[Pathways of intracellular cholesterol metabolism in a model study]

We had concluded from former own investigations that the cells in the arteriosclerotic plaque effect a change of the ester proportion of cholesterol. One of the possible mechanisms ible bond and from double unsaturated (linoleic acid) to higher unsaturated acids. Therefore we investigated by radioactive labelling of the fatty acid moity of cholesterol esters whether such desaturation reactions take place in the model experiment. For this purpose we implanted cholesterol stearate which was 14C-labelled in the proportion of fatty acid subcutaneously into the skin of a rat. We demonstrated radiohistochromatographically that after 7 to 14 days the fraction of the cholesterol esters with 1 double bond was additionally labelled. Other fractions were not labelled. From this results that the proportion of the saturated fatty acid of the cholesterol ester is actually desaturated, in which case the desaturation as we expect only goes to the fraction with one double bond, because the double unsaturated linoleic acid is not synthetized in vivo in the mamal.