THE MECHANISM OF HYPERCHOLESTEREMIA INDUCED BY THE INGESTION OF FAT

The specific activities of fatty acid of cholesterol esters in the liver and the serum of rats which were administered C14 palmitic acid and cholesterol or C14 linoleic acid and cholesterol after 2 weeks feeding with the diet containing cholesterol palmitic acid or cholesterol linoleic acid were determined, and the specific activities of cholesterols in the livers and the sera of rats which wereadministered C14 glucose, C14 palmitic acid, C14 oleic acid or C14 linoleic acid for 3 days after 2 or 4 weeks of feeding with the diet containing palmitic acid, oleic acid or linoleic acid were also determined. There were no differences of the rates of degradation of cholesterol between rats administered palmitic acid and that administered linoleic acid. The synthesis of cholesterol was promoted in course of day by the administration of palmitic acid or oleic acid, but those from linoleic acid and glucose did not increase.From these results, it is considered that the hypercholesteremia by the ingestion of the large amount of saturated fatty acids is mainly due to the promotion of the cholesterol synthesis from saturated fatty acids and the invariability of the serum cholesterol by the ingestion of polyunsaturated fatty acids (to maintain the normal level) is mainly due to that the cholesterol synthesis from linoleic acid does not increase.