The effect of dietary fat type on the fatty acid composition of sphingomyelin in rat liver and heart

Weanling rats were fed semi-purified diets containing either coconut oil (CCO), corn oil (GO), olive oil (OO) or herring oil (HO). After 5 weeks, dietary fat type had a significant effect on the relative concentration of the fatty acids 18:0, 20:0, 22:0, 23:0, iso-24:0, 24:0, 24:1 and 24:2n-6 in sphingomyelin (SM) from both liver and heart. The most pronounced effects were the elevation (3-4 fold) of 24:2n-6 in heart SM from corn oil-fed rats and the elevation (3-4 fold) of the 24:1/24:0 ratio in heart and liver SM from herring oil-fed rats. The magnitude of these changes was similar to the magnitude of changes in levels of 20:4n-6 and 22:6n-3 in PC in liver and/or heart in these rats.