Influence of an atherogenic diet on the structure of XXXX low density lipoproteins.

@entity1707 @entity844 @entity412 @entity731 @entity8557 @entity165
Five groups of three @entity1707 each were fed a basal diet supplemented with 15% tallow and either 0.0, 1.0, 1.5, 2.0%, or 2.5% @entity165 . The animals were studied over a period of 9 weeks to observe changes in plasma lipids and low density lipoproteins (LDL). At the end of the study period, LDL was analyzed by rate zonal ultracentrifugation, characterized chemically, and examined by differential scanning calorimetry. Within 3 weeks of initiation of the @entity165 -supplemented diets, there was an increase in the plasma levels of @entity165 and total LDL. LDL from @entity1707 fed the basal diet and the basal diet plus 1.0% @entity165 appeared in two LDL populations (LDL1 and LDL2) when analyzed by rate zonal ultracentrifugation. After diets containing 1.5, 2.0, and 2.5% dietary @entity165 , there was an increase in the mean flotation rate of total LDL which shifted to a lower density. LDL1 from the high @entity165 diets had a decreased @entity412 content when compared to those of the low @entity165 diets. When examined by differential scanning calorimetry, the LDL1 from the animals fed at least 1.5% @entity165 had phase transitions above body temperature, whereas the LDL from those fed 0 and 1.0% @entity165 had phase transitions below 37 degrees C. In contrast, the thermal behavior and @entity844 compositions of the extracted @entity8557 of the LDL obtained after the five different diets were not remarkably different. Since LDL @entity412 and @entity8557 are predicted to coexist in a common phase in the LDL core, the different thermal behavior of the LDL obtained after diets with different @entity165 contents is due to differences in @entity412 content which are a secondary effect of @entity165 -feeding. From these data we conclude that dietary @entity165 increases plasma LDL content, decreases LDL @entity412 content, and alters the particle structure. These changes in lipoprotein structure may contribute to the known development of @entity731 in @entity165 -fed @entity1707 .
