Subbiah M T, Tyler N E, Buscaglia M D, Marai L
J Lipid Res. 1976 Jan;17(1):78-84.
Bile acid excretion was studied in 9 human subjects simultaneously by the Lindstedt (Lindstedt, S. 1957. Acta Physiol. Scand. 40:1-9) isotopic turnovermethod and by fecal chemical analysis during a balance study. The identities of the fecal bile acids were confirmed by combined gas-liquid chromatography/mass spectrometry. Under the steady state conditions of the patient studies, bile acid excretion values obtained by fecal analysis were lower (by 18.1 to 44.2%) than the values obtained by the isotopic turnover method. This difference persisted even in those patients given [14C]chenodeoxycholic acid instead of [3H]chenodeoxycholic acid. The fecal excretion values were similar when calculated using either beta-sitosterol or chromium sesquioxide as fecal flow markers. The fecal excretion values during the earlier part of the isotopic study were higher than those during the latter part of the study. The lower values of bile acid excretion obtained from fecal analysis could not be explained by the loss of bile acids as sulfate conjugates or by losses due to bile acid degradation in the intestine. This study suggests that bile acid turnover is consistently higher than bile acid excretion under experimental conditions. It is recommended that the data obtained from the isotopic turnover method should not be compared with fecal excretion data.
在一项平衡研究中，采用林德施泰特（Lindstedt, S. 1957. Acta Physiol. Scand. 40:1 - 9）同位素周转法和粪便化学分析法，同时对9名人类受试者的胆汁酸排泄情况进行了研究。通过气相色谱/质谱联用技术确认了粪便胆汁酸的种类。在患者研究的稳态条件下，粪便分析所得的胆汁酸排泄值低于同位素周转法所得的值（低18.1%至44.2%）。即使在那些给予[14C]鹅去氧胆酸而非[3H]鹅去氧胆酸的患者中，这种差异依然存在。使用β - 谷甾醇或三氧化二铬作为粪便流量标记物计算时，粪便排泄值相似。同位素研究前期的粪便排泄值高于后期。粪便分析得出的胆汁酸排泄值较低，这无法用胆汁酸以硫酸盐结合物形式流失或肠道中胆汁酸降解导致的损失来解释。该研究表明，在实验条件下，胆汁酸周转始终高于胆汁酸排泄。建议不要将同位素周转法获得的数据与粪便排泄数据进行比较。
