文章基本信息

标题：Validation of a dual-isotope plasma ratio method for measurement of cholesterol absorption in rats
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作者：D. B. Zilversmit ; L. Barry Hughes
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：1974
卷号：15
期号：5
页码：465-473
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Several methods for measuring cholesterol absorption in the rat have been compared. After administration of an oral dose of labeled cholesterol (¹⁴C or ³H) and an intravenous dose of colloidal labeled cholesterol (³H or ¹⁴C) the ratio of the two labels in plasma or whole blood 48 hr or more after dosing compared closely to the ratio of areas under the respective specific activity-time curves. The area ratio method is independent of a time lag between the appearance of oral and intravenous label in the bloodstream. Both measures of cholesterol absorption agree fairly well with a method based on measuring the unabsorbed dietary cholesterol in a pooled fecal sample. The plasma isotope ratio method gave more reproducible results than the fecal collection method when the measurement was repeated in the same animals 5 days after the first measurement. Cholesterol absorption was overestimated by the use of Tween 20-solubilized labeled cholesterol for the intravenous dose. The plasma disappearance curves of injected labeled colloidal cholesterol and cholesterol-labeled chylomicrons infused intravenously over a 3.5-hr period in the same animal coincided within experimental error from the first day until 75 days after injection. The plasma isotope ratio method for cholesterol absorption gave the same results in rats practicing coprophagy as in those in which this practice was prevented. The addition of sulfaguanidine to the diet lowered cholesterol absorption as measured by the plasma isotope ratio to the same degree as that measured by the fecal collection method.
关键词：fecal labeled sterols ; colloidal cholesterol ; Tween 20-solubilized cholesterol ; production rates ; sulfaguanidine ; chylomicrons