Sterol Ester Formation by Rat Liver Homogenates.

The formation of sterol esters from acetate-1-C14, mevalonic acid-2-C14 and choIesterol-4-C14 by whole rat liver homogenates has been investigated. Labeled sterol esters were formed from the above substrates without addition of cofactors. The greatest synthesis of free and esterified sterols from acetate-1-C14 and mevalonic acid-2-C14 occurred in systems with DPN and/or TPN. Oleic acid markedly inhibited the synthesis of both free and esterified sterols. When the synthesis of free sterol was stimulated corresponding stimulation of esterified sterol formation also occurred. The greatest esterification of cholesterol-4-C14 occurred when DPN, TPN, ATP and CoA in various combinations were added to the homogenate. Addition of oleic acid did not stimulate esterification of cholesterol. The significance of these findings is discussed.