Publication Date

1979

Document Type

Dissertation/Thesis

First Advisor

Mehta, Sudha Wadhwa||Kresheck, Gordon C.

Degree Name

M.S. (Master of Science)

Department

Department of Home Economics

LCSH

Lipids||Soy-bean as food||Low-cholesterol diet||Lecithin

Abstract

The effect of cholesterogenic diet with and without soya-lecithin supplementation on the liver lipid levels of two strains of rats was investigated. Sixteen Sprague-Dawley Albino rats and eleven Long-Evans Hooded rats were divided into three groups. One group of four Albino rats and five Long-Evans Hooded rats each was fed the control diet containing 5% corn oil for two weeks. Another group of six Albino rats and six Long-Evans Hooded rats was fed a cholesterogenic diet containing 40% butter fat and 5% cholesterol for two weeks. A third group of six Albino rats was given the cholesterogenic diet supplemented with 200-300 mg lecithin for two weeks. After the two week period all animals were killed and their livers were removed and frozen and analyzed for total lipid, total cholesterol, free cholesterol, esterified cholesterol and phospholipids. Prior to the two week study all animals were given similar dietary treatments for eight weeks to study the serum lipid changes.The relative liver weights of the rats fed the cholesterogenic diet almost doubled and were significantly greater (p < 0.01) than that of the controls. Rats fed the cholesterogenic diets supplemented with lecithin had slightly but not significantly lower relative liver weights. The feeding of cholesterogenic diet to the rats increased the total liver lipid levels 5-fold and total liver cholesterol 23-fold in the two week period. Most of the increase of cholesterol was observed in the ester form which showed a 50-fold increase while the free cholesterol increased only slightly. The phospholipid levels remained the same for the Albino rats but decreased by 50% in the Long-Evans Hooded rats. Supplementing the cholesterogenic diet with lecithin decreased the total lipids and the total cholesterol levels only to a small degree which was not significant. However, cholesterol ester levels decreased significantly (p < 0.05). Two Albino rats continued to increase their liver lipid levels after lecithin supplementation. The reason for this is not known and can only be speculated to be due to individual variation. From the serum and liver lipid observations the following mechanism of action of lecithin was postulated. The primary effect of lecithin is to remove cholesterol from the serum to the liver in the ester form where it is further metabolized. Thus, while the hypocholesterolemic effect of lecithin supplementation of cholesterogenic diet was apparent in two weeks, the effective removal of cholesterol from the liver required much longer period. Strain differences were observed between the Albino and Long-Evans Hooded rats. The latter group showed higher total lipid and cholesterol levels as compared to the former.

Comments

Includes bibliographical references.||Includes illustrations.

Extent

iv, 70 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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