Kiyohisa Uchida (1), Takashi Satoh (1), Toshiyuki Chikai (2), Haruto Takase (2), Yasuharu Nomura (2), Hiroyuki Nakao (2) and Nozomu Takeuchi (3)
(1) Strategic Information Unit, Shionogi & Co., Ltd., Shibuya-ku, Tokyo 150, Japan (2) Shionogi Research Laboratories, Fukushima-ku, Osaka 553, Japan (3) Central Laboratories, Ehime University Hospital, Shigenobu-cho, Ehime 791-02, Japan
Abstract: The effects of cholesterol feeding on serum and liver cholesterol levels, fecal and biliary bile acid levels, bile acid pool size and bile acid composition were examined in 2-, 12- and 24-month-old male germ-free rats. The major bile acids in these animals were cholic and beta-muricholic acids. Cholesterol feeding increased synthesis of bile acids by 3- to 4-fold, especially that of chenodeoxycholic acid (mainly beta- muricholic acid in the rat), decreasing the cholic acid/chenodeoxycholic acid (CA/CDCA) ratio in all rats regardless of age, even though the CA/CDCA ratio increased as a linear function of age in both diet groups. Cholesterol feeding increased the serum cholesterol level markedly in aged rats. This hypercholesterolemia may be produced by the increase in CA/CDCA ratio in aged rats.
Keywords:
Dietary cholesterol, Bile acid metabolism, Cholic acid/chenodeoxycholic acid ratio,
Germ-free rat, Aging