Bile acids are increasingly gaining attention since they were discovered to be activators of the transcription factor farnesoid X receptor (FXR) in addition to their well-established role in dietary lipid emulsification. Moreover, the differential activation potency of bile acids on FXR, which is due to structural variation of the ligands, generates the need for new analytical tools that are se...

We recently showed that feeding the cytoprotective bile acid ursodeoxycholic acid (UDCA) to rats resulted in significant reduction in polyps and especially cancers, both in number and size (D. L. Earnest et al., Cancer Res., 54: 5071-5074, 1994). Because fecal secondary bile acids [particularly deoxycholic acid (DCA)] are considered to promote formation of colon adenomas and cancer, we have now...

Diets enriched in retrograded amylose (RS3) have been shown to lower serum cholesterol concentrations in rats. The possibility was tested that this hypocholesterolaemic effect of RS3 is caused by an increase in excretion of neutral steroids and/or bile acids. Six groups of ten rats were fed on purified diets containing either 12 or 140 g RS3/kg solid ingredients with and without added cholester...

Bile acids play a pivotal role in the pathological development of inflammatory bowel disease (IBD). However, the mechanism of bile acid dysregulation in IBD remains unanswered. Here we show that intestinal peroxisome proliferator-activated receptor α (PPARα)-UDP-glucuronosyltransferases (UGTs) signalling is an important determinant of bile acid homeostasis. Dextran sulphate sodium (DSS)-induced...

Perfusion studies were performed in healthy volunteers to test whether the secretory effect of conjugated bile acids, previously shown for the colon, was also present in the jejunum. A perfusion system with a proximal occlusive balloon (and continuous aspiration of duodenal secretions) was used; isotonic test solutions contained glycine-conjugated bile acids with or without lecithin. Fluid move...

An improved synthesis of 24-13C-labeled bile acids has been achieved using formyl derivatives of bile acids and a modified lead tetraacetate procedure. The formylated bile acides were degraded by lead tetraacetate and lithium chloride to formylated 23-chloronorcholanes in 72-83% yield. Formylated 23-chloronorcholanes were converted to nitriles in dimethylformamide, which were then hydrolyzed to...

BACKGROUND & AIMS Bile acids are physiological detergents that also activate nuclear receptors to regulate glucose and lipid homeostasis. Cholesterol 7α-hydroxylase (Cyp7a1), the rate-limiting enzyme that converts cholesterol to bile acids, is transcriptionally regulated by bile acids and circadian rhythms. Fasting, nutrients and the circadian clock critically control hepatic bile acid and lipi...

Amberlite XAD-2 was used to extract bile acids from urine or diluted serum of patients with hepatobiliary diseases. Columns containing Sephadex LH-20 were then used to separate the sulfated and nonsulfated bile acids. Thin-layer chromatography of the sulfated bile acid fraction obtained from urine revealed several spots with R(F) values different from those of the taurine or glycine conjugates....

We recently identified that the Y' bile acid binders are 3a-hydroxysteroid dehydrogenases (3a-HSD). In the present studies, purified 3a-HSD catalyzed rapid 3H loss from 13,1-3H, C24-4Cllithocholic and chenodeoxycholic acids without net conversion to 3-oxo bile acids under physiologic pH and redox conditions. 13,6-3HICholic acid was a poor substrate. The Y' fraction of hepatic cytosol was exclus...