title: Increase of bile acids synthesis and excretion caused by taurine administration prevents the ovariectomy-induced increase in cholesterol concentrations in the serum low-density lipoprotein fraction of Wistar rats.
abstract: We examined the effect of dietary taurine on the concentrations of serum cholesterol and apolipoprotein in lipoprotein fractions of Six-month-old ovariectomized, which were used as a model of hypercholesterolemia in postmenopausal woman, or sham operated rats. Taurine significantly reduced the serum total and low-density lipoprotein cholesterol concentrations only in the ovariectomized rats. In contrast, taurine significantly lowered the serum apolipoprotein B concentration and serum very low-density lipoprotein-apolipoprotein E concentration only in the sham operated rats. The serum total and high density lipoprotein-apolipoprotein E concentrations were significantly lower in the rats fed taurine than in those fed the control diet regardless of whether they had undergone ovariectomy. The esterified cholesterol level in the liver was significantly lower and the level of hepatic cholesterol 7 alpha-hydroxylase activity was significantly higher in the rats fed taurine than in those fed the control diet. The total bile acids concentration in the feces and intestinal contents of rats fed taurine were significantly higher than those in rats fed the control diet regardless of whether they had undergone ovariectomy. In the sham-rats, taurine accelerated bile acid synthesis and excretion, thereby increasing cholesterol consumption. The increased cholesterol consumption might be compensated by accelerating cholesterol synthesis and/or reducing the synthesis and release of very low-density lipoprotein from the liver. But in the ovariectomized rats, although taurine also accelerated bile acid synthesis and excretion, cholesterol demand might be compensated by excess cholesterol in the blood.
authors.affiliation: Department of Biological Resources, Faculty of Agriculture, Ehime University, 790-8566 Matsuyama, Japan. kishida@agr.ehime-u.ac.jp
authors.forename: Taro
authors.initials: T
authors.lastname: Kishida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Masaya
authors.initials: M
authors.lastname: Tsukaoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohga
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ogawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ebihara
mesh_terms: D000818:Animals; D001053:Apolipoproteins / Q000097:blood; D001647:Bile Acids and Salts / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism; D008078:Cholesterol, LDL / Q000097:blood*; D004032:Diet; D005243:Feces / Q000737:chemistry; D005260:Female; D008074:Lipoproteins / Q000097:blood; D008099:Liver / Q000201:enzymology; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood
chemical_list: D001053:Apolipoproteins; D001647:Bile Acids and Salts; D008078:Cholesterol, LDL; D008074:Lipoproteins; D014280:Triglycerides; D013654:Taurine; D002784:Cholesterol; D002790:Cholesterol 7-alpha-Hydroxylase