% ßbeta;-sitosterol and 1% cholesterol, ßbeta;-sitosterol content increased 50% whereas cholesterol was modestly decreased compared to their controls fed only cholesterol. Intestinal ACAT was unchanged in the animals fed both sterols when compared to their controls. ßbeta;-Sitosterol esterification was determined by incubating intestinal microsomal membranes with either [¹⁴C]ßbeta;-sitosterol-albumin emulsion or [¹⁴C]ßbeta;-sitosterol:dipalmitoyl phosphatidylcholine (DPPC) liposomes to radiolabel the endogenous sterol pool. Oleoyl-CoA was then added. The CoA-dependent esterification rate of ßbeta;-sitosterol was very slow compared to that of cholesterol using both techniques. An increased amount of endogenous microsomal ßbeta;-sitosterol, which occurs in animals fed 1% ßbeta;-sitosterol, did not interfere with the stimulation of ACAT activity secondary to cholesterol enrichment of the membranes. Enriching microsomal membranes three- to five-fold with ßbeta;-sitosterol did not affect ACAT activity. Freshly isolated intestinal cells were incubated for 1 hour with [³H]oleic acid and ßbeta;-sitosterol:DPPC or 25-hydroxycholesterol:DPPC. Incorporation of oleic acid into cholesteryl esters did not change in the presence of ßbeta;-sitosterol but increased fourfold after the addition of 25-hydroxycholesterol. We conclude that the CoA-dependent esterification rate of cholesterol is at least 60 times greater than that of ßbeta;-sitosterol. Membrane ßbeta;-sitosterol does not interfere with nor compete with cholesterol esterification. Inadequate esterification of this plant sterol may play a role in the poor absorption of ßbeta;-sitosterol by the gut.—Field, F. J., and S. N. Mathur. ßbeta;-Sitosterol: esterification by intestinal acylcoenzyme A:cholesterol acyltransferase (ACAT) and its effect on cholesterol esterification.

Supplementary key words dipalmitoyl phosphatidylcholine • 25-hydroxycholesterol • microsomal membranes

Submitted on January 29, 1982
Revised on October 12, 1982

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				Y. Fujiwara, N. Kiyota, M. Hori, S. Matsushita, Y. Iijima, K. Aoki, D. Shibata, M. Takeya, T. Ikeda, T. Nohara, et al. Esculeogenin A, a New Tomato Sapogenol, Ameliorates Hyperlipidemia and Atherosclerosis in ApoE-Deficient Mice by Inhibiting ACAT Arterioscler. Thromb. Vasc. Biol., November 1, 2007; 27(11): 2400 - 2406. [Abstract] [Full Text] [PDF]

				L. Bao, Y. Li, S.-X. Deng, D. Landry, and I. Tabas Sitosterol-containing Lipoproteins Trigger Free Sterol-induced Caspase-independent Death in ACAT-competent Macrophages J. Biol. Chem., November 3, 2006; 281(44): 33635 - 33649. [Abstract] [Full Text] [PDF]

				F. J. Field, E. Born, and S. N. Mathur LXR/RXR ligand activation enhances basolateral efflux of {beta}-sitosterol in CaCo-2 cells J. Lipid Res., May 1, 2004; 45(5): 905 - 913. [Abstract] [Full Text] [PDF]

				L. Yu, K. von Bergmann, D. Lutjohann, H. H. Hobbs, and J. C. Cohen Selective sterol accumulation in ABCG5/ABCG8-deficient mice J. Lipid Res., February 1, 2004; 45(2): 301 - 307. [Abstract] [Full Text] [PDF]

				R. E. Temel, A. K. Gebre, J. S. Parks, and L. L. Rudel Compared with Acyl-CoA:Cholesterol O-Acyltransferase (ACAT) 1 and Lecithin:Cholesterol Acyltransferase, ACAT2 Displays the Greatest Capacity to Differentiate Cholesterol from Sitosterol J. Biol. Chem., November 28, 2003; 278(48): 47594 - 47601. [Abstract] [Full Text] [PDF]

				J. PLAT and R. P. MENSINK Increased intestinal ABCA1 expression contributes to the decrease in cholesterol absorption after plant stanol consumption FASEB J, August 1, 2002; 16(10): 1248 - 1253. [Abstract] [Full Text] [PDF]

				O. A Matvienko, D. S Lewis, M. Swanson, B. Arndt, D. L Rainwater, J. Stewart, and D L. Alekel A single daily dose of soybean phytosterols in ground beef decreases serum total cholesterol and LDL cholesterol in young, mildly hypercholesterolemic men Am. J. Clinical Nutrition, July 1, 2002; 76(1): 57 - 64. [Abstract] [Full Text] [PDF]

				A. H. Lichtenstein and R. J. Deckelbaum Stanol/Sterol Ester-Containing Foods and Blood Cholesterol Levels : A Statement for Healthcare Professionals From the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association Circulation, February 27, 2001; 103(8): 1177 - 1179. [Abstract] [Full Text] [PDF]