Scheibner J, Lange K, Empen K, Stange E F
Department of Internal Medicine I, Medical University of Lübeck, Germany.
Z Ernahrungswiss. 1997 Dec;36(4):368-71. doi: 10.1007/BF01617830.
Hypersecretion of biliary cholesterol appears to be the key defect in the pathogenesis of cholesterol gallstones, and this may be due to an enhanced synthesis of cholesterol. To measure fractional syntheses of biliary and plasma cholesterol, five male and 3 female healthy humans with an intact enterohepatic circulation were infused intravenously with [1-13C]acetate for 15 h. Samples of duodenal bile and blood were taken hourly and an enteral formula diet was given. Free cholesterol mass distribution was analyzed by gas chromatography mass spectrometry. The Mass Isotopomer Distribution Analysis (MIDA) technique allowed to calculate fractional synthesis. After 6 hours of infusion, the [13C]label of the cytosolic acetate pool reached a plateau of approximately 12%. Individual fractional cholesterol synthesis is plasma and bile correlated significantly (6-15 h) and amounted to 4.2% and 5.3% after 15 h, respectively. It may be concluded from this study, that newly synthesized cholesterol is secreted into bile to a higher extent than into plasma.
胆汁中胆固醇分泌过多似乎是胆固醇胆结石发病机制的关键缺陷，这可能是由于胆固醇合成增加所致。为了测量胆汁和血浆胆固醇的分数合成，对5名男性和3名女性具有完整肠肝循环的健康人静脉输注[1-13C]乙酸盐15小时。每小时采集十二指肠胆汁和血液样本，并给予肠内配方饮食。通过气相色谱-质谱分析游离胆固醇质量分布。质量同位素异构体分布分析（MIDA）技术可以计算分数合成。输注6小时后，胞质乙酸盐池的[13C]标记达到约12%的平台期。个体血浆和胆汁中胆固醇的分数合成显著相关（6-15小时），15小时后分别为4.2%和5.3%。从这项研究可以得出结论，新合成的胆固醇分泌到胆汁中的程度高于分泌到血浆中的程度。
