CHOLESTEROL PEROXIDATION POTENTIAL AS INFLUENCED BY DIETARY-FAT TYPE

Oxidation of lipoproteins is believed to play a key role in atherogene sis. In this study, influence of two fat vehicles, corn oil (unsaturat ed) or beef tallow (saturated) on cholesterol induced effects in terms of a) plasma lipoprotein peroxidation and b) aortic accumulation of c holesterol, cholesterol oxide and malonaldehyde was investigated in we anling rabbits. Although the increase in plasma cholesterol induced by cholesterol feeding was similar in both the groups Cu2+ ion induced p eroxidation of lipoprotein cholesterol to oxysterols was significantly higher in corn oil group. This difference persisted even at 5 weeks a fter switching to chow diet. Aortic content of cholesterol and cholest erol oxides was also significantly higher in corn oil group at the end of chow diet period. Aortic accumulation of malonaldehyde (detected b y immunocytochemistry) appeared to be greater in corn oil group af the end of the study. These results suggest that fatty acid composition o f a given diet during exposure to high dietary cholesterol can influen ce cholesterol peroxidation to oxysterols and its accumulation in aort a.