Palmer R H
J Lipid Res. 1971 Nov;12(6):680-7.
Sulfate esterification has been shown previously to be a prominent feature of lithocholate metabolism in man. These studies were undertaken to ascertain whether this metabolic pathway is also present in rats, and to investigate the physiological significance of bile acid sulfate formation. Lithocholic acid-24-(14)C was administered to bile fistula rats, and sulfated metabolites were identified in bile by chromatographic and appropriate degradative procedures. They constituted only a small fraction (2-9%) of the total metabolites but a more significant fraction (about 20%) of the secreted monohydroxy bile acids, most of the lithocholate having been hydroxylated by the rat liver. When sulfated glycolithocholate was administered orally, it was absorbed from the intestine without loss of the sulfate, presumably by active transport, and secreted intact into the bile. In comparison with non-sulfated lithocholate, an unusually large fraction (24%) of the sulfated bile acid was excreted in the urine, and fecal excretion took place more rapidly. Both the amino acid and sulfate moieties were extensively removed prior to excretion in the feces. Hydroxylation of bile acid sulfates or sulfation of polyhydroxylated bile acids did not occur to any great extent, if at all.
硫酸酯化先前已被证明是人体内石胆酸代谢的一个显著特征。进行这些研究是为了确定这种代谢途径是否也存在于大鼠体内，并研究胆汁酸硫酸酯形成的生理意义。将24-(14)C标记的石胆酸给予胆瘘大鼠，并通过色谱和适当的降解程序在胆汁中鉴定出硫酸化代谢产物。它们仅占总代谢产物的一小部分（2 - 9%），但占分泌的单羟基胆汁酸的比例更高（约20%），大部分石胆酸已被大鼠肝脏羟基化。当口服硫酸化甘氨石胆酸时，它从肠道吸收且硫酸基团未丢失，推测是通过主动转运，并完整地分泌到胆汁中。与未硫酸化的石胆酸相比，硫酸化胆汁酸有异常大比例（24%）经尿液排泄，且粪便排泄更快。在粪便排泄之前，氨基酸和硫酸部分都被大量去除。胆汁酸硫酸酯的羟基化或多羟基化胆汁酸的硫酸化在很大程度上并未发生，即便有发生也程度极低。
