The Quantitative Effects of Cholesterol, Cholic Acid and Type of Fat on Serum Cholesterol and Vascular Sudanophilia in the Rat

Abstract

Marked differences in the effect of various oils on the serum cholesterol levels of rats fed diets containing cholic acid and cholesterol are readily measured with considerable accuracy. In general, the effects of the oils tested tend to be similar to their reported effects upon serum cholesterol levels in human beings, suggesting that the active factors in the two species may be similar. The rat assay may thus be a useful, rapid, and relatively accurate method for determining the effects of the various constituents of fats upon serum cholesterol levels. In general, the highly unsaturated oils result in lower serum cholesterol levels. Tung oil, rich in eleostearic acid, is a marked exception and produced the highest serum cholesterol levels of any oil tested. Admixture with corn oil counteracts this hypercholesteremic activity in proportion to the amount of corn oil added. The effect of varying levels of cholic acid and cholesterol on serum cholesterol levels has been quantitated in two different oils. With all oils and at various levels of cholic acid and cholesterol, the amount of Sudanophilic material under the endothelium was proportional to the mean serum cholesterol level. The “atherogenic” activity thus appears to be mediated through the serum cholesterol levels.