Ichimiya H, Yanagisawa J, Nakayama F
Department of Surgery I, Kyushu University Faculty of Medicine, Fukuoka, Japan.
J Lipid Res. 1987 Sep;28(9):1028-37.
Urinary excretion of bile alcohols and bile acids in patients with complete extrahepatic cholestasis before and after the release by external biliary drainage was studied. Following extraction, isolation, and hydrolysis, bile alcohols were determined by capillary gas-liquid chromatography-mass spectrometry as dimethylethylsilyl derivatives. During cholestasis, 8.89 mumol/day of bile alcohol and 140.4 mumol/day of bile acid were excreted in urine. The amount of bile alcohol excreted was 6.1% of that of bile acid. Positive correlation between excretion of bile alcohols and bile acids was observed. The major bile alcohols excreted were also present in urine from healthy individuals but in much smaller amounts. After the release of extrahepatic cholestasis, urinary excretion of bile acid decreased rapidly, but that of bile alcohol decreased only gradually. The latter often increased again and remained high. The results indicate that the increased excretion of bile alcohols in complete extrahepatic cholestasis may reflect the expansion of a normally existing pathway of bile alcohol synthesis and excretion leading to the modification of bile alcohols for their efficient urinary elimination. It is also suggested that the rate of synthesis of bile alcohols is determined partly by the size of the substrate pool available.
研究了完全性肝外胆汁淤积患者在经体外胆管引流解除胆汁淤积前后胆汁醇和胆汁酸的尿排泄情况。提取、分离和水解后，胆汁醇通过毛细管气液色谱 - 质谱法测定为二甲基乙基硅烷基衍生物。胆汁淤积期间，尿中胆汁醇排泄量为8.89 μmol/天，胆汁酸排泄量为140.4 μmol/天。胆汁醇排泄量为胆汁酸排泄量的6.1%。观察到胆汁醇和胆汁酸排泄之间呈正相关。排泄的主要胆汁醇在健康个体的尿液中也有，但量要少得多。肝外胆汁淤积解除后，胆汁酸的尿排泄迅速减少，但胆汁醇的尿排泄仅逐渐减少。后者常常再次增加并保持在较高水平。结果表明，完全性肝外胆汁淤积时胆汁醇排泄增加可能反映了正常存在的胆汁醇合成和排泄途径的扩展，导致胆汁醇发生修饰以便于其有效地经尿排泄。还提示胆汁醇的合成速率部分由可用底物池的大小决定。
