出版社：American Society for Biochemistry and Molecular Biology
摘要：The effect of cholesterol feeding (3 g/day) on bile acid synthesis was examined in 10 New Zealand white rabbits (NZW), 8 Watanabe heterozygous and 10 homozygous rabbits with partial and complete deficiencies of LDL receptors. After 10 days of cholesterol feeding, bile fistulas were constructed and bile acid pool sizes were measured. Cholesterol feeding increased plasma and hepatic cholesterol levels in all rabbit groups. Baseline bile acid pool sizes were smaller ( P P P These results demonstrated that dietary cholesterol increased hepatic sterol 27-hydroxylase activity and alternative bile acid synthesis to expand the bile acid pool and inhibited cholesterol 7α-hydroxylase in NZW and in Watanabe heterozygous rabbits but not in homozygotes with absent hepatic LDL receptor function. Thus, in rabbits, sterol 27-hydroxylase is up-regulated by the increased hepatic cholesterol that enters the liver via LDL receptors whereas cholesterol 7α-hydroxylase is controlled by the circulating hepatic bile acid flux.—Xu, G., G. Salen, S. Shefer, G. S. Tint, L. B. Nguyen, T. T. Parker, T. S. Chen, J. Roberts, X. Kong, and D. Greenblatt. Regulation of classic and alternative bile acid synthesis in hypercholesterolemic rabbits: effects of cholesterol feeding and bile acid depletion. J. Lipid Res. 1998. 39: 1608–1615.
