[Effect of vitamin E on the alteration of the cholesterol metabolism with the aging of mice (author's transl)].

1. Vitamin E (alpha-tochopherol acetate) 200 mg/kg was injected twelve times every five days into two groups of dd mice, one six months old and the other one month old. Thereafter the incorporation of acetate-1-14C or mevalonic acid-2-14C into sterols in the liver and kidney was examined. (1) In the liver, the incorporation of acetate-14C or mevalonic acid -14C into total lipid, total cholesterol, total fatty acid and proteins was lower in the old group than in the young group. When vitamin E was administered to the young group, hepatic cholesterol biosynthesis from the acetate-1-14C was reduced while total lipids, total fatty acid and proteins were not affected. Whereas when vitamin E was administered to the old group, the body weight increased, the hepatic cholesterol was reduced and the incorporation of acetate-1-14C into total lipids and proteins was increased while that into total cholesterol was reduced, and that into total fatty acid was not affected. The cholesterol biosynthesis was inhibited at the step of conversion of acetate to mevalonic acid in both young and old groups by the injection of vitamin E. (2) In the kidney the incorporation of acetate-1-14C into total lipid, total fatty acid and total cholesterol was more reduced in the old group of mice than in the young group. The administration of vitamin E to the young group of mice reduced the incorporation of acetate-1-14C into total lipid, total fatty acid and total cholesterol, while in the old group of mice administered with vitamin E the incorporation into total lipid and total cholesterol was not affected but that into total fatty acid was increased. The incorporation of mevalonic acid-2-14C into cholesterol was reduced in the young group of mice administered with vitamin E while the same was not affected in the old group. 2. When the old group of mice was fed with a diet containing vitamin E for two months, the excretion of bile acid-14C derived from injected cholesterol4-14C or cholic acid-24-14C was increased and the disappearance of hepatic cholesterol-14C became more rapid. As a result, it may be said that aging brought about the reduction of the lipid biosynthesis in liver and kidney, which was recovered partially by the administration of vitamin E. With regard to the cholesterol metabolism, the aging increased total cholesterol level, which was adjusted by vitamin E. The effect of vitamin E appeared to depend upon the supression of cholesterol biosynthesis as well as the increase of cholesterol catabolism and the excretion of bile acid.