出版社：American Society for Biochemistry and Molecular Biology
摘要：We measured the percent absorption, turnover, and distribution of campestanol (24-methyl-5α-cholestan-3β-ol) in a sitosterolemic homozygote, her obligate heterozygous mother, and three healthy human control subjects. For reasons relating to sterol hyperabsorption, the homozygote consumed a diet low in plant sterols that contained campestanol at about 2 mg/day. The heterozygote and three control subjects were fed a diet supplemented with a spread that contained campestanol at 540 mg/day and sitostanol (24-ethyl-5α-cholestan-3β-ol) at 1.9 g/day as fatty acid esters. Plasma campestanol concentrations determined by capillary gasliquid chromatography were 0.72 ± 0.03 mg/dl in the homozygote, 0.09 ± 0.04 mg/dl in the heterozygote, and 0.05 ± 0.03 mg/dl for the control mean. After simultaneous pulse labeling with [3α-3H]campestanol intravenously and [23-14C]campestanol orally, the maximum percent absorption measured by the plasma dual-isotope ratio method as a single time point was 80% in the homozygote, 14.3% in the heterozygote, and 5.5 ± 4.3% as the mean for three control subjects. Turnover (pool size) values estimated by mathematical analysis of the specific activity versus time [3α-3H]campestanol decay curves were as follows: 261 mg in the homozygote, 27.3 mg in the heterozygote, and 12.8 ± 7.6 mg in the three control subjects (homogygote vs. controls, P A) was prolonged markedly in the homozygote, but was 100 times more rapid in the heterozygote and three control subjects. Thus, campestanol, like other noncholesterol sterols, is hyperabsorbed and retained in sitosterolemic homozygotes. However, campestanol absorption was only slightly increased in the sitosterolemic heterozygote and removal was as rapid as in control subjects. —Salen, G., G. Xu, G. S. Tint, A. K. Batta, and S. Shefer. Hyperabsorption and retention of campestanol in a sitosterolemic homozygote: comparison with her mother and three control subjects. J. Lipid Res. 2000. 41: 1883–1889.
