The effect of polyunsaturated fatty acids on cholesterol metabolism
Thesis (M.Sc.)--Memorial University of Newfoundland, 1992. Biochemistry Bibliography: leaves 112-125. Atherosclerosis is characterized by deposition of cholesterol and esterified cholesterol in cells of the vascular intima. These lipid laden cells are called foam cells due to their microscopic appea...
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ftmemorialunivdc:oai:collections.mun.ca:theses2/197988 2023-05-15T17:23:31+02:00 The effect of polyunsaturated fatty acids on cholesterol metabolism Pal, Sebely, 1965- Memorial University of Newfoundland. Dept. of Biochemistry 1991 xi, 125 leaves : ill. Image/jpeg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses2/id/197988 Eng eng Electronic Theses and Dissertations (13.99 MB) -- http://collections.mun.ca/PDFs/theses/Pal_Sebely.pdf 76118656 http://collections.mun.ca/cdm/ref/collection/theses2/id/197988 The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Unsaturated fatty acids Blood cholesteral--Synthesis Text Electronic thesis or dissertation 1991 ftmemorialunivdc 2015-08-06T19:17:13Z Thesis (M.Sc.)--Memorial University of Newfoundland, 1992. Biochemistry Bibliography: leaves 112-125. Atherosclerosis is characterized by deposition of cholesterol and esterified cholesterol in cells of the vascular intima. These lipid laden cells are called foam cells due to their microscopic appearance and arise primarily from smooth muscle cells and monocyte macrophages. It is believed that the transformation of these cells into foam cells is a key step in the initiation of atherosclerosis. Therefore, to better understand the process of atherogenesis it is important to investigate the mechanisms that may regulate cholesterol esterification and hence the formation of foam cells. -- Polyunsaturated fatty acids (PUFAs) in the diet can substantially reduce the incidence of coronary heart disease. However, dietary ω-3 polyunsaturated fatty acids found primarily in marine oils have been shown to be better in reducing the risk of atherosclerosis than other polyunsaturated fatty acids. Unfortunately, it is unclear how ω-3 PUFAs are involved in delaying the atherogenic process. It is possible that these fatty acids may be antiatherogenic by inhibiting cholesterol esterification or increasing cholesterol removal from cells thereby inhibiting the initial step of foam cell formation. -- The major objective of this study was to investigate the impact of different polyunsaturated fatty acid enrichment of nonhepatic tissues on cholesterol esterification and cholesterol efflux. Human fibroblasts and macrophages were enriched with either linoleic acid (18:3, ω-6) or eicosapentaenoic acid (20:5, ω-3) by supplementing the culture medium. The incorporation of radiolabelled oleoyl CoA into cholesterol esters was reduced by 44% when human fibroblasts were enriched with ω-3 polyunsaturated fatty acids compared with cells enriched with ω-6 polyunsaturated fatty acids. Also, macrophages enriched with ω-3 PUFAs had significantly lower (52%) total cholesterol content than those enriched with ω-6 PUFAs. Cholesterol efflux was measured in cells enriched with ω-3 PUFAs and ω-6 PUFAs. In the presence of HDL, the rate of efflux of radiolabelled cholesterol from cells enriched with ω-3 PUFAs was substantially faster (2x) than efflux from cells enriched with ω-6 PUFA enriched cells. The data suggests that ω-3 PUFAs may be antiatherogenic by inhibiting cholesterol esterification and by accelerating cholesterol efflux from nonhepatic cells. Thesis Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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English |
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Unsaturated fatty acids Blood cholesteral--Synthesis |
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Unsaturated fatty acids Blood cholesteral--Synthesis Pal, Sebely, 1965- The effect of polyunsaturated fatty acids on cholesterol metabolism |
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Unsaturated fatty acids Blood cholesteral--Synthesis |
description |
Thesis (M.Sc.)--Memorial University of Newfoundland, 1992. Biochemistry Bibliography: leaves 112-125. Atherosclerosis is characterized by deposition of cholesterol and esterified cholesterol in cells of the vascular intima. These lipid laden cells are called foam cells due to their microscopic appearance and arise primarily from smooth muscle cells and monocyte macrophages. It is believed that the transformation of these cells into foam cells is a key step in the initiation of atherosclerosis. Therefore, to better understand the process of atherogenesis it is important to investigate the mechanisms that may regulate cholesterol esterification and hence the formation of foam cells. -- Polyunsaturated fatty acids (PUFAs) in the diet can substantially reduce the incidence of coronary heart disease. However, dietary ω-3 polyunsaturated fatty acids found primarily in marine oils have been shown to be better in reducing the risk of atherosclerosis than other polyunsaturated fatty acids. Unfortunately, it is unclear how ω-3 PUFAs are involved in delaying the atherogenic process. It is possible that these fatty acids may be antiatherogenic by inhibiting cholesterol esterification or increasing cholesterol removal from cells thereby inhibiting the initial step of foam cell formation. -- The major objective of this study was to investigate the impact of different polyunsaturated fatty acid enrichment of nonhepatic tissues on cholesterol esterification and cholesterol efflux. Human fibroblasts and macrophages were enriched with either linoleic acid (18:3, ω-6) or eicosapentaenoic acid (20:5, ω-3) by supplementing the culture medium. The incorporation of radiolabelled oleoyl CoA into cholesterol esters was reduced by 44% when human fibroblasts were enriched with ω-3 polyunsaturated fatty acids compared with cells enriched with ω-6 polyunsaturated fatty acids. Also, macrophages enriched with ω-3 PUFAs had significantly lower (52%) total cholesterol content than those enriched with ω-6 PUFAs. Cholesterol efflux was measured in cells enriched with ω-3 PUFAs and ω-6 PUFAs. In the presence of HDL, the rate of efflux of radiolabelled cholesterol from cells enriched with ω-3 PUFAs was substantially faster (2x) than efflux from cells enriched with ω-6 PUFA enriched cells. The data suggests that ω-3 PUFAs may be antiatherogenic by inhibiting cholesterol esterification and by accelerating cholesterol efflux from nonhepatic cells. |
author2 |
Memorial University of Newfoundland. Dept. of Biochemistry |
format |
Thesis |
author |
Pal, Sebely, 1965- |
author_facet |
Pal, Sebely, 1965- |
author_sort |
Pal, Sebely, 1965- |
title |
The effect of polyunsaturated fatty acids on cholesterol metabolism |
title_short |
The effect of polyunsaturated fatty acids on cholesterol metabolism |
title_full |
The effect of polyunsaturated fatty acids on cholesterol metabolism |
title_fullStr |
The effect of polyunsaturated fatty acids on cholesterol metabolism |
title_full_unstemmed |
The effect of polyunsaturated fatty acids on cholesterol metabolism |
title_sort |
effect of polyunsaturated fatty acids on cholesterol metabolism |
publishDate |
1991 |
url |
http://collections.mun.ca/cdm/ref/collection/theses2/id/197988 |
genre |
Newfoundland studies University of Newfoundland |
genre_facet |
Newfoundland studies University of Newfoundland |
op_source |
Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries |
op_relation |
Electronic Theses and Dissertations (13.99 MB) -- http://collections.mun.ca/PDFs/theses/Pal_Sebely.pdf 76118656 http://collections.mun.ca/cdm/ref/collection/theses2/id/197988 |
op_rights |
The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. |
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