Takita M, Ikawa S, Ogura Y
Division of Chemistry, Tottori University School of Medicine.
J Biochem. 1988 May;103(5):778-86. doi: 10.1093/oxfordjournals.jbchem.a122346.
The effects of bile duct ligation on bile acid and cholesterol metabolism were examined in male Wistar strain rats. Quantitative and qualitative changes of bile acids and cholesterol in serum and urine occurred; beta-muricholic acid predominantly increased in serum and urine and the ratio of urinary cholic acid and beta-muricholic acid changed from about 5:3 on day 1 to about 1:8 on day 5 under biliary obstruction. The form of the increased urinary bile acids was mainly taurine-conjugated and partly sulfated. Under conditions of bile duct ligation on day 5, 14C-labeled 3 beta-hydroxy-5-cholenoic, lithocholic, and chenodeoxycholic acids were intragastrically administered to the rats after pretreatment with antibiotics and the metabolites of these three acids were investigated. 3 beta-Hydroxy-5-cholenoic acid was most efficiently converted to beta-muricholic acid. The present study strongly suggested the presence of an alternative metabolic pathway induced by bile duct ligation, which caused the change in composition of urinary bile acids, and especially the marked increase in beta-muricholic acid formation. A possible alternative pathway for bile acid biosynthesis under biliary obstruction in rats is postulated.
在雄性Wistar品系大鼠中研究了胆管结扎对胆汁酸和胆固醇代谢的影响。血清和尿液中的胆汁酸和胆固醇出现了定量和定性变化；在胆道梗阻情况下，β-鼠胆酸在血清和尿液中主要增加，尿胆酸与β-鼠胆酸的比例从第1天的约5:3变为第5天的约1:8。尿中胆汁酸增加的形式主要是牛磺酸结合型，部分为硫酸化型。在第5天胆管结扎的情况下，在用抗生素预处理后，将14C标记的3β-羟基-5-胆烯酸、石胆酸和鹅去氧胆酸经胃内给予大鼠，并研究这三种酸的代谢产物。3β-羟基-5-胆烯酸最有效地转化为β-鼠胆酸。本研究强烈提示存在由胆管结扎诱导的另一种代谢途径，该途径导致尿胆汁酸组成的变化，尤其是β-鼠胆酸形成的显著增加。推测了大鼠胆道梗阻时胆汁酸生物合成的一种可能的替代途径。
