Effect of diet on the cholesterol ester composition of liver and of plasma lipoproteins in the rat

Abstract

The relationship between the cholesterol ester composition of the liver and the plasma lipoproteins was studied in groups of rats maintained for 5–11 weeks on the following diets: (I) rat pellets, (II) rat pellets with added olive oil and cholesterol, and (III) fat-free diets containing 0.4% cholesterol.In the control animals (Group I), the cholesterol esters of liver and d 1.063 lipoprotein cholesterol esters were mainly linoleate and arachidonate.In the livers of rats fed olive oil and cholesterol (Group 11), the cholesterol esters contained largely oleic acid and the d 1.006–1.019 lipoproteins had a very similar cholesterol ester composition. The d > 1.063 lipoproteins had a high proportion of esters of polyunsaturated acids and oleate.The livers of rats on the fat-free diet contained no linoleate and increased amounts of monoenoate esters as compared to the Group I control animals, and the d 1.063 lipoproteins contained a high proportion of monoenoic acids, relatively small amounts of linoleate and arachidonate, and significant amounts of eicosatrienoate.These results suggest that different mechanisms are involved in the formation of the cholesterol esters of the various lipoproteins.

Keywords

• cholesterol esters
• liver
• plasma lipoproteins
• rat
• cholesterol feeding
• fat-deficient diet