QUANTITATIVE ISOLATION AND GAS--LIQUID CHROMATOGRAPHIC ANALYSIS OF TOTAL DIETARY AND FECAL NEUTRAL STEROIDS.
QUANTITATIVE ISOLATION AND GAS--LIQUID CHROMATOGRAPHIC ANALYSIS OF TOTAL DIETARY AND FECAL NEUTRAL STEROIDS.
复制标题
总膳食和粪便中性类固醇的定量分离和气相色谱分析。
作者：
T. Miettinen;E. H. Ahrens;S. Grundy
本文描述了一种分离和定量粪便中性类固醇的方法，该方法可以在不需要在体内使用放射性同位素的情况下，对人体或小型实验动物体内的固醇平衡进行研究。胆固醇植物甾醇及其转化产物的关键分离依赖于薄层色谱法将其初步分离成三个亚组分。然后，用气液色谱法定量测量未取代的3-酮类固醇和甾醇的三甲基硅醚的三个亚组分中的单个组分。体外添加的胆固醇-7~~-H~和体内合成的c14标记的中性类固醇的提取是定量的，高重复性的。几条证据线证实了GLC测定单个粪便中性类固醇的有效性。本文给出了应用该技术的例子：对一位饮食中含有植物固醇和胆固醇的病人进行了为期27天的固醇平衡研究。将人类和大鼠的代表性结果与先前描述的方法获得的结果进行比较。该方法的灵敏度使得含有25pg混合中性类固醇的I-g粪便等分液可以被准确地分析，但该方法适合于更明确地研究单个中性类固醇的准备规模工作。
SUMMARY A method for isolation and quantification of fecal neutral steroids is described which allows studies to be made of sterol balance in man or in small laboratory animals without requiring the use of radioisotopes in vivo. The critical separations of cholesterol plant sterols and their conversion products depend upon preliminary separations into three subfractions by thin-layer chromatography. Individual components in the three subfractions thus obtained are then quantitatively measured by gas-liquid chromatography of the unsubstituted 3-ketosteroids and of the trimethylsilyl ethers of the sterols. Extractions of cholesterol-7~~-H~ added in vitro and of C14labeled neutral steroids synthesized in vivo were quantitative and highly reproducible. Several lines of evidence validate the determination of individual fecal neutral steroids by GLC. Examples are given of the application of this technique: a sterol balance study of 27 days' duration is described in a patient whose diet included plant sterols as well as cholesterol. Representative results in man and in rats are compared to others obtained by previously described methods. The sensitivity of the method is such that I-g fecal aliquots containing as little as 25 pg of mixed neutral steroids can be analyzed accurately, but the procedure lends itself well to preparative scale work for more definitive study of individual neutral steroids.