Incorporation and Distribution of Dietary Elaidate in the Major Lipid Classes of Rat Heart and Plasma Lipoproteins

Abstract

Male weanling Holtzman rats were fed diets containing 20% of either partially hydrogenated soybean fat, HF (48% elaidate) or beef tallow, BT (0.5% elaidate) for 10, 15 and 20 weeks. At the end of each dietary period the animals were killed. The lipids of the heart, plasma very low density, low density and high density lipoproteins, as well as the elaidate content of appropriate lipid classes, were determined. At comparable time periods, the animals fed HF contained significantly more heart total lipids than those fed BT. Elaidate concentration in the lipid classes was variable, especially among the lipoprotein classes, and was not a direct function of the duration of feeding. The results suggest differences in the mechanism of incorporation and turnover of elaidate not only in different tissues, but also among the major lipoprotein types. Furthermore, these differences are also evident among the various lipid classes within a given lipoprotein type.